Long-term effects of early parasite exposure on song duration and singing strategy in great tits

Song is a sexually selected trait in many bird species and has been suggested to function as a signal of a male's health and parasite resistance. Here we present an experimental field study on the long-term effects of parasite exposure early in life on adult bird song. We exposed nestling great tits (Parus major) to ectoparasitic hen fleas (Ceratophyllus gallinae) and on their recruitment into the local breeding population assessed the response to a playback of a challenging male in their breeding territory. We show, to our knowledge for the first time in a wild bird population, that parasite exposure early in life affects bird song: song duration of males that were exposed to parasites early in life was reduced by 32% compared with males that grew up in a flea-free environment. Early parasite exposure also significantly reduced the degree of song overlap with the playback, which has been shown to correlate with social status. There was no effect of early parasite exposure on the number of different song types sung or on the latency until the males started the vocal response to the playback. These results suggest that mates or rivals can use song duration and song overlap as proxies for an individual's exposure to parasites early in life. It thereby highlights both the importance of parasites in maintaining honesty of sexually selected traits and the costs of parasitism in terms of reduced attractiveness and competitivenes

A question of origin: Where and how to collect seed for ecological restoration

Native plant species are routinely planted or sown in ecological restoration projects, but successful establishment and survival depend on where and how seeds are collected. Research suggests that it is important to use locally adapted seeds. Local populations often show a home-site advantage and non-local genotypes may be maladapted to local environmental conditions. Furthermore, intraspecific hybridisation of local and non-local genotypes may have a negative impact on the genetic structure of local populations via mechanisms such as outbreeding depression. Many species show a strong small-scale genetic differentiation between different habitats so that matching habitats of the restoration and donor site can be more important than minimizing geographical separation. It is a challenge to identify appropriate seed sources because strong small-scale population differentiation makes it difficult to delineate geographically defined seed zones to which seed exchange should be limited. Moreover, it is important to consider the genetic diversity of introduced material because it may be crucial to avoid genetic bottlenecks, inbreeding depression and poor establishment of plant populations. Repeated propagation in stock, which is often required to obtain a sufficient amount of seeds, can further reduce genetic diversity and may select for particular genotypes. Negative impacts of improper seed choice for nursery planting stock may become detectable only after many years, especially in long-lived and slow growing plants. Although scientific information on many species remains limited, the increasing demand for translocation of seed means that mandatory regulations are necessary. Guidelines should prescribe a specification of seed provenance, a record of genetic diversity of wild collections and rules for subsequent processing such as direct transfer and propagation of stock or seed orchards. We use a literature review to evaluate current legislation and to develop recommendations for herbaceous and woody species

Inadequate medical treatment of patients with coronary artery disease by primary care physicians in Germany

Aims: The DETECT study was performed to obtain representative data about the frequency, distribution, and treatment of patients with coronary artery disease (CAD) in the primary care setting in Germany. Methods and results: The DETECT study was a cross–sectional clinical– epidemiological survey of a nationally representative sample of 3795 primary care offices and 55 518 patients. Overall, 12.4% of patients were diagnosed with CAD. Stable angina pectoris and myocardial infarction were the most frequent (4.2%) subgroups, followed by status post (s/p) percutaneous coronary interventions (PCI, 3.0%) and s/p coronary bypass surgery (2.2%). Patients with CAD were prescribed AT1 receptor antagonists (in 19.4% of cases), beta blockers (57.2%), ACE inhibitors (49.9%), antiplatelet agents (52.7%), statins (43.0%), and long–term nitrates (24.5%). When comparing all CAD patients with social health care insurance to those who had private insurance, private patients had significantly higher rates of revascularisation procedures and use of preventive medications. Conclusion: Great potential remains for improving secondary prevention in primary care in Germany to reduce the risk of further coronary or vascular events, especially in patients with social health care insurance

Molecular epidemiology and antimicrobial resistance of Clostridioides difficile detected in chicken, soil and human samples from Zimbabwe

Background: Clostridioides difficile is the major cause of infectious nosocomial diarrhoea in industrialized nations. Data on the occurrence of C. difficile in Africa, ribotype (RT) distribution, antimicrobial susceptibility patterns and potential zoonotic transmission are scarce. Methods: 80 Zimbabwean C. difficile isolates from different sources (chicken [n = 30], soil [n = 21] and humans [n = 29]) were investigated using ribotyping, toxin gene detection, resistance testing, multiple-locus variable-number tandem repeat analysis (MLVA), and whole genome sequencing (WGS). Results: Among chicken isolates, the most common RTs were RT103 (6/30), RT025 (5/30) and RT070 (4/30). Within soil samples, RT025 and RT056 were most common (3/21 each). In contrast, the non-toxigenic RT084 was most frequently found in human isolates (4/29). Toxin genes were detected in only 19/29 human isolates. Susceptibility testing showed no resistance against metronidazole and vancomycin, and resistance against macrolides and rifampicin was scarce (3/80 and 2/80, respectively); however, 26/80 isolates showed moxifloxacin resistance. MLVA and WGS of strains with identical RTs stemming from different sources revealed clustering of RT025 and RT084 isolates from human und non-human samples. Conclusion: No "hypervirulent” strains were found. The detected clusters between human, chicken and soil isolates indicate ongoing transmission between humans and environmental sources and might point towards a zoonotic potential

Discrimination between hypervirulent and non-hypervirulent ribotypes of Clostridioides difficile by MALDI-TOF mass spectrometry and machine learning

