Mycoplasma hyorhinis as a possible cause of fibrinopurulent meningitis in pigs? - a case series

Abstract

AbstractBackgroundMycoplasma hyorhinisis an invader of the upper respiratory tract in swine that is considered to have ubiquitous distribution. It is mainly known for causing polyserositis and polyarthritis in weaned piglets, even though the mechanisms of systemic spread are not fully understood.Mycoplasma hyorhinishas also been associated with other diseases in pigs such as pneumonia or otitis media, but so far has not been known to cause central nervous disorders. This case series reports the isolation ofMycoplasma hyorhinisfrom cerebrospinal fluid and/ or meningeal swabs from piglets originating from four different piglet producing farms in Austria.Case presentationOn farm 1, coughing, stiff movement and central nervous signs occurred in nursery piglets.Mycoplasma hyorhiniswas the only pathogen isolated from meningeal swabs from two piglets showing central nervous signs. Fibrinopurulent leptomeningitis was only observed in one piglet. Only one of two nursery piglets from farm 2 showed mild central nervous signs but no histologic lesions;Mycoplasma hyorhiniswas isolated from cerebrospinal fluid of the piglet with neurologic signs.Mycoplasma hyorhiniswas isolated from cerebrospinal fluid of all three investigated piglets from farm 3, all of which showed central nervous signs and purulent leptomeningitis. Further,Streptococcus suiswas isolated from the cerebrospinal fluid of one piglet. Fibrinopurulent leptomeningitis was detected in two piglets from farm 4 that had died overnight without showing any clinical signs andMycoplasma hyorhiniswas isolated from meningeal swabs from both piglets.ConclusionWhile causality has yet to be proven by experimental infection and in situ detection of the pathogen in histologic sections, the findings of this study and the absence of other pathogens suggestMycoplasma hyorhinisas a potential causative agent of meningitis in swine.