Long-term dynamics of Mycoplasma conjunctivae at the wildlife-livestock interface in the Pyrenees

Abstract

Functional roles of domestic and wild host populations in infectious keratoconjunctivitis (IKC) epidemiology have been extensively discussed claiming a domestic reservoir for the more susceptible wild hosts, however, based on limited data. With the aim to better assess IKC epidemiology in complex host-pathogen alpine systems, the long-term infectious dynamics and molecular epidemiology of Mycoplasma conjunctivae was investigated in all host populations from six study areas in the Pyrenees and one in the Cantabrian Mountains (Northern Spain). Detection of M. conjunctivae was performed by qPCR on 3600 eye swabs collected during seven years from hunted wild ungulates and sympatric domestic sheep (n = 1800 animals), and cluster analyses of the strains were performed including previous reported local strains. Mycoplasma conjunctivae was consistently detected in three Pyrenean chamois (Rupicapra p. pyrenaica) populations, as well as in sheep flocks (17.0% of sheep) and occasionally in mouflon (Ovis aries musimon) from the Pyrenees (22.2% in one year/area); statistically associated with ocular clinical signs only in chamois. Chamois populations showed different infection dynamics with low but steady prevalence (4.9%) and significant yearly fluctuations (0.0%– 40.0%). Persistence of specific M. conjunctivae strain clusters in wild host populations is demonstrated for six and nine years. Cross-species transmission between chamois and sheep and chamois and mouflon were also sporadically evidenced. Overall, independent M. conjunctivae sylvatic and domestic cycles occurred at the wildlife-livestock interface in the alpine ecosystems from the Pyrenees with sheep and chamois as the key host species for each cycle, and mouflon as a spill-over host. Host population characteristics and M. conjunctivae strains resulted in different epidemiological scenarios in chamois, ranging from the fading out of the mycoplasma to the epidemic and endemic long-term persistence. These findings highlight the capacity of M. conjunctivae to establish diverse interactions and persist in host populations, also with different transmission conditions.

Sanitary Emergencies at the Wild/Domestic Caprines Interface in Europe

“…Most recently, persistence of M. conjunctivae strains in wild Caprinae in the Alps was robustly suggested by merging field observations and molecular analyses [28]. Moreover, independent M. conjunctivae sylvatic and domestic cycles were shown to coexist in the Pyrenees, with sheep and chamois ( R. pyrenaica ) as key host species [46]. It follows that if the cross-transmission of the agent between domestic and wild Caprinae is a relatively rare event [46], little or no benefit to unaffected wildlife herds can be expected from implementing measures such as the enhanced clinical surveillance of transhumant flocks or the isolation and treatment of clinically affected individuals prior to being moved uphill.…”

Molecular Detection and Identification of Chlamydiaceae in the Eyes of Wild and Domestic Ruminant Hosts from Northern Spain

“…Among the sampled ruminants, 63 animals had ocular clinical signs that ranged from mild ocular discharge to corneal perforation [ 20 ]. However, none of the Chlamydiaceae -positive ruminants were also positive for M. conjunctivae or had signs of ocular disease.…”

Spatiotemporal monitoring of selected pathogens in Iberian ibex ( Capra pyrenaica )

“…In P2, however, seroprevalence was low (1.1%) and similar to the 0.9% found in captive ibexes sampled in area 1 by Astorga Márquez et al (2014) between 2008 and 2009. Temporal variations may be related to M. agalactiae exposure at a particular point in time and the short‐lived IgG response in this species (Fernández‐Aguilar et al., 2017). Environmental changes or interactions with other reservoirs have been shown to be factors involved in spatiotemporal fluctuations of Mycoplasma spp.…”

“…Environmental changes or interactions with other reservoirs have been shown to be factors involved in spatiotemporal fluctuations of Mycoplasma spp. in wild Caprinae species (Fernández‐Aguilar et al., 2017).…”