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Bartonella is a bacterial genus that comprises arthropod-borne microorganisms. Several Bartonella isolates have been detected from bats worldwide, which are thought to be undescribed species. We aimed to test the presence of Bartonella spp. among bats from Colombia, and evaluate the genetic diversity of bat-associated Bartonella spp. through phylogenetic analyses. A total of 108 bat blood samples were collected from three bat species (Carollia perspicillata, Mormoops megalophylla, and Natalus tumidirostris) that inhabit the Macaregua cave. The Bartonella ssrA gene was targeted through real-time and end-point PCR; additionally, the gltA and rpoB genes were detected by end-point PCR. All obtained amplicons were purified and bidirectionally sequenced for phylogenetic analysis using a concatenated supermatrix and a supertree approaches. A detection frequency of 49.1 % (53/108) for Bartonella spp. was evidenced among bat blood samples, of which 59.1 % (26/44), 54.3 % (19/35) and 27.6 % (8/29) were identified in Carollia perspicillata, Natalus tumidirostris and Mormoops megalophylla respectively. A total of 35 ssrA, 5 gltA and 4 rpoB good-quality sequences were obtained which were used for phylogenetic analysis. All obtained bat sequences clustered together with sequences obtained from Neotropical bat species into two bat-restricted clades namely clade A and clade N. We detected the presence of Bartonella spp. that clustered within two different bat-associated Bartonella clades, giving the first data of the genetic diversity of these bacteria among bats from Colombia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Bats are known reservoirs for a wide range of pathogenic microorganisms, including viruses, bacteria, fungi, helminths, and protozoa, which can be transmitted and infect other zoonotic organisms. Various studies have utilised next-generation sequencing (NGS) to describe the pathogens associated with bats. Although most have characterised microbial communities in specific body fluids, few have analysed the composition and diversity of these microbial communities across different body fluids at the individual level. In this study, we employed two next-generation sequencing techniques: amplicon-based sequencing of the V4 hypervariable region of the 16S- and 18S-rRNA genes and viral metagenomics, to describe the prokaryotic, eukaryotic, and viral communities present in blood, faeces, and oral swab samples collected from two genera of bats (Carollia and Phyllostomus) in the department of Casanare, eastern Colombia. A total of 60 samples corresponding to the three bodily fluids were processed and analysed. The results indicated that the microbial communities across the body fluids were mainly composed of bacteria, fungi, protozoa, and various DNA and RNA viruses, showing a variability of microbial genera and species. The abundances, diversity metrics, and correlations of these microorganisms displayed patterns associated with bat genus and body fluids, suggesting that the ecological characteristics of these microbial communities may be influenced by the ecological and physiological traits of the bats. Additionally, we found similar community compositions of bacteria, some fungal genera, and viruses in the three body fluids, indicating a possible circulation of these microbes within the same bat. This could be due to microbial movement from the gut microbiota to other physiological systems or transmission via blood-feeding vectors. Furthermore, our results revealed the presence of various microbes of public health concern, including Bartonella spp., Mannheimia haemolytica, Rhodotorula spp., Piroplasmida spp., Toxoplasma gondii, Alphacoronavirus spp., and Bat circovirus. The abundance of these pathogenic microbial species across the three bodily fluids suggests potential transmission routes from bats to other organisms, which may contribute to the emergence of zoonotic disease outbreaks. These findings highlight the variability of microorganisms present within the same bat and the different pathogen-host interactions that may regulate the presence and transmission of these zoonotic microbes. Further research is required to elucidate the genomic features, ecological interactions, and biological activities of these microbial communities in bats., (© 2024. The Author(s).)

Background: Potentially zoonotic pathogens have been previously detected in bat-associated ticks, but their role in disease transmission and their frequency of feeding on non-bat hosts is poorly known., Methodology/principal Findings: We used molecular blood meal analysis to reveal feeding patterns of the bat-associated tick species Ixodes ariadnae, I. simplex, and I. vespertilionis collected from cave and mine walls in Central and Southeastern Europe. Vertebrate DNA, predominantly from bats, was detected in 43.5% of the samples (70 of 161 ticks) but in these ticks we also detected the DNA of non-chiropteran hosts, such as dog, Canis lupus familiaris, wild boar, Sus scrofa, and horse, Equus caballus, suggesting that bat-associated ticks may exhibit a much broader host range than previously thought, including domestic and wild mammals. Furthermore, we detected the zoonotic bacteria Neoehrlichia mikurensis in bat ticks for the first time, and other bacteria, such as Bartonella and Wolbachia., Conclusions/significance: In the light of these findings, the role of bat ticks as disease vectors should be urgently re-evaluated in more diverse host systems, as they may contribute to pathogen transmission between bats and non-chiropteran hosts., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Szentiványi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The role of the skin microbiome in resistance and susceptibility of wildlife to fungal pathogens has been examined from a taxonomic perspective but skin microbial function, in the context of fungal infection, has yet to be studied. Our objective was to understand effects of a bat fungal pathogen site infection status and course of invasion on skin microbial function. We sampled seven hibernating colonies of Myotis lucifugus covering three-time points over the course of Pseudogymnoascus destructans (Pd) invasion and white nose syndrome (pre-invasion, epidemic, and established). Our results support three new hypotheses about Pd and skin functional microbiome: (1) there is an important effect of Pd invasion stage, especially at the epidemic stage; (2) disruption by the fungus at the epidemic stage could decrease anti-fungal functions with potential negative effects on the microbiome and bat health; (3) the collection site might have a larger influence on microbiomes at the pre-invasion stage rather than at epidemic and established stages. Future studies with larger sample sizes and using meta-omics approaches will help confirm these hypotheses, and determine the influence of the microbiome on wildlife survival to fungal disease., (© The Author(s) 2024. Published by Oxford University Press on behalf of FEMS.)

Emerging mycoses are an increasing concern in wildlife and human health. Given the historical rarity of fungal pathogens in warm-bodied vertebrates, there is a need to better understand how to manage mycoses and facilitate recovery in affected host populations. We explore challenges to host survival and mechanisms of host recovery in three bat species (Myotis lucifugus, Perimyotis subflavus, and M. septentrionalis) threatened with extinction by the mycosis, white-nose syndrome (WNS) as it continues to spread across North America. We present evidence from the literature that bats surviving WNS are exhibiting mechanisms of avoidance (by selecting microclimates within roosts) and tolerance (by increasing winter fat reserves), which may help avoid costs of immunopathology incurred by a maladaptive host resistance response. We discuss management actions for facilitating species recovery that take into consideration disease pressures (e.g., environmental reservoirs) and mechanisms underlying persistence, and suggest strategies that alleviate costs of immunopathology and target mechanisms of avoidance (protect or create refugia) and tolerance (increase body condition). We also propose strategies that target population and species-level recovery, including increasing reproductive success and reducing other stressors (e.g., wind turbine mortality). The rarity of fungal pathogens paired with the increasing frequency of emerging mycoses in warm-bodied vertebrate systems, including humans, requires a need to challenge common conventions about how diseases operate, how hosts respond, and how these systems could be managed to increase probability of recovery in host populations., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

