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Emerging trends in genome editing of wild animals.

Globally, nearly one million species are currently threatened with extinction, highlighting the need for more efficient solutions to biological conservation. Genome editing, which allows for faster and more precise changes in genomes, is a promising technique for boosting populations through facilitated adaptation, management of invasive or pathogenic populations, and potentially even facilitating the revival of extinct species. These approaches belong to a new field of research termed conservation biotechnology, which places a great responsibility on researchers and decision makers to ensure sustainability. In this paper, we have mapped the emerging trends in genome editing of wild animals. Current projects primarily focus on population control and de-extinction, with fewer initiatives aimed at preserving threatened species. We then explore four critical dimensions of conservation biotechnology: the technology itself, new perspectives on conservation practices, research organization, and governance and policy. Despite its potential, key questions remain-particularly whether genome editing can increase genetic diversity without causing unintended non-target impacts. Genome editing also provokes new perspectives on conservation practices where ecosystem-wide impact assessment, case-by-case evaluations, and post-release monitoring needs to be prioritized. Furthermore, conservation biotechnology is heavily funded through private funding showing varying stakeholder interest, which can lead to untraditional and less transparent research processes. Stakeholders, including local and indigenous people, are only to a certain degree involved, which may weaken inclusion of local knowledge and monitoring efforts. Finally, concerning governance and policy, there is an urgent need to develop more adequate regulation of conservation biotechnology, as environmental release of genome-edited animals challenges definitions and guidelines in current nature protection laws and GMO regulations. Based on our analysis, we outline key points for further investigation toward a more sustainable approach to conservation biotechnology.

Animals

Wildlife as a reservoir of OXA-48-like carbapenemase-producing Enterobacterales.

Carbapenemase-producing Enterobacterales (CPEs) have globally emerged and spread beyond human compartments. However, data in wild animals, especially from low- and middle-income countries, such as Algeria, are still very scarce. Here, we investigated CPEs recovered from feces samples collected between October 2021 and June 2023 from wild terrestrial and aquatic mammals, wild migratory/nesters/sedentary birds, and zoo animals, including their environment (water, food, and fecal samples of animal care workers) distributed over six Algerian provinces. Carbapenem-resistant Enterobacterales were characterized using MALDI-TOF-MS, Carba NP, immunochromatographic assay NG-Test CARBA 5, antimicrobial susceptibility testing, and whole-genome sequencing. Thirty CPEs were identified out of the 1,899 samples collected (1.6%). The carriage rate was higher in captive animals (3.2%) than in wild animals (1.2%). Twenty-six produced OXA-48, three OXA-244, and one OXA-181, along with CTX-M-15 ESBL. Clonal expansion of Enterobacter hormaechei hoffmannii ST145 and Klebsiella pneumoniae ST13 was evidenced. Plasmid analysis confirmed that 24/30 isolates harbored a transferable 62 kb IncL pOXA-48 plasmid. Five/six E. coli isolates belonged to high-risk clones with chromosome-mediated blaOXA-244 gene in three isolates, blaOXA-48 in two isolates, and blaOXA-181 gene encoded on an IncFII-ColKP3 hybrid plasmid in one isolate. This study showed widespread dissemination of OXA-48-like producing Enterobacterales in free and captive wild animals, largely driven by epidemic plasmids and clones. It underscores the role of wild animals as a reservoir of CPEs, particularly species living close to humans, such as gulls and pigeons, and occasionally food-producing animals, increasing the risk of bidirectional dissemination between animal, environmental, and human sectors.IMPORTANCEThe global rise of carbapenemase-producing Enterobacterales (CPEs) harboring blaOXA-48-like has been increasingly documented in clinical settings. However, their emergence and transmission in wild and captive animals are less documented. This study provides a high-resolution genomic characterization of CPEs isolated from the feces of wild animals, especially migratory birds, and from captive wild animals, to evaluate the potential risk of dissemination through these animals. Whole-genome sequencing data, genetic investigations, and antimicrobial susceptibility results highlighted the spread of multidrug-resistant CPEs in both animals and humans. The widespread detection of blaOXA-48 across multiple niches suggests sustained circulation beyond hospital settings in Algeria. Human-associated lineages, such as E. coli ST131, ST38, and ST540, were identified with a clear link with humans. This study demonstrates carriage of CPEs in multiple bird species living in areas commonly inhabited by humans and provides further evidence for an effective dissemination of resistance in wildlife, facilitated by feeding habits.

Animals

Genomic Analysis of CTX-M-15-Producing E. coli Colonizing a Rescued Capuchin Monkey.

Illegal wild animal trade and possession represents a threat to One Health due to the pathogens exchange between wild animals and humans. We report the detection and genomic characterization of a multidrug-resistant (MDR) Escherichia coli strain (MP02) colonizing a capuchin monkey (Sapajus sp.) rescued from illegal possession. MP02 exhibited ExPEC-related genes, harbored an IncHI2-ST1 plasmid composed of quinolones, aminoglycosides, and sulfonamides resistance genes, besides the extended-spectrum β-lactamase (ESBL)-encoding gene blaCTX-M-15 located in a conserved Tn3-like transposon. To the author's knowledge, this is the first report and genomic analysis of a MDR bacterium isolated from an illegally traded non-human primate.

antibiotic resistance

Detection of opportunistic bacterial pathogens with intrinsic amoxicillin- and cephalosporin-resistance in wild koala faecal microbiomes.

Opportunistic bacterial pathogens frequently associated with human clinical infections, including antimicrobial-resistant strains, are infiltrating the microbiomes of wild animals, where they have the potential to negatively impact wildlife health. Bacterial genes conferring resistance to amoxicillin have previously been reported in koala (Phascolarctos cinereus) faecal DNA. Koalas are facing several key threats, including wildfires, and affected individuals may receive amoxicillin therapy to treat burn wounds. This study aimed to identify the species of amoxicillin-resistant bacteria in koala gut microbiomes and determine if they are opportunistic pathogens. Faecal samples collected from 98 wild-caught koalas were cultured using amoxicillin-supplemented media to isolate amoxicillin-resistant Gram-negative enteric bacteria. Isolates were screened using 16S rRNA PCR and Sanger sequencing to identify opportunistic pathogenic species, which then underwent whole-genome sequencing and antimicrobial susceptibility testing. Intrinsically amoxicillin-resistant opportunistic pathogens were obtained from 9.2% (9/98) of koala faecal samples and comprised Klebsiella oxytoca (6/98, 6.1%), Klebsiella pneumoniae (1/98, 1.0%) and Citrobacter spp. (2/98, 2.0%). Seven of nine amoxicillin-resistant opportunistic pathogens also exhibited cephalosporin resistance. Four K. oxytoca isolates belonged to lineages associated with human clinical infections, which also have the potential to cause disease in koalas, including fatal systemic infections in pouch young. The presence of amoxicillin- and cephalosporin-resistant strains may also increase the risk of gut dysbiosis and opportunistic infections when penicillins or cephalosporins are required to treat bacterial infections in koalas, highlighting the importance of good antimicrobial stewardship. The study findings demonstrate the One Health perspective of microbial pathogens and the intertwined microbial ecology between humans and wildlife.

Animals

First case of Brucella suis biovar 1 infection in a dog in Switzerland.

As one of the most common zoonoses globally, brucellosis threatens not only animals but also humans with Brucella (B.) melitensis, B. abortus and B. suis biovar 1&3, being more virulent for humans than B. canis, B. ovis and B. suis biovar 2. Canine brucellosis is caused mainly by B. canis, however, B. suis infections in dogs have been reported sporadically in Europe and more frequently in Australia. B. suis infection in dogs is mainly associated with hunting or wild-animal exposure and rarely with consumption of commercial raw meat products. In Switzerland, B. canis is sporadically diagnosed in dogs and B. suis biovar 2 is present in wild boar and brown hare. We report a case of brucellosis in a dog from Switzerland, neither having a history of hunting nor travel-associated risk of exposure. The intact male dog showed clinical signs (fever and epididymitis) consistent with brucellosis, which was confirmed by culture and molecular methods in urine and by serological methods. Culture and subsequent whole genome sequencing revealed the isolate as B. suis biovar 1, ST-14. The most closely related strain was shown to be a strain isolated in 2021 from a dog in Germany. Based on the lack of any previous report, infection by B. suis in dogs has not previously been diagnosed in Switzerland. This case highlights the need for vigilance regarding this less expected pathogen of high zoonotic importance in dogs.

