Seasonal variation and characterization of Micrococcaceae present in ewes' raw milk

Abstract

SUMMARYSamples (120) of ewes' raw milk collected over a 12-month period on arrival at the dairy and freshly drawn ewes’ milk samples (30) collected at the farm were analysed for total viable counts and staphylococci. Total viable counts reached on the average 54 × 106/ml in dairy samples and 6·0 × 105/ml in farm samples, whereas mean levels of staphylococci were 5·9 × 104/ml and 3·3 × 103/ml, respectively. A high proportion (62%) of coagulase-positive isolates from Baird-Parker agar plates was detected in spring months.Staphylococcus aureus(42%),Staph. haemolyticus(23%) andStaph. epidermidis(10%) were the predominant species in 210 characterized isolates of staphylococci from ewes' raw milk. Seven coagulase-positive, maltose-negative staphylococci could not be identified with any of the recognizedStaphylococcusspecies. EighteenMicrococcusstrains were identified asM. varians, whereas 111Micrococcusstrains of uncertain taxonomic status were separated into three groups, according to their physiological characters.