Body condition and colonization by fungi of House Sparrows Passer domesticus in the urban and rural environment

Wild and partially synanthropic bird yeast diversity, in vitro virulence, and antifungal susceptibility of Candida parapsilosis and Candida tropicalis strains isolated from feces

Yeast complexes in the fecal samples of wild (Dendrocopos major, Picus viridis) and partially synanthropic (Bombycilla garrulus, Garrulus glandarius, Pica pica, and Pyrrhula pyrrhula) birds were studied in a forest ecosystem during winter. A total of 18 yeast species were identified: 16 ascomycetes and two basidiomycetes belonging to five subphyla of fungi: Saccharomycotina (15), Pezizomycotina (1), Agaricomycotina (1), and Pucciniomycotina (1). Most yeast species were found in the fecal samples of P. pyrrhula (Candida parapsilosis, C. zeylanoides, Debaryomyces hansenii, Hanseniaspora uvarum, Metschnikowia pulcherrima, Meyerozyma carpophila, M. guilliermondii, Rhodotorula mucilaginosa); the lowest number of yeast species was observed in the feces of B. garrulus (C. parapsilosis, C. zeylanoides, Met. pulcherrima, and Rh. mucilaginosa). The opportunistic species of the genus Candida were found only in feces of partially synanthropic birds: C. parapsilosis was observed in the feces of B. garrulus, G. glandarius, P. pica, and P. pyrrhula; its relative abundance was 69.3%, 49.1%, 10.5%, and 1.1%, respectively; C. tropicalis was observed in the feces of P. pica and G. glandarius; its relative abundance was 54.6% and 7.1%, respectively. Strains of C. parapsilosis and C. tropicalis isolated from the feces of partially synanthropic birds were evaluated for their susceptibility to conventional antifungal agents (fluconazole, voriconazole, amphotericin B) and hydrolytic activity. A total of 160 strains were studied. Resistance to fluconazole was detected in 86.8% of C. parapsilosis strains and in 87% of C. tropicalis strains; resistance to voriconazole was detected in 71.7% of C. parapsilosis and in 66.7% of C. tropicalis strains, and the lowest percentage of resistant strains was detected to amphotericin B, 2.8% and 3.7% in C. parapsilosis and C. tropicalis strains, respectively. Multiresistance was detected in one strain of C. parapsilosis isolated from P. pica feces and in one strain of C. tropicalis isolated from G. glandarius feces. Phospholipase and hemolysin activities in the strains of C. parapsilosis were low (mean Pz values of 0.93 and 0.91, respectively); protease activity was moderate (mean Pz value of 0.53). The ability to produce hydrolytic enzymes was higher in the isolated strains of C. tropicalis. The mean Pz values of phospholipase and hemolysin activities were moderate (mean Pz values of 0.63 and 0.60, respectively), whereas protease activity was high (mean Pz value of 0.32). Thus, wild and partially synanthropic birds play an important role in disseminating of various yeast species. These yeasts can enter the topsoil via feces and contribute to the formation of allochthonous and uneven soil yeast diversity in natural ecosystems. In addition, partially synanthropic birds can be vectors of virulent strains of opportunistic Candida species from urban environments to natural biotopes.

Using point-of-care devices to examine covariation among blood nutritional-physiological parameters and their relationships with poxvirus infection, habitat urbanization, and male plumage coloration in house finches (Haemorhous mexicanus)