Species interactions between bats and fungi are poorly known. We documented the association between fungal and bat diversities along a landscape gradient. Ten, eight, and seven bat species were captured in conserved, semi-conserved, and urban sites, respectively. Eptesicus fuscus, Myotis ciliolabrum and Corynorhinus townsendii were the most abundant in conserved and semi-conserved sites. E. fuscus, Myotis velifer, and Lasiurus cinereus were abundant in urban sites. C. townsendii was the least abundant bat. A total of 15 cultivated fungi genera included the fungal diversity in bats, of which nine fungi genera were shared along the landscape gradient. Penicillium and Aspergillus were the most abundant genera, and Aureobasidium, Bispora, Stachybotrys, and Verticillium were only documented in the conserved sites. We observed a higher fungal diversity associated with bat species along this landscape gradient. The individual site-based accumulation curves of fungal diversity showed significant decreasing values along the conserved, semi-conserved, and urban sites, respectively. In conserved and urban sites, M. californicus and M. velifer showed the highest fungal diversity, respectively. E. fuscus was associated to the fungi genera Scopulariopsis, Alternaria, Penicillium and Beauveria; L. cinereus to Cladosporium and Aspergillus, and M. velifer to Alternaria sp1, Bispora and Trichoderma. Conserved sites showed both high bat and fungal diversities [species richness and abundance] compared to semi-conserved and urban sites. More studies associating bat and fungal diversities in other ecosystems are needed to corroborate this pattern., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Gutiérrez-Granados et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Disease can act as a driving force in shaping genetic makeup across populations, even species, if the impacts influence a particularly sensitive part of their life cycles. White-nose disease is caused by a fungal pathogen infecting bats during hibernation. The mycosis has caused massive population declines of susceptible species in North America, particularly in the genus Myotis. However, Myotis bats appear to tolerate infection in Eurasia, where the fungal pathogen has co-evolved with its bat hosts for an extended period of time. Therefore, with susceptible and tolerant populations, the fungal disease provides a unique opportunity to tease apart factors contributing to tolerance at a genomic level to and gain an understanding of the evolution of non-harmful in host-parasite interactions. To investigate if the fungal disease has caused adaptation on a genomic level in Eurasian bat species, we adopted both whole-genome sequencing approaches and a literature search to compile a set of 300 genes from which to investigate signals of positive selection in genomes of 11 Eurasian bats at the codon-level. Our results indicate significant positive selection in 38 genes, many of which have a marked role in responses to infection. Our findings suggest that white-nose syndrome may have applied a significant selective pressure on Eurasian Myotis-bats in the past, which can contribute their survival in co-existence with the pathogen. Our findings provide an insight on the selective pressure pathogens afflict on their hosts using methodology that can be adapted to other host-pathogen study systems., (© 2024. The Author(s).)

Bats from three provinces in Vietnam (Lai Chau, Son La, and Dong Thap) were examined for the presence of pathogenic Leptospira or specific antibodies using polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and microscopic agglutination test (MAT). Tissue specimens from 298 bats belonging to 11 species were analyzed using a real-time PCR assay specific for leptospires of pathogenic species. Leptospiral DNA was identified in 40 bats from following species: Rousettus amplexicaudatus (5/9; 55.5 %), Rousettus leschenaultii (17/42; 40.4 %), Myotis hasseltii (8/25; 32 %), Taphozous longimanus (3/12; 25 %), and Eonycteris spelaea (7/32; 21.9 %). Based on secY phylogeny, sequences from M. hasseltii bore a strong resemblance to L. borgpetersenii. Sequences from other species revealed unique lineages: one of them resembled Leptospira sp., previously identified in Rousettus madagascariensis (Madagascar) and Rousettus aegyptiacus (South Africa); the second lineage showed close relation to L. kirshneri; and the third held an intermediary position between L. noguchii and L. interrogans. Through ELISA, anti-Leptospira antibodies were found in 83 of 306 bats, with the highest seroprevalence observed in R. leschenaultii (44/48; 91.6 %), R. amplexicaudatus (6/8; 75 %), and E. spelaea (19/25; 76 %). 66 of these ELISA-positive samples were tested using MAT; 41 of them were confirmed in MAT as positive. The predominant serogroups in our study were Tarassovi and Mini., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Despite the great diversity of bats (64 species) in the State of Acre, northwestern Brazil, there are no studies on occurrence and diversity of Bartonella spp. in bats in this region. The present study investigated the occurrence and molecular identity of Bartonella spp. in spleen samples (n = 271) from bats of 30 different species from this region, within the Amazon biome. Twenty-one out of 208 (10.1%) samples positive in the PCR for the mammalian gapdh endogenous genes were positive in the qPCR for Bartonella spp. based on the nuoG gene. The two gltA Bartonella genotypes detected grouped with those previously identified in bats from other locations, expanding the diversity of genotypes associated with bats. This study provided the first molecular evidence of the presence of Bartonella spp. in bats in the state of Acre and in bats of the species Lophostoma silvicolum, Vampyressa thyone, Tonatia saurophila and Phyllostomus elongatus., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Research into various bacterial pathogens that can be transmitted between different animals and may have zoonotic potential has led to the discovery of different strains of Bartonella sp. in bats and their associated ectoparasites. Despite their enormous species diversity, only a few studies have focussed on the detection of bacterial pathogens in insectivorous bats of boreal forests and their associated Macronyssidae and Spinturnicidae mites. We collected and molecularly analysed mite samples from forest-dwelling bat species distributed all along the boreal belt of the Palearctic, from Central Europe to Far East. Ectoparasitic mites were pooled for DNA extraction and DNA amplification polymerase chain reaction (PCRs) were conducted to detect the presence of various bacterial (Anaplasmataceae, Bartonella sp., Rickettsia sp., Mycoplasma sp.) and protozoal (Hepatozoon sp.) pathogens. Bartonella sp. DNA was detected in four different mite species (Macronyssidae: Steatonyssus periblepharus and Spinturnicidae: Spinturnix acuminata, Sp. myoti and Sp. mystacinus), with different prevalences of the targeted gene (gltA, 16-23S ribosomal RNA intergenic spacer and ftsZ). Larger pools (>5 samples pooled) were more likely to harbour Bartonella sp. DNA, than smaller ones. In addition, cave-dwelling bat hosts and host generalist mite species are more associated with Bartonella spp. presence. Spinturnicidae mites may transmit several distinct Bartonella strains, which cluster phylogenetically close to Bartonella species known to cause diseases in humans and livestock. Mites with ubiquitous presence may facilitate the long-term maintenance (and even local recurrence) of Bartonella-infestations inside local bat populations, thus acting as continuous reservoirs for Bartonella spp in bats., (© 2024 The Author(s). Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society.)

The emergence of white-nose syndrome (WNS) in North America has resulted in mass mortalities of hibernating bats and total extirpation of local populations. The need to mitigate this disease has stirred a significant body of research to understand its pathogenesis. Pseudogymnoascus destructans, the causative agent of WNS, is a psychrophilic (cold-loving) fungus that resides within the class Leotiomycetes, which contains mainly plant pathogens and is unrelated to other consequential pathogens of animals. In this review, we revisit the unique biology of hibernating bats and P. destructans and provide an updated analysis of the stages and mechanisms of WNS progression. The extreme life history of hibernating bats, the psychrophilic nature of P. destructans, and its evolutionary distance from other well-characterized animal-infecting fungi translate into unique host-pathogen interactions, many of them yet to be discovered., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

