Molecular epidemiology and population genetic diversity of caprine hemoplasmas in Southeastern Türkiye: First detection of Candidatus Mycoplasma haemovis

Abstract

Background Hemotropic Mycoplasma species are significant yet insufficiently investigated pathogens of small ruminants, and their molecular diversity and population structure remain poorly characterized in many endemic regions, including T & uuml;rkiye. This study primarily aimed to determine the molecular prevalence of caprine hemotropic Mycoplasma species in Southeastern T & uuml;rkiye and to characterize the detected isolates using phylogenetic, haplotype, and population genetic approaches. Results A total of 448 goat blood samples were screened by nested PCR targeting the 16S rRNA gene, and hemotropic Mycoplasma DNA was detected in 12.5% (56/448) of the samples. Although no significant differences were observed among provinces, breed and age were identified as significant risk factors, with higher infection rates in Hair goats and animals older than one year. Sequencing of 26 PCR-positive samples identified Mycoplasma (M.) ovis (21/26, 80.8%) as the predominant species and Candidatus (Ca.) M. haemovis (5/26, 19.2%). Phylogenetic analyses showed that the Turkish isolates clustered closely with previously submitted GenBank sequences from Asia, Europe, Africa, and North America, reflecting the highly conserved nature of the 16S rRNA gene. In contrast, haplotype and population genetic analyses revealed substantial intraspecific diversity. Analysis of an expanded global dataset, combining Turkish sequences with GenBank reference isolates, identified 27 haplotypes for M. ovis (n = 97) and 7 haplotypes for Ca. M. haemovis (n = 29). Minimum-spanning networks demonstrated widely distributed ancestral haplotypes shared across continents, together with multiple singleton haplotypes likely representing locally maintained variants. Neutrality and Fixation Index analyses further indicated microevolutionary diversification and geographically influenced population structuring. Conclusion The detection of both species in clinically healthy goats suggests subclinical circulation and a potential reservoir role in sustaining transmission. Overall, this study expands the global genetic framework of caprine hemoplasmas and provides the first molecular evidence of Ca. M. haemovis in T & uuml;rkiye, as well as the first report of hemotropic Mycoplasma infection in goats from Southeastern T & uuml;rkiye.