Browse

You are looking at 11 - 20 of 5,594 items for :

  • Biology and Life Sciences x
Clear All
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.

Restricted access

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.

Restricted access

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.

Restricted access
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