Abstract

Mycoplasma haemocanis is prevalent in the endangered Darwin's fox (Lycalopex fulvipes) in its main stronghold, Chiloe Island (Chile). The origin of the infection, its dynamics, its presence in other fox populations and the potential consequences for fox health remain unexplored. For 8 years, hemoplasmal DNA was screened and characterized in blood from 82 foxes in Chiloe and two other fox populations and in 250 free-ranging dogs from Chiloe. The prevalence of M. haemocanis in foxes was constant during the study years, and coinfection with "Candidatus Mycoplasma haematoparvum" was confirmed in 30% of the foxes. Both hemoplasma species were detected in the two mainland fox populations and in Chiloe dogs. M. haemocanis was significantly more prevalent and more genetically diverse in foxes than in dogs. Two of the seven M. haemocanis haplotypes identified were shared between these species. Network analyses did not show genetic structure by species (foxes versus dogs), geographic (island versus mainland populations), or temporal (years of study) factors. The probability of infection with M. haemocanis increased with fox age but was not associated with sex, season, or degree of anthropization of individual fox habitats. Some foxes recaptured years apart were infected with the same haplotype in both events, and no hematological alterations were associated with hemoplasma infection, suggesting tolerance to the infection. Altogether, our results indicate that M. haemocanis is enzootic in the Darwin's fox and that intraspecific transmission is predominant. Nevertheless, such a prevalent pathogen in a threatened species represents a concern that must be considered in conservation actions.