Ecological Studies on Coagulase-negative Staphylococci in and around Bovine Udder

The purpose of this work is to investigate the distribution of coagulase-negative staphylococci isolated from milk and skin samples of 35 cows. These strains were identified mainly according to the sheme described by Kloos and Schleifer. The results are summarized as follows: 1) A total of 243 strains of coagulase-negative staphylococci were isolated. These were classified into 9 species according to Kloos and Schleifer's method. From the abnormal milk samples in which coagulase-negative staphylococci were predominant, 4 species (35 strains) were isolated and 66 percent of the strains were S. epidermidis. From the other abnormal milk samples and the normal samples, 6 and 8 species were isolated, respectively. In both cases, S. epidermidis occupies one-third of the strains. Nine species were detected in the skin samples. One-third of the strains were S. haemolyticus and only a few strains were S. epidermidis. It was recognized that the distribution pattern in terms of species in milk samples differed from that in skin samples. 2) From these results, it seems likely that S. epidermidis play more significant role than the other species as a cause of abnormal milk. 3) A fewer number of species than the Kloos and Schleifer's method was obtained by the other methods for classification of staphylococci conducted at the same time; i.e., the biotype method by Baird-Paker, the modified method by Pelzer et al. and phage-typing method