White-nose syndrome (WNS) is a fungal wildlife disease of bats that has caused precipitous declines in certain Nearctic bat species. A key driver of mortality is premature exhaustion of fat reserves, primarily white adipose tissue (WAT), that bats rely on to meet their metabolic needs during winter. However, the pathophysiological and metabolic effects of WNS have remained ill-defined. To elucidate metabolic mechanisms associated with WNS mortality, we infected a WNS susceptible species, the Little Brown Myotis (Myotis lucifugus), with Pseudogymnoascus destructans (Pd) and collected WAT biopsies for histology and targeted lipidomics. These results were compared to the WNS-resistant Big Brown Bat (Eptesicus fuscus). A similar distribution in broad lipid class was observed in both species, with total WAT primarily consisting of triacylglycerides. Baseline differences in WAT chemical composition between species showed that higher glycerophospholipids (GPs) levels in E. fuscus were dominated by unsaturated or monounsaturated moieties and n-6 (18:2, 20:2, 20:3, 20:4) fatty acids. Conversely, higher GP levels in M. lucifugus WAT were primarily compounds containing n-3 (20:5 and 22:5) fatty acids. Following Pd-infection, we found that perturbation to WAT reserves occurs in M. lucifugus, but not in the resistant E. fuscus. A total of 66 GPs (primarily glycerophosphocholines and glycerophosphoethanolamines) were higher in Pd-infected M. lucifugus, indicating perturbation to the WAT structural component. In addition to changes in lipid chemistry, smaller adipocyte sizes and increased extracellular matrix deposition was observed in Pd-infected M. lucifugus. This is the first study to describe WAT GP composition of bats with different susceptibilities to WNS and highlights that recovery from WNS may require repair from adipose remodeling in addition to replenishing depot fat during spring emergence., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Symbiotic microorganisms that reside on the host skin serve as the primary defense against pathogens in vertebrates. Specifically, the skin microbiome of bats may play a crucial role in providing resistance against Pseudogymnoascus destructans ( Pd ), the pathogen causing white-nose syndrome. However, the epidermis symbiotic microbiome and its specific role in resisting Pd in highly resistant bats in Asia are still not well understood. In this study, we collected and characterized skin microbiota samples of 19 Myotis pilosus in China and explored the differences between Pd -positive and negative individuals. We identified inhibitory effects of these bacteria through cultivation methods. Our results revealed that the Simpson diversity index of the skin microbiota for positive individuals was significantly lower than that of negative individuals, and the relative abundance of Pseudomonas was significantly higher in positive bats. Regardless of whether individuals were positive or negative for Pd , the relative abundance of potentially antifungal genera in skin microbiota was high. Moreover, we successfully isolated 165 microbes from bat skin and 41 isolates from positive individuals able to inhibit Pd growth compared to only 12 isolates from negative individuals. A total of 10 genera of Pd -inhibiting bacteria were screened, among which the genera Algoriella , Glutamicibacter , and Psychrobacter were newly discovered as Pd -inhibiting genera. These Pd -inhibiting bacteria metabolized a variety of volatile compounds, including dimethyl trisulfide, dimethyl disulfide, propylene sulfide, 2-undecanone, and 2-nonanone, which were able to completely inhibit Pd growth at low concentrations.IMPORTANCERecently, white-nose syndrome has caused the deaths of millions of hibernating bats, even threatening some with regional extinction. Bats in China with high resistance to Pseudogymnoascus destructans can provide a powerful reference for studying the management of white-nose syndrome and understanding the bats against the pathogen's intrinsic mechanisms. This study sheds light on the crucial role of host symbiotic skin microorganisms in resistance to pathogenic fungi and highlights the potential for harnessing natural defense mechanisms for the prevention and treatment of white-nose syndrome. In addition, this may also provide promising candidates for the development of bioinsecticides and fungicides that offer new avenues for addressing fungal diseases in wildlife and agricultural environments., Competing Interests: The authors declare no conflict of interest.

To improve the knowledge on the role of bats in the maintenance and transmission of tick-borne pathogens, a molecular approach was used to characterize Anaplasma spp., Rickettsia spp., Coxiella burnetii, Borrelia burgdorferi s.l., piroplasmids, Hepatozoon spp., flaviviruses and nairoviruses in ticks collected from Iberian bats. A total of 732 bats from 25 species were captured at 38 sampling sites distributed in seven provinces of Spain between 2018 and 2022. Seventy-nine Ixodes simplex ticks were collected from 31 bats (Eptesicus isabellinus, Hypsugo savii, Myotis capaccini, Myotis emarginatus, Myotis myotis, Miniopterus schreibersii, Pipistrellus pipistrellus and Rhinolophus ferrumequinum). Sixty of 79 I. simplex were positive for at least one pathogen tested and were collected from 23 bats captured in southeast Spain. We detected the presence of Rickettsia slovaca in 12 ticks collected from M. emarginatus, H. savii, M. schreibersii and E. isabellinus; Rickettsia aeschlimannii in 1 tick from M. schreibersii; Anaplasma ovis in 3 ticks from H. savii and M. schreibersii; C. burnetii in 2 ticks from H. savii; Occidentia massiliensis in 1 tick from H. savii; piroplasmids in 12 ticks from H. savii, M. schreibersii and E. isabellinus; and a novel nairovirus in 1 tick from M. schreibersii. Furthermore, blood samples obtained from 14 of the 31 tick-infested bats were negative in all PCR analyses. This study describes new host and pathogen associations for the bat-specialist I. simplex, highlights the risk of spread of these pathogens, and encourages further research to understand the role of Iberian bats in the epidemiology of tick-borne pathogens., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Despite the worldwide occurrence and high genetic diversity of Bartonella spp. in bats, few studies investigate their occurrence in bat-associated mites. To date, 26 species of Macronyssidae mite species have been reported from Brazil, and 15 of which were found parasitizing bats. The present study aimed to investigate the presence of Bartonella DNA in bat-associated macronyssid mites from Brazil. For this purpose, 393 macronyssid specimens were selected by convenience from the tissue bank of the Acari Collection of the Instituto Butantan (IBSP). These mites were collected from 14 different bat species in three different Brazilian States (Minas Gerais, Paraná, and Rio de Janeiro). Out of 165 mites positive in the PCR for the endogenous 18S rRNA gene, only eight were positive in the qPCR for Bartonella spp. based on the nuoG gene, and we were able to obtain two sequences base in this same gene, and one sequence based on the 16S rRNA gene. The phylogenetic inference based on the nuoG gene grouped the obtained sequences with Bartonella genotypes previously detected in bats and associated bat flies, while the phylogeny based on the 16S rRNA grouped the obtained sequence in the same clade of Bartonella genotypes previously detected in Dermanyssus gallinae. These findings suggest that macronyssid mites might be associated with the maintenance of bartonellae among bats., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Introduction: Bats are a diverse group of mammals that have unique features allowing them to act as reservoir hosts for several zoonotic pathogens such as Leptospira. Leptospires have been classified into pathogenic, intermediate, and saprophytic groups and more recently into clades P1, P2, S1, and S2, being all the most important pathogenic species related to leptospirosis included within the P1/pathogenic clade. Leptospira has been detected from bats in several regions worldwide; however, the diversity of leptospires harboured by bats is still unknown., Aim: The aim of the present study was to determine the genetic diversity of Leptospira spp. harboured by bats worldwide., Methods: A systematic review was conducted on four databases to retrieve studies in which Leptospira was detected from bats. All studies were screened to retrieve all available Leptospira spp. 16S rRNA sequences from the GenBank database and data regarding their origin. Sequences obtained were compared with each other and reference sequences of Leptospira species and analysed through phylogenetic analysis., Results: A total of 418 Leptospira spp. 16S rRNA sequences isolated from 55 bat species from 14 countries were retrieved from 15 selected manuscripts. From these, 417 sequences clustered within the P1/pathogenic group, and only one sequence clustered within the P2/intermediate group. Six major clades of P1/pathogenic Leptospira spp. were identified, three of them composed exclusively of sequences obtained from bats., Conclusion: We identified that bats harbour a great genetic diversity of Leptospira spp. that form part of the P1/pathogenic clade, some of which are closely related to leptospirosis-associated species. This finding contributes to the knowledge of the diversity of leptospires hosted by bats worldwide and reinforces the role of bats as reservoirs of P1/pathogenic Leptospira spp., (© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)

A fungus uses different cell entry strategies, depending on its host's hibernation status.

Millions of hibernating bats across North America have died from white-nose syndrome (WNS), an emerging disease caused by a psychrophilic (cold-loving) fungus, Pseudogymnoascus destructans , that invades their skin. Mechanisms of P. destructans invasion of bat epidermis remain obscure. Guided by our in vivo observations, we modeled hibernation with a newly generated little brown bat ( Myotis lucifugus ) keratinocyte cell line. We uncovered the stealth intracellular lifestyle of P. destructans , which inhibits apoptosis of keratinocytes and spreads through the cells by two epidermal growth factor receptor (EGFR)-dependent mechanisms: active penetration during torpor and induced endocytosis during arousal. Melanin of endocytosed P. destructans blocks endolysosomal maturation, facilitating P. destructans survival and germination after return to torpor. Blockade of EGFR aborts P. destructans entry into keratinocytes.

