Research Information System
BULLETIN OF THE VETERINARY INSTITUTE IN PULAWY, vol.49, no.4, pp.419-422, 2005 (SCI-Expanded)
The milk-tube coagulase test (mTCT) was utilized for direct detection of coagulase-positive staphylococci in 287-quarter milk samples from cows with subclinical mastitis. The test was performed in sterile tubes by adding 0.5 ml of milk sample to 0.5 ml of reconstituted rabbit plasma. Coagulase activity was detected only in the samples from which Staphylococcus aureus had been isolated. When compared with culture results, sensitivity and specificity of the mTCT were 91% and 100%, respectively. The number of S. aureus colonies grown on Baird Parker agar from samples considered as positive for coagulase activity was 102 Colony forming units/ml and higher. Although the positive reactions in mTCT occurred as the number of S. aureus increased in the quarter milk samples, a statistically significant correlation was not observed between the number of S. aureus cultured from the milk sample and the reaction time to yield a positive mTCT. It is concluded that the assay appears to be useful only in detecting coagulase-positive S. aureus from subclinical mastitic milk.