Of Microbes and Mange: Consistent changes in the skin microbiome of three canid species infected with sarcoptic mange

ABSTRACTSarcoptic mange is a highly contagious skin disease caused by the ectoparasitic mite, Sarcoptes scabiei. Although it afflicts over 100 mammal species worldwide, sarcoptic mange remains a disease obscured by variability at the individual, population, and species levels. Amid this variability, it is critical to identify consistent drivers of morbidity, particularly at the skin barrier. We characterized the skin microbiome of three species of North American canids: coyotes (Canis latrans), red foxes (Vulpes vulpes), and gray foxes (Urocyon cinereoargenteus). Comparing mange-infected and uninfected individuals, we found remarkably consistent signatures of microbial dysbiosis associated with mange infection. Across genera, mange-infected canids exhibited reduced microbial diversity, altered community composition, and increased abundance of opportunistic pathogens. The primary bacteria comprising these secondary infections were Staphylococcus pseudintermedius, previously associated with canid ear and skin infections, and Corynebacterium spp, previously found among the gut flora of S. scabiei mites and hematophagous arthropods. Considered together, this evidence suggests that mange infection consistently alters the canid skin microbiome and facilitates secondary bacterial infection. These results provide valuable insights into the pathogenesis of mange at the skin barrier of North American canids and can inspire novel treatment strategies. By further adopting a “One Health” framework that considers mites, microbes, and the potential for interspecies transmission, we can better elucidate the patterns and processes underlying this ubiquitous and enigmatic disease.