The aim of this study was to detect vector-borne pathogens (Anaplasmataceae family, Rickettsia genus, and Bartonella genus) in bats from Misiones (Argentina). Thirty-three specimens were captured over 8 days using mist nets. Twenty (60.6%) blood samples were positive (11/13 Artibeus lituratus, 4/10 Desmodus rotundus, 4/8 Carollia perspicillata, and 1/2 Myotis nigricans) by PCR for the gltA gene fragment of Bartonella. All samples were negative by PCR for the Anaplasmataceae family and Rickettsia genus. The phylogenetic analysis showed seven Bartonella genotypes. The three genotypes obtained from A. lituratus, 2 from C. perspicillata, and 1 from D. rotundus were related to Bartonella spp. from New World bats, while the sequence obtained from M. nigricans was related to Old World bats. We identified a considerable diversity of Bartonella genotypes in a small number of bats, thus further research is required to better understand the complex bat-pathogen interaction., (Copyright © 2024 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Bats worldwide play significant roles in ecosystem functions, encompassing pollination, seed dispersal, and pest control while concurrently serving as diseases reservoirs. As part of a comprehensive wildlife health surveillance effort, bats were systematically sampled within two national protected areas in Argentina. During this study 67 bats were examined and samples were collected from eight Molossus spp. individuals exhibiting conspicuous yellowish or white lesions on their noses. All samples were cultured on Sabouraud dextrose agar and lactrimel agar for fungal growth evaluation. Fungal isolates were identified using morphologic and molecular taxonomic techniques, leading to the detection of Microascus sp. in three Molossus rufus from Ibera National Park and Cephalotheca sp. in five Molossus molossus from Marsh Deer National Park. No fungal growth was identified in samples collected from the healthy hairs of the bats displaying lesions on their noses. The two fungi, which have not previously been isolated from bats, should be considered potentially pathogenic, evidenced by diseased hairs in the affected individuals., (© Wildlife Disease Association 2024.)

Enterocytozoon bieneusi is a common cause of human microsporidiosis and can infect a variety of animal hosts worldwide. In Thailand, previous studies have shown that this parasite is common in domestic animals. However, information on the prevalence and genotypes of this parasite in other synanthropic wildlife, including bats, remains limited. Several pathogens have been previously detected in bats, suggesting that bats may serve as a reservoir for this parasite. In this study, a total of 105 bat guano samples were collected from six different sites throughout Thailand. Of these, 16 from Chonburi (eastern), Ratchaburi (western), and Chiang Rai (northern) provinces tested positive for E. bieneusi, representing an overall prevalence of 15.2%. Based on ITS1 sequence analysis, 12 genotypes were identified, including two known genotypes (D and type IV) frequently detected in humans and ten novel potentially zoonotic genotypes (TBAT01-TBAT10), all belonging to zoonotic group 1. Lyle's flying fox (Pteropus lylei), commonly found in Southeast Asia, was identified as the host in one sample that was also positive for E. bieneusi. Network analysis of E. bieneusi sequences detected in this study and those previously reported in Thailand also revealed intraspecific divergence and recent population expansion, possibly due to adaptive evolution associated with host range expansion. Our data revealed, for the first time, multiple E. bieneusi genotypes of zoonotic significance circulating in Thai bats and demonstrated that bat guano fertilizer may be a vehicle for disease transmission., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The Gypsum Karst of Sorbas, Almeria, southeast Spain, includes a few caves whose entrances are open and allow the entry and roosting of numerous bats. Caves are characterized by their diversity of gypsum speleothems, such as stalactites, coralloids, gypsum crusts, etc. Colored biofilms can be observed on the walls of most caves, among which the Covadura and C3 caves were studied. The objective was to determine the influence that bat mycobiomes may have on the fungal communities of biofilms. The results indicate that the fungi retrieved from white and yellow biofilms in Covadura Cave (Ascomycota, Mortierellomycota, Basidiomycota) showed a wide diversity, depending on their location, and were highly influenced by the bat population, the guano and the arthropods that thrive in the guano, while C3 Cave was more strongly influenced by soil- and arthropod-related fungi (Ascomycota, Mortierellomycota), due to the absence of roosting bats., (© 2024. The Author(s).)

Few studies have examined the genetic population structure of vector-borne microparasites in wildlife, making it unclear how much these systems can reveal about the movement of their associated hosts. This study examined the complex host–vector–microbe interactions in a system of bats, wingless ectoparasitic bat flies (Nycteribiidae), vector-borne microparasitic bacteria ( Bartonella ) and bacterial endosymbionts of flies ( Enterobacterales ) across an island chain in the Gulf of Guinea, West Africa. Limited population structure was found in bat flies and Enterobacterales symbionts compared to that of their hosts. Significant isolation by distance was observed in the dissimilarity of Bartonella communities detected in flies from sampled populations of Eidolon helvum bats. These patterns indicate that, while genetic dispersal of bats between islands is limited, some non-reproductive movements may lead to the dispersal of ectoparasites and associated microbes. This study deepens our knowledge of the phylogeography of African fruit bats, their ectoparasites and associated bacteria. The results presented could inform models of pathogen transmission in these bat populations and increase our theoretical understanding of community ecology in host–microbe systems.

Bats stand as one of the most diverse groups in the animal kingdom and are key players in the global transmission of emerging pathogens. However, their role in transmitting Enterocytozoon bieneusi and Cryptosporidium spp. remains unclear. This study aimed to evaluate the occurrence and genetic diversity of the two pathogens in fruit bats (Rousettus leschenaultii) in Hainan, China. Ten fresh fecal specimens of fruit bats were collected from Wanlvyuan Gardens, Haikou, China. The fecal samples were tested for E. bieneusi and Cryptosporidium spp. using Polymerase Chain Reaction (PCR) analysis and sequencing the internal transcribed spacer (ITS) region and partial small subunit of ribosomal RNA (SSU rRNA) gene, respectively. Genetic heterogeneity across Cryptosporidium spp. isolates was assessed by sequencing 4 microsatellite/minisatellite loci (MS1, MS2, MS3, and MS16). The findings showed that out of the ten specimens analyzed, 2 (20 %) and seven (70.0 %) were tested positive for E. bieneusi and Cryptosporidium spp., respectively. DNA sequence analysis revealed the presence of two novel Cryptosporidium genotypes with 94.4 to 98.6 % sequence similarity to C. andersoni, named as Cryptosporidium bat-genotype-XXI and bat-genotype-XXII. Three novel sequences of MS1, MS2 and MS16 loci identified here had 95.4 to 96.9 % similarity to the known sequences, which were deposited in the GenBank. Two genotypes of E. bieneusi were identified, including a novel genotype named HNB-I and a zoonotic genotype PigEbITS7. The discovery of these novel sequences provides meaningful data for epidemiological studies of the both pathogens. Meanwhile our results are also presented that the fruit bats infected with E. bieneusi, but not with Cryptosporidium, should be considered potential public health threats., Competing Interests: Declaration of competing interest The authors do not have a commercial or other association that represents a conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The mycosis histoplasmosis is also considered a zoonosis that affects humans and other mammalian species worldwide. Among the wild mammals predisposed to be infected with the etiologic agent of histoplasmosis, bats are relevant because they are reservoir of Histoplasma species, and they play a fundamental role in maintaining and spreading fungal propagules in the environments since the infective mycelial phase of Histoplasma grows in their accumulated guano. In this study, we detected the fungal presence in organ samples of bats randomly captured in urban areas of Araraquara City, São Paulo, Brazil. Fungal detection was performed using a nested polymerase chain reaction to amplify a molecular marker (Hcp100) unique to H. capsulatum , which revealed the pathogen presence in organ samples from 15 out of 37 captured bats, indicating 40.5% of infection. Out of 22 Hcp100-amplicons generated, 41% corresponded to lung and trachea samples and 59% to spleen, liver, and kidney samples. Data from these last three organs suggest that bats develop disseminated infections. Considering that infected bats create environments with a high risk of infection, it is important to register the percentage of infected bats living in urban areas to avoid risks of infection to humans, domestic animals, and wildlife.