Animals

Discovery of a novel Betacoronavirus 1, cpCoV, in goats in China: The new risk of cross-species transmission.

Betacoronavirus is a causative agent of respiratory and enteric diseases in humans and animals. Several ruminants are recognized to be intermediate hosts in the transmission of emerging coronaviruses from reservoir hosts to humans. Here, we first report a novel Betacoronavirus isolated from goats suffering from diarrhea in China, putatively named caprine coronavirus (cpCoV). Full-genome characterization and nuclear acid comparisons demonstrated that this virus is an evolutionarily distinct Betacoronavirus belonging to the subgenus Embecovirus and is a Betacoronavirus 1 species. Notably, on phylogenetic trees based on complete genomes and RdRp, S, and N genes, the cpCoVs were grouped into a clade distinct from other Betacoronavirus strains and were closely related to the HKU23- and HKU23-associated coronaviruses. CpCoV possessed a unique genome organization with a truncated NS4a protein and an elongated NS4b protein that showed no significant matches in the GenBank database. The homology of the S and NS4a-4b genes between cpCoV and Embecovirus was less than 95%. Analysis revealed possible recombination events occurred during the evolution of cpCoV and HKU23, and there are striking similarities between the two viruses in evolutionary terms. In addition, cpCoV showed a narrow cell tropism, replicating in human- and bovine-origin cells in vitro, and caused diarrhea and enteric pathologic changes in goats and calves in vivo. We have provided epidemiological, virological, evolutionary, and experimental evidence that cpCoV is a novel etiological agent for enteric disease in goats. Evidently, a spilling-over event might have occurred between ruminants, including goats, camels, cattle, and wild animals. This study highlights the importance of identifying coronavirus diversity and inter-species transmission in ruminants worldwide, broadens our understanding of the ecology of coronaviruses, and aids in the prevention of animal-to-human transmission and outbreaks.

Animals

Whole Genome Characterization of Klebsiella Strains in European Hedgehogs and Human Nosocomial Settings Identified Shared Sequence Types, Antimicrobial Resistance Genes and Plasmids.

INTRODUCTION: Klebsiella pneumoniae is a pathogen associated with healthcare-acquired infections and antimicrobial resistance (AMR) to beta-lactams and carbapenems. Although wild animals are not typically exposed to antibiotics, they can harbour resistant strains. The European hedgehog (Erinaceus europaeus) is increasingly found in urban areas, where it interacts with humans and livestock. Studies have identified concerning levels of AMR in hedgehogs, including Extended-Spectrum β-Lactam (ESBL) and carbapenems-resistant Klebsiella pneumoniae strains. METHODS: This study focuses on Klebsiella spp. isolated in hedgehogs from urban areas, using whole-genome sequencing (WGS). We compared these isolates with openly available strains isolated from humans in the same region with the objective to have a thorough understanding of ST, AMR gene, and plasmid overlap between human and environmental compartments. RESULTS: High AMR gene levels, including the carbapenemase blaOXA-48, were found in the hedgehog population. Notably, human nosocomial clones, including ST307 and ST392, globally distributed sequence types also found in wildlife, were identified in both hedgehogs and humans. The presence of conjugative plasmids, including IncFIB(K) and IncL1 types, was identified in both hedgehogs and humans, highlighting plasmid dissemination as a significant factor in AMR spread. CONCLUSIONS: Although no direct transmission from wildlife to hospital settings has been conclusively demonstrated, our findings suggest that hedgehogs may play a role in bridging environmental and healthcare environments. The study underscores the need for further investigation into multidrug-resistant Klebsiella spp. and other resistant bacteria in wildlife to better understand their potential role in the dissemination of resistance genes across ecosystems.

