Identification of Mycoplasma species and related organisms from ruminants in England and Wales during 2005–2019

BACKGROUND: Mycoplasma species have been associated with economically important diseases affecting ruminants worldwide and include contagious bovine pleuropneumonia (CBPP), contagious caprine pleuropneumonia (CCPP) and contagious agalactia, listed by the World Organisation for Animal Health (OIE). The Mycoplasma Team at the Animal and Plant Health Agency provides an identification service for Mycoplasma and Ureaplasma species of veterinary importance to the United Kingdom (UK), supporting the detection of new and emerging pathogens, as well as contributing to the surveillance of endemic, and the OIE listed diseases exotic to the UK. Mycoplasma and other Mollicutes species were identified from diagnostic samples from farmed ruminants in England and Wales using a combination of culture and 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis, submitted between 2005 and 2019. RESULTS: A total of 5578 mollicutes identifications, which include mycoplasmas and the related acholeoplasmas and ureaplasmas, were made from farmed ruminant animals during the study period. Throughout the study period, the pathogen Mycoplasma bovis was consistently the most frequently identified species, accounting for 1411 (32%) of 4447 molecular identifications in cattle, primarily detected in the lungs of pneumonic calves, followed by joints and milk of cattle showing signs of arthritis and mastitis, respectively. M. bovirhinis, M. alkalescens, M. dispar, M. arginini and Ureaplasma diversum, were also common. Mixed species, principally M. bovis with M. alkalescens, M. arginini or M. bovirhinis were also prevalent, particularly from respiratory samples. The non-cultivable blood-borne haemoplasmas Candidatus ‘Mycoplasma haemobos’ and Mycoplasma wenyonii were identified from cattle, with the latter species most often associated with milk-drop. M. ovipneumoniae was the predominant species identified from sheep and goats experiencing respiratory disease, while M. conjunctivae preponderated in ocular samples. The UK remains free of the ruminant mycoplasmas listed by OIE. CONCLUSIONS: The continued high prevalence of M. bovis identifications confirms its ongoing dominance and importance as a significant pathogen of cattle in England and Wales, particularly in association with respiratory disease. M. ovipneumoniae has seen a general increase in prevalence in recent years, notably in coughing lambs and should therefore be considered as a primary differential diagnosis of respiratory disease in small ruminants.