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Abstract

Infections with multi-drug resistant (MDR) bacteria including carbapenem-resistant Klebsiella pneumoniae are emerging worldwide but are difficult to treat with the currently available antibiotic compounds and therefore constitute serious threats to human health. This prompted us to perform a literature survey applying the MEDLINE database and Cochrane Register of Controlled Trials including clinical trials comparing different treatment regimens for infections caused by carbapenem-resistant K. pneumoniae. Our survey revealed that a combined application of antibiotic compounds such as meropenem plus vaborbactam, meropenem plus colistin and carbapenem plus carbapenem, resulted in significantly increased clinical cure and decreased mortality rates as compared to respective control treatment. However, further research on novel antibiotic compounds, but also on antibiotic-independent molecules providing synergistic or at least resistance-modifying properties needs to be undertaken in vitro as well as in large clinical trials to provide future options in the combat of emerging life-threatening infections caused by MDR bacteria.

Open access
Authors: Dorothea Wiemer, Norbert Georg Schwarz, Gerd-Dieter Burchard, Hagen Frickmann, Ulrike Loderstaedt and Ralf-Matthias Hagen

Abstract

Diarrhoea is a frequent symptom associated with travelling to tropical regions, but the cause is often not found. Epidemiology was assessed including up-to-date real-time PCR approaches.

We analysed datasets of 528 patients who presented at the Bernhard Nocht Institute for Tropical Medicine in Hamburg, Germany, between 2006 and 2010 for screening purposes or because of diarrhoea. Stool samples were obtained and investigated by microscopy, bacterial culture, two PCR assays targeting Entamoeba histolytica, Entamoeba dispar, Giardia duodenalis, and Cryptosporidium parvum, or Salmonella spp., Shigella/EIEC spp., Campylobacter jejuni, and Yersinia spp.

Among patients with gastrointestinal symptoms, 51% tested positive for bacteria or parasites, of which 66% had a known enteropathogenic potential. In patients without diarrhoea, 53% (n = 80) were positive, and 33% of these cases harboured agents of pathogenic potential. Association with clinical symptoms was primarily found for bacterial infections. Blastocystis hominis, however, was more frequent in asymptomatic than in symptomatic travellers.

In conclusion, the study stresses the etiological relevance of bacterial gastroenteritis in travellers returning from the tropics, the need for molecular approaches to increase diagnostic sensitivity and demonstrates that asymptomatic carriage of enteropathogens after prolonged stays in the tropics is similarly frequent compared with symptomatic infections in travellers.

Open access

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.

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The performance of a semisynthetic bisexual lure (SBL, containing isoamyl alcohol, acetic acid and red wine) previously found attractive for a number of noctuids was compared with that of the respective synthetic sex attractants of Orthosia cerasi (=stabilis), O. cruda, O. gothica, O. incerta, Anorthoa munda and Conistra vaccini. The respective sex attractants performed significantly better in the Orthosia spp. than the SBL lure, which, although regularly catching low numbers of both females and males, did not differ significantly from zero catch in unbaited control traps. On the other hand, the SBL lure performed as well as the sex attractant in C. vaccini. Sizeable catches of C. rubiginea, C. rubiginosa and C. erythrocephala were also recorded in traps with the SBL lure. The SBL lure can prove to be a useful tool in ecological and faunistical studies of Conistra and related hibernating Xylenini species.

Open access

Aceria bambusae ChannaBasavanna, 1966 is reported from Hungary for the first time. The species was collected from the leaf sheaths of the introduced bamboo species, Phyllostachys rubromarginata McClure and Phyllostachys tianmuensis Z.P. Wang et N.X. Ma (both Poaceae) in Hungary. Morphological differences distinguishing this species from other bambusoid inhabiting congeners are discussed. In addition, new date-locality-host records for 3 eriophyoid species collected from 7 bamboo species are given.

Open access

Onion thrips, Thrips tabaci Lindeman, 1889 (Thysanoptera: Thripidae) has three distinctive reproductive modes: arrhenotokous, thelytokous and deuterotokous. This experiment was focused on the arrhenotokous leek-(L1) and tobacco-associated (T) T. tabaci lineages. These two lineages are distinctively varied genetically and in host adaptations. L1 and T lineages perform better on leek and tobacco plants, respectively. Fighting occurs between males when they compete for food, mating, and oviposition sites. The aim of this research was to examine the fighting behaviour and characterize the fighting elements of males in L1 and T lineages. The experiment was performed in the laboratory by using a Euromex VC.3036 video camera and each experiment was recorded for a duration of 10 minutes. Transparent PCR tube caps formed the arena to observe the fighting interactions in both lineages. A total of 40 video recordings have been observed and each recording had a different arena. The fighting performance was observed at 2, 5, 8, 10, 12 days old specimens in four replications. This result has shown L1 lineage had better fighting performance and a more aggressive fighting ability than T lineage. Antennal bouts, jumping, flipping, stabbing and pitching are the most commonly observed fighting elements.

Open access

Aculus epiphyllus (Nalepa, 1892) is reported from green ash in Europe for the first time. Ash rust mite has never been found on green ash, and we therefore re-describe and illustrate the female and male, and describe the nymph. The species was collected from the underside of the leaflets of the introduced ash species, Fraxinus pennsylvanica Marshall (Oleaceae) in Hungary.

Open access

Powdery mildew (Blumeria graminis) is a major fungal disease of barley causing economical yield losses worldwide. Breeding for resistance to this disease is crucial due to the rapid change in pathotype patterns of B. graminis in fields. In the present work, powdery mildew-resistant barley germplasm was developed by crossing four cultivars currently used in Europe and West Asia. Out of 265 doubled haploid lines derived from these crosses, 40 lines were evaluated at seedling and adult stages. Data showed significant differences among barley lines with a continuum of resistance levels ranging from highly susceptible to tolerant which were consistent during the two growth stages. Two promising lines were more tolerant to powdery disease than the others. Across lines, there was a high correlation between field and greenhouse reaction (r=0.80, P<0.01), indicating the utility of greenhouse evaluations for screening barley for powdery mildew. This study suggests that, the newly identified resistance lines can serve as potential donors for ongoing powdery mildew resistance breeding program, and both types of seedling and adult plant resistance identified here can offer promising genetic stocks for accumulating both resistances to acquire durable resistance and long lasting control against B. graminis in Mediterranean and similar environments.

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Antagonistic microorganisms have been used as biological control agents to reduce the use of chemical fungicides in the control of crop diseases. The present work was conducted to determine the antagonistic potential of Bacillus sp. isolates against the soil-borne fungus Cochliobolus sativus, the causal agent of barley common root (CRR) disease. Out of 525 isolates, 40 were showed in vitro antagonistic activity against the virulent C. sativus isolate CRR16. On the basis of 16S rRNA gene sequencing Bacillus sp. isolates are identified as B. atrophaeus, B. subtilis, Paenibacillus polymyxa, B. amyloliquefaciens, B. simplex and B. tequilensis. Results showed that Bacillus sp. had significant (P<0.05) antagonistic activities against the C. sativus where the percentage of radial growth inhibition of the fungi colonies ranged from 59 to 92%, compared to the untreated control. The B. subtilis isolate SY41B had the highest inhibition effect on the vegetative growth zones as compared with the other species isolates. In view of these, our results indicate that the antagonistic effect of the Bacillus sp. isolates may be important contributors as a biocontrol approach that could be employed as a part of integrated CRR management system.

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Authors: M. Tóth, A. Nagy, I. Szarukán, K. Ary, A. Cserenyec, B. Fenyődi, D. Gombás, T. Lajkó, L. Merva, J. Szabó, P. Winkler and J. K. Jósvai

The addition of synthetic (E)-anethol to the known attractant phenylacetaldehyde synergized attraction of the cotton bollworm Helicoverpa armigera, the blend invariably catching 4 to 6 times more than phenylacetaldehyde on its own. Highest catches were recorded by the 1:1-3:1 blends. The addition of salicyl aldehyde, ±linalool, (R)-(+)-limonene, 2-methoxybenzyl alcohol and 4-methoxybenzyl alcohol (compounds described earlier in the literature as co-attractants for H. armigera), increased catches when added to phenylacetaldehyde. However, the addition of these compounds did not increase catches of the (E)-anethol+pheny- lacetaldehyde blend. When directly compared with performance of the synthetic pheromone, the (E)-anethol +phenylacetaldehyde blend caught an average of 27% of the catch in pheromone baited traps. On an average 79% of moths caught in traps with the (E)-anethol+phenylacetaldehyde blend were females, while traps with pheromone caught only males. The (E)-anethol+phenylacetaldehyde blend described in this study may form the basis for the development of an efficient bisexual lure for H. armigera AFTER further optimization.