Animals

Whole-genome surveillance supports hazard profiling of Escherichia coli lineages in recycled water treatment systems.

UNLABELLED: The use of treated wastewater is increasingly important for sustainable water management under a changing climate, yet conventional monitoring based on Escherichia coli enumeration provides limited insight into strain diversity and associated public health hazards. Here, we applied longitudinal whole-genome sequencing (WGS) to 180 E. coli isolates collected across the treatment continuum of a recycled water facility, from influent to final effluent. Genomic analysis revealed extensive strain-level heterogeneity, comprising 88 sequence types across eight phylogroups, with greater diversity in influent than in treated effluent. Phylogenetic comparisons with contextual Australian genomes indicated clustering with strains associated with companion animals, wild birds, humans, and livestock, suggesting multiple potential source reservoirs rather than a single dominant origin, although source contributions were not definitive. Despite a >90% reduction in total E. coli loads, isolates recovered from upstream and downstream stages exhibited broadly comparable virulence factor and antimicrobial resistance gene (ARG) profiles, suggesting that, within the cultured isolate collection, reductions in abundance exceeded shifts in genomic composition. To assess operational relevance, we prototyped a genomics-informed hazard framework integrating virulence determinants, ARGs, plasmid-associated mobility, and reuse-specific exposure context. Using this framework, 92.8% of isolates were classified as low hazard, and 7.2% as moderate hazard, with no isolates meeting criteria for high or critical hazard classifications. These findings demonstrate that genomic profiling of indicator organisms can reveal population structure and hazard heterogeneity not captured by conventional enumeration alone, and can provide a practical basis for incorporating genomic information into hazard-informed monitoring of recycled water systems. IMPORTANCE: Routine recycled water monitoring relies largely on culture-based E. coli counts, which indicate regulatory compliance but provide limited insight into strain diversity, persistence, and genomic characteristics relevant to public health. Using longitudinal whole-genome sequencing, we show that genetically distinct E. coli lineages, including isolates carrying combinations of virulence and antimicrobial resistance determinants, can persist through advanced treatment despite substantial reductions in overall E. coli loads. While most isolates were classified as low genomic hazard and no high- or critical-hazard isolates were detected, these findings demonstrate that conventional enumeration alone cannot distinguish between genetically diverse lineages with differing hazard potential in highly treated systems. By integrating genomic data into a hazard classification framework, this study demonstrates an applied approach to contextualize E. coli detections and distinguish low-risk background populations from isolates with elevated genomic hazard profiles. This work supports the use of genomic profiling of indicator organisms to improve surveillance, inform treatment performance assessment, and enable more risk-based management of recycled water systems.

Escherichia coli

Antimicrobial-resistant Staphylococcus aureus isolated from Australian wildlife admitted to a veterinary hospital.

Although antimicrobial resistance (AMR) is a growing One Health concern, little is known about AMR in Staphylococcus aureus from Australian wildlife. This study investigated the occurrence, phenotypic AMR profiles, and genetic characteristics of S. aureus from six representative Australian wildlife species admitted to a wildlife hospital in Western Australia, including the western grey kangaroo (Macropus fuliginosus), quenda (Isoodon fusciventer), pelican (Pelecanus conspicillatus), galah (Eolophus roseicapilla), shingleback skink (Tiliqua rugosa) and long-necked turtle (Chelodina colliei). Staphylococcus aureus was isolated from 11.7% (21/180, 95% CI: 7.4%-17.3%) of the animals on admission. Whole genome sequencing identified 13 multi-locus sequence types (STs) and various virulence factors, including the human-specific immune evasion cluster (IEC). Resistance to at least one antimicrobial class was observed in 63.6% of the isolates. The blaZ, erm(T), aac(6')-aph(2″), and tet(L) AMR genes were detected in 63.6%, 13.6%, 4.5%, and 4.5% of S. aureus, respectively. After 7 days of hospitalisation, S. aureus was isolated from 16.5% (16/97, 95% CI: 9.7%-25.4%) of the animals, including two methicillin-resistant S. aureus (MRSA) isolated from two pelicans. The two MRSA were identified as community-associated MRSA clones (mecA-positive ST1-IV and ST93-IV), suggesting direct or indirect transmission between humans and wildlife during hospitalisation may have occurred. This study highlighted Australian wildlife may be a potential reservoir for genetically diverse antimicrobial-resistant S. aureus. AMR surveillance including wildlife using a One Health approach may be required.

