STAPHYLOCOCCI IN BREAST-MILK FROM WOMEN WITH AND WITHOUT MASTITIS

Breast milk from nineteen women, ten with and nine without mastitis, w as examined for the presence of staphylococci. Staphylococci was prese nt in all breast milk samples, 10(2) to 10(4) cfu/ml. Plating on Baird -Parker agar plates revealed a variety of staphylococci, with typical Baird-Parker colonies present in all samples except one. Staphylococcu s aureus (coagulase and thermonuclease-positive and anaerobic fermenta tion of mannitol) was present in 13 samples. Several typical and atypi cal colonies lacked one or two typical characteristics of S. aureus, s uch as coagulase or thermonuclease production and anaerobic mannitol f ermentation. Some colonies lacked all three characteristics, but only one sample contained only colonies that lacked all three characteristi cs. Only eight of the nineteen samples contained staphylococci that pr oduced enterotoxin detectable by gel diffusion. Some samples contained staphylococci that produced low amounts of enterotoxin or the toxic s hock syndrome toxin, detectable by the reversed passive latex agglutin ation method.