Biological invasion is a crucial problem in the world because of its negative consequences for protected areas. The degradation stage of vegetation might affect the success of invasion. One of the most abundant and threatening invasive species is the common milkweed (Asclepias syriaca L.) which has invaded already 23 countries of Europe and in several habitat types its further spreading is promoted by climate change. Pannonian sand grassland is one of the most threatened habitat by common milkweed invasion. Therefore, invasion in sand grassland vegetation is an important issue. However, the effects of the invasive plant in the open sand grassland are rather controversial. In order to clarify the existing contradictory results, the study was carried out in a strictly protected area, near Fülöpháza (Hungary) in a reserve core area in a UNESCO biosphere reserve. Microcoenological study was applied to determinate the fine-scale community characteristics of non-invaded and invaded stands in natural and seminatural vegetation and data were processed by Juhász-Nagy's information theory models. Shannon diversity of species combinations (compositional diversity) which describes the ways of the coexistence of species, and the number of realized species combinations were used for measuring beta diversity. Differences between stands were analyzed by two-way ANOVA. The maximum compositional diversity of species and main life-forms (annuals, perennials and cryptogams) did not differ significantly between the non-invaded and invaded stands. In contrast, significantly larger characteristic areas of compositional diversity were detected in the invaded stands. Based on these results, it could be concluded that diversity of species combinations did not change but those values have shifted to coarser scales in case of invaded stands. The direction of this change suggests a kind of impoverishment in the presence of Asclepias. Thus, it is worth mentioning from the invasion management point of view that protection of the habitats against disturbance is a more cost-effective and successful way than protection against the establishment or extirpation of invasive species, since disturbance facilitates the invasions throughout the impoverishment of the community.
Functional responses measure the trophic interactions between species, taking into account the density and behavior of the interacting species. In predator-prey interactions, the prey preference of the predator and the antipredator behavior of the prey together determine the feeding rate of the predator and the survival rate of the prey. Consequently, the behavior dependent functional responses make it possible to establish dynamic ecological models providing insight, among others, into the coexistence of predator and prey species and the efficiency of agents in biological pest control. In this paper the derivation methods of functional responses are reviewed. Basically, there are three classes of such methods: heuristic, stochastic and deterministic ones. All of them can take account of the behavior of the predator and prey. There are three main stochastic methods for the derivation of functional responses: renewal theory, Markov chain and the Wald equality-based method. All these methods assume that during the foraging process the prey densities do not change, which provides a mathematical basis for heuristic derivation. There are two deterministic methods using differential equations. The first one also assumes that during the foraging process the prey densities do not change, while the second one does not use that assumption. These derivation methods are appropriate to handle the behavior dependent functional responses, which is essential in the derivation of ecological games, when the payoff of prey and predator depends on the strategies of the prey and predator at the same time.
Authors:Carlo Pazzini, Parviz Ahmad-Nejad, and Beniam Ghebremedhin
Nowadays, multidrug-resistant bacteria are considered as an increasing serious threat to public health worldwide. Global and local surveillance data are helpful in the application of the most efficient antimicrobial agent in bacterial infections. In the current study, we aimed to analyze the activity of the previously cleared agent ceftolozane/tazobactam (C/T) in African and European multidrug-resistant Gram-negative bacteria. Susceptibility testing was performed on 147 extended-spectrum β-lactamase (107 Escherichia coli and 40 Klebsiella pneumoniae) and 103 carbapenemase-producing Gram-negative bacteria using Etest according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints. Among the extended-spectrum β-lactamase producing isolates, 91 Escherichia coli isolates (85%) and 23 Klebsiella pneumoniae isolates (57.5%) were susceptible towards C/T whereas out of the 103 carbapenemase-producing isolates 102 (99.0%) were C/T-resistant. C/T should be included in susceptibility testing to fairly administer this antimicrobial agent in infections caused by multidrug-resistant bacteria. It may be considered as a therapy option for infections caused by extended-spectrum β-lactamase-producing bacteria once susceptibility to this antimicrobial combination has been confirmed.
This paper presents the phytosociological description of a drained swamp community, Veratro albi-Fraxinetum angustifoliae, so far found only in the Nyírség at Nyírábrány “Kis-kőrises”, “Mogyorósi-erdő”; Vámospércs “Jónásrész-Kőrises”; and Vámospércs “Jónásrész-Buzita”. The habitat of the community is transitional between that of alder swamps (Fraxino pannonicae-Alnetum glutinosae), and hardwood riparian forests (Fraxino pannonicae-Ulmetum). The community is characterised by high proportions of character species of Alnion glutinosae and Molinion coerulei as well as Quercetea pubescentis-petraeae s. l. whereas character species of the order Fagetalia are almost completely absent. It hosts several rare, often threatened species, such as Angelica palustris, Ophioglossum vulgatum, Trollius europaeus and Veratrum album.
