title: Staphylococcus aureus reservoirs during traditional Austrian raw milk cheese production.
abstract: Sampling approaches following the dairy chain, including microbiological hygiene status of critical processing steps and physicochemical parameters, contribute to our understanding of how Staphylococcus aureus contamination risks can be minimised. Such a sampling approach was adopted in this study, together with rapid culture-independent quantification of Staph. aureus to supplement standard microbiological methods. A regional cheese production chain, involving 18 farms, was sampled on two separate occasions. Overall, 51·4% of bulk milk samples were found to be Staph. aureus positive, most of them (34·3%) at the limit of culture-based detection. Staph. aureus positive samples >100 cfu/ml were recorded in 17·1% of bulk milk samples collected mainly during the sampling in November. A higher number of Staph. aureus positive bulk milk samples (94·3%) were detected after applying the culture-independent approach. A concentration effect of Staph. aureus was observed during curd processing. Staph. aureus were not consistently detectable with cultural methods during the late ripening phase, but >100 Staph. aureus cell equivalents (CE)/ml or g were quantifiable by the culture-independent approach until the end of ripening. Enterotoxin gene PCR and pulsed-field gel electrophoresis (PFGE) typing provided evidence that livestock adapted strains of Staph. aureus mostly dominate the post processing level and substantiates the belief that animal hygiene plays a pivotal role in minimising the risk of Staph. aureus associated contamination in cheese making. Therefore, the actual data strongly support the need for additional sampling activities and recording of physicochemical parameters during semi-hard cheese-making and cheese ripening, to estimate the risk of Staph. aureus contamination before consumption.
authors.affiliation: Department for Farm Animals and Veterinary Public Health,Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna,Veterinärplatz 1, 1210 Vienna,Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Walcher
authors.affiliation: Department for Farm Animals and Veterinary Public Health,Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna,Veterinärplatz 1, 1210 Vienna,Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Gonano
authors.affiliation: Department for Pathobiology,Institute of Bacteriology, Mycology and Hygiene, Functional Microbiology, University of Veterinary Medicine,Veterinärplatz 1, 1210 Vienna,Austria.
authors.forename: Judith
authors.initials: J
authors.lastname: Kümmel
authors.affiliation: Institute of Food Research,Norwich Research Park, Colney, Norwich NR4 7UA,UK.
authors.forename: Gary C
authors.initials: GC
authors.lastname: Barker
authors.affiliation: Department for Farm Animals and Veterinary Public Health, Institute for Veterinary Public Health, University of Veterinary Medicine,Vienna,Austria.
authors.forename: Karin
authors.initials: K
authors.lastname: Lebl
authors.affiliation: Department of Dairy,Chamber of Agriculture Vorarlberg,Montfortstraße 9-11, 6900 Bregenz,Austria.
authors.forename: Othmar
authors.initials: O
authors.lastname: Bereuter
authors.affiliation: Department for Pathobiology,Institute of Bacteriology, Mycology and Hygiene, Functional Microbiology, University of Veterinary Medicine,Veterinärplatz 1, 1210 Vienna,Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Ehling-Schulz
authors.affiliation: Department for Farm Animals and Veterinary Public Health,Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna,Veterinärplatz 1, 1210 Vienna,Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Department for Farm Animals and Veterinary Public Health,Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna,Veterinärplatz 1, 1210 Vienna,Austria.
authors.forename: Beatrix
authors.initials: B
authors.lastname: Stessl
mesh_terms: D000818:Animals; D001317:Austria; D002417:Cattle; D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D005260:Female; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D008892:Milk / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology