Phage typing of Staphylococcus aureus associated with subclinical bovine mastitis

Abstract

SummarySix hundred and seventeen isolates of Staphylococcus aureus from sub-clinical mastitis cases in 63 dairy herds in Northern Ireland were typed using a set of 25 phages. Ninety-four per cent of the isolates were typable, with nine phages, predominantly from groups I and III, being responsible for almost all of the lysis. Although 68 phage patterns were found, six of them typed 47·2 % of the isolates. One strain accounted for 14·7% of the isolates, but the largest number of strains (44) was restricted to individual farms. The epidemiological significance of these findings for on-farm mastitis control is discussed.