Open access

Wheat and its derivatives are a main staple food for the Algerian populations. The objective of this study aims to analyze local and imported wheat grains for fungi particularly Fusarium graminearum chemotype DON and evaluate deoxynivalenol (DON) contaminated wheat collected from Bechar region, in south-western Algeria. A total of 64 of wheat samples were examined for fungal contamination and fungal load was determined by means of standard microbiological method. DON was detected using the ELISA technique. The results revealed that 98.44% of analyzed samples showed positive results regarding fungal contamination. More precisely, local wheat was dominated by Aspergillus and Penicillium and imported wheat was dominated by Fusarium, Penicillium and Aspergillus species. Results showed that 62.5% of F. graminearum strains produced DON. Contamination levels of wheat with DON ranging from <0.04 ppm to >5ppm for soft wheat and from <0.12ppm to >15ppm for durum wheat. So, 62.96% of soft wheat grains and 55.56% of durum wheat imported from France, and also 18.18% of local durum wheat exceed the permissible limit by far. This study provides basic grounds in assessing the degree of fungal and potential DON contamination in Algerian wheat.

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The pine pest, Cenopalpus lineola (Canestrini and Fanzago, 1876) was discovered after 45 years again in Hungary. Proto-, deutonymphs, male and female specimens were collected, therefore a new and detailed re-description are presented with description of the leg chaetotaxy of the immature stages.

Open access
Authors: N. Aiter, A. Lehad, B. Haddad, A. Taibi, S. Meziani, Mohand-Larbi Rabhi, L. Khelifi and C. Chaouia

Several grapevine viruses were reported in Algeria and especially in grapevine germplasm collection, therefore it is a great challenge to free these varieties from virus infection before any breeding programs. Our study focused on the development of chemotherapy on autochthonous varieties collected in the grapevine germplasm collection of ITAFV. All these varieties were tested by DAS-ELISA and the presence of GLRaV-3 and GFLV was confirmed in all used samples for the sanitation. After 8 weeks of shoot tips in vitro culture in a modified M S medium containing ribavirin, DAS-ELISA test revealed that GLRaV-3 was completely eliminated and GFLV to a significant rate.

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In South Africa, the avocado (Persea americana) is an important fruit, grown primarily for export and contributing ZAR 1.75 billion to the gross domestic product of the country. As an export driven industry, optimising exportable avocado fruit volume is a primary concern. Wind induced abrasion and damage by thrips (Thysanoptera: Thripidae), through their feeding on avocado fruit results in corky tissue development (scarring) and making the fruit unsuitable for export. The study aimed to determine the economic losses caused by these agents as well as assess different cultivar responses to scarring damage. Across cultivars, the 1.49% revenue annually due to Scirtothrips aurantii downgrading (3.86% loss factor), translating to ZAR 34.90 million (US$2.39 million). Packhouse study results showed that both thrips and wind abrasion damage accounted for 30% scarring damage, a loss factor of 13.72% and a combined revenue loss of 5.57%. The cultivar ‘Pinkerton’ showed the greatest susceptibility to scarring damage by both wind and S. aurantii whilst the cultivar ‘Carmen®-Hass’ showed a natural predisposition to higher levels of thrips damage. The presence of macadamia trees near avocado trees predisposes avocado fruit to S. aurantii damage.

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Authors: Ingrid E. Pereira, Kyssia P. Silva, Laura M. Menegati, Aimara C. Pinheiro, Elaine A. O. Assunção, Maria de Lourdes P. Araújo, Elfadil Abass, Malcolm S. Duthie, Ulrich Steinhoff and Henrique C. Teixeira

Abstract

Control of canine visceral leishmaniasis (CVL), a major zoonotic disease in Brazil and many other tropical and subtropical countries, remains difficult as an accurate and reliable diagnosis is still missing. In endemic regions, infected dogs are the main parasitic reservoir host of human Visceral leishmaniasis (VL) infection. Vaccination of dogs against Leishmania infection constitutes an important strategy to prevent or to better control CVL, thus, a serological test that can discriminate between antibodies induced by immunization versus infection is highly desirable in order to improve and simplify diagnosis. Here, four recombinant proteins were evaluated for their ability to detect and differentiate between dogs that are infected with Leishmania or have been immunized with the anti-Leishmania vaccine Leish-Tec®. Receiver operating characteristic (ROC) curve analysis of the four Leishmania-specific IgG ELISA revealed superior performance of rK28, followed by rKLO8, rK39 and rLb6H. The rK28-based ELISA revealed not only the best accuracy against CVL, but also the lowest cross-reactivity with sera from Leish-Tec® immunized dogs. Our data show that the rK28-based ELISA is highly suitable for CVL screening as it shows high sensitivity with simultaneous low cross-reactivity. Further, the high specificity of the rKLO8 indicates its suitability for the confirmation of CVL diagnosis.

Open access

Abstract

Introduction

To evaluate the automated cartridge-based PCR approach ARIES SARS-CoV-2 Assay targeting the ORF-sequence and the N-gene of SARS-CoV-2.

Methods

In line with the suggestions by Rabenau and colleagues, the automated ARIES SARS-CoV-2 Assay was challenged with strongly positive samples, weakly positive samples and negative samples. Further, intra-assay and inter-assay precision as well as the limit-of-detection (lod) were defined with quantified target RNA and DNA. The Cepheid Xpert Xpress SARS-Cov-2 Assay was used as gold standard.

Results

Concordance between the ARIES assay and the Cepheid assay was 100% for strongly positive samples and for negative samples, respectively. For weakly positive samples as confirmed applying the Cepheid assay, a relevant minority of 4 out of 15 samples (26.7%) went undetected by the ARIES assay. Intra- and inter-assay precision were satisfactory, while the lod was in the 103 DNA copies/reaction-range, in the 103 virus copies/reaction-range, or in the 103–104 free RNA copies/reaction-range in our hands.

Conclusions

The automated ARIES assay shows comparable test characteristics as the Cepheid assay focusing on strongly positive and negative samples but a slightly reduced sensitivity with weakly positive samples. Decisions on diagnostic use should include considerations on the lod.

Open access
Authors: Sara M. van Bonn, Sebastian P. Schraven, Tobias Schuldt, Markus M. Heimesaat, Robert Mlynski and Philipp C. Warnke

Abstract

We report a case of a chronic mesotympanic otitis media with a smelly purulent secretion from both ears and recurrent otalgia over the last five years in a six-year-old girl after swimming in the German Baltic Sea. Besides Staphylococcus aureus a non-O1/non-O139 Vibrio cholerae strain could be isolated from patient samples. An antibiotic therapy with ciprofloxacin and ceftriaxone was administered followed by atticotomy combined with tympanoplasty. We conclude that V. cholerae should not be overlooked as a differential diagnosis to otitis infections, especially when patients present with extra-intestinal infections after contact with brackish- or saltwater aquatic environments.

Open access

Abstract

Carvacrol, a primary constituent of plant essential oils (EOs), and its antimicrobial activity have been the subject of many in vitro studies. Due to an increasing demand for alternative antimicrobials and an emerging number of antibiotic resistant bacteria, the use of essential oils has played a major role in many recent approaches to reduce Campylobacter colonization in poultry before slaughter age. For that purpose, the reducing effect of carvacrol on Campylobacter jejuni prevalence in broilers was determined in vivo in an experimental broiler chicken model during an entire fattening period. Carvacrol was added to the feed in a concentration of 120 mg/kg feed four days post hatch until the end of the trial. In this study, we demonstrated a statistically significant decrease of C. jejuni counts by 1.17 decadic logarithm (log10) most probable number (MPN)/g in cloacal swabs during starter and grower periods (corresponding to a broilers age between 1 and 28 days). Similar results were observed for colon enumeration at the end of the trial where C. jejuni counts were significantly reduced by 1.25 log10 MPN/g. However, carvacrol did not successfully reduce Campylobacter cecal colonization in 33-day-old broilers.