Authors:Katharina Mrazek, Stefan Bereswill, and Markus M. Heimesaat
Intestinal carriage of multi-drug resistant (MDR) Gram-negative bacteria including Pseudomonas aeruginosa (Psae) constitutes a pivotal prerequisite for subsequent fatal endogenous infections in patients at risk. We here addressed whether fecal microbiota transplantation (FMT) could effectively combat MDR-Psae carriage. Therefore, secondary abiotic mice were challenged with MDR-Psae by gavage. One week later, mice were subjected to peroral FMT from either murine or human donors on 3 consecutive days. Irrespective of murine or human origin of fecal transplant, intestinal MDR-Psae loads decreased as early as 24 h after the initial FMT. Remarkably, the murine FMT could lower intestinal MDR-Psae burdens by approximately 4 log orders of magnitude within 1 week. In another intervention study, mice harboring a human gut microbiota were perorally challenged with MDR-Psae and subjected to murine FMT on 3 consecutive days, 1 week later. Strikingly, within 5 days, murine FMT resulted in lower loads and carrier rates of MDR-Psae in mice with a human gut microbiota. In conclusion, FMT might be a promising antibiotics-independent option to combat intestinal MDR-Psae carriage and thus prevent from future endogenous infections of patients at risk.
Authors:Andrea Heinzlmann, Márk Oláh, and Katalin Köves
It was previously shown that intracerebroventricular administration of pituitary adenylate cyclase-activating polypeptide (PACAP) prior to GnRH mobilization in proestrus prevents ovulation in rats. In this study, we examined whether PACAP given intranasally could influence luteinizing hormone (LH) and prolactin (PRL) surges and ovulation.
On the day of proestrus PACAP, β-cyclodextrin (modifier of blood–brain barrier) or PACAP + β-cyclodextrin was applied intranasally between 12:30 and 13:00. Blood samples were taken at 16:00, 18:00, and 20:00 for measuring plasma hormone levels. In the next morning, the expelled ova were counted. β-Cyclodextrin was also administered to male and diestrous female rats between 12:30 and 13:00 and blood was taken at 18:00.
PACAP prevented LH and PRL surges and ovulation in about half of the rats, β-cyclodextrin alone more effectively prevented ovulation. When PACAP and β-cyclodextrin were administered together, more rats ovulated like when PACAP given alone. β-Cyclodextrin did not influence LH and PRL levels in diestrous females; however, in males, it significantly enhanced PRL level.
Not only the intracerebroventricular, but the intranasal application of PACAP prevented ovulation. β-Cyclodextrin alone is more effective than PACAP and enhances PRL levels in male rats. PACAP and β-cyclodextrin given together weaken each other’s effect. β-Cyclodextrin, as excipient of various drugs, has to be used carefully in human medications.
Authors:Souba Diandé, Gisèle Badoum, Adjima Combary, Issaka Zombra, Tandaogo Saouadogo, Léon T. Sawadogo, Bayéma Nébié, Saïdou Gnanou, Adama Zigani, Seydou Mohamed Ouédraogo, Adama Diallo, Seydou Kaboré, and Lassana Sangaré
Setting: A survey of the prevalence of drug-resistant tuberculosis (DR-TB) in new and previously treated patients (PTPs) was performed in Burkina Faso from 2016 to 2017.
Design: In this cross-sectional survey, a structured questionnaire was administered to eligible smear-positive patients in all 86 diagnostic and treatment centers of the country to collect their socio-demographic characteristics and medical histories. Their sputa were tested using the Mycobacterium tuberculosis/rifampicin (MTB/RIF) Xpert assay. Those which were found to be positive for TB and rifampicin-resistant were also tested with GenoType MTBDRplus2.0 and MTBDRsl2.0. Univariate and multivariate logistic regressions were performed to determine risk factors associated with rifampicin resistance.
Results: Of the 1140 smear-positive patients enrolled, 995 new and 145 PTPs were positive for MTB complex by Xpert. Of these, 2.0% (20/995, 95% confidence interval (CI): 1.1–2.9) of the new cases and 14.5% (95% CI: 14.2–20.2) of the PTPs were resistant to rifampicin; 83% of them has multidrug-resistant tuberculosis (MDR-TB). None were pre-extensively drug-resistant TB (pre-XDR-TB) or XDR-TB. Only the previous treatment was significantly associated with rifampicin resistance, p < 0.0001.
Conclusion: Similar to global trends, rifampicin resistance was significantly higher in patients with prior TB treatment (14.5%) than in naïve patients (2.0%). These percentages are slightly below the global averages, but nonetheless suggest the need for continued vigilance. Extending the use of Xpert testing should strengthen the surveillance of DR-TB in Burkina Faso.
Authors:Margit Kollaricsné Horváth, Borbála Hoffmann, István Cernák, Szilveszter Baráth, Zsolt Polgár, and János Taller
Significant differences in nitrogen use efficiency (NUE) were detected previously among potato cultivars. Exploration of the genetic background may facilitate the breeding of cultivars with highly effective nitrogen use.
Expression of NUE genes was analyzed at three different N-supply levels in five potato genotypes. Correlations of NUE gene expressions and agronomical parameters with such indices as the nitrogen uptake efficiency, nitrogen utilization efficiency, NUE, and harvest indices were analyzed.
The correlations between expression level of the nitrate–reductase, nitrite–reductase, ammonium transporter, and asparagine synthase genes and different agronomically important parameters were detected.
Our results contribute to more rational, genotype-dependent nitrogen use in potato production and have relevance in breeding of new cultivars with better nitrogen utilization, as well as in production of seed potato.
Authors:Luis Francisco Sánchez-Anguiano, Nadia Velázquez-Hernández, Fernando Martín Guerra-Infante, Marisela Aguilar-Durán, Alma Rosa Pérez-Álamos, Sergio Estrada-Martínez, José Antonio Navarrete-Flores, Ada Agustina Sandoval-Carrillo, Elizabeth Irasema Antuna-Salcido, Jesús Hernández-Tinoco, and Cosme Alvarado-Esquivel
Purpose: We aimed to determine the association between Chlamydia trachomatis infection and female sex work, and the association between sociodemographic, obstetric, and behavioral characteristics of female sex workers and C. trachomatis infection.
Methods: Through a case–control study design, we studied 201 female sex workers and 201 age-matched women without sex work in Durango City, Mexico. C. trachomatis DNA was detected in cervical swab samples using polymerase chain reaction.
Results: C. trachomatis DNA was detected in 32 (15.9%) of the 201 cases and in 6 (3.0%) of the 201 controls (odds ratio [OR] = 6.15; 95% confidence interval [CI]: 2.5–15.0; P < 0.001). The frequency of infection with C. trachomatis in female sex workers did not vary (P > 0.05) regardless of the history of pregnancies, deliveries, cesarean sections, or miscarriages. Regression analysis of the behavioral characteristics showed that infection with C. trachomatis was associated only with consumption of alcohol (OR = 2.39; 95% CI: 1.0–5.71; P = 0.04).
Conclusions: We conclude that C. trachomatis infection is associated with female sex work in Durango City, Mexico. This is the first age-matched case–control study on the prevalence of C. trachomatis infection in female sex workers in Mexico using detection of C. trachomatis DNA in cervical samples.
Authors:Hans Kollenda, Hagen Frickmann, Rania Ben Helal, Dorothea Franziska Wiemer, Habiba Naija, Mohamed Sélim El Asli, Melanie Egold, Joachim Jakob Bugert, Susann Handrick, Roman Wölfel, Farouk Barguellil, and Mohamed Ben Moussa
Background: Carbapenem-resistance is frequently detected in Enterobacteriaceae isolated from patients in Tunisia. The study was performed to identify frequent carbapenemases in Tunisian isolates.
Methods: Between May 2014 and January 2018, 197 ertapenem-resistant Enterobacteriaceae were isolated at the microbiological department of the Military Hospital of Tunis. The strains were phenotypically characterized and then subjected to in-house polymerase chain reaction (PCR) targeting the carbapenemase genes blaIMP, blaVIM, blaNDM, blaSPM, blaAIM, blaDIM, blaGIM, blaSIM, blaKPC, blaBIC, and blaOXA-48.
Results: The assessed 197 ertapenem-resistant Enterobacteriaceae from Tunis comprised 170 Klebsiella pneumoniae, 19 Enterobacter cloacae, 6 Escherichia coli, 1 Citrobacter sedlakii, and 1 Enterobacter asburiae. Thereby, 55 out of 197 isolates (27.9%) were from blood cultures, suggesting a systemic disease. The carbapenemase gene blaOXA-48 quantitatively dominated by far with 153 detections, followed by blaNDM with 14 detections, which were distributed about the whole study interval. In contrast, blaBIC and blaVIM were only infrequently identified in 5 and 3 cases, respectively, while the other carbapenamases were not observed.
Conclusions: The carbapenemase gene blaOXA-48 was identified in the vast majority of ertapenem-resistant Tunisian Enterobacteriaceae while all other assessed carbapenemases were much less abundant. In a quantitatively relevant minority of isolates, the applied PCR-based screening approach did not identify any carbapenemases.