More Like this

1. Campylobacter in aquatic and terrestrial mammals is driven by life traits: A systematic review and meta-analysis

   https://doi.org/10.3389/fevo.2023.1070519  

   Brooks, Michael R.; Medley, Sarah; Ponder, Monica; Alexander, Kathleen A. (February 2023, Frontiers in Ecology and Evolution)

   Introduction Campylobacter spp. infections are responsible for significant diarrheal disease burden across the globe, with prevalence thought to be increasing. Although wild avian species have been studied as reservoirs of Campylobacter spp., our understanding of the role of wild mammalian species in disease transmission and persistence is limited. Host factors influencing infection dynamics in wild mammals have been neglected, particularly life traits, and the role of these factors in zoonotic spillover risk is largely unknown. Methods Here, we conducted a systematic literature review, identifying mammalian species that had been tested for Campylobacter spp. infections (molecular and culture based). We used logistic regression to evaluate the relationship between the detection of Campylobacter spp. in feces and host life traits (urban association, trophic level, and sociality). Results Our analysis suggest that C. jejuni transmission is associated with urban living and trophic level. The probability of carriage was highest in urban-associated species ( p = 0.02793) and the most informative model included trophic level. In contrast, C. coli carriage appears to be strongly influenced by sociality ( p = 0.0113) with trophic level still being important. Detection of Campylobacter organisms at the genus level, however, was only associated with trophic level ( p = 0.0156), highlighting the importance of this trait in exposure dynamics across host and Campylobacter pathogen systems. Discussion While many challenges remain in the detection and characterization of Camploybacter spp., these results suggest that host life traits may have important influence on pathogen exposure and transmission dynamics, providing a useful starting point for more directed surveillance approaches. 

   more » « less
2. A trait‐based framework for predicting foodborne pathogen risk from wild birds

   https://doi.org/10.1002/eap.2523  

   Smith, Olivia M.; Olimpi, Elissa M.; Navarro‐Gonzalez, Nora; Cornell, Kevin A.; Frishkoff, Luke O.; Northfield, Tobin D.; Bowles, Timothy M.; Edworthy, Max; Eilers, Johnna; Fu, Zhen; et al (February 2022, Ecological Applications)

   Abstract Recent foodborne illness outbreaks have heightened pressures on growers to deter wildlife from farms, jeopardizing conservation efforts. However, it remains unclear which species, particularly birds, pose the greatest risk to food safety. Using >11,000 pathogen tests and 1565 bird surveys covering 139 bird species from across the western United States, we examined the importance of 11 traits in mediating wild bird risk to food safety. We tested whether traits associated with pathogen exposure (e.g., habitat associations, movement, and foraging strategy) and pace‐of‐life (clutch size and generation length) mediated foodborne pathogen prevalence and proclivities to enter farm fields and defecate on crops.Campylobacterspp. were the most prevalent enteric pathogen (8.0%), whileSalmonellaand Shiga‐toxin producingEscherichia coli(STEC) were rare (0.46% and 0.22% prevalence, respectively). We found that several traits related to pathogen exposure predicted pathogen prevalence. Specifically,Campylobacterand STEC‐associated virulence genes were more often detected in species associated with cattle feedlots and bird feeders, respectively.Campylobacterwas also more prevalent in species that consumed plants and had longer generation lengths. We found that species associated with feedlots were more likely to enter fields and defecate on crops. Our results indicated that canopy‐foraging insectivores were less likely to deposit foodborne pathogens on crops, suggesting growers may be able to promote pest‐eating birds and birds of conservation concern (e.g., via nest boxes) without necessarily compromising food safety. As such, promoting insectivorous birds may represent a win‐win‐win for bird conservation, crop production, and food safety. Collectively, our results suggest that separating crop production from livestock farming may be the best way to lower food safety risks from birds. More broadly, our trait‐based framework suggests a path forward for co‐managing wildlife conservation and food safety risks in farmlands by providing a strategy for holistically evaluating the food safety risks of wild animals, including under‐studied species. 

   more » « less
3. Host-specific microbiomes of blow flies: ecological drivers and implications for pathogen carriage

   https://doi.org/10.3389/fimmu.2025.1673934  

   Mikaelyan, Aram; Receveur, Joseph; Bernstein, Kadie; Babcock, Nicholas J; Pechal, Jennifer L; Welsh, Michael V; Waters, Kelly A; Yoskowitz, Katherine H; Benbow, M Eric (November 2025, Frontiers in Immunology)