The gut microbiome is a symbiotic microbial community associated with the host and plays multiple important roles in host physiology, nutrition, and health. A number of factors have been shown to influence the gut microbiome, among which diet is considered to be one of the most important; however, the relationship between diet composition and gut microbiota in wild mammals is still not well recognized. Herein, we characterized the gut microbiota of bats and examined the effects of diet, host taxa, body size, gender, elevation, and latitude on the gut microbiota. The cytochrome C oxidase subunit I (COI) gene and 16S rRNA gene amplicons were sequenced from the feces of eight insectivorous bat species in southern China, including Miniopterus fuliginosus , Aselliscus stoliczkanus , Myotis laniger , Rhinolophus episcopus , Rhinolophus osgoodi , Rhinolophus ferrumequinum , Rhinolophus affinis, and Rhinolophus pusillus . The results showed that the composition of gut microbiome and diet exhibited significant differences among bat species. Diet composition and gut microbiota were significantly correlated at the order, family, genus, and operational taxonomic unit levels, while certain insects had a marked effect on the gut microbiome at specific taxonomic levels. In addition, elevation, latitude, body weight of bats, and host species had significant effects on the gut microbiome, but phylosymbiosis between host phylogeny and gut microbiome was lacking. These findings clarify the relationship between gut microbiome and diet and contribute to improving our understanding of host ecology and the evolution of the gut microbiome in wild mammals., Importance: The gut microbiome is critical for the adaptation of wildlife to the dynamic environment. Bats are the second-largest group of mammals with short intestinal tract, yet their gut microbiome is still poorly studied. Herein, we explored the relationships between gut microbiome and food composition, host taxa, body size, gender, elevation, and latitude. We found a significant association between diet composition and gut microbiome in insectivorous bats, with certain insect species having major impacts on gut microbiome. Factors like species taxa, body weight, elevation, and latitude also affected the gut microbiome, but we failed to detect phylosymbiosis between the host phylogeny and the gut microbiome. Overall, our study presents novel insights into how multiple factors shape the bat's gut microbiome together and provides a study case on host-microbe interactions in wildlife., Competing Interests: The authors declare no conflict of interest.

White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans, has decimated bat populations across North America. Despite ongoing management programs, WNS continues to expand into new populations, including in US states previously thought to be free from the pathogen and disease. This expansion highlights a growing need for surveillance tools that can be used to enhance existing monitoring programs and support the early detection of P. destructans in new areas. We evaluated the feasibility of using a handheld, field-portable, real-time (quantitative) PCR (qPCR) thermocycler known as the Biomeme two3 and the associated field-based nucleic acid extraction kit and assay reagents for the detection of P. destructans in little brown bats (Myotis lucifugus). Results from the field-based protocol using the Biomeme platform were compared with those from a commonly used laboratory-based qPCR protocol. When using dilutions of known conidia concentrations, the lowest detectable concentration with the laboratory-based approach was 108.8 conidia/mL, compared with 1,087.5 conidia/mL (10 times higher, i.e., one fewer 10× dilution) using the field-based approach. Further comparisons using field samples suggest a high level of concordance between the two protocols, with positive and negative agreements of 98.2% and 100% respectively. The cycle threshold values were marginally higher for most samples using the field-based protocol. These results are an important step in establishing and validating a rapid, field-assessable detection platform for P. destructans, which is urgently needed to improve the surveillance and monitoring capacity for WNS and support on-the-ground management and response efforts., (© Wildlife Disease Association 2024.)

In addition to zoonotic viral pathogens, bats can also harbor bacterial pathogens, including hemoplasmas (hemotropic mycoplasmas) and Coxiella burnetii. The present study aimed to investigate, using molecular techniques, the presence of hemoplasmas and C. burnetii in spleen samples from vampire bats in northern Brazil. For this purpose, between 2017 and 2019, spleen samples were collected from Desmodus rotundus (n = 228) and Diaemus youngii (n = 1) captured in the states of Pará (n = 207), Amazonas (n = 1), Roraima (n = 18) and Amapá (n = 3). DNA samples extracted from the bat spleen and positive in PCR for the endogenous gapdh gene were subjected to conventional PCR assays for the 16S rRNA, 23S rRNA and RNAse P genes from hemoplasmas and to qPCR based on the IS1111 gene element for C. burnetii. All spleen samples from vampire bats were negative in the qPCR for C. burnetii. Hemoplasmas were detected in 10 % (23/229) of spleen samples using a PCR based on the 16S rRNA gene. Of these, 21.73 % (5/23) were positive for the 23S rRNA gene and none for the RNAseP gene. The seven hemoplasma 16S rRNA sequences obtained were closely related to sequences previously identified in vampire bats from Belize, Peru and Brazil. The 23S rRNA sequence obtained revealed genetic proximity to hemoplasmas from non-hematophagous bats from Brazil and Belize. The analysis revealed different circulating genotypes among Brazilian vampire bats, in addition to a trend towards genera-specific hemoplasma genotypes. The present study contributes to the knowledge of the wide diversity of hemoplasmas in vampire bats., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Importance: Inherent complexities in the composition of microbiomes can often preclude investigations of microbe-associated diseases. Instead of single organisms being associated with disease, community characteristics may be more relevant. Longitudinal microbiome studies of the same individual bats as pathogens arrive and infect a population are the ideal experiment but remain logistically challenging; therefore, investigations like our approach that are able to correlate invasive pathogens to alterations within a microbiome may be the next best alternative. The results of this study potentially suggest that microbiome-host interactions may determine the likelihood of infection. However, the contrasting relationship between Pd and the bacterial microbiomes of Myotis lucifugus and Perimyotis subflavus indicate that we are just beginning to understand how the bat microbiome interacts with a fungal invader such as Pd., Competing Interests: The authors declare no conflict of interest.

Since the emergence of White-nose Syndrome, a fungal disease in bats, caused by Pseudogymnoascus destructans, hibernating populations of little brown bats ( Myotis lucifugus ) have declined by 70-90% within P. destructans positive hibernacula. To reduce the impact of White-nose Syndrome to North American little brown bat populations we evaluated if exposure to volatile organic compounds produced by induced cells from Rhodococcus rhodochrous strain DAP96253 could improve the overwinter survival of bats infected by P. destructans . Two simultaneous field treatment trials were conducted at natural hibernacula located in Rockcastle and Breckinridge counties, Kentucky, USA. A combined total of 120 little brown bats were randomly divided into control groups ( n  = 60) which were not exposed to volatile organic compounds and treatment groups ( n  = 60) which were exposed to volatile organic compounds produced by non-growth, fermented cell paste composed of R. rhodochrous strain DAP96253 cells. Cox proportional hazard models revealed a significant decreased survival at the Rockcastle field trial site but not the Breckinridge field site. At the Breckinridge hibernacula, overwinter survival for both treatment and control groups were 60%. At the Rockcastle hibernacula, Kaplan-Meier survival curves indicated significantly increased overwinter survival of bats in the control group (43% survived) compared to the treatment group (20% survived). Although complete inhibition of P. destructans by volatile organic compounds produced by induced R. rhodochrous strain DAP96253 cells was observed in vitro studies, our results suggest that these volatile organic compounds do not inhibit P. destructans in situ and may promote P. destructans growth., Competing Interests: Sybill Amelon is an employee of the USDA.

