Detection of mycoplasma in mastitic milk by PCR analysis and culture method.

Mycoplasma alkalescens, M. bovigenitalium, M. bovirhinis and M. bovis were directly detected from milk specimens by a polymerase chain reaction (PCR) when milk specimens were centrifuged and treated with mycoplasmal lysis buffer. The sensitivity of this PCR method was 110 to 1,400 colony forming units (CFU). This method was useful for the detection of mycoplasmas in milk specimens from cows at an early stage of mycoplasmal mastitis since a small amount of mycoplasma could be detect in milk without culture. The results were available within 12 hr, which is faster than conventional culture techniques. M. bovirhinis was detected in more than 70% of mastitic milk specimens when mycoplasmas were detected in milk specimens from 30 cows with mastitis by this PCR method.