Animals

Phylogenetics and genomic variation of Hepatocystis isolated from shotgun sequencing of wild primate hosts.

Hepatocystis are apicomplexan parasites nested within the Plasmodium genus that infect primates and other vertebrates, yet few isolates have been genetically characterized. Using taxonomic classification and mapping characteristics, we searched for Hepatocystis infections within publicly available, blood-derived whole genome sequence (WGS) data from 326 wild non-human primates (NHPs) in 17 genera. We identified 37 Hepatocystis infections in Papio cynocephalus (yellow baboons) and four species of Chlorocebus monkeys (grivets, green monkeys, vervet monkeys, and malbroucks) sampled from locations in west, east, and south Africa. Hepatocystis cytb sequences from Papio and Chlorocebus hosts each clustered within host species among previously reported isolates from other NHP taxa. Utilizing the low-coverage sequence data (0.11-0.76X per sample) recovered across the nuclear Hepatocystis genome, we identified 349,893 polymorphic sites. Principle components analysis based on genotype likelihoods across all samples showed evidence for population structure by primate host species. Across the genome, windows of high SNP density revealed candidate hypervariable loci including Hepatocystis-specific gene families possibly involved in immune evasion and genes that may be involved in adaptation to their insect vector and hepatocyte invasion. Overall, this work demonstrates how WGS data from wild NHPs can be leveraged to study the evolution of apicomplexan parasites and potentially test for association between host genetic variation and parasite infection.

Animals

Wildlife Trade and Genetic Basis of Disease Susceptibility: A Review.

The surge in the trade of wildlife and wildlife products drives several species to extinction while coinciding with the increase in several zoonotic diseases. It is therefore essential to explore the roles of wildlife trade in disease transmission, and how the knowledge of genetics and immunogenetics can help in alleviating the attending challenges. Pathogen-driven selection plays a fundamental role in maintaining immune gene diversity, as individuals with alleles conferring resistance to endemic diseases have higher survival rate. However, anthropogenic disturbances, such as wildlife exploitation, can disrupt these evolutionary processes, leading to reduced genetic diversity and increased disease vulnerability. Advanced genomic tools, such as next-generation sequencing (NGS), whole-genome sequencing (WGS), CRISPR-Cas9 gene editing, genome-wide association studies (GWAS), epigenetics and transcriptomic analysis, can help identify immune gene variations and predict disease susceptibility in both wild and captive populations. Massive research targeting wildlife markets and the interface between the wild and the market players is necessary. It would be interesting to understand dynamics of pathogens and disease susceptibility, through the application of genetics and immunogenetics, thereby enhancing efforts to address the challenges posed by wildlife trade and zoonotic disease emergence.

Animals

First surveillance study of avian orthoavulavirus type 1 in wild birds in Morocco: Insights and implications for future monitoring.

