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

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.

Assessing cross-species transmission of hemoplasmas at the wild-domestic felid interface in Chile using genetic and landscape variables analysis

“…NtSTs from sampled guignas and domestic cats from Chile were positioned within clades shared by domestic cats and wild felid and carnivore host species from around the world, suggesting a worldwide distribution of hemoplasmas and no phylogeographic differentiation among continents within each species-specific clade. Worldwide interspecific transmission of these pathogens between wild and domestic carnivore host species has been described by other authors 23,25,27 .…”

“…These results suggest that cross-species transmission events between both hosts may occur for some hemoplasma species but are most-likely relatively rare. As other authors have suggested 23,27 , domestic cats may be the source of the global distribution of multiple strains of hemoplasmas in wild felids, and these may persist through onward transmission following spillover. Overall, we found evidence for higher levels of intraspecific, versus interspecific, transmission in both guignas and domestic cats.…”

“…euptilurus ), European wildcat ( Felis silvestris silvestris ), several Brazilian felid species, Iriomote cat ( Prionailurus bengalensis iriomotensis ) and African lion ( Panthera leo ) 22–28 . Hemoplasma sequences from wildlife species often share close identity to those found in domestic cats 23,25,27 . Based on genetic evidence, domestic cats may be the source of the global distribution of multiple strains of hemoplasmas in wild felids.…”

“…Based on genetic evidence, domestic cats may be the source of the global distribution of multiple strains of hemoplasmas in wild felids. Persistent onward transmission following spillover may be possible due to high prevalence among some species of wild felids 23,27 .…”

Molecular screening indicates high prevalence and mixed infections of Hepatozoon parasites in wild felines from South Africa

“…Predation as a pathway of pathogen spillover from domestic cats to wild felids has been documented in various cases (e.g. Kellner et al 2018 ), and would fit within the emerging paradigm of trophic pathways leading to infections from Hepatozoon species (e.g. Maia et al 2014 ).…”