Wildlife-Livestock Host Community Maintains Simultaneous Epidemiologic Cycles of Mycoplasma conjunctivae in a Mountain Ecosystem

Infectious keratoconjunctivitis is an eye disease caused by Mycoplasma conjunctivae that affects domestic and wild caprines, including Iberian ibex (Capra pyrenaica) and domestic sheep and goats. This study assessed M. conjunctivae in the host community of the Natural Space of Sierra Nevada (NSSN), a mountain habitat in southern Spain. Mycoplasma conjunctivae strains circulated endemically without causing clinical signs in Iberian ibex and livestock, either shared or maintained independently by each host species. In Iberian ibex, endemic infection was maintained by naïve subadults, with an epizootic outbreak when the infection spread to adults. Goat was at least as important as sheep in maintaining M. conjunctivae. The results suggest that the epidemiological role of wild ungulates should be considered in mountain ecosystems, as their mobility may contribute to the spread of IKC and other shared pathogens among spatially segregated livestock flocks. Infectious keratoconjunctivitis (IKC) is an eye disease caused by Mycoplasma conjunctivae that affects domestic and wild caprines, including Iberian ibex (Capra pyrenaica), a medium-sized mountain ungulate. However, its role in IKC dynamics in multi-host communities has been poorly studied. This study assessed M. conjunctivae in Iberian ibex and seasonally sympatric domestic small ruminants in the Natural Space of Sierra Nevada (NSSN), a mountain habitat in southern Spain. From 2015 to 2017, eye swabs were collected from 147 ibexes (46 subadults, 101 adults) and 169 adult domestic small ruminants (101 sheep, 68 goats). Mycoplasma conjunctivae was investigated through real-time qPCR and statistically assessed according to species, sex, age category, year, period, and area. The lppS gene of M. conjunctivae was sequenced and phylogenetically analysed. Mycoplasma conjunctivae was endemic and asymptomatic in the host community of the NSSN. Three genetic clusters were shared by ibex and livestock, and one was identified only in sheep, although each host species could maintain the infection independently. Naïve subadults maintained endemic infection in Iberian ibex, with an epizootic outbreak in 2017 when the infection spread to adults. Wild ungulates are epidemiologically key in maintaining and spreading IKC and other shared diseases among spatially segregated livestock flocks.