Open access

Abstract

Non-antibiotic feed additives including competitive exclusion products have been shown effective in reducing pathogen loads including multi-drug resistant strains from the vertebrate gut. In the present study we surveyed the intestinal bacterial colonization properties, potential macroscopic and microscopic inflammatory sequelae and immune responses upon peroral application of the commercial competitive exclusion product Aviguard® to wildtype mice in which the gut microbiota had been depleted by antibiotic pre-treatment. Until four weeks following Aviguard® challenge, bacterial strains abundant in the probiotic suspension stably established within the murine intestines. Aviguard® application did neither induce any clinical signs nor gross macroscopic intestinal inflammatory sequelae, which also held true when assessing apoptotic and proliferative cell responses in colonic epithelia until day 28 post-challenge. Whereas numbers of colonic innate immune cell subsets such as macrophages and monocytes remained unaffected, peroral Aviguard® application to microbiota depleted mice was accompanied by decreases in colonic mucosal counts of adaptive immune cells such as T and B lymphocytes. In conclusion, peroral Aviguard® application results i.) in effective intestinal colonization within microbiota depleted mice, ii.) neither in macroscopic nor in microscopic inflammatory sequelae and iii.) in lower colonic mucosal T and B cell responses.

Open access
Authors: Edna Madai Méndez-Hernández, Jesús Hernández-Tinoco, José Manuel Salas-Pacheco, Luis Francisco Sánchez-Anguiano, Oscar Arias-Carrión, Ada Agustina Sandoval-Carrillo, Francisco Xavier Castellanos-Juárez, Luis Ángel Ruano-Calderón and Cosme Alvarado-Esquivel

Abstract

The link between Toxoplasma gondii infection and multiple sclerosis remains controversial. In the present study, we aimed to determine the association between T. gondii seropositivity and multiple sclerosis. Using an age- and gender-matched case-control study, we studied 45 patients who had multiple sclerosis attended in two public hospitals and 225 control subjects without this disease and other neurological disorders in Durango City, Mexico. Serum samples of cases and controls were analyzed for detection of anti-Toxoplasma IgG using a commercially available enzyme-linked immunoassay. One (2.22%) of the 45 patients with multiple sclerosis, and 15 (6.67%) of the 225 control subjects without this disease were seropositive for anti-T. gondii IgG antibodies. No statistically significant difference (OR = 0.31; 95% CI: 0.04–2.47; P = 0.48) in seroprevalence of anti-T. gondii IgG antibodies between cases and controls was found. The frequency of T. gondii seropositivity did not vary among cases and controls about sex or age groups. Results of this study do not support an association between seropositivity to T. gondii and multiple sclerosis. However, additional research with larger sample sizes to confirm this lack of association should be conducted.

Open access

Abstract

Listeria monocytogenes (Lm) is a food-borne pathogen with a high chance of infecting neonates, pregnant women, elderly and immunocompromised individuals. Lm infection in neonates can cause neonatal meningitis and sepsis with a high risk of severe neurological and developmental sequelae and high mortality rates. However, whether an acute neonatal Lm infection causes long-term effects on the immune system persisting until adulthood has not been fully elucidated. Here, we established a neonatal Lm infection model and monitored the composition of major immune cell subsets at defined time points post infection (p.i.) in secondary lymphoid organs and the intestine. Twelve weeks p.i., the CD8+ T cell population was decreased in colon and mesenteric lymph nodes (mLNs) with an opposing increase in the spleen. In the colon, we observed an accumulation of CD4+ and CD8+ effector/memory T cells with an increase of T-bet+ T helper 1 (Th1) cells. In addition, 12 weeks p.i. an altered composition of innate lymphoid cell (ILC) and dendritic cell (DC) subsets was still observed in colon and mLNs, respectively. Together, these findings highlight organ-specific long-term consequences of an acute neonatal Lm infection on both the adaptive and innate immune system.

Open access

Abstract

Introduction

Chronic sinusitis caused by anaerobes is a particular concern clinically, because many of the complications are associated with infections caused by these organisms. The aim of this study was to evaluate the incidence of anaerobic bacteria in chronic sinusitis in adults as a part of a prospective microbiological study.

Materials and methods

Over a one-year period, aspirations of maxillary sinus secretions and/or ethmoid cavities were derived in n = 79 adult patients with chronic sinusitis by endoscopy in a tertiary-care teaching hospital in Hungary. The qualitative and quantitative compositions of the total cultivable aerobic and anaerobic bacterial and fungal flora cultured on the samples were compared. Correct anaerobic species level identifications were carried out according to standard methods.

Results

Bacteria were recovered for all of the 79 aspirates and the numbers of the significant cultured isolates (with colony forming units ≥103) were between 1 and 10. A total of 206 isolates, 106 anaerobic and 100 aerobic or facultative-anaerobic strains were isolated. The most common aerobic bacteria were Streptococcus pneumoniae (n = 40), Haemophilus influenzae (n = 29), Moraxella catarrhalis (n = 6), Staphylococcus aureus (n = 7) and Streptococcus pyogenes (n = 6). The anaerobic bacteria included black-pigmented Prevotella spp. and Porphyromonas spp. (n = 27), Actinomyces spp. (n = 13), Gram-positive anaerobic cocci (n = 16), Fusobacterium spp. (n = 19) and Cutibacterium acnes (n = 8).

Conclusions

This study illustrates the microbial dynamics in which anaerobic and aerobic bacteria prevail and highlights the importance of obtaining cultures from patients with chronic sinusitis for guidance in selection of proper antimicrobial therapy.

Open access

Abstract

Obligate anaerobic bacteria are considered important constituents of the microbiota of humans; in addition, they are also important etiological agents in some focal or invasive infections and bacteremia with a high level of mortality. Conflicting data have accumulated over the last decades regarding the extent in which these pathogens play an intrinsic role in bloodstream infections. Clinical characteristics of anaerobic bloodstream infections do not differ from bacteremia caused by other pathogens, but due to their longer generation time and rigorous growth requirements, it usually takes longer to establish the etiological diagnosis. The introduction of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) has represented a technological revolution in microbiological diagnostics, which has allowed for the fast, accurate and reliable identification of anaerobic bacteria at a low sample cost. The purpose of this review article is to summarize the currently available literature data on the prevalence of anaerobic bacteremia in adults for physicians and clinical microbiologists and to shed some light on the complexity of this topic nowadays.

Open access
Authors: Ernst-Jürgen Finke, Wolfgang Beyer, Ulrike Loderstädt and Hagen Frickmann

Abstract

Anthrax is an infectious disease of relevance for military forces. Although spores of Bacillus anthracis obiquitously occur in soil, reports on soil-borne transmission to humans are scarce. In this narrative review, the potential of soil-borne transmission of anthrax to humans is discussed based on pathogen-specific characteristics and reports on anthrax in the course of several centuries of warfare. In theory, anthrax foci can pose a potential risk of infection to animals and humans if sufficient amounts of virulent spores are present in the soil even after an extended period of time. In praxis, however, transmissions are usually due to contacts with animal products and reported events of soil-based transmissions are scarce. In the history of warfare, even in the trenches of World War I, reported anthrax cases due to soil-contaminated wounds are virtually absent. Both the perspectives and the experience of the Western hemisphere and of former Soviet Republics are presented. Based on the accessible data as provided in the review, the transmission risk of anthrax by infections of wounds due to spore-contaminated soil is considered as very low under the most circumstance. Active historic anthrax foci may, however, still pose a risk to the health of deployed soldiers.

Open access

Abstract

The physiological colonization resistance exerted by the murine gut microbiota prevents conventional mice from Campylobacter jejuni infection. In the present study we addressed whether this also held true for Campylobacter coli. Following peroral application, C. coli as opposed to C. jejuni could stably establish within the gastrointestinal tract of conventionally colonized mice until 3 weeks post-challenge. Neither before nor after either Campylobacter application any changes in the gut microbiota composition could be observed. C. coli, but not C. jejuni challenge was associated with pronounced regenerative, but not apoptotic responses in colonic epithelia. At day 21 following C. coli versus C. jejuni application mice exhibited higher numbers of adaptive immune cells including T-lymphocytes and regulatory T-cells in the colonic mucosa and lamina propria that were accompanied by higher large intestinal interferon-γ (IFN-γ) concentrations in the former versus the latter but comparable to naive levels. Campylobacter application resulted in decreased splenic IFN-γ, tumor necrosis factor-α (TNF-α), and IL-6 concentrations, whereas IL-12p70 secretion was increased in the spleens at day 21 following C. coli application only. In either Campylobacter cohort decreased IL-10 concentrations could be measured in splenic and serum samples. In conclusion, the commensal gut microbiota prevents mice from C. jejuni, but not C. coli infection.