Bats are widespread mammals that play key roles in ecosystems as pollinators and insectivores. However, there is a paucity of information about bat-associated microbes, in particular their fungal communities, despite the important role microbes play in host health and overall host function. The emerging fungal disease, white-nose syndrome, presents a potential challenge to the bat microbiome and understanding healthy bat-associated taxa will provide valuable information about potential microbiome-pathogen interactions. To address this knowledge gap, we collected 174 bat fur/skin swabs from 14 species of bats captured in five locations in New Mexico and Arizona and used high-throughput sequencing of the fungal internal transcribed (ITS) region to characterize bat-associated fungal communities. Our results revealed a highly heterogeneous bat mycobiome that was structured by geography and bat species. Furthermore, our data suggest that bat-associated fungal communities are affected by bat foraging, indicating the bat skin microbiota is dynamic on short time scales. Finally, despite the strong effects of site and species, we found widespread and abundant taxa from several taxonomic groups including the genera Alternaria and Metschnikowia that have the potential to be inhibitory towards fungal and bacterial pathogens., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Desmodus rotundus, vampire bats, transmit dangerous infections, and brucellosis is a hazardous zoonotic disease, two adversities that coexist in the subtropical and tropical areas of the American continent. Here, we report a 47.89% Brucella infection prevalence in a colony of vampire bats inhabiting the tropical rainforest of Costa Rica. The bacterium induced placentitis and fetal death in bats. Wide-range phenotypic and genotypic characterization placed the Brucella organisms as a new pathogenic species named Brucella nosferati sp. nov., isolated from bat tissues, including the salivary glands, suggesting feeding behavior might favor transmission to their prey. Overall analyses placed B. nosferati as the etiological agent of a reported canine brucellosis case, demonstrating its potential for infecting other hosts. To assess the putative prey hosts, we analyzed the intestinal contents of 14 infected and 23 non-infected bats by proteomics. A total of 54,508 peptides sorted into 7,203 unique peptides corresponding to 1,521 proteins were identified. Twenty-three wildlife and domestic taxa, including humans, were foraged by B. nosferati -infected D. rotundus , suggesting contact of this bacterium with a broad range of hosts. Our approach is appropriate for detecting, in a single study, the prey preferences of vampire bats in a diverse area, demonstrating its suitability for control strategies where vampire bats thrive. IMPORTANCE The discovery that a high proportion of vampire bats in a tropical area is infected with pathogenic Brucella nosferati and that bats forage on humans and many wild and domestic animals is relevant from the perspective of emerging disease prevention. Indeed, bats harboring B. nosferati in their salivary glands may transmit this pathogenic bacterium to other hosts. This potential is not trivial since, besides the demonstrated pathogenicity, this bacterium possesses all the required virulent arsenal of dangerous Brucella organisms, including those that are zoonotic for humans. Our work has settled the basis for future surveillance actions in brucellosis control programs where these infected bats thrive. Moreover, our strategy to identify the foraging range of bats may be adapted for exploring the feeding habits of diverse animals, including arthropod vectors of infectious diseases, and therefore of interest to a broader audience besides experts on Brucella and bats., Competing Interests: The authors declare no conflict of interest.

Histoplasma species infect humans and animals, notably bats. Histoplasma species are thermally dimorphic fungi existing in mycelial form in the natural environment and in yeast form in infected tissues. In this narrative literature review, we summarize the occurrence of Histoplasma spp. in different species of bat tissues (n = 49) and in soil admixed with bat guano where the species of bat dwelling nearby has been identified (an additional 18 species likely infected) to provide an up-to-date summary of data. Most positive isolations are from the Americas and Caribbean, with some studies from Thailand, Malaysia, Nigeria, Slovenia, France, and Australia. We also summarize some of the early experimental work to elucidate pathogenicity, latency, immune response, and faecal excretion in bats. Given the recent recognition of the global extent of histoplasmosis, thermal dimorphism in Histoplasma spp., and global heating, additional work on understanding the complex relationship between Histoplasma and bats is desirable., (© The Author(s) 2023. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)

Skin microbiota play an important role in protecting bat hosts from the fungal pathogen Pseudogymnoascus destructans, which has caused dramatic bat population declines and extinctions. Recent studies have provided insights into the bacterial communities of bat skin, but variation in skin bacterial community structure in the context of the seasonal dynamics of fungal invasion, as well as the processes that drive such variation, remain largely unexplored. In this study, we characterized bat skin microbiota over the course of the bat hibernation and active season stages and used a neutral model of community ecology to determine the relative roles of neutral and selective processes in driving microbial community variation. Our results showed significant seasonal shifts in skin community structure, as well as less diverse microbiota in hibernation than in the active season. Skin microbiota were influenced by the environmental bacterial reservoir. During both the hibernation and active season stages, more than 78% of ASVs in bat skin microbiota were consistent with neutral distribution, implying that neutral processes, that is, dispersal or ecological drift contributing the most to shifts in skin microbiota. In addition, the neutral model showed that some ASVs were actively selected by the bats from the environmental bacterial reservoir, accounting for approximately 20% and 31% of the total community during hibernation and active season stages, respectively. Overall, this research provides insights into the assemblage of bat-associated bacterial communities and will aid in the development of conservation strategies against fungal disease., (© 2023 John Wiley & Sons Ltd.)

The importance of species that connect the different types of interactions is becoming increasingly recognized, and this role may be related to specific attributes of these species. Multilayer networks have two or more layers, which represent different types of interactions, for example, between different parasites and hosts that are nonetheless connected. The understanding of the ecological relationship between bats, ectoparasites, and vector-borne bacteria could shed some light on the complex transmission cycles of these pathogens. In this study, we investigated a multilayer network in Brazil formed by interactions between bat-bacteria, bat-ectoparasite, and ectoparasite-bacteria, and asked how these interactions overlap considering different groups and transmission modes. The multilayer network was composed of 31 nodes (12 bat species, 14 ectoparasite species, and five bacteria genera) and 334 links, distributed over three layers. The multilayer network has low modularity and shows a core-periphery organization, that is, composed of a few generalist species with many interactions and many specialist species participating in few interactions in the multilayer network. The three layers were needed to accurately describe the multilayer structure, while aggregation leads to loss of information. Our findings also demonstrated that the multilayer network is influenced by a specific set of species that can easily be connected to the behavior, life cycle, and type of existing interactions of these species. Four bat species (Artibeus lituratus, A. planirostris, Phyllostomus discolor, and Platyrrhinus lineatus), one ectoparasite species (Steatonyssus) and three bacteria genera (Ehrlichia, hemotropic Mycoplasma and Neorickettsia) are the most important species for the multilayer network structure. Finally, our study brings an ecological perspective under a multilayer network approach on the interactions between bats, ectoparasites, and pathogens. By using a multilayer approach (different types of interactions), it was possible to better understand these different ecological interactions and how they affect each other, advancing our knowledge on the role of bats and ectoparasites as potential pathogen vectors and reservoirs, as well as the modes of transmission of these pathogens., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

White-nose syndrome (WNS) has notably affected the abundance of Myotis lucifugus (little brown myotis) in North America. Thus far, substantial mortality has been restricted to the eastern part of the continent where the cause of WNS, the invasive fungus Pseudogymnoascus destructans, has infected bats since 2006. To date, the state of Washington is the only area in the Western US or Canada (the Rocky Mountains and further west in North America) with confirmed cases of WNS in bats, and there the disease has spread more slowly than it did in Eastern North America. Here, we review differences between M. lucifugus in western and eastern parts of the continent that may affect transmission, spread, and severity of WNS in the West and highlight important gaps in knowledge. We explore the hypothesis that western M. lucifugus may respond differently to WNS on the basis of different hibernation strategies, habitat use, and greater genetic structure. To document the effect of WNS on M. lucifugus in the West most effectively, we recommend focusing on maternity roosts for strategic disease surveillance and monitoring abundance. We further recommend continuing the challenging work of identifying hibernation and swarming sites to better understand the microclimates, microbial communities, and role in disease transmission of these sites, as well as the ecology and hibernation physiology of bats in noncavernous hibernacula., (© Wildlife Disease Association 2023.)

Bats can be affected by fungal pathogens such as Pseudogymnoascus destructans , the causative agent of the white-nose syndrome. Their body surface can also be colonized by fungal commensals or carry transient fungal species and participate in their dispersal. In this study, 114 bat specimens belonging to seven species were sampled from various locations in northern Belgium. Culture-based methods revealed an important mycological diversity, with a total of 209 different taxa out of the 418 isolates. Overall, a mean of 3.7 taxa per bat was recorded, but significant differences were observed between sampling sites and seasons. The mycobiomes were dominated by cosmopolitan and plant-associated species, in particular from the genera Cladosporium, Penicillium , and Aspergillus . Other species known to be related to bats or their environment, such as Apiotrichum otae , were also retrieved. Sampling of hibernacula indicated that diverse fungal species can inhabit these sites, including a yet undescribed Pseudogymnoascus species, distinct from Ps. destructans , namely, Ps. cavicola .