Hypervirulent ribotypes (HVRTs) of Clostridioides difcile such as ribotype (RT) 027 are epidemiologically important. This study evaluated whether MALDI-TOF can distinguish between strains of HVRTs and non-HVRTs commonly found in Europe. Obtained spectra of clinical C. difcile isolates (training set, 157 isolates) covering epidemiologically relevant HVRTs and non-HVRTs found in Europe were used as an input for diferent machine learning (ML) models. Another 83 isolates were used as a validation set. Direct comparison of MALDI-TOF spectra obtained from HVRTs and non-HVRTs did not allow to discriminate between these two groups, while using these spectra with certain ML models could diferentiate HVRTs from non-HVRTs with an accuracy >95% and allowed for a sub-clustering of three HVRT subgroups (RT027/ RT176, RT023, RT045/078/126/127). MALDI-TOF combined with ML represents a reliable tool for rapid identifcation of major European HVRTs

Molecular epidemiology and antimicrobial resistance of Clostridioides difficile in Germany, 2014-2019

Clostridioides difficile is a Gram positive spore-forming rod and mainly responsible for nosocomial diarrhea in developed nations. Molecular and antimicrobial surveillance is important for monitoring the strain composition including genotypes of high epidemiological importance such as ribotype 027 (RT027) and corresponding resistance patterns. 1535 isolates obtained from samples sent between 2014 and 2019 to the German National Reference Center (NRC) for diagnostic reasons (NRC strain set), and 1143 isolates from a Tertiary Care University Center in Saarland, Germany (non-NRC strain set), were evaluated using antibiotic susceptibility testing and ribotyping. In the NRC strain set, RT027 overtook RT001, the main RT found in the preceding studies, and dominated with 36.2%, followed by RT001 (13.3%), and RT014 (8.5%). Of note, since 2016 a constant decrease of RT027 could be noticed. In the non-NRC strain set a large strain diversity was present with RT014 (18%) and RT001 (8.9%) being most prevalent. In NRC samples, resistance towards metronidazole, vancomycin, moxifloxacin, clarithromycin and rifampicin was 2.7%, 0%, 57.1%, 53.2% and 19.2%, respectively. Metronidazole resistance was almost exclusively found in RT027 isolates. Rifampicin resistance was also observed predominantly in isolates of RT027, constituting an almost four-fold increase, when compared to preceeding studies in this region. In conclusion these data demonstrate that RT027 is a driver for rifampicin and metronidazole resistance, underlining the importance of continuous surveillance efforts

Irritable bowel syndrome - An inflammatory disease involving mast cells

Irritable bowel syndrome (IBS) is traditionally defined as a functional disorder - that is the presence of symptoms in the absence of demonstrable pathological abnormalities. In recent times, low grade inflammatory infiltrates in both the small and large bowel of some patients with IBS - often rich in mast cells, along with serological markers of low grade inflammation have focussed attention on IBS as an inflammatory disease. The observation that mast cells often lie in close association to enteric neurons, and in-vitro and in-vivo animal studies demonstrating that mast cell mediators may influence enteric motility provides a biologically plausible causal mechanism in IBS. Pilot studies on patients with IBS using the mast cell stabiliser sodium cromoglycate ('proof of concept') have been encouraging. The essential question remains why mast cells infiltrate the bowel of IBS patients. A disturbance of the 'brain-gut axis' is the current favoured hypothesis, whereby childhood stress or psychiatric comorbidity act via neuro-immune mechanisms to modulate low grade inflammation. An alternative hypothesis is that food allergy may be responsible. Serum specific IgE, and skin prick tests are not elevated in IBS patients, suggesting type 1 IgE mediated food allergy is not the cause. However questionnaire based studies indicate IBS patients have higher rates of atopic disease, and increased bronchial reactivity to methacholine has been demonstrated. In this review, we highlight the potential role of mast cells in IBS, and current and future research directions into this intriguing condition

Molecular characterization, toxin detection and resistance testing of human clinical Clostridium difficile isolates from Lebanon

Clostridium (Clostridioides) difficile is the main cause for nosocomial diarrhoea in industrialised nations. Epidemiologic data on the pathogen’s occurrence in other world regions are still scarce. In this context we characterized with phenotypic and molecular genetic methods C. difficile isolates stemming from hospitalised patients with diarrhoea in Lebanon. From 129 stool samples of symptomatic patients at a tertiary care University hospital in Lebanon, a total of 107 C. difficile strains were cultivated and underwent ribotyping, toxin gene detection and antibiotic resistance testing. Ribotype 014 (RT014, 16.8%) predominated, followed by RT002 (9.3%), RT106 (8.4%) and RT070 (6.5%). Binary toxin gene-positive isolates (RT023, RT078 and RT126) were rarely detected and RT027 was absent. Interestingly, within one isolate only the toxin A gene (tcdA) was detected. Multiple-locus variable-number tandem repeat analysis (MLVA) revealed strong strain diversity in most RTs. The isolates were sensitive to metronidazole and vancomycin, and only a small proportion of strains displayed resistance against moxifloxacin, rifampicin, and clarithromycin (5.6%, 1.9%, and 2.8%), respectively. The data indicate that the genetic strain composition of Lebanese strains differs markedly from the situation seen in Europe and North America. Especially the epidemic RTs seen in the latter regions were almost absent in Lebanon. Interestingly, most strains showed almost no resistance to commonly used antibiotics that are suspected to play a major role in the development of C. difficile infection, despite frequent use of these antibiotics in Lebanon. Thus, the role of antimicrobial resistance as a major driving force for infection development remains uncertain in this area