Animal fecal carriership and biotypes of Staphylococcus aureus.

Staphylococcus aureus was found in 44% of the rectal swabs from 377 pigs and in 12% of the swabs from 147 cows. Seventy-one percent of the isolates from pigs showed fibrinolytic activity and grew in colonies of the negative violet type on crystal violet agar. In this group, 47% of the isolates coagulated both human and bovine plasmas and were characterized as intermediate type, whereas 24% coagulated human plasma and were classified as human biotype A. Among the fibrinolysin-negative isolates, 15, 12, and 2% were identifiable as animal biotypes B, C, and E, respectively. The cow isolates were classified as intermediate type (51%), human biotype A (40%), and animal biotype C (9%).