Open access

Abstract

Stenotrophomonas maltophilia is an aerobic, oxidase-negative and catalase-positive bacillus. S. maltophilia is a recognized opportunistic pathogen. Due to the advancements in invasive medical procedures, organ transplantation and chemotherapy of malignant illnesses, the relevance of this pathogen increased significantly. The therapy of S. maltophilia infections is challenging, as these bacteria show intrinsic resistance to multiple classes of antibiotics, the first-choice drug is sulfamethoxazole/trimethoprim. Our aim was to assess the epidemiology of S. maltophilia from various clinical samples and the characterization of resistance-levels and resistotyping of these samples over a long surveillance period. The study included S. maltophilia bacterial isolates from blood culture samples, respiratory samples and urine samples and the data for the samples, received between January 2008 until December 2017, a total of 817 S. maltophilia isolates were identified (respiratory samples n = 579, 70.9%, blood culture samples n = 175, 21.4% and urine samples n = 63, 7.7%). Levofloxacin and colistin-susceptibility rates were the highest (92.2%; n = 753), followed by tigecycline (90.5%, n = 739), the first-line agent sulfamethoxazole/trimethoprim (87.4%, n = 714), while phenotypic resistance rate was highest for amikacin (72.5% of isolates were resistant, n = 592). The clinical problem of sulfamethoxazole/trimethoprim-resistance is a complex issue, because there is no guideline available for the therapy of these infections.

Open access
Authors: Silke Dubbert, Birgit Klinkert, Michael Schimiczek, Trudy M. Wassenaar and Rudolf von Bünau

Probiotic Escherichia coli strain Nissle 1917 (EcN) has a long history of safe use. However, the recently discovered presence of a pks locus in its genome presumably producing colibactin has questioned its safety, as colibactin has been implicated in genotoxicity. Here, we assess the genotoxic potential of EcN. Metabolic products were tested in vitro by the Ames test, a mutagenicity assay developed to detect point mutation-inducing activity. Live EcN were tested by an adapted Ames test. Neither the standard nor the adapted Ames test resulted in increased numbers of revertant colonies, indicating that EcN metabolites or viable cells lacked mutagenic activity. The in vivo Mammalian Alkaline Comet Assay (the gold standard for detecting DNA-strand breaks) was used to determine potentially induced DNA-strand breaks in cells of the gastro-intestinal tract of rats orally administered with viable EcN. Bacteria were given at 109–1011 colony forming units (CFU) per animal by oral gavage on 2 consecutive days and daily for a period of 28 days to 5 rats per group. No significant differences compared to negative controls were found. These results demonstrate that EcN does not induce DNA-strand breaks and does not have any detectable genotoxic potential in the test animals.

Open access

The gastric pathogen Helicobacter pylori colonizes approximately half of the human world population. The bacterium injects the effector protein cytotoxin associated gene A (CagA) via a type-IV secretion system into host epithelial cells, where the protein becomes phosphorylated at specific EPIYA-motifs by cellular kinases. Inside the host cell, CagA can interact with over 25 different proteins in both phosphorylation-dependent and phosphorylation-independent manners, resulting in manipulation of host-cell signaling pathways. During the course of an H. pylori infection, certain host-cell proteins undergo tyrosine dephosphorylation in a CagA-dependent manner, including the actin-binding proteins cortactin and vinculin. A predominant response of intracellular CagA is the binding and activation of tyrosine phosphatase, the human Src-homology-region-2-domain-containing-phosphatase-2 (SHP2). Here, we considered the possibility that activated SHP2 might be responsible for the dephosphorylation of cortactin and vinculin. To investigate this, phosphatase inhibitor studies were performed. Additionally, a complete knockout mutant of SHP2 in AGS cells was created by CRISPR/Cas9 technology, and these cells were infected with H. pylori. However, neither the presence of an inhibitor nor the inactivation of SHP2 prevented the dephosphorylation of cortactin and vinculin upon CagA delivery. Tyrosine dephosphorylation of these proteins is therefore independent of SHP2 and instead must be caused by another, as yet unidentified, protein tyrosine phosphatase.

Open access

The terricolous species Cladonia foliacea (Cladoniaceae, lichenised Ascomycota) widely distributed in open, dry lowland steppe and rocky mountain grassland vegetation in Europe was chosen as a potential test organism for ecological experiments, since their thalli are producing cortical solar radiation-protective and UV screening pigment dibenzofuran usnic acid and medullary secondary substance depsidone fumarprotocetraric acid. Significant seasonal differences were found in the amounts of lichen secondary metabolites analysed by HPTLC and HPLC-PDA between summer and winter collected thalli in sandy grassland area in Hungary. The concentrations of usnic acid varied between 7.34 and 15.52 mg/g in summer collected samples and 13.90 and 21.61 mg/g in winter collected ones. A comparable amount (11.61±0.29 mg/g) was measured in pulverised samples. The concentrations of fumarprotocetraric acid varied between 0.60 and 3.01 mg/g in summer collected samples and 2.26 and 5.81 mg/g in winter collected thalli. A comparable amount (2.45±0.21 mg/g) was found in pulverised samples. The range of concentration values is comparable with data known from lichens. A higher amount of usnic acid is produced in winter probably to ensure sufficient protection also for summer. The fumarprotocetraric acid content of the medulla might contribute to the solar irradiation reflecting role of the pale lower surface lobes turning upwards in dry condition.

Open access
Authors: M. Dudáš, P. Eliáš jun., D. R. Letz, Z. Bártová and V. Kolarčik

The distribution of Sonchus palustris in Slovakia was studied using herbarium specimens and literary sources. The herbarium studies, supplemented with targeted field search in the years 2015–2018, revealed 61 new localities and confirmed many other older locations. The species has been recorded in 19 phytogeographical districts and sub-districts of Slovakia. Most of the records are concentrated in the Podunajská nížina lowland in SW Slovakia and in the Ipel'sko-rimavská brázda region in southern Slovakia. Our results showed that the species is relatively common in different types of wetlands and its re-evaluation in the recent version of the Slovak red list is not needed. Chromosome number data for two new populations in eastern Slovakia (both 2n = 18) were counted. The distribution map is given.

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Authors: M. F. Vianna, S. Pelizza, M. L. Russo, S. Rodriguez and A. C. Scorsetti

The diversity of fungal endophytes is poorly known and particularly in the case of Nicotiana tabacum, the literature is limited. The present study assessed and compared the diversity and distribution of endophytic fungi between different organs of tobacco plants. We calculated the relative frequency and rates of colonisation and of isolation of endophytic fungi in roots, stems and leaves, as well as the Shannon–Wiener and Simpson diversity indexes. Similarities between assemblages from the studied organs were also analysed. A total of 1588 endophytic fungal strains assigned to 31 morphospecies were isolated. The highest diversity of endophytes was found in leaves, being Fusarium graminearum and Alternaria botrytis the most common fungal species. This study provides information on the distribution of fungal endophytes inhabiting leaves, stems, and roots of N. tabacum and thus can serve as a starting point for increasing our comprehension on the interactions in which these fungi are involved.

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Heterocentron subtriplinervium (Link et Otto) A. Braun et C. D. Bouche, a potential invasive alien species is reported here for the first time for Asia from the Western Ghats of India. The plant is probably introduced deliberately into gardens for ornamental purpose from where it escaped and become naturalised in the Western Ghats. This species is a potential weed, which quickly conquers areas wherever introduced displacing the indigenous flora. A detailed description, illustration, photograph and relevant notes are provided for easy identification in the field.

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For restoration purposes nature conservation preferably requests the use of local seed sources based on the “local-is-best” (LIB) approach. However, counter-arguments against this usage are potential benefits by increased variation, which could be beneficial especially in times of global change. We here investigate intraspecific morphological variability of one of the most common herbaceous, insect pollinated and zoochorous plants from seed mixtures used for landscape restoration processes in central Europe, the wild carrot, Daucus carota L. (Apiaceae). Our results show that D. carota features no vegetative but two generative characters that significantly differed among plants originating from seeds of natural (I) and restored (R) sites. We could show that effects of mowing always overlay origin-specific characteristics. The earlier genetic analysis did not support a regional provenance concept for restoration purposes, while slight differences in phenological parameters related to fitness pinpoint to ‘mix and match-admixture provenancing’ as a compromise strategy.

