Mycoplasma hyopharyngis isolated from the joint of a weaner: A case report.

Background: Mycoplasma hyopharyngis is a commensal bacterium in the upper respiratory tract of swine. As it is recognized to be apathogenic, examinations regarding this species are scarce, compared to other swine mycoplasmas. However, in a few cases, M. hyopharyngis was detected in lesions of different organs. This report presents a case study in which M. hyopharyngis (along with other bacteria) was isolated from the joint of a pig showing lameness.

Case presentation: A Hungarian farm was repopulated with 250 gilts and 1,700 finishers after undergoing a complete depopulation and disinfection. Two days later, cases of diarrhoea and septicaemia caused by Salmonella enterica serovar typhimurium were seen in the finishers. At the same time, following the first farrowing, swollen joints were observed in 21-25 days old piglets. Joint samples were collected, and isolation of Mycoplasma sp. and other bacteria was attempted. Analysis of the joint samples revealed the presence of Staphylococcus haemolyticus, Staphylococcus hyicus, Aerococcus viridans, Trueperella pyogenes, Streptococcus agalactiae and M. hyopharyngis.

Conclusions: This is the second isolation of M. hyopharyngis from joints, which highlights the necessity of a better understanding the biology of this often-overlooked species, and its role in the progress of arthritis or other lesions.