   Blow flies (Lucilia sericataandPhormia regina) are necrophagous insects that interact with dense microbial reservoirs and are opportunistic vectors of human and animal pathogens. Despite constant exposure to diverse environmental microbes, it is unclear whether their bacterial communities are primarily acquired stochastically or shaped by host factors that could influence pathogen carriage. We conducted a systematic comparison of wildL. sericataandP. reginacollected from seven cities across an urban-rural gradient to determine whether microbiome composition is structured by host species identity or environmental variables. Using 16S rRNA gene sequencing of individual flies, we profiled bacterial communities and applied alpha- and beta-diversity analyses, PERMANOVA, and Random Forest classification to quantify species-level microbiome differentiation. Species identity was the strongest predictor of microbiome composition (PERMANOVA,p = 0.001), while location, land cover type, sampling month, and sex had no significant effects. Random Forest modeling identified multiple bacterial taxa that consistently distinguished the two species, includingIgnatzschineriaandDysgonomonas, which were enriched inP. regina, andVagococcusandEscherichia-Shigella, which were enriched inL. sericata. These taxa are of clinical relevance, withIgnatzschineriain particular increasingly reported from human myiasis and soft-tissue infections, sometimes exhibiting antimicrobial resistance. Our findings demonstrate that wild blow flies maintain species-specific microbiomes despite shared environments, suggesting that host identity strongly filters microbial communities. The presence of opportunistic pathogens within these structured microbiomes underscores the need to understand how blow fly–microbe associations contribute to pathogen persistence and dissemination. By revealing predictable, species-dependent microbiome patterns, this study highlights potential targets for microbiome-based strategies aimed at mitigating blow fly–associated disease risks. 

   more » « less
4. Reactivation of latent infections with migration shapes population-level disease dynamics

   https://doi.org/10.1098/rspb.2020.1829  

   Becker, Daniel J.; Ketterson, Ellen D.; Hall, Richard J. (September 2020, Proceedings of the Royal Society B: Biological Sciences)

   null (Ed.)

   Annual migration is common across animal taxa and can dramatically shape the spatial and temporal patterns of infectious disease. Although migration can decrease infection prevalence in some contexts, these energetically costly long-distance movements can also have immunosuppressive effects that may interact with transmission processes in complex ways. Here, we develop a mechanistic model for the reactivation of latent infections driven by physiological changes or energetic costs associated with migration (i.e. ‘migratory relapse’) and its effects on disease dynamics. We determine conditions under which migratory relapse can amplify or reduce infection prevalence across pathogen and host traits (e.g. infectious periods, virulence, overwinter survival, timing of relapse) and transmission phenologies. We show that relapse at either the start or end of migration can dramatically increase prevalence across the annual cycle and may be crucial for maintaining pathogens with low transmissibility and short infectious periods in migratory populations. Conversely, relapse at the start of migration can reduce the prevalence of highly virulent pathogens by amplifying culling of infected hosts during costly migration, especially for highly transmissible pathogens and those transmitted during migration or the breeding season. Our study provides a mechanistic foundation for understanding the spatio-temporal patterns of relapsing infections in migratory hosts, with implications for zoonotic surveillance and understanding how infection patterns will respond to shifts in migratory propensity associated with environmental change. Further, our work suggests incorporating within-host processes into population-level models of pathogen transmission may be crucial for reconciling the range of migration–infection relationships observed across migratory species. 

   more » « less
5. Functional traits explain waterbirds' host status, subtype richness, and community‐level infection risk for avian influenza

   https://doi.org/10.1111/ele.14294  

   Yin, Shenglai; Li, Ning; Xu, Wenjie; Becker, Daniel J; de_Boer, Willem F; Xu, Chi; Mundkur, Taej; Fountain‐Jones, Nicholas M; Li, Chunlin; Han, Guan‐zhu; et al (October 2023, Ecology Letters)

   Abstract Species functional traits can influence pathogen transmission processes, and consequently affect species' host status, pathogen diversity, and community‐level infection risk. We here investigated, for 143 European waterbird species, effects of functional traits on host status and pathogen diversity (subtype richness) for avian influenza virus at species level. We then explored the association between functional diversity and HPAI H5Nx occurrence at the community level for 2016/17 and 2021/22 epidemics in Europe. We found that both host status and subtype richness were shaped by several traits, such as diet guild and dispersal ability, and that the community‐weighted means of these traits were also correlated with community‐level risk of H5Nx occurrence. Moreover, functional divergence was negatively associated with H5Nx occurrence, indicating that functional diversity can reduce infection risk. Our findings highlight the value of integrating trait‐based ecology into the framework of diversity–disease relationship, and provide new insights for HPAI prediction and prevention. 

   more » « less