title: Staphylococcus aureusEntrance into the Dairy Chain: TrackingS. aureusfrom Dairy Cow to Cheese.
abstract: Staphylococcus aureusis one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control ofS. aureusis not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associatedS. aureusas reservoir forS. aureuscontamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n= 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spatyping and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point ofS. aureusinto the dairy chain. Our data clearly show that certainS. aureussubtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity ofS. aureussubtypes was observed in QM and BTM at the farms, only certainS. aureussubtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile:sea/sed/sej) of the recently describedS. aureusgenotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype BS. aureusrepresent a specific challenge in control ofS. aureusin the dairy chain that requires effective clearance strategies and hygienic measures already in primary production to avoid a potential transfer of enterotoxic strains or enterotoxins into the dairy processing and the final retail product.
authors: Department of Pathobiology, Functional Microbiology, Institute of Microbiology, University of Veterinary MedicineVienna, Austria; Clinic for Ruminants, Department for Farm Animals and Herd Management, University of Veterinary MedicineVienna, Austria.
authors: Judith
authors: J
authors: Kümmel
authors: Department for Farm Animals and Herd Management, Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna, Austria.
authors: Beatrix
authors: B
authors: Stessl
authors: Department for Farm Animals and Herd Management, Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna, Austria.
authors: Monika
authors: M
authors: Gonano
authors: Department for Farm Animals and Herd Management, Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna, Austria.
authors: Georg
