A quantitative study of enterotoxin production by sheep milk staphylococci.
Of 124 staphylococcal strains isolated from sheep milk, 78 produced enterotoxin A, B, C, or D when evaluated by an enzyme-linked immunosorbent assay. Enterotoxins A and D, elaborated by 44 and 43 strains, respectively, showed the highest incidence. Enterotoxin production by coagulase-negative strains (one Staphylococcus cohnii, three S. epidermidis, five S. haemolyticus, and four S. xylosus) was detected. Linear and logarithmic-logarithmic regressions of optical density on enterotoxin concentration yielded the best-fitting equations for enterotoxin quantitation. A significantly higher incidence of enterotoxin producers and significantly higher levels of enterotoxins produced were recorded for coagulase-positive, thermostable nuclease-positive, hemolysis-positive, or mannitol-positive strains. Mannitol utilization was the best test for discriminating between enterotoxigenic and nonenterotoxigenic staphylococci.
Bautista
L
L
Departamento de Bioquímica y Microbiología, INIA, Madrid, Spain.
Gaya
P
P
Medina
M
M
Nuñez
M
M
D000818:Animals; D004768:Enterotoxins / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D008892:Milk / Q000382:microbiology*; D012756:Sheep; D013210:Staphylococcus / Q000378:metabolism*
D004768:Enterotoxins; C019368:enterotoxin D, Staphylococcal; C026066:enterotoxin A, Staphylococcal; C031818:enterotoxin B, staphylococcal; C034959:enterotoxin C, staphylococcal