BACKGROUND: Wild birds, particularly migratory species, can act as natural reservoirs and vectors of avian orthoavulavirus type 1 (AOAV-1) or Newcastle disease virus (NDV), contributing to its spread across regions and potentially threatening domestic poultry populations. AOAV-1, also known as NDV, is a major pathogen affecting avian species and poses a global threat to poultry production. It belongs to the Paramyxoviridae family and is an RNA virus encoding six key proteins, including the fusion (F) protein, which determines pathogenicity. AOAV-1 is classified into three pathotypes based on virulence: velogenic (highly pathogenic), mesogenic (moderately pathogenic), and lentogenic (mild or asymptomatic). In Morocco, AOAV-1 is endemic in poultry production systems, as evidenced by recent studies reporting a 52.1% seroprevalence and active viral RNA detection in backyard chickens in the Khemisset and Skhirat-Temara provinces; however, effective vaccination strategies have contributed to controlling the clinical signs and widespread dissemination of the virus. AIM: The main objective of this study was to investigate the presence of AOAV-1 in wild bird populations across Morocco, providing insights into possible transmission of infection affecting domestic poultry. METHODS: From November 2016 to April 2022, a total of 1984 samples were collected from 840 individual birds, encompassing 79 species, 25 families, and 12 orders. The majority of the samples belonged to Charadriiformes, Anseriformes, Pelecaniformes, and Passeriformes. Sampling was conducted at 17 wetlands and six additional locations throughout Morocco. Viral detection was performed using real-time reverse transcriptase PCR (RT-qPCR) targeting Matrix (M) and RNA polymerase (L) genes to confirm the presence of AOAV-1. RESULTS: Although the study spanned 6 years and included a large number of samples from bird orders considered primary AOAV-1 reservoirs, all samples tested negative for NDV RNA using both M and L gene targets. CONCLUSION: This study represents the first effort in Morocco to monitor wild birds for AOAV-1. The samples analyzed were initially collected for avian influenza surveillance, which shares epidemiological similarities with Newcastle's disease. However, to improve future surveillance efforts, sample collection should be optimized to target scenarios with the highest probability of virus detection.

Animals

Sociality and kinship constrain the free-mixing of pathogens in a wild mammal host population.

Pathogens rarely mix freely throughout host populations, and the presence of barriers to transmission can be detected as patterns of increased genetic isolation among pathogen isolates. Despite the importance of transmission patterns in host societies, and the risk of epizootics from wildlife disease systems, barriers to open pathogen transmission are poorly understood in wild hosts. We tested the influence of host kinship and social structure on genetic divergence among strains of Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), in a wild badger population. We measured genetic distances between M. bovis isolates from badger hosts that varied in their own genetic similarity (a proxy for kinship) and in their social group affiliations. Using jack-knifing analyses to control for pseudoreplication, we found that genetic distances between pathogen isolates decreased with increasing kinship of host dyads, but only when hosts shared the same social group. Our findings suggest that the open transmission of bTB in wild hosts is constrained by a combination of social and kin structure, in particular the sharing of similar pathogen strains among kin within social groups. We discuss the implications of these transmission structures for the understanding and management of wildlife diseases.

Animals

Metagenomic insights into the global wild boar faecal microbiome reveal novel taxa and carbohydrate degraders distinguishing wild and domesticated Sus.

BACKGROUND: The inclusion of fibre in domestic pig diets is favourable from a digestive health, environmental, and socio-economic perspective. Unlike the highly optimized formulated diets of domestic pigs, wild boars feed opportunistically, consuming a broad range of foods that consist predominantly of plant materials. Consequently, the intestinal microbiota of wild boars is thought to be adapted to a versatile, fibre-rich diet and may represent a valuable source of probiotics for enhancing fibre degradation. However, comprehensive studies characterizing the wild boar gut microbiome, particularly its community structure and carbohydrate utilization potential, and comparison to that of domestic pigs are still lacking. RESULTS: We collected 89 faecal samples from wild boars across four countries and analysed them primarily using metagenomic sequencing. De novo assembly yielded 3,288 high- and medium-quality metagenome-assembled genomes (MAGs) representing 968 distinct species, of which 538 were previously unknown. Incorporating these MAGs enabled robust microbiome comparisons with 125 previously published samples largely from domestic pigs, which revealed significant structural and functional differences. These differences resolved into two community types, determined not by host species but by diet and lifestyle: C1 comprising 81% of samples from free-ranging, foraging wild boars and C2 consisting of 93% of samples from captive, fed domestic pigs. The lower alpha-diversity observed in C1 likely reflected the impact of highly fluctuating dietary resources and environmental conditions, resulting in dominance of fewer resilient or adaptable taxa. Nevertheless, both community types maintained substantial carbohydrate utilization potential: while C2 exhibited a higher relative abundance of CAZymesub genes associated with a broader range of carbohydrate substrate (CHO) classes, C1 was enriched in individual species that were generally richer in CAZymesub genes and CHO classes. To leverage this potential, we curated a catalogue of carbohydrate degraders from both community types and identified 47 highly versatile species, with several novel species amongst them. CONCLUSIONS: This study uncovered the previously untapped microbial diversity in the wild boar faecal microbiome and demonstrated that the faecal microbiome of Sus is primarily shaped by diet and lifestyle. The two community types identified, which differed both structurally and functionally, represent alternative states of microbiome homeostasis in wild versus domesticated Sus populations. The curated catalogue of carbohydrate degraders provides a valuable resource to guide tailored probiotic supplementation during dietary transitions to novel fibrous feedstocks. Video Abstract.

