STUDIES OF THE DETECTION OF LISTERIA-MONOCYTOGENES BY CULTURE AND PCRIN CEREBROSPINAL-FLUID SAMPLES FROM RUMINANTS WITH LISTERIC ENCEPHALITIS

A total of 14 cerebrospinal fluid (CSF) samples from ruminants clinica lly suspected of suffering from listeric encephalitis were examined by polymerase chain reaction (PCR) for the detection of Listeria monocyt ogenes (L. m.). Of these samples, 11 were examined bacteriologically. Although the clinical diagnosis was confirmed in eight of 11 ruminants by histological and/or bacteriological examination of the brains, L. m. was only detected in one of the CSF samples using PCR, and in none by culture. The PCR-positive CSF sample was obtained from a sheep whic h had been treated with antibiotics prior to CSF sampling. From these findings, it was concluded that L. m. only occasionally gains access t o the meningoventricular system in the course of listeric encephalitis of ruminants and that a reliable aetiological in vivo diagnosis of li steric encephalitis generally cannot be based on the detection of L. m . in the CSF of affected ruminants.