MYCOPLASMAS INFECTION OF WILD SMALL RUMINANTS
ROBIN A.J. NICHOLAS
Mycoplasma Group, Animal Health and Veterinary Laboratories Agency (Weybridge), New Haw, Weybridge, UK
Small ruminants are affected by several important mycoplasma diseases.
Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. caprip- neumoniae, has not been seen in Europe for nearly 100 years but was detected in Thrace in 2005 threatening the borders of Greece and Bulgaria(2). CCPP has now been shown to be capable of infecting wildlife, so surveillance should be extended to susceptible species in which acute respiratory disease accompanied by high mortality is reported.Of most relevance to Europe is the World Organisation for Animal Health (OIE)-listed disease contagious agalactia. This disease can be caused by four different mycoplasmas, which are, in descending order of importance: M. agalactiae, M. mycoides subsp. capri (formerly M. mycoides subsp. mycoides LC), M. capricolum subsp. capricolum and M. putrefaciens. During a survey of over 300 free-ranging Spanish Ibex (Capra pyrenaica hispanica), the majority of which had been hunted or captured live in the mountains of Andalucia, single or mixed cultures of mycoplasmas were detected in the ears and eyes of 18% of animals(3). The most common species was M. agalactiae, which was detected in nearly half of the positive cases, frequently with the commensal M. arginini. The respiratory pathogen, M. mycoides subsp. capri, was detected less frequently. Interestingly, Mconjunctivae was not detected in any ibex, although the authors pointed out that no clinical signs or lesions were seen in the population studied; it is also possible that the techniques used may have not detected the highly fastidious M. conjunctivae. The high prevalence of M. aga- lactiae in this wild population is almost certainly a result of the interaction with domestic small ruminant flocks in which contagious agalactia is endemic and will seriously compromise any attempts to eradicate the disease from the region.
I n other parts of the European uplands, M. mycoides subsp. capri has been isolated from the eyes of adult male Alpine ibex ( Capra ibex) originating from the Valle d’Aosta Region in Northern Italy. The animals suffered bilateral ocular discharge with diffuse inflammation, severe corneal involvement of the left eye and mild corneal opacity of the right eye. Histological examination revealed a keratoconjunctivitis characterized by lymphocytic and plasmacellu- lar infiltration1-4). Highly sensitive molecular tests confirmed the absence of M conjunctivae from these samples.