Animals

Host immunogenetic variation and gut microbiome functionality in a wild vertebrate population.

BACKGROUND: The gut microbiome (GM) -important for host health and survival- is partially shaped by host immunogenetics. However, to date, no study has investigated the influence of host Major Histocompatibility Complex (MHC) genes on gut microbiome functionality in a wild population. Here we use a natural population of the Seychelles warbler (Acrocephalus sechellensis) to assess the effects of MHC genes on GM taxonomy and functionality using shotgun metagenomics. RESULTS: Our results show that taxonomic GM composition was associated with MHC-II diversity and the presence of one specific MHC-I allele (Ase-ua 7). Specifically, MHC-II diversity was associated with decreased Lactococcus lactis and increased Staphylococcus lloydii abundance, while Ase-ua 7 was linked to reduced Enterococcus casselifavus and Gordonia sp OPL2 but increased Escherichia coli and Vulcaniibacterium thermophilum. These taxonomic changes may reflect differences in MHC-mediated microbial recognition. In contrast, functional GM composition was significantly associated with increasing individual MHC-I diversity but not MHC-II diversity. In particular, increasing MHC-I diversity was associated with an increased prevalence of microbial defence genes but a reduced prevalence of microbial metabolism genes. Analysis also revealed that functional GM networks were more fragmented in high compared to low MHC-I diversity hosts. CONCLUSION: These results suggest that MHC variation (particularly at MHC-I) plays an important role in shaping both the taxonomy and function of the GM in wild vertebrates. In the Seychelles warbler, this results in trade-offs whereby there is an increase in microbial defence and a reduction in GM metabolic potential in individuals with higher MHC-I diversity. Thus, this work sheds light on the possible costs and benefits of maintaining a healthy microbiome, which is essential for understanding how the GM and immune system co-evolve. Video Abstract.

Animals

Wildlife forensic DNA evidence links a suspected vehicle to a fatal lowland tapir (Tapirus terrestris) collision in Misiones, Argentina.

Vehicle collisions are recognized as a major driver of biodiversity loss, particularly in road-dense landscapes, exceeding the impact of invasive species and wildlife trafficking. For large-bodied, slow-reproducing, and low-abundance species, such as the lowland tapir (Tapirus terrestris), this threat can have major impacts. Here, we present a wildlife forensic investigation in Misiones, Argentina, involving a tapir, a species afforded the highest level of legal protection as a Provincial Natural Monument. The fatal hit-by-vehicle (HBV) incident occurred in northern Misiones on 31 March 2019 along Provincial Route 19, in a portion that bisects Parque Provincial Urugua-í, with the driver involved in the collision leaving the scene. The suspect was later located and claimed that the damage to the vehicle resulted from a collision with a horse (Equus caballus) rather than a tapir. To legally resolve the incident, DNA (hair and blood) recovered from the suspected vehicle's bumper (evidence) was compared with tissue samples from the tapir carcass (reference). Genetic confirmation of species identity used a 110-bp region of the mitochondrial cytochrome b gene, and individual identity was assessed using 12 species-specific microsatellite loci. These analyses confirmed that all evidence matched the tapir carcass at both species and individual levels, strongly supporting the association between the suspected vehicle and the HBV tapir, and refuting the alternative explanation proposed by the driver. This case demonstrates the value of using wildlife forensic genetics to reconstruct wildlife-vehicle collisions, supporting environmental law enforcement, and strengthening conservation efforts in the Atlantic Forest of Misiones, Argentina.