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Blue-green algae (also called cyanobacteria) are ubiquitous, pristine and pioneer photosynthetic microorganisms. Many species of cyanobacteria are capable of fixing atmospheric nitrogen and such species in wet soils are simultaneously augmenting the fertility of the soil, acting as natural bio-fertilizers. Nostoc and Anabaena are the two important genera of heterocystous cyanobacteria capable of contributing nitrogen to soil, especially in paddy fields. The major objectives of the investigation included survey, collection, isolation and pure culture of nitrogen-fixing species of Cyanobacteria in the soils of Kerala state, India. Altogether, pure cultures of 12 species of Nostoc and 5 species of Anabaena are prepared.

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The identification of the diversity of microscopic fungi of lithobiont communities of the Argentine Islands in specimens collected during the 22nd Ukrainian Antarctic Expedition was the purpose of this work. Samples of rock, soil, mosses and lichens of rock micro-habitats of “Crustose lichen sub-formation and fruticose lichen and moss cushion sub-formation” were used in the work. These samples were used for extracting and cultivation of filamentous fungi on dense nutrient media. Determination of physiological and biochemical characteristics and identification of yeast-like fungi were performed using a microbiological analyser ‘Vitek-2’ (‘Bio Merieux’, France). Cultivation of microorganisms was carried out at temperatures from +2 to +37 °C. In results cultures of microscopic fungi of Zygomycota (Mucor circinelloides), Ascomycota (species of the genera cf. Tlielebolus, Talaromyces), representatives of the Anamorphic fungi group (Geomyces pannorum, species of the genera Alternaria, Acremonium, Aspergillus, Penicillium, and Cladosporium) were isolated from Antarctic samples. Microscopic fungi Penicillium spp. were dominated after the frequency in the studied samples (54.5%). Rhodotorula rubra and Candida sp. among isolated yeast fungi, and dark pigmented fungi represented by Aureobasidium pulhdans and Exophiala spp. were identified. The biological properties of a number of isolated fungi (the potential ability to synthesise important biologically active substances: melanins, carotenoids, lipids) are characterised. Mycobiota of rock communities of Argentine Islands is rich on filamentous and yeast fungi similarly to other regions of Antarctica. A number of fungi investigated are potentially able to synthesise biologically active substances. The dark pigmented species of the genera Cladosporium, Exophiala, Aureobasidium pulhdans, capable of melanin synthesis; ‘red’ yeast Rhodotorula rubra (carotenoid producers and resistant to toxic metals); Mucor circinelloides and Geomyces pannorum, lipid producers, are among these fungi. Yeast-like fungi assimilated a wide range of carbohydrates, which will allow them to be further used for cultivation in laboratory and process conditions. The collection of technologically promising strains of microorganisms, part of the Culture Collection of Fungi at Taras Shevchenko National University of Kyiv (Ukraine), is updated with isolated species (strains) of filamentous fungi and yeast – potential producers of biologically active substances, obtained within this study.

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Authors: S. Y. Kondratyuk, D. K. Upreti, G. K. Mishra, S. Nayaka, K. K. Ingle, O. O. Orlov, A. S. Kondratiuk, L. Lőkös, E. Farkas, J.-J. Woo and J.-S. Hur

Eight species, new for science, i.e.: Lobothallia gangwondoana S. Y. Kondr., J.-J. Woo et J.-S. Hur and Phyllopsora dodongensis S. Y. Kondr. et J.-S. Hur from South Korea, Eastern Asia, Ioplaca rinodinoides S. Y. Kondr., K. K. Ingle, D. K. Upreti et S. Nayaka, Letrouitia assamana S. Y. Kondr., G. K. Mishra et D. K. Upreti, and Rusavskia indochinensis S. Y. Kondr., D. K. Upreti et S. Nayaka from India and China, South Asia, Caloplaca orloviana S. Y. Kondr. and Rusavskia drevlyanica S. Y. Kondr. et O. O. Orlov from Ukraine, Eastern Europe, as well as Xanthoria ibizaensis S. Y. Kondr. et A. S. Kondr. from Ibiza Island, Spain, Mediterranean Europe, are described, illustrated and compared with closely related taxa.

Fominiella tenerifensis S. Y. Kondr., Kärnefelt, A. Thell et Feuerer is for the first time recorded from Mediterranean Europe, Huriella loekoesiana S. Y. Kondr. et Upreti is provided from Russia for the first time, and H. pohangensis S. Y. Kondr., L. Lőkös et J.-S. Hur for the first time from China, Phoma candelariellae Z. Kocakaya et Halıcı is new to Ukraine, and Staurothele frustulenta Vain. is recorded from the Forest Zone of Ukraine for the first time.

Twelve new combinations, i.e.: Bryostigma apotheciorum (for Sphaeria apotheciorum A. Massal.), Bryostigma biatoricola (for Arthonia biatoricola Ihlen et Owe-Larss.), Bryostigma dokdoense (for Arthonia dokdoensis S. Y. Kondr., L. Lőkös, B. G. Lee, J.-J. Woo et J.-S. Hur), Bryostigma epiphyscium (for Arthonia epiphyscia Nyl.), Bryostigma lobariellae (for Arthonia lobariellae Etayo), Bryostigma lapidicola (for Lecidea lapidicola Taylor), Bryostigma molendoi (for Tichothecium molendoi Heufl. ex Arnold), Bryostigma neglectulum (for Arthonia neglectula Nyl.), Bryostigma parietinarium (for Arthonia parietinaria Hafellner et Fleischhacker), Bryostigma peltigerinum (for Arthonia vagans var. peltigerina Almq.), Bryostigma phaeophysciae (for Arthonia phaeophysciae Grube et Matzer), Bryostigma stereocaulinum (for Arthonia nephromiaria var. stereocaulina Ohlert), are proposed based on results of combined phylogenetic analysis based on mtSSU and RPB2 gene sequences.

Thirty-one new combinations for members of the genus Polyozosia (i.e.: Polyozosia actophila (for Lecanora actophila Wedd.), Polyozosia agardhiana (for Lecanora agardhiana Ach.), Polyozosia altunica (for Myriolecis altunica R. Mamut et A. Abbas), Polyozosia antiqua (for Lecanora antiqua J. R. Laundon), Polyozosia bandolensis (for Lecanora bandolensis B. de Lesd.), Polyozosia behringii (for Lecanora behringii Nyl.), Polyozosia caesioalutacea (for Lecanora caesioalutacea H. Magn.), Polyozosia carlottiana (for Lecanora carlottiana C. J. Lewis et Śliwa), Polyozosia congesta (for Lecanora congesta Clauzade et Vězda), Polyozosia eurycarpa (for Lecanora eurycarpa Poelt, Leuckert et Cl. Roux), Polyozosia expectans (Lecanora expectans Darb.), Polyozosia flowersiana (Lecanora flowersiana H. Magn.), Polyozosia fugiens (for Lecanora fugiens Nyl.), Polyozosia invadens (for Lecanora invadens H. Magn.), Polyozosia juniperina (for Lecanora juniperina Śliwa), Polyozosia latzelii (for Lecanora latzelii Zahlbr.), Polyozosia liguriensis (for Lecanora liguriensis B. de Lesd.), Polyozosia massei (for Myriolecis massei M. Bertrand et J.-Y. Monnat), Polyozosia mons-nivis (for Lecanora mons-nivis Darb.), Polyozosia oyensis (for Lecanora oyensis M.-P. Bertrand et Cl. Roux), Polyozosia percrenata (for Lecanora percrenata H. Magn.), Polyozosia persimilis (for Lecanora hagenii subsp. persimilis Th. Fr.), Polyozosia poeltiana (for Lecanora poeltiana Clauzade et Cl. Roux), Polyozosia prominens (for Lecanora prominens Clauzade et Vězda), Polyozosia prophetae-eliae (for Lecanora prophetae-eliae Sipman), Polyozosia salina (for Lecanora salina H. Magn.), Polyozosia schofieldii (for Lecanora schofieldii Brodo), Polyozosia sverdrupiana (for Lecanora sverdrupiana Øvstedal), Polyozosia torrida (for Lecanora torrida Vain.), Polyozosia wetmorei (for Lecanora wetmorei Śliwa), Polyozosia zosterae (for Lecanora subfusca? zosterae Ach.)) are proposed.

