Biology subjects

Fenton, B.

Publications and source records attributed to Fenton, B..

8 recordsLinked to original sources

bioRxiv2026

Validating wing biopsies for blood-borne pathogen characterization in bats

Wildlife surveillance is critical for tracking disease emergence, characterizing pathogen diversity, and assessing spillover risks. Blood-borne pathogens are of particular interest for such efforts due to their global distribution, broad host taxa, and zoonotic potential. Despite the need to monitor blood-borne pathogens, blood collection efforts are costly for both biologists and the wildlife being sampled (i.e., time-consuming and stressful), hindering our ability to expand and enhance surveillance efforts. There is thus a pressing need for reliable methods for detecting blood-borne pathogens that minimize sampling efforts and wildlife stress. Vascular tissues can contain enough blood to detect infections while minimizing sampling effort and stress on wildlife, but it is unclear how pathogen detection and characterization from these tissues compared to blood. To evaluate the reliability of using vascular tissues for detecting blood-borne pathogens in wildlife, we collected paired samples of blood and wing biopsies from individual common vampire bats (Desmodus rotundus) and molecularly screened them for bartonellae, hemotropic mycoplasmas (hemoplasmas), and trypanosomes. The probability of detection was consistently lower in wing tissues than in blood for all pathogens, possibly due to blood vessel avoidance when collecting the former. However, we detected infection in wing tissues of at least two individual bats for each blood-borne pathogen. Paired-positive individuals mostly showed high sequence concordance between tissues, indicating frequent detection of the same infections. Estimated sample sizes needed to detect a single infection and the reported prevalences were similar (i.e., n = 10-39). Due to the lower probability of infection in wing tissues compared to blood, we suggest that using these samples to estimate infection prevalence of blood-borne pathogens is not ideal. However, our results demonstrate that vascular tissues are viable for initial pathogen assessment and discovery to help target surveillance efforts in the future.

ecology↗

bioRxiv2025

Habitat and seasonal drivers of leukocyte profiles within and across Neotropical bat species

Land conversion is a widespread form of environmental change that can alter infection dynamics in wildlife by modifying host immune defense. Such effects may be compounded by seasonal variation in resources and reproduction and differ among members of a host community, yet the combined effects of habitat, season, and species identity on wildlife immunity remain poorly understood. We tested within- and across-species effects of land conversion and seasonality on immunity in Neotropical bats by quantifying hematological markers of physiological stress and inflammation. We sampled seven species across a large forest preserve and smaller nearby forest fragment in northern Belize during the dry and wet seasons. Using phylogenetic generalized linear mixed models, we tested overall effects of habitat and season and quantified per-species impacts. Total leukocyte counts and neutrophil-to-lymphocyte ratios showed no overall habitat or seasonal effects but had strong species-specific responses to these predictors. In contrast, the systemic inflammation response index was higher across species in the dry season and in the smaller fragment, suggesting poor health in unfavorable conditions. Species-specific effects did not align with diet guilds, indicating potential roles for finer-scale ecological traits. Our results highlight the complex, species-dependent effects of environmental change on wildlife immunity.

ecology↗

bioRxiv2025

Design and Characterisation of Photoactivatable and Lysine Reactive o-Nitrobenzyl Alcohol-Based Crosslinkers

Photoreactive groups are invaluable tools in structural proteomics, offering reagent-free activation and temporal control of protein labelling. However, traditional UV-activatable functional groups often produce unstable intermediates and diverse products, making these chemistries difficult to deploy at scale. In this study, we performed a systematic analysis of ortho-nitrobenzyl alcohol (oNBA) reactivity for integration into novel reagents for chemical crosslinking-mass spectrometry. oNBA photochemistry represents a promising alternative to traditional photoactivatable crosslinkers due to its unique specificity towards lysine residues. Here, we synthesised two molecules comprising oNBA functional groups with different substituents and assessed their labelling efficiency against a model protein. To ensure high labelling yields while maintaining a short irradiation time, we constructed a high power 365 nm irradiation device which improves the efficiency of oNBA photolysis. Our studies identified an amide-substituted probe that labels proteins with high efficiency. We next incorporated this optimised oNBA moiety into a homo-bifunctional crosslinker and a hetero-bifunctional crosslinker in combination with an NHS ester, which both resulted in high yields of crosslinked products. Our findings highlight that optimised oNBA-based reactive groups are viable UV-activated warheads that can deliver high labelling yields and efficient protein crosslinking, unlocking a wealth of potential structural proteomics applications.

biophysics↗

bioRxiv2025

229E- and NL63-like coronaviruses in phyllostomid bats, Belize

We report novel and previously identified alphacoronavirus (-CoV) diversity in three phyllostomid bat species (Desmodus rotundus, Carollia sowelli, and Sturnira parvidens) in Belize. Phylogenetic analysis suggests strong similarity between two Neotropical bat -CoV lineages and human CoVs (229E and NL63) compared to prior bat -CoVs.

