Potential Facilitation Between a Commensal and a Pathogenic Microbe in a Wildlife Disease

AbstractWe assessed the potential for microbial interactions influencing a well-documented host –pathogen system.Mycoplasma agassizii is the known etiological agent of upper respiratory tract disease in Mojave desert tortoises (Gopherus agassizii), but disease in wild animals is extremely heterogeneous. For example, a much larger proportion of animals harborM. agassizii than those that develop disease. With the availability of a new quantitative PCR assay for a microbe that had previously been implicated in disease,Pasteurella testudinis, we tested 389 previously collected samples of nasal microbes from tortoise populations across the Mojave desert. We showed thatP. testudinis is a common commensal microbe. However, we did find that its presence was associated with higher levels ofM. agassizii among the tortoises positive for this pathogen. The best predictor ofP. testudinis prevalence in tortoise populations was average size of tortoises, suggesting that older populations have higher levels ofP. testudinis. The prevalence of co-infection in populations was associated with the prevalence of URTD, providing additional evidence for an indirect interaction between the two microbes and inflammatory disease. We showed that URTD, like many chronic, polymicrobial diseases involving mucosal surfaces, shows patterns of a polymicrobial etiology.
Source: EcoHealth - Category: Environmental Health Source Type: research