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Lichenes Delicati Exsiccati Editae of little, fine, special lichens is edited in honour of Antonín Vězda (1920–2008). The fifth fascicle of the exsiccate is consisted of 20 species of lichens and lichenicolous fungi and distributed to 12 lichen herbaria of the world. Collectors are K. Buaruang, D. Kalb, K. Kalb, G. E. Lee, L. Lőkös, A. Mertens, W. Polyiam, T. Pócs, W. Saipunkaew, D. Tang, N. Varga and E. Farkas.

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Tamarix L. (Tamaricaceae) is a halophytic shrub in different parts of Asia and North Africa. Taxonomy and species limitation of Tamarix is very complex. This genus has three sections as Tamarix, Oligadenia, and Polyadenia, which are mainly separated by petal length, the number of stamens, the shape of androecial disk and attachment of filament on the androecial disk. As there was no palynological data on pollen features of Tamarix species of Iran, in the present study 12 qualitative and quantitative pollen features were evaluated to find diagnostic ones. Pollen grains of 8 Tamarix species were collected from nature. Pollen grains were studied without any treatment. Measurements were based on at least 50 pollen grains per specimen. Light and scanning electron microscopes were used. Multivariate statistical methods were applied to clarify the species relationships based on pollen data. All species studied showed monad and tricolpate (except some individuals of T. androssowii). Some Tamarix species show a high level of variability, in response to ecological niches and phenotypic plasticity, which make Tamarix species separation much more difficult. Based on the results of the present study, pollen grains features are not in agreement with previous morphological and molecular genetics about the sectional distinction.

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Between the years 2015–2018, 147 stands of Ficus carica L. was found out of cultivation in Baranya county. In 2008 presence of fig wasp (Blastophaga psenes L.) and caprificus individuals that are necessary for pollination, then for producing fertile seeds were detected in Pécs at first time. For germination tests fig seeds were collected from several different stands in Pécs and successful reproduction of the species was confirmed under in vitro conditions. According to former and recent observations (i.e. subspontaneous seedlings and/or successful in vitro germination of common fig seeds in 2010 and 2014) fig wasp may have occurred in Budapest and Máriagyűd too, at least in the last ten years. These results confirm that F. carica is an old ‘new’ casual or may be a naturalised neophyte element of the Hungarian flora. According to the new records the northernmost escaped individuals of F. carica was found at 47.475° N in the Carpathian Basin, 116.5 km N of the closest Slovenian stand in the latitudinal direction.

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Authors: S. Y. Kondratyuk, L. Lőkös, E. Farkas, I. Kärnefelt, A. Thell, Y. Yamamoto and J.-S. Hur

Three new for science genera, i.e.: Erichansenia S. Y. Kondr., Kärnefelt et A. Thell for the ‘Caloplaca’ epithallina group of the subfamily Xanthorioideae, as well as Lendemeriella S. Y. Kondr. for the Caloplaca reptans group, and Pisutiella S. Y. Kondr., L. Lőkös et E. Farkas for the Caloplaca conversa group of the subfamily Caloplacoideae of the Teloschistaceae, are described on the basis of results of the three gene phylogeny of the Teloschistaceae based on nrITS, nrLSU and mtSSU sequences.

Twenty-seven new combinations, i.e.: Erichansenia epithallina (for Caloplaca epithallina Lynge), Erichansenia cryodesertorum (for Shackletonia cryodesertorum Garrido-Ben., Søchting et Pérez-Ort.), Erichansenia sauronii (for Caloplaca sauronii Søchting et Øvstedal), Fauriea mandshuriaensis (for Caloplaca mandshuriaensis S. Y. Kondr., L. Lőkös et J.-S. Hur), Fauriea trassii (for Caloplaca trassii Galanina et S. Y. Kondr.), Lendemeriella borealis (for Lecanora pyracea f. borealis Vain.), Lendemeriella dakotensis (for Caloplaca dakotensis Wetmore), Lendemeriella exsecuta (for Lecanora exsecuta Nyl.), Lendemeriella lucifuga (for Caloplaca lucifuga G. Thor), Lendemeriella nivalis (for Zeora nivalis Körb.), Lendemeriella reptans (for Caloplaca reptans Lendemer et B. P. Hodk.), Lendemeriella sorocarpa (for Placodium sorocarpum Vain.), Lendemeriella tornoensis (for Caloplaca tornoensis H. Magn.), Pisutiella congrediens (for Lecanora congrediens Nyl.), Pisutiella conversa (for Callopisma conversum Kremp.), Pisutiella furax (for Caloplaca furax Egea et Llimona), Pisutiella grimmiae (for Lecanora grimmiae Nyl.), Pisutiella ivanpisutii (for Caloplaca ivanpisutii S. Y. Kondr., L. Lőkös et Hur), Pisutiella phaeothamnos (for Caloplaca phaeothamnos K. Kalb et J. Poelt), Pyrenodesmia aetnensis (for Caloplaca aetnensis B. de Lesd.), Pyrenodesmia albolutescens (for Lecanora albolutescens Nyl.), Pyrenodesmia aractina (for Parmelia aractina Fr.), Pyrenodesmia atroflava (for Lecidea atroflava Turner), Pyrenodesmia bicolor (for Caloplaca bicolor H. Magn.), Pyrenodesmia molariformis (for Caloplaca molariformis Frolov, Vondrák, Nadyeina et Khodos.), Pyrenodesmia neotaurica (for Caloplaca neotaurica Vondrák, Khodos., Arup et Søchting), Pyrenodesmia peliophylla (for Placodium peliophyllum Tuck.) are proposed based on results from a combined phylogenetic analysis using nrITS, nrLSU and mtSSU gene sequences.

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Authors: Zoltán Attila Köbölkuti, Klára Cseke, Attila Benke, Mátyás Báder, Attila Borovics and Róbert Németh

Introduction

Since Populus has veritable value as timber, plywood, pulp, and paper, genomic research should create the sound basis for further breeding toward desirable wood quality attributes.

Materials and methods

In this study, we addressed the need for a research methodology that initially identifies and then characterize candidate genes encoding enzymes with wood property phenotypic traits, toward the aim of developing a genomics-based breeding technology.

Results

On 23 different poplar species/hybrid samples, we successfully amplified 55 primers designed on Populus trichocarpa L. Considering the number of polymorphic sites, out of 73,206 bp, 51 SNPs and 31 indel events were found. Non-synonymous single base mutations could be detected in number of 30, 21 out of 164 sequences were the number of minimum recombination events and 41 significant pairwise comparisons between loci could be detected.

Discussion and conclusion

Our results provide a roadmap for a future association genetic study between nucleotide diversity and precise evaluation of phenotype.

Open access
Authors: Gergely Sámuel Bartha, Gergő Tóth, Péter Horváth, Eszter Kiss, Nóra Papp and Monika Kerényi

Introduction

Several Aristolochia species were used as medicinal herb across Europe and in recent years, their antimicrobial activity has also been investigated.

Materials and methods

In this study, A. clematitis was selected to evaluate the aristolochic acids I and II (AA I and AA II) concentrations and the antimicrobial activity of methanol, hexane, butanol, and ethyl acetate extracts of the root, stem, leaf, root, and fruit. AA I and AA II contents were measured by a validated high-performance liquid chromatography–ultraviolet method.

Results

Each fraction of the plant contained AA I and AA II and the root was found to have the highest contents of AA I (1.09%) and AA II (0.7454%). The minimum inhibitory concentrations of all extracts were determined by standard microdilution method. The fruit’s extracts showed the most efficient antimicrobial effect against both methicillin sensitive and resistant Staphylococcus aureus strains.

Conclusion

Correlation between the AA I and AA II concentrations and the antimicrobial effect was not found.

Open access

Abstract

Ecological communities are shaped by a complex interplay between abiotic forcing, biotic regulation and demographic stochasticity. However, community dynamics modelers tend to focus on abiotic forcing overlooking biotic interactions, due to notorious challenges involved in modeling and quantifying inter-specific interactions, particularly for species-rich systems such as planktonic assemblages. Nevertheless, inclusive models with regard to the full range of plausible drivers are essential to characterizing and predicting community response to environmental changes. Here we develop a Bayesian model for identifying, from in-situ time series, the biotic, abiotic and stochastic factors underlying the dynamics of species-rich communities, focusing on the joint biomass dynamics of biologically meaningful groups. We parameterize a multivariate model of population co-variation with an explicit account for demographic stochasticity, density-dependent feedbacks, pairwise interactions, and abiotic stress mediated by changing environmental conditions and resource availability, and work out explicit formulae for partitioning the temporal variance of each group in its biotic, abiotic and stochastic components. We illustrate the methodology by analyzing the joint biomass dynamics of four major phytoplankton functional types namely, diatoms, dinoflagellates, coccolithophores and phytoflagellates at Station L4 in the Western English Channel using weekly biomass records and coincident measurements of environmental covariates describing water conditions and potentially limiting resources. Abiotic and biotic factors explain comparable amounts of temporal variance in log-biomass growth across functional types. Our results demonstrate that effective modelling of resource limitation and inter-specific interactions is critical for quantifying the relative importance of abiotic and biotic factors.