Understanding how host-associated microbial assemblages respond to pathogen invasion has implications for host health. Until recently, most investigations have focused on understanding the taxonomic composition of these assemblages. However, recent studies have suggested that microbial assemblage taxonomic composition is decoupled from its function, with assemblages being taxonomically varied but functionally constrained. The objective of this investigation was to understand how the Tri-colored bat, Perimyotis subflavus cutaneous microbial assemblage responds to fungal pathogen invasion within a functional context. We hypothesized that at a broad scale (e.g., KEGG pathways), there will be no difference in the functional assemblages between the white nose pathogen, Pseudogymnoascus destructans, positive and negative bats; and this pattern will be driven by the functional redundancy of bacterial taxa. At finer scales (e.g., gene models), we postulate differences in function attributed to interactions between bacteria and P. destructans, resulting in the production of antifungal metabolites. To test this, we used a combination of shotgun metagenomic and amplicon sequencing to characterize the bat cutaneous microbial assemblage in the presence/absence of P. destructans. Results showed that while there was a shift in taxonomic assemblage composition between P. destructans positive and negative bats, there was little overall difference in microbial function. Functional redundancy across bacterial taxa was clear at a broad-scale; however, both redundancy and variation in bacterial capability related to defense against pathogens was evident at finer scales. While functionality of the microbial assemblage was largely conserved in relation to P. destructans, the roles of particular functional pathways in resistance to fungal pathogens require further attention., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Demographic factors are fundamental in shaping infectious disease dynamics. Aspects of populations that create structure, like age and sex, can affect patterns of transmission, infection intensity and population outcomes. However, studies rarely link these processes from individual to population-scale effects. Moreover, the mechanisms underlying demographic differences in disease are frequently unclear. Here, we explore sex-biased infections for a multi-host fungal disease of bats, white-nose syndrome, and link disease-associated mortality between sexes, the distortion of sex ratios and the potential mechanisms underlying sex differences in infection. We collected data on host traits, infection intensity and survival of five bat species at 42 sites across seven years. We found females were more infected than males for all five species. Females also had lower apparent survival over winter and accounted for a smaller proportion of populations over time. Notably, female-biased infections were evident by early hibernation and likely driven by sex-based differences in autumn mating behaviour. Male bats were more active during autumn which likely reduced replication of the cool-growing fungus. Higher disease impacts in female bats may have cascading effects on bat populations beyond the hibernation season by limiting recruitment and increasing the risk of Allee effects.

Pathogens with persistent environmental stages can have devastating effects on wildlife communities. White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans, has caused widespread declines in bat populations of North America. In 2009, during the early stages of the WNS investigation and before molecular techniques had been developed to readily detect P. destructans in environmental samples, we initiated this study to assess whether P. destructans can persist in the hibernaculum environment in the absence of its conclusive bat host and cause infections in naive bats. We transferred little brown bats (Myotis lucifugus) from an unaffected winter colony in northwest Wisconsin to two P. destructans contaminated hibernacula in Vermont where native bats had been excluded. Infection with P. destructans was apparent on some bats within 8 weeks following the introduction of unexposed bats to these environments, and mortality from WNS was confirmed by histopathology at both sites 14 weeks following introduction. These results indicate that environmental exposure to P. destructans is sufficient to cause the infection and mortality associated with WNS in naive bats, which increases the probability of winter colony extirpation and complicates conservation efforts., (© 2023. The Author(s).)

Background: North American bat populations have suffered severe declines over the last decade due to the Pseudogymnoascus destructans fungus infection. The skin disease associated with this causative agent, known as white-nose syndrome (WNS), is specific to bats hibernating in temperate regions. As cultured fungal isolates are required for epidemiological and phylogeographical studies, the purpose of the present work was to compare the efficacy and reliability of different culture approaches based on either skin swabs or wing membrane tissue biopsies for obtaining viable fungal isolates of P. destructans., Results: In total, we collected and analysed 69 fungal and 65 bacterial skin swabs and 51 wing membrane tissue biopsies from three bat species in the Czech Republic, Poland and the Republic of Armenia. From these, we obtained 12 viable P. destructans culture isolates., Conclusions: Our results indicated that the efficacy of cultures based on wing membrane biopsies were significantly higher. Cultivable samples tended to be based on collections from bats with lower body surface temperature and higher counts of UV-visualised lesions. While cultures based on both skin swabs and wing membrane tissue biopsies can be utilised for monitoring and surveillance of P. destructans in bat populations, wing membrane biopsies guided by UV light for skin lesions proved higher efficacy. Interactions between bacteria on the host's skin also appear to play an important role., (© 2023. The Author(s).)

The bacterial genus Borrelia comprises vector-borne spirochetes that have been classified into three major groups: the relapsing fever group (RFG), the Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner sensu lato group (Bbsl), and the reptile-monotreme group (RMG). All three groups have been associated mainly with ticks and wild animals, especially rodents, birds, and reptiles. Here, we searched for Borrelia infection among 99 vampire bats [Desmodus rotundus (É. Geoffroy)] (Chiroptera: Phyllostomidae) from the Brazilian semiarid region. Through molecular investigation of bat internal organs, haplotypes of a potentially novel Borrelia organism were detected in 5% (5/99) of the bats. Borrelia DNA was detected in the liver, blood, spleen, kidney and brain, suggesting a systemic infection. Phylogenetic analyses inferred from partial sequences of the borrelial rrs and flaB genes indicated that the vampire bat-associated Borrelia sp. of this study form a monophyletic group with a newly reported Borrelia associated with a Colombia bat, distinct from the three main currently recognized groups of Borrelia spp., Bbsl, RFG, and RMG. These novel bat-associated Borrelia spp. from South America might have arisen through an independent event along the borrelial evolutionary history, since previous molecular reports of Borrelia organisms in bats or bat-associated ticks from Africa, Europe, and North America were all classified in the RFG., (© The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Pseudogymnoascus destructans is the etiological agent of white-nose syndrome (WNS), a fungal skin infection of hibernating bats. Pathophysiology of the disease involves disruption of bat metabolism and hibernation patterns, which subsequently causes premature emergence and mortality. However, information on the mechanism(s) and virulence factors of P. destructans infection is minimally known. Typically, fungal adherence to host cells and extracellular matrix (ECM) is the critical first step of the infection. It allows pathogenic fungi to establish colonization and provides an entry for invasion in host tissues. In this study, we characterized P. destructans conidial adherence to laminin and fibronectin. We found that P. destructans conidia adhered to laminin and fibronectin in a dose-dependent, time-dependent and saturable manner. We also observed changes in the gene expression of secreted proteases, in response to ECM exposure. However, the interaction between fungal conidia and ECM was not specific, nor was it facilitated by enzymatic activity of secreted proteases. We therefore further investigated other P. destructans proteins that recognized ECM and found glyceraldehyde-3-phosphate dehydrogenase and elongation factor 1-alpha among the candidate proteins. Our results demonstrate that P. destructans may use conidial surface proteins to recognize laminin and fibronectin and facilitate conidial adhesion to ECM. In addition, other non-specific interactions may contribute to the conidial adherence to ECM. However, the ECM binding protein candidates identified in this study highlight additional potential fungal virulence factors worth investigating in the P. destructans mechanism of infection in future studies., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kevin Keel reports financial support was provided by The American Association of Zoo VeterinariansWild Animal Health Fund. Piyaporn Eiamcharoen reports financial support was provided by The Anandamahidol Foundation Scholarship under the royal patronage of His Majesty the King of Thailand., (Copyright © 2022. Published by Elsevier Ltd.)