The development of inexpensive and portable point-of-care devices for measuring nutritional physiological parameters from blood (e.g., glucose, ketones) has accelerated our understanding and assessment of real-time variation in human health, but these have infrequently been tested or implemented in wild animals, especially in relation to other key biological or fitness-related traits. Here we used point-of-care devices to measure blood levels of glucose, ketones, uric acid, and triglycerides in free-ranging house finches (Haemorhous mexicanus)-a common songbird in North America that has been well-studied in the context of urbanization, nutrition, health, and sexual selection-during winter and examined (1) repeatability of these methods for evaluating blood levels in these wild passerines, (2) intercorrelations among these measurements within individuals, (3) how blood nutritional-physiology metrics related to a bird's body condition, habitat of origin (urban vs. suburban), poxvirus infection, and sex; and (4) if the expression of male sexually selected plumage coloration was linked to any of the nutritional-physiological metrics. All blood-nutritional parameters were repeatable. Also, there was significant positive covariation between concentrations of circulating triglycerides and glucose and triglycerides and uric acid. Urban finches had higher blood glucose concentrations than suburban finches, and pox-infected individuals had lower blood triglyceride concentrations than uninfected ones. Last, redder males had higher blood glucose, but lower uric acid levels. These results demonstrate that point-of-care devices can be useful, inexpensive ways of measuring real-time variation in the nutritional physiology of wild birds.

Effect of Management of Grassland on Prey Availability and Physiological Condition of Nestling of Red-Backed Shrike Lanius collurio

The study aimed to determine the influence of grassland management on the potential food base of the red-backed shrike Lanius collurio and the condition of chicks in the population inhabiting semi-natural grasslands in the Narew floodplain. The grassland area was divided into three groups: extensively used meadows, intensively used meadows fertilised with mineral fertilisers, and intensively used meadows fertilised with liquid manure, and selected environmental factors that may influence food availability were determined. Using Barber traps, 1825 samples containing 53,739 arthropods were collected, and the diversity, abundance, and proportion of large arthropods in the samples were analysed depending on the grassland use type. In the bird population, the condition of the chicks was characterised by the BCI (Body Condition Index) and haematological parameters (glucose level, haemoglobin level, haematocrit, and H:L ratio). The diversity of arthropods was highest in extensively used meadows. Still, the mean abundance and proportion of arthropods over 1 cm in length differed significantly for Orthoptera, Hymenoptera, Arachne, and Carabidae between grassland use types, with the highest proportion of large arthropods and the highest abundance recorded in manure-fertilised meadows. The highest Body Condition Indexes and blood glucose levels of nestlings indicating good nestling nutrition were recorded in nests of birds associated with extensive land use. The H:L ratio as an indicator of the physiological condition of nestlings was high on manure-fertilised and extensively managed meadows, indicating stress factors associated with these environments. This suggests that consideration should be given to the effects of chemicals, such as pesticides or drug residues, that may come from slurry poured onto fields on the fitness of red-backed shrike chicks.

Effects of ophidiomycosis on movement, survival, and reproduction of eastern foxsnakes (Pantherophis vulpinus)

Ophidiomycosis (snake fungal disease) is caused by the fungal pathogen Ophidiomyces ophidiicola, which causes dermal lesions, occasional systemic infections, and in some cases, mortality. To better understand potential conservation implications of ophidiomycosis (i.e., population-level effects), we investigated its impacts on individual fitness in a population of endangered eastern foxsnakes (Pantherophis vulpinus). We tracked 38 foxsnakes over 6 years and quantified body condition, movement patterns, oviposition rates, and survival. Body condition, distance travelled, and oviposition rates were similar between snakes with and without ophidiomycosis. Interestingly, snakes that tested positive for the pathogen travelled farther, suggesting that movement through a greater diversity of habitats increases risk of exposure. Ophidiomycosis did not negatively affect survival, and most apparently infected snakes persisted in a manner comparable to snakes without ophidiomycosis. Only one mortality was directly attributed to ophidiomycosis, although infected snakes were overrepresented in a sample of snakes killed by predators. Overall, our results suggest that ophidiomycosis may have sublethal effects on eastern foxsnakes, but do not suggest direct effects on survival, ovipositioning, or viability of the study population.