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Due to its overall environmental impact, the residual dye in the wastewater from the synthetic dye manufacturing and textile industries is a global concern. The discharge contains a high content of pigments and other additives, possessing complex structures. As per the requirement for dyed clothing, dyestuff in the effluent is less susceptible to acids, bases, and oxygen. Thus, conventional physical and chemical methods are not always efficient in degrading the dyes. Some microorganisms growing in an area affected with textile effluent have the capability to utilize the dyes as a source of carbon or nitrogen or both. As a very clean, inexpensive, and sufficient alternative, bioremediation of textile wastewater using these microorganisms has gained major popularity. This review primarily centers the contribution of bacteria in this sector and the isolation of such bacteria from textile effluent. A secondary focus is discussing the factors which influence the performance by different bacteria.

Open access

Purpose

This study aims to characterize plant growth-promoting rhizobacteria (PGPR) in sunflowers growing in different locations at North West of Iran.

Materials and methods

Sunflower plants were collected from different regions of West Azarbaijan, and rhizospheric bacterial strains were isolated and screened for PGP traits. Identification and characterization of the PGPR were conducted based on 16s rDNA sequences and phenotypic analysis, the strains clustered for genetic diversity by rep-PCR method.

Results

Among the 80 bacterial isolates, 20 showed PGP traits and were selected for other potentials. All the selected isolates produced indole-3-acetic acid at the rate of 9.2–33.7 mg/ml. In addition, 13, 15, 12, and 16 were positive for phosphate solubilization, siderephore, hydrogen cyanide, and ammonia production, respectively. The results from a subsequent pot experiment indicated that PGPRs distinctly increased sun flower shoot and root length, shoot and root fresh weight, as well as shoot and root dry weight. Based on 16S rDNA sequences and biochemical and physiological characteristics, 20 PGPRs were identified as Pseudomonas fluorescens (five isolates), Pseudomonas aeruginosa (four isolates), Pseudomonas geniculata (one isolate), Bacillus subtilis (four isolates), Bacillus pumilus (two isolates), Stenotrophomonas maltophilia (two isolates), and Brevibacterium frigoritolerans (two isolates). In rep-PCR, PGPR isolates were differentiated into seven clusters (A–G) at 65% similarity level. These results demonstrated the existence of a considerable species richness and genetic diversity among PGPRs isolated from different regions of North West of Iran.

Conclusions

To the best of our knowledge, this is first report for the identification and characterization of B. frigoritolerans as PGPR in sunflower plants.

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Authors: Rubina Tu¨nde Szabó, Mária Kovács-Weber, Márta Erdélyi, Krisztián Balogh, Natasa Fazekas, Ákos Horváth, Miklós Mézes and Balázs Kovács

Background and aims

The aim of this study was to verify that the comet assay can be used to investigate the DNA damaging effects of T-2 and HT-2 toxins in the liver of broiler chickens. The comet assay is a favorable genotoxic analysis because it is cheap, simple, and can be used in many organisms and different tissues.

Materials and methods

Male broiler chickens were fed with T-2/HT-2 toxins-contaminated diet for 14 days. The comet assay was successfully adapted to chicken liver cells, and the DNA damage was determined by a decrease in the comet parameter (DNA % in the tail) in the experimental groups.

Results

The method of evaluation was found to be critical because DNA damage could not be detected exactly using the CometScore software, due to inaccurate separation of head and comet. However, this problem can be solved by visual evaluation.

Conclusion

In the case of the visual evaluation, each toxin-treated group differed significantly from the control group, indicating that the assay can be useful for the assessment of primary DNA damage caused by T-2/HT-2 toxins.

Open access

Introduction

In this study, we analyzed gynandromorphs with female terminalia, to dissect mating-related female behaviors in Drosophila.

Materials and methods

We used gynandromorphs, experimentally modified wild-type (Oregon-R) females, and mutant females that lacked different components of the female reproductive apparatus.

Results

Many of the gynandromorphs mated but did not expel the mating plug (MP). Some of these – with thousands of sperm in the uterus – failed to take up sperm into the storage organs. There were gynandromorphs that stored plenty of sperm but failed to release them to fertilize eggs. Expelling the MP, sperm uptake into the storage organs, and the release of stored sperm along egg production are separate steps occurring during Drosophila female fertility. Cuticle landmarks of the gynandromorphs revealed that while the nerve foci that control MP expelling and also those that control sperm uptake reside in the abdominal, the sperm release foci derive from the thoracic region of the blastoderm.

Discussion and conclusion

The gynandromorph study is confirmed by analyses of (a) mutations that cause female sterility: Fs(3)Avar (preventing egg deposition), Tm2gs (removing germline cells), and iab-4DB (eliminating gonad formation) and (b) by experimentally manipulated wild-type females: decapitated or cut through ventral nerve cord.

Open access
Authors: F. Tóth, Franciska Tóthné Bogdányi, Renáta Petrikovszki, Anita Gódor, M. Zalai, B. Bálint, P. Sunder and A. Myrta

The effectiveness of dimethyl disulfide (DMDS) to control root-knot nematodes (Meloidogyne spp.) and weeds was tested for the first time in Hungary in two consecutive protected cucumber crops with application made only before the first crop. The treatments were Accolade EC (DMDS 94.1%) at 400 l/ha applied by driplines, Nemathorin 10 G (fosthiazate) at 30 kg/ha, and an untreated control. During the first cucumber cycle vigour-index, yield, root-gall index, Meloidogyne juveniles in the soil and germination of weeds were evaluated. All considered parameters were significantly improved by using DMDS compared respectively to the chemical standard and untreated control: (i) vigour-index of 7.0, 4.3 and 3.6; (ii) cumulative yield/sample of 45.1 kg, 30.9 kg, and 16.6 kg; root-gall index (RGI) of 1.2, 4.9, and 5.9; (iii) M. incognita J2/25 g soil of 0.25, 48.5 and 78.0, and (iv) number of weed seedlings/sample in the 20–30 cm soil profile of 1.1, 2.6, and 4.2. During the second cucumber crop, only root-gall index was evaluated. Results showed that a single DMDS treatment applied before the first crop had a prolonged beneficial effect on the following crop. In the second crop cycle, root gall indices were 5.58, 9.18, and 8.44 for DMDS treated plots, chemical control and untreated control, respectively.

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Authors: Elisabetta Gerace, Vincenzo Di Marco Lo Presti and Carmelo Biondo

Cryptosporidium is a protozoan that infects a wide variety of vertebrates, including humans, causing acute gastroenteritis. The disease manifests with abdominal pain and diarrhea similar to that of choleric infection. In the immunocompromised hosts, the parasite causes prolonged infections that can also be fatal. For this reason, cryptosporidiosis is considered one of riskiest opportunistic infections for patients with acquired immunodeficiency syndrome. The best way to control the infection in these patients is setting up sensitive and specific diagnostic tests for epidemiological surveillance and morbidity reduction. Here, we summarized the general aspects of Cryptosporidium infection focusing on available diagnostic tools used for the diagnosis of cryptosporidiosis. Molecular methods currently available for its detection and progress in the development of new diagnostics for cryptosporidiosis are also discussed.