We investigated the prevalence of Bartonella in 123 northern bats (Eptesicus nilssonii) and their ectoparasites from Hokkaido, Japan. A total of 174 bat fleas (Ischnopsyllus needhami) and two bat bugs (Cimex japonicus) were collected from the bats. Bartonella bacteria were isolated from 32 (26.0%) of 123 bats. Though Bartonella DNA was detected in 79 (45.4%) of the bat fleas, the bacterium was isolated from only one bat flea (0.6%). The gltA sequences of the isolates were categorized into genotypes I, II, and III, which were found in both bats and their fleas. The gltA sequences of genotypes I and II showed 97.6% similarity with Bartonella strains from a Finnish E. nilssonii and a bat flea from a E. serotinus in the Netherlands. The rpoB sequences of the genotypes showed 98.9% similarity with Bartonella strain 44722 from E. serotinus in Republic of Georgia. The gltA and rpoB sequences of genotype III showed 95.9% and 96.7% similarity with Bartonella strains detected in shrews in Kenya and France, respectively. Phylogenetic analysis revealed that Bartonella isolates of genotypes I and II clustered with Bartonella strains from Eptesicus bats in Republic of Georgia and Finland, Myotis bats in Romania and the UK, and a bat flea from an Eptesicus bat in Finland. In contrast, genotype III formed a clade with B. florencae, B. acomydis, and B. birtlesii. These data suggest that northern bats in Japan harbor two Bartonella species and the bat flea serves as a potential vector of Bartonella transmission among the bats., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Bats have attracted global attention because of their zoonotic association with severe acute respiratory syndrome coronavirus (SARS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous and ongoing studies have predominantly focused on bat-borne viruses; however, the prevalence or abundance of bat-borne pathogenic bacteria and their potential public health significance have largely been neglected. For the first time, this study used both metataxonomics (16S rRNA marker gene sequencing) and culturomics (traditional culture methods) to systematically evaluate the potential public health significance of bat fecal pathogenic bacteria. To this end, fecal samples were obtained from five bat species across different locations in China, and their microbiota composition was analyzed. The results revealed that the bat microbiome was most commonly dominated by Proteobacteria, while the strictly anaerobic phylum Bacteroidetes occupied 35.3% of the relative abundance in Rousettus spp. and 36.3% in Hipposideros spp., but less than 2.7% in the other three bat species ( Taphozous spp., Rhinolophus spp., and Myotis spp.). We detected 480 species-level phylotypes (SLPs) with PacBio sequencing, including 89 known species, 330 potentially new species, and 61 potentially higher taxa. In addition, a total of 325 species were identified by culturomics, and these were classified into 242 named species and 83 potentially novel species. Of note, 32 of the 89 (36.0%) known species revealed by PacBio sequencing were found to be pathogenic bacteria, and 69 of the 242 (28.5%) known species isolated by culturomics were harmful to people, animals, or plants. Additionally, nearly 40 potential novel species which may be potential bacterial pathogens were identified. IMPORTANCE Bats are one of the most diverse and widely distributed groups of mammals living in close proximity to humans. In recent years, bat-borne viruses and the viral zoonotic diseases associated with bats have been studied in great detail. However, the prevalence and abundance of pathogenic bacteria in bats have been largely ignored. This study used high-throughput sequencing techniques (metataxonomics) in combination with traditional culture methods (culturomics) to analyze the bacterial flora in bat feces from different species of bats in China, revealing that bats are natural hosts of pathogenic bacteria and carry many unknown bacteria. The results of this study can be used as guidance for future investigations of bacterial pathogens in bats.

Leptospirosis is an infectious disease caused by Leptospira spp. and affects animals and humans. Reports of leptospirosis in bats have increased and prompted epidemiological research in Brazil. This study aimed to perform a molecular and epidemiological investigation of pathogenic Leptospira spp. in bat kidneys. The total DNA was extracted from 102 kidney samples from chiropterous of different species and cities in Rio Grande do Sul State (RS), Brazil. The polymerase chain reaction was used to amplify a fragment corresponding to lipL32 gene, which is only present in pathogenic Leptospira spp. lipL32 gene was detected in 22.5% (23/102) of the bat kidney tissues. Phylogenetic analysis showed that L. interrogans is circulating in bats in RS. Most species of the bats collected were insectivores. Pathogenic Leptospira spp. detection in bats demonstrated that these animals participate in the infection chain of leptospirosis and, therefore, may play as reservoirs and disseminators of this microorganism. Thus, it is important to monitor infectious agents, especially with zoonotic potential in bats., (© 2022. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

White-nose syndrome has killed millions of bats, yet both the origins and infection strategy of the causative fungus, Pseudogymnoascus destructans , remain elusive. We provide evidence for a novel hypothesis that P. destructans emerged from plant-associated fungi and retained invasion strategies affiliated with fungal pathogens of plants. We demonstrate that P. destructans invades bat skin in successive biotrophic and necrotrophic stages (hemibiotrophic infection), a mechanism previously only described in plant fungal pathogens. Further, the convergence of hyphae at hair follicles suggests nutrient tropism. Tropism, biotrophy, and necrotrophy are often associated with structures termed appressoria in plant fungal pathogens; the penetrating hyphae produced by P. destructans resemble appressoria. Finally, we conducted a phylogenomic analysis of a taxonomically diverse collection of fungi. Despite gaps in genetic sampling of prehistoric and contemporary fungal species, we estimate an 88% probability the ancestral state of the clade containing P. destructans was a plant-associated fungus.

In the United States, the discovery and spread of white-nose syndrome (WNS) has drastically changed how bats and caves are managed. The U.S. National Park Service has been instrumental in the national response to WNS, as it manages extensive cave resources and has a close relationship with the public. However, managers lack information on visitor support for disease prevention measures designed to slow the spread of WNS and minimize human disturbance of vulnerable bat populations. This study utilized the Theory of Planned Behavior to determine how visitor attitudes, subjective norms, and perceived behavioral controls influenced their behavior regarding WNS preventive actions, including participation in educational programming on bats, wearing clothes or shoes in caves that have not been contaminated with the fungus that causes WNS, walking over decontamination mats, and complying with cave closures. During summer of 2019, data were collected using an on-site survey of 1365 visitors to eight U.S. national park units: Oregon Caves, Lava Beds, Carlsbad Caverns, El Malpais, Wind Cave, Jewel Cave, Mammoth Cave, and Cumberland Gap. Visitors were willing to participate in all preventative actions addressed in the survey (77.7%-96.7%). Visitors expressed that engaging in these actions was very desirable (36.0%-65.6%), and their decision to engage in these actions was most strongly influenced by park staff (39.2%-68.8%) or signage (35.5%-61.9%). Attitudes and subjective norms were positive predictors of behavioral intentions for all measures. Perceived behavioral control was not a direct predictor for behavioral intent, but its interaction with attitudes and subjective norms had a moderating influence on intention to comply with multiple WNS preventive actions. With the continued spread of WNS and emergence of other threats to bats, understanding visitor behavioral intent and underlying factors will facilitate successful implementation of preventive actions that are publicly supported and promote conservation of bat populations in U.S. national parks., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Leptospirosis is the most common bacterial zoonosis globally. The pathogen, Leptospira spp., is primarily associated with rodent reservoirs. However, a wide range of other species has been implicated as reservoirs or dead-end hosts. We conducted a survey for Leptospira spp. in bats and rodents from Papua New Guinea. Kidney samples were collected from 97 pteropodid bats (five species), 37 insectivorous bats from four different families (six species) and 188 rodents (two species). Leptospires were detected in a high proportion of pteropodid bats, including Nyctimene cf. albiventer (35%), Macroglossus minimus (34%) and Rousettus amplexicaudatus (36%). Partial sequencing of the secY gene from rodent and bat leptospires showed host species clustering, with Leptospira interrogans and L. weilii detected in rodents and L. kirschneri and a potential novel species of Leptospira detected in bats. Further research is needed in Papua New Guinea and other locales in the Pacific region to gain a better understanding of the circulation dynamics of leptospires in reservoir species and the risks to public and veterinary health., (© 2022 The Authors. Transboundary and Emerging Diseases published by Wiley-VCH GmbH.)

Bats are the only flying mammalian animals and are distributed worldwide. Bats are well-known hosts of several zoonotic viruses and bacteria, including Leptospira sp. Here, we performed a systematic review and a meta-analysis of evidence of Leptospira sp. infection in bats by examining studies published between 1964 and 2021. We reported the frequencies of various species and serogroups on all continents, several species and feeding habits of bats, and different diagnostic tools. Together, 33 papers from all continents with seven to 2077 individuals from one to 31 species were included. Molecular detection was conducted in most studies, followed by MAT (Microscopic Agglutination Test) and isolation and identification. Molecular characterization of Leptospira sp. revealed L. borgpetersenii as the most frequent species. Moreover, 179 positive samples for MAT contained the most likely infecting serogroups described, particularly the Australis serogroup. The percentage of positive tests in isolation and identification ranged between 0% and 0.5%. The highest frequency of Leptospira infection among the continents was observed in Asia, whereas South America had the lowest percentage. Finally, Nycteridae and Rhinonycteridae were the most frequently infected bat families. Our study provides valuable information about the epidemiology of Leptospira sp. infection in bats., (© 2022 Wiley-VCH GmbH.)