Theromyzon maculosum (Rathke, 1862) as a vector of potentially pathogenic fungi in aquatic ecosystems

The aim of the study was to check the integument and alimentary tract of Theromyzon for the occurrence of fungi. Moreover, the mycological purity of water sources from which leeches were collected was analyzed. The potential role of the duck leech Theromyzon maculosum in transmitting pathogenic fungi has not been studied until now. Mycological analyses were performed according to the procedure approved in mycological diagnostic laboratories, using classical diagnostic methods (macro- and microcultures, microscopic observations). In total, 22 species of yeasts were detected. The specimens belong to eight genera: Candida, Citeromyces, Debaryomyces, Kluyveromyces, Lodderomyces, Pichia, Saccharomyces and Saccharomycodes. Overall, 18 species of fungi were isolated from leeches Theromyzon maculosum, including seven species from the integument and 11 species from the gastrointestinal system. Among fungi isolated from body integument, fungi of the genus Candida were dominant, whereas in the gastrointestinal system, the genus Saccharomyces dominated. From the river waters, nine fungi species were isolated, and yeasts of the genera Candida and Kluyveromyces dominated. Isolation of the same species of microfungi from the integument of leeches and the river water suggests that Theromyzon maculosum may be a potential vector of pathogenic yeasts for vertebrates living in the same ecosystems and for humans.

Chronic stress and captivity alter the cloacal microbiome of a wild songbird

There are complex interactions between an organism's microbiome and its response to stressors, often referred to as the “gut-brain axis;” however, the ecological relevance of this axis in wild animals remains poorly understood. Here, we used a chronic mild stress protocol to induce stress in wild-caught house sparrows (Passer domesticus), and compared microbial communities among stressed animals, those recovering from stress, captive controls (unstressed), and a group not brought into captivity. We assessed changes in microbial communities and abundance of shed microbes by culturing cloacal samples on multiple media to select for aerobic and anaerobic bacteria and fungi. We complemented this with cultivation-independent 16S and ITS rRNA gene amplification and sequencing, pairing these results with host physiological and immune metrics, including body mass change, relative spleen mass, and plasma corticosterone concentrations. We found significant effects of stress and captivity on the house sparrow microbiomes, with stress leading to an increased relative abundance of endotoxin-producing bacteria— a possible mechanism for the hyperinflammatory response observed in captive avians. While we found evidence that the microbiome community partially recovers after stress cessation, animals may lose key taxa, and the abundance of endotoxin-producing bacteria persists. Our results suggest an overall link between chronic stress, host immune system, and the microbiome, with the loss of potentially beneficial taxa (e.g., lactic acid bacteria), and an increase in endotoxin-producing bacteria due to stress and captivity. Ultimately, consideration of the host's microbiome may be useful when evaluating the impact of stressors on individual and population health.

Search for Cryptococcus neoformans/gattii Complexes and Related Genera (Filobasidium, Holtermanniella, Naganishia, Papiliotrema, Solicoccozyma, Vishniacozyma) spp. Biotope: Two Years Surveillance of Wild Avian Fauna in Southern France

Fungi belonging to the Cryptococcus genus and related genera (Filobasidium, Holtermanniella, Naganishia, Papiliotrema, Solicoccozyma, Vishniacozyma) are encapsulated yeasts found in either the environment or animal sources. However, the precise biotopes of most species remain poorly defined. To assess whether wild birds from southern France can carry or spread the most pathogenic species (i.e., species belonging to the C. neoformans and C. gattii complexes), as well as lesser-studied species (non-neoformans/gattii Cryptococcus and former Cryptococcus spp.), 669 birds belonging to 89 species received for care over a two-year period at the Centre de Protection de la Faune Sauvage of Villeveyrac (Bird Protection League nongovernmental organization (NGO) care center) were sampled. Samples were cultured, and Cryptococcus and former Cryptococcus yeasts were identified by PCR sequencing. The purpose was to evaluate whether there was any health risk to local populations or care personnel in aviaries and gather new data on the ecological niches of lesser-known species. One hundred and seven birds (16%) were found to be positive for at least one Cryptococcus or former Cryptococcus species. No yeasts belonging to the highly pathogenic C. neoformans or C. gattii complexes were isolated. However, diversity was notable, with 20 different Cryptococcus or former Cryptococcus species identified. Furthermore, most bird–yeast species associations found in this study have never been described before.