Animals

Mouse Prkar1a haploinsufficiency leads to an increase in tumors in the Trp53+/- or Rb1+/- backgrounds and chemically induced skin papillomas by dysregulation of the cell cycle and Wnt signaling.

PRKAR1A inactivation leads to dysregulated cAMP signaling and Carney complex (CNC) in humans, a syndrome associated with skin, endocrine and other tumors. The CNC phenotype is not easily explained by the ubiquitous cAMP signaling defect; furthermore, Prkar1a(+/-) mice did not develop skin and other CNC tumors. To identify whether a Prkar1a defect is truly a generic but weak tumorigenic signal that depends on tissue-specific or other factors, we investigated Prkar1a(+/-) mice when bred within the Rb1(+/-) or Trp53(+/-) backgrounds, or treated with a two-step skin carcinogenesis protocol. Prkar1a(+/-) Trp53(+/-) mice developed more sarcomas than Trp53(+/-) mice (P < 0.05) and Prkar1a(+/-) Rb1(+/-) mice grew more (and larger) pituitary and thyroid tumors than Rb1(+/-) mice. All mice with double heterozygosity had significantly reduced life-spans compared with their single-heterozygous counterparts. Prkar1a(+/-) mice also developed more papillomas than wild-type animals. A whole-genome transcriptome profiling of tumors produced by all three models identified Wnt signaling as the main pathway activated by abnormal cAMP signaling, along with cell cycle abnormalities; all changes were confirmed by qRT-PCR array and immunohistochemistry. siRNA down-regulation of Ctnnb1, E2f1 or Cdk4 inhibited proliferation of human adrenal cells bearing a PRKAR1A-inactivating mutation and Prkar1a(+/-) mouse embryonic fibroblasts and arrested both cell lines at the G0/G1 phase of the cell cycle. In conclusion, Prkar1a haploinsufficiency is a relatively weak tumorigenic signal that can act synergistically with other tumor suppressor gene defects or chemicals to induce tumors, mostly through Wnt-signaling activation and cell cycle dysregulation, consistent with studies in human neoplasms carrying PRKAR1A defects.

Animals

Exploring shotgun metagenomic data to detect microeukaryotic pathogens in wildlife.

BACKGROUND: Microeukaryotic parasites of the intestinal tract are an understudied group of organisms that infect humans and many other animals. Targeted sequencing methods focused on individual loci are usually employed for detection of these parasites, making comprehensive studies of microeukaryotic parasite diversity within hosts or other systems difficult. Exploratory approaches such as shotgun metagenomic sequencing to survey the diversity of microeukaryotic parasites in new and existing datasets are not well developed. RESULTS: Utilizing existing datasets from 12 goose fecal samples, we explored some of the benefits and challenges of using shotgun metagenome sequencing to detect microeukaryotic parasites. We demonstrated the importance of careful curation of read classification data to avoid erroneously linking pathogens to hosts or environments as unsupported classifications were common in the data and varied widely depending on analysis parameters. However, we were able to establish strong support for the presence of sequences of Eimeria and Enterocytozoon bieneusi. In addition, examination of trichomonad reads indicated that parasite reads mapping to human pathogens unlikely to colonize geese may in fact represent cryptic microeukaryotic species that are not included in existing curated databases opening new potential avenues of study. CONCLUSIONS: Taken together these findings support the idea that exploring microeukaryotic parasite diversity within shotgun metagenomic datasets can be beneficial to our understanding of the presence and diversity of these organisms in wildlife hosts.

Animals