Mycoplasma alkalescens, M. bovigenitalium, M. bovirhinis and M. bovis were
directly detected from milk specimens by a poly merase chain reaction (PCR)
when milk specimens were centrifuged and treated with mycoplasmal lysis bu
ffer. The sensitivity of this PCR method was 110 to 1,400 colony forming un
its (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 tech
niques. M. bovirhinis was detected in more than 70% of mastitic milk specim
ens when mycoplasmas were detected in milk specimens from 30 cows with mast
itis by this PCR method.