ecology↗

bioRxiv2023

Expanded diversity of hemoplasmas in rare and undersampled Neotropical bats

Hemotropic mycoplasmas are emerging as a model system for studying bacterial pathogens in bats, but taxonomic coverage of sampled host species remains biased. We leveraged a long-term field study in Belize to uncover novel hemoplasma diversity in bats by analyzing 80 samples from 19 species, most of which are infrequently encountered. PCR targeting the partial 16S rRNA gene found 41% of bats positive for hemoplasmas. Phylogenetic analyses found two novel host shifts of hemoplasmas, four entirely new hemoplasma genotypes, and the first hemoplasma detections in four bat species. One of these novel hemoplasmas (from Neoeptesicus furinalis) shared 97.6% identity in the partial 16S rRNA gene to a human hemoplasma (Candidatus Mycoplasma haemohominis). Additional analysis of the partial 23S rRNA gene allowed us to also designate two novel hemoplasma species, in Myotis elegans and Phyllostomus discolor, with the proposed names Candidatus Mycoplasma haematomyotis sp. nov. and Candidatus Mycoplasma haematophyllostomi sp. nov., respectively. Our analyses show that additional hemoplasma diversity in bats can be uncovered by targeting rare or undersampled host species.

microbiology↗

bioRxiv2022

Serum proteomics identifies immune pathways and candidate biomarkers of coronavirus infection in wild vampire bats

The apparent ability of bats to harbor many virulent viruses without showing disease is likely driven by distinct immune responses that coevolved with mammalian flight and the exceptional longevity of this order. Yet our understanding of the immune mechanisms of viral tolerance is restricted to a small number of bat-virus relationships and remains poor for coronaviruses (CoVs), despite their relevance to human health. Proteomics holds particular promise for illuminating the immune factors involved in bat responses to infection, because it can accommodate especially low sample volumes (e.g., sera) and thus can be applied to both large and small bat species as well as in longitudinal studies where lethal sampling is necessarily limited. Further, as the serum proteome includes proteins secreted from not only blood cells but also proximal organs, it provides a more general characterization of immune proteins. Here, we expand our recent work on the serum proteome of wild vampire bats (Desmodus rotundus) to better understand CoV pathogenesis. Across 19 bats sampled in 2019 in northern Belize with available sera, we detected CoVs in oral or rectal swabs from four individuals (21.1% positivity). Phylogenetic analyses identified all vampire bat sequences as novel -CoVs most closely related to known human CoVs. Across 586 identified serum proteins, we found no strong differences in protein composition nor abundance between uninfected and infected bats. However, receiver operating characteristic curve analyses identified seven to 32 candidate biomarkers of CoV infection, including AHSG, C4A, F12, GPI, DSG2, GSTO1, and RNH1. Enrichment analyses using these protein classifiers identified downregulation of complement, regulation of proteolysis, immune effector processes, and humoral immunity in CoV-infected bats alongside upregulation of neutrophil immunity, overall granulocyte activation, myeloid cell responses, and glutathione processes. Such results denote a mostly cellular immune response of vampire bats to CoV infection and identify putative biomarkers that could provide new insights into CoV pathogenesis in wild and experimental populations. More broadly, applying a similar proteomic approach across diverse bat species and to distinct life history stages in target species could improve our understanding of the immune mechanisms by which wild bats tolerate viruses.

ecology↗

bioRxiv2020

Surveying the vampire bat (Desmodus rotundus) serum proteome: a resource for identifying immunological proteins and detecting pathogens

Bats are increasingly studied as model systems for longevity and as natural hosts for some virulent viruses. Yet our ability to characterize immune mechanisms of viral tolerance and to quantify infection dynamics in wild bats is often limited by small sample volumes and few species-specific reagents. Here, we demonstrate how proteomics can overcome these limitations by using data-independent acquisition-based shotgun proteomics to survey the serum proteome of 17 vampire bats (Desmodus rotundus) from Belize. Using just 2 L of sample and relatively short separations of undepleted serum digests, we identified 361 proteins across five orders of magnitude. Data are available via ProteomeXchange with identifier PXD022885. Levels of immunological proteins in vampire bat serum were then compared to human plasma via published databases. Of particular interest were anti-viral and anti-bacterial components, circulating 20S proteasome complex, and proteins involved in redox activity; whether any results are specific to vampire bats could be assessed by future pan-mammalian analyses. Lastly, we used known virus proteomes to identify Rh186 from Macacine herpesvirus 3 and ORF1a from Middle East respiratory syndrome-related coronavirus, indicating that mass spectrometry-based techniques show promise for pathogen detection. Overall, these results can be used to design targeted mass-spectrometry assays to quantify immunological markers and detect pathogens. More broadly, our findings also highlight the application of proteomics in advancing wildlife immunology and pathogen surveillance.

molecular biology↗

bioRxiv2019

The benefits of insect-swarm hunting in echolocating bats, and its influence on the evolution of bat echolocation signals

Predation on swarms of prey, especially using visual information, has drawn much interest in studies of collective movement. Surprisingly, in the field of biosonar this aspect of prey detection, which is probably very common, has received little to no attention. Here, we combine computer simulations and actual echo measurements to accurately estimate the echo intensity of insect swarms of different size and density. We show that swarm echo intensity increases with 3dB for every doubling of insect number, irrespective of swarm density. Thus swarms will be much easier to detect than single insects. Many of the insects bats eat are so small that they are only detectable by echolocation at very short distances. By focusing on detection of swarms of insects, a bat may increase its operating range and diversify its diet. Interestingly, interference between the sound waves reflected from a swarm of insects can sometimes result in echoes that are much much weaker than echoes from single insects. We show that bats can reduce this problem by increasing the bandwidth of their echolocation calls. Specifically, a bandwidth of 3-8 kHz would guarantee receiving loud echoes from any angle relative to the swarm. Indeed, many bat species, and specifically bats hunting in open spaces, where swarms are abundant, use echolocation signals with a bandwidth of several kHz. Our results might also explain how the first echolocating bats that probably had limited echolocation abilities, could detect insects through swarm hunting.

animal behavior and cognition↗