Transmission pathways and spillover of an erythrocytic bacterial pathogen from domestic cats to wild felids.

Annie Kellner,Clifton D Mckee,Michael F Antolin,Kevin R Crooks,Michael Lappin,Sue Vandewoude,Scott Carver,Valeria Scorza

doi:10.1002/ece3.4451

Annie Kellner, Clifton D Mckee + Show 6 more

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https://doi.org/10.1002/ece3.4451

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Abstract

Many pathogens infect multiple hosts, and spillover from domestic to wild species poses a significant risk of spread of diseases that threaten wildlife and humans. Documentation of cross‐species transmission, and unraveling the mechanisms that drive it, remains a challenge. Focusing on co‐occurring domestic and wild felids, we evaluate possible transmission mechanisms and evidence of spillover of “Candidatus Mycoplasma haemominutum” (CMhm), an erythrocytic bacterial parasite of cats. We examine transmission and possibility of spillover by analyzing CMhm prevalence, modeling possible transmission pathways, deducing genotypes of CMhm pathogens infecting felid hosts based on sequences of the bacterial 16S rRNA gene, and conducting phylogenetic analyses with ancestral state reconstruction to identify likely cross‐species transmission events. Model selection analyses suggest both indirect (i.e., spread via vectors) and direct (i.e., via interspecific predation) pathways may play a role in CMhm transmission. Phylogenetic analyses indicate that transmission of CMhm appears to predominate within host species, with occasional spillover, at unknown frequency, between species. These analyses are consistent with transmission by predation of smaller cats by larger species, with subsequent within‐species persistence after spillover. Our results implicate domestic cats as a source of global dispersal and spillover to wild felids via predation. We contribute to the emerging documentation of predation as a common means of pathogen spillover from domestic to wild cats, including pathogens of global conservation significance. These findings suggest risks for top predators as bioaccumulators of pathogens from subordinate species.

Highlights

It is widely acknowledged that the majority of known pathogens infect multiple host species; for example, 90% of pathogens infecting domestic dogs and cats infect other mammalian hosts (Cleaveland, Laurenson, & Taylor, 2001)
To evaluate factors relating to intra- and interspecific Candidatus Mycoplasma haemominutum” (CMhm) transmission among felids, we developed algebraic expressions describing possible transmission pathways, categorized by host species and incorporating species- and site-specific parameters derived from the literature and/or determined by the authors (Tables 1 and 2)
Wild felids experience multiple stressors, including habitat degradation (Schipper et al, 2008; Wilcove, Rothstein, Dubow, Phillips, & Losos, 1998), range restriction and fragmentation (Crooks, 2002; Crooks, Burdett, Theobald, Rondinini, & Boitani, 2011; Gaona, Ferreras, & Delibes, 1998), poaching (Kenney, Smith, Starfield, & McDougal, 1995), persecution (Inskip & Zimmermann, 2009), prey depletion (Karanth & Stith, 1999), climate change (Parmesan & Yohe, 2003), and restricted population size that may result in inbreeding depression (O’Brien & Yuhki, 1999; Roelke et al, 1993)

Summary

| INTRODUCTION

It is widely acknowledged that the majority of known pathogens infect multiple host species; for example, 90% of pathogens infecting domestic dogs and cats infect other mammalian hosts (Cleaveland, Laurenson, & Taylor, 2001). Important predictors of pathogen spillover include phylogenetic relatedness, geographic overlap, and interspecific interactions among host species (Olival et al, 2017). Compelling genetic evidence suggests domestic cats may be the source of the global distribution of multiple strains of haemoplasmas in wild felids, and high prevalence among some wild felids (Willi, Filoni, et al, 2007) may suggest persistent onward transmission following spillover. This study evaluates spillover of CMhm in domestic and wild felids, including assessment of transmission mechanisms and evidence of onward transmission. We predict patterns of cross-species transmission of CMhm will support predation as a mechanism for pathogen spillover from domestic to wild cats and demonstrate onward transmission in wild felid species following spillover

| METHODS

Intraspecific pathways

| DISCUSSION

Findings

| Conclusion

CONFLICT OF INTEREST