[Enterotoxic staphylococci in the milk of cows and sheep with mastitis]

Studied were the occurrence and the biochemical and phage characteristic of enterotoxic staphylococci in cow and sheep milk from animals with mastitis. Milk samples taken from 150 cows and 120 ewes were investigated for the presence of Staphylococcus aureus. This organism was found in 88 per cent of the cow milk samples and in 89.2 per cent of the sheep milk ones. The count of bacteria was within the 10(1) to 10(5)/cm3 range. A total of 239 strains of Staphylococcus aureus were isolated from both kinds of milk. They were tested for enterotoxigenicity after Ouchterlony. It was shown that 28.8 per cent of those isolated from mastitis cow milk and 7.5 per cent of those isolated from mastitis ewe milk produced an enterotoxin. Those from the cow milk samples produced enterotoxin A in 65.8 per cent of the cases, enterotoxin B in 13.1 per cent, and enterotoxin C in 5.3 per cent. Simultaneous production of A and D toxin was found in 15.8 per cent of the strains. Those isolated from the ewe milk samples produced enterotoxin C in 75 per cent of the cases, and enterotoxins A and C in 25 per cent. The enterotoxigenic Staphylococcus strains were distinguished by high biochemical and enzyme activity, however, none of the methods tested proved specific for enterotoxic Staphylococci only. The enterotoxic staphylococci of cow milk were typed by II and IV phages and by a mixed group of phages (II/M, III/M, IV/M, II/IV). Most spread were the 116 and 116/118 phage types.(ABSTRACT TRUNCATED AT 250 WORDS)