CASE REPORT: AN INFECTIOUS KERATOCONJUNCTIVITIS OUTBREAK CAUSED BYMYCOPLASMA CONJUNCTIVAEIN A DAIRY GOAT FARM

Although infectious keratoconjunctivitis (IKC) has occurred worldwide, no report has mentioned an IKC case in a dairy goat farm in an indoor management system. Moreover, few clinicians follow the IKC syndrome development throughout the clinical course. The aim of the present study was to report an IKC outbreak caused by Mycoplasma conjunctivae (MC) in indoor dairy goat barns. Severe IKC breakouts had been found consecutively in two nearby goat barns in a cooperated farm. To confirm the etiology, samples were collected from the infected goats to perform hematological, biochemical, bacterial examinations and polymerase chain reactions. A treatment of 4% boric acid and 0.5% povidone iodine solution, and a preventive spray of quaternary ammonium at 09:00 AM and 1% Virkon-S[Formula: see text] solution at 17:00 PM were useful to control disease in the adult goat barn, wherein 60% (31/55) animals showed different IKC signs. A total of 12 (14%) goat kids, died, without treatment, showed variable degrees of bronchointerstitial pneumonia. In all cases, only the DNA fragments of MC, but not other pathogens implicated in IKC, were detected. Goats began to recover after 30 days in an episodic duration of 81 days resulting in an estimated 240,000 New Taiwan dollars loss. In conclusion, this is the first goat MC report in an indoor system. The treatment and the preventive measure described in the current study were useful to control the event.

Infectious keratoconjunctivitis and occurrence ofMycoplasma conjunctivaeand Chlamydiaceae in small domestic ruminants from Central Karakoram, Pakistan

Infectious keratoconjunctivitis (IKC) is a contagious eye disease primarily caused byMycoplasma conjunctivaein domestic and wild Caprinae.Chlamydophilaspecies have also been detected in ruminants with IKC. The objectives of this study are to investigate the ocular infection ofM. conjunctivaeand Chlamydiaceae and assess its interaction in relation to IKC in sheep and goats from remote communities around the Central Karakoram National Park in Pakistan, performing a combination of cross-sectional and case–control study design. Mostly asymptomatic and endemic infections ofM. conjunctivaeand Chlamydiaceae were found in sheep (19.3 per cent and 4.5 per cent, respectively) and goats (9.5 per cent and 1.9 per cent, respectively) from all communities, assessed by qPCR. Prevalence significantly differed between species only forM. conjunctivae(P=0.0184), which was also more prevalent in younger sheep (P<0.01).Chlamydophila pecorumwas identified by sequencing and was related with IKC only when coinfection withM. conjunctivaeoccurred, which suggest a synergic interaction. Cluster analysis ofM. conjunctivaestrains revealed higher diversity of strains than expected, evidenced interspecific transmission and suggested a higher local livestock trade than previously assumed. These results highlight the widespread occurrence ofM conjunctivaein sheep worldwide and its implications for wildlife should be assessed from a conservation perspective.

Postepizootic Persistence of Asymptomatic Mycoplasma conjunctivae Infection in Iberian Ibex

ABSTRACT The susceptibility of the Iberian ibex (Capra pyrenaica) to Mycoplasma conjunctivae ocular infection and the changes in their interaction over time were studied in terms of clinical outcome, molecular detection, and IgG immune response in a captive population that underwent a severe infectious keratoconjunctivitis (IKC) outbreak. Mycoplasma conjunctivae was detected in the Iberian ibex, coinciding with the IKC outbreak. Its prevalence had a decreasing trend in 2013 that was consistent with the clinical resolution (August, 35.4%; September, 8.7%; November, 4.3%). Infections without clinical outcome were, however, still detected in the last handling in November. Sequencing and cluster analyses of the M. conjunctivae strains found 1 year later in the ibex population confirmed the persistence of the same strain lineage that caused the IKC outbreak but with a high prevalence (75.3%) of mostly asymptomatic infections and with lower DNA load of M. conjunctivae in the eyes (mean quantitative PCR [qPCR] cycle threshold [CT ], 36.1 versus 20.3 in severe IKC). Significant age-related differences of M. conjunctivae prevalence were observed only under IKC epizootic conditions. No substantial effect of systemic IgG on M. conjunctivae DNA in the eye was evidenced with a linear mixed-models selection, which indicated that systemic IgG does not necessarily drive the resolution of M. conjunctivae infection and does not explain the epidemiological changes observed. The results show how both epidemiological scenarios, i.e., severe IKC outbreak and mostly asymptomatic infections, can consecutively occur by entailing mycoplasma persistence. IMPORTANCE Mycoplasma infections are reported in a wide range of epidemiological scenarios that involve severe disease to asymptomatic infections. This study allows a better understanding of the transition between two different Mycoplasma conjunctivae epidemiological scenarios described in wild host populations and highlights the ability of M. conjunctivae to adapt, persist, and establish diverse interactions with its hosts. The proportion of asymptomatic and clinical M. conjunctivae infections in a host population may not be regarded only in response to intrinsic host species traits (i.e., susceptibility) but also to a specific host-pathogen interaction, which in turn influences the infection dynamics. Both epidemic infectious keratoconjunctivitis and a high prevalence of asymptomatic M. conjunctivae infections may occur in the same host population, depending on the circulation of M. conjunctivae, its maintenance, and the progression of the host-pathogen interactions.