Comparison of methods for routine separation of coagulase-negative staphylococci from micrococci isolated from sheep

Staphylococci isolated from healthy goats

A study was made of the staphylococcal population on the skin and on the nasal mucosa and in the milk of 133 healthy goats. Of a total of 346 strains isolated and characterised as belonging to the genus Staphylococcus, 74 (21.4%) were coagulase-positive (68 S. aureus and 6 S. hyicus), and 272 (78.6%) coagulase-negative. The novobiocin-sensitive species S. haemolyticus (23.5%), S. warneri (16.5%), S. epidermidis (11.8%), S. chromogenes (8.5%), S. caprae (6.6%) and S. hyicus (2.6%), and the novobiocin-resistant species S. xylosus (8.5%), S. sciuri (7.4%), S. saprophyticus (4.8%), S. cohnii (2.2%), S. lentus (1.1%), S. equorum (1.1%) and S. kloosii (1.1%) were identified. Twelve (4.4%) of coagulase-negative strains remained unidentified. Strains isolated in the skin of the udder and teats of the 133 goats were mainly novobiocin-sensitive coagulase-negative staphylococci, the most prevalent species being S. haemolyticus, S. warneri and S. epidermidis. Staphylococci indicative of subclinical infection were determined in the milk of 47 (35.3%) of the 133 goats sampled.