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Phthorimaea operculella is a significant insect pest of cultivated potatoes in tropical and subtropical regions such as Iran. Since the potato is one of the most valuable sources of human food, non-chemical control of potato pests is essential. Application of medicinal plant extracts is a low-risk alternative method to synthetic chemical insecticides. Hence, the present study was conducted to investigate a potential strategy to improve the insecticidal activity of plant extracts for efficient management of P. operculella. The insecticidal efficacy of pure methanolic extract (PME) and Fe3O4@methanolic extract (FME) of Cuminum cyminum were evaluated against the potato tuber moth under laboratory conditions. The morphological characteristics of Fe3O4@Cumin were investigated by scanning electron microscope. Magnetic properties of the samples were determined using a vibration sample magnetometer. XRD was used to prove the crystalline structure of Fe3O4@Cumin. SEM, FTIR, XRD, and VSM analyses confirmed that the methanolic extract was loaded on Fe3O4. The toxicity of PME and Fe3O4@Cumin were evaluated on one-day-old eggs and penetration the first instar larvae of P. operculella into potato tubers and leaves. The LC50 values of Cumin extract and Fe3O4@ Cumin were 961.07 and 601.48 and 496.84 and 268.82 ppm for penetrating neonate larvae to tubers and leaves, and 874.90 and 595.16 ppm for eggs, respectively. Bioassays revealed that Fe3O4@Cumin was more toxic than non-formulated Cumin methanolic extract against eggs and neonate larvae of P. operculella. The formulated methanolic extract was significantly more repellent against the pest. Our results suggested that the prepared nanocomposite could be used as a new effective tool for P. operculella management strategies to protect potatoes.

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Abstract

Foundation species and invasive species strongly influence community diversity and structure, but typically in different ways. However, when widespread invasive species provide novel habitat within a community, their net effect may depend on both the environment and community composition. Fouling communities in northern and southern California harbors were surveyed to determine whether there was variation between two locations in the percent cover of an invasive bryozoan, Watersipora subtorquata (d'Orbigny, 1852), and its relationship to community diversity and composition in these two environments. Diversity significantly differed between locations and had a location-dependent association with W. subtorquata abundance. Communities were significantly dissimilar between locations, and W. subtorquata abundance had the highest percent contribution to community dissimilarity when compared to other species in the community. These results suggest that invasive species may have both facilitative and inhibitive relationships with species in a community, but that the net balance of these interactions depends on both the environmental and community context.

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The economic threshold level of Meloidogyne incognita, Alternaria dauci and Rhizoctonia solani were determined on carrot (Daucus carota L.) under greenhouse conditions. The results revealed that plant length, plant fresh weight, shoot and root dry weight, chlorophyll and carotenoid decreased progressively with the corresponding increase in the inoculum levels of each pathogen. The significant reduction in plant growth parameters, chlorophyll and carotenoid occurred when 2000 or more second stage juveniles (J2s) of M. incognita, 1.0 g or more inoculum of A. dauci or R. solani per kg soil were inoculated. Maximum reduction in plant growth attributes, chlorophyll and carotenoid occurred at the highest inoculum level of the test pathogens. Increase in the inoculum level of M. incognita caused an increase in the number of root galls, while the multiplication of nematode was found inversely related to the inoculum density. The increase in the inoculum levels of A. dauci and R. solani resulted in a progressive increase in leaf blight and crown rot indices and caused a higher reduction in plant growth parameters. The damaging threshold level of M. incognita was 2000 J2 per kg soil while 1.0 g per kg soil of A. dauci or R. solani was threshold level on carrot. The assessment of infestation levels of test pathogens will enable growers to cost-effectively select and implement the management tactics.

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Introduction

Effect of water stress on the physiology and biochemistry of two different Coleus species, Coleus forskholii and Coleus amboinicus, was studied.

Materials and methods

Drought stress was imposed by withholding the water supply until leaf water potentials reached −0.4, −0.8, and −1.2 MPa. Physiological parameters such as relative water content and water uptake capacity were studied along with lipid peroxidation, superoxide, H2O2, and OH accumulation-, 1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging assays. Antioxidant defense system in Coleus under drought stress was studied by quantifying the Trolox equivalent antioxidant capacity, ascorbic acid, reduced glutathione-, and α-tocopherol content as well as activities of superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and glutathione reductase. Accumulation of osmolytes proline, glycine betaine, and phytohormone abscisic acid was also used as key parameters for assessing their performance.

Results

There was a marked variation in the antioxidative defense system and osmolyte accumulation in these two species under drought stress. Relative water content was reduced and water uptake capacity was increased.

Discussion

A comparative study in the perspectives of osmolyte accumulation, antioxidant, and physiological responses inferred C. amboinicus as a drought stress-tolerant species when compared to C. forskholii.

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Authors: S. Leon-Cisneros, A. Quirola-Garcés, J. Alvarez-Santana, N. Barriga-Medina, D. Ramirez-Villacís, M. Caviedes, L. Ramirez-Cárdenas and A. Leon-Reyes

Anthocyanins are plants metabolites that are recognized by its red/purple coloration produced in flowers, seeds and leaves. These molecules are potentially important to the industry for its antioxidant capacity, disease prevention and as a natural dye. Currently, the production of anthocyanins is carried out using in vitro culture of Vitis vinifera and its yield is increased by using elicitors or stress factors. Zea mays is relevant due to its high content of cyanidin-3-β-glucoside anthocyanin. In the present study the production of cyanidin-3-β-glucoside was evaluated with different mechanisms of elicitation using in vivo and in vitro culture of purple and white maize varieties. The highest callus induction (85%) for white maize was obtained in MS medium supplemented with 2 mg/L of 2,4-Dichlorophenoxyacetic acid, while for purple maize (93%) was obtained in N6 medium with 2 mg/L of 2,4-Dichlorophenoxyacetic acid, using germinated seed as explant for both varieties. Methyl jasmonate was evaluated as an elicitation tool, however no cyanidin-3-β-glucoside was found to be accumulated or produced in vitro. In contrast, using germinated seeds and radicle tissue, elicitation using phosphorus deficiency treatment produced the highest cyanidin-3-β-glucoside accumulation (0.06 mg g−1) in white maize. No elicitation and further production of anthocyanins was found when purple maize were used using this method. Therefore, in vivo elicitation in white maize is a potential method to produce a stable anthocyanin that could be optimized for future applications.

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Cereal breeding programs are interested in increasing the number of generations per year to reduce the time needed to develop new cultivars. A common method to accomplish this is to extend the photoperiod to speed up plant growth. For oat, this method is problematic because the species responds to changes in light and temperature. Current methods of fast generation cycling in oat require embryo rescue, which is labor intensive and has a low success rate. Recently a method was developed using increased photoperiod and foliar mineral supplement to reduce generation time for wheat and barley. We evaluated this newly published method in oat and found that anthesis occurred 15 ± 3 days faster, however there was a 3-fold reduction in seed count and a 2-fold reduction in inflorescence weight. In addition, we measured endogenous ascorbate to evaluate the physiological status of the plants under fast generation cycling conditions. For oat, fast generation cycling would be effective to more rapidly advance populations using single seed descent, but not as useful when seed yield is important.

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Authors: D. Huang, H. Zhang, M. Tar, Y. Zhang, F. Ni, J. Ren, D. Fu, L. Purnhauser and J. Wu

Stripe or yellow rust (Yr), caused by Puccinia striiformis Westend. (Pst), is one of the most important wheat diseases worldwide. New aggressive Pst races can spread quickly, even between countries and continents. To identify and exploit stripe rust resistance genes, breeders must characterize first the Pst resistance and genotypes of their cultivars. To find new sources of resistances it is important to study how wheat varieties respond to Pst races that predominate in other continents. In this study we evaluated stripe rust resistance in 53 Hungarian winter wheat cultivars in China. Twenty-four cultivars (45.3%) had all stage resistance (ASR) and 1 (1.9%) had adult-plant resistance (APR), based on seedling tests in growth chambers and adult-plant tests in fields. We molecularly genotyped six Yr resistance genes: Yr5, Yr10, Yr15, Yr17, Yr18, and Yr36. Yr18, an APR gene, was present alone in five cultivars, and in ‘GK Kapos’, that also had seedling resistance. The other five Yr genes were absent in all cultivars tested.

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Few researches address the compatibility of organic mulching and entomopathogenic (EPN) and slug-parasitic (SPN) nematodes, although organic mulching may provide favourable conditions for these beneficial organisms. Our aim was to examine the effect of different concentrations (0.1, 0.5, 1 and 5%) of aqueous extracts of green waste compost, the dry leaf litters of the common walnut (Juglans regia) and Norway maple (Acer platanoides) on EPN (Heterorhabditis bacteriophora, Steinernema carpocapsae, Steinernema feltiae, Steinernema kraussei) and SPN (Phasmarhabditis hermaphrodita) species. Experiments were set up in 96-well, flat-bottom microplates. After a 24-hour exposure time, the number of dead animals was counted under a transmission microscope. Green wast