title: Staphylococcus aureus, thermostable nuclease and staphylococcal enterotoxins in raw ewes' milk Manchego cheese.
abstract: Growth and survival of two enterotoxigenic strains of Staphylococcus aureus were studied during manufacture and ripening of eight batches of raw ewes' milk Manchego cheese. Only 2-3 generations of Staph. aureus occurred in the vat and during pressing. The death rate of Staph. aureus (mean decrease in log cfu/g/week of ripening) from day 1 to day 60 was 0.421 in cheese made with 1% Streptococcus lactis starter and 0.404 in cheese made without starter. Thermostable nuclease was produced in the vat by growing Staph. aureus cells; it was inactivated by rennet during the first 24 h and synthesized again by surviving cells of Staph. aureus from day 1 to day 60. Staphylococcal enterotoxins A, B, C and D were not detected in any batches of cheese, even though Staph. aureus counts exceeded 10(7) cfu/g.
authors.affiliation: Departamento de Bioquímica y Microbiología, Instituto Nacional de Investigaciones Agrarias, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Nuñez
authors.forename: L
authors.initials: L
authors.lastname: Bautista
authors.forename: M
authors.initials: M
authors.lastname: Medina
authors.forename: P
authors.initials: P
authors.lastname: Gaya
mesh_terms: D000818:Animals; D002611:Cheese; D015169:Colony Count, Microbial; D004768:Enterotoxins / Q000096:biosynthesis*; D005260:Female; D008836:Micrococcal Nuclease / Q000096:biosynthesis*; D012044:Regression Analysis; D012756:Sheep; D013211:Staphylococcus aureus / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism
chemical_list: D004768:Enterotoxins; D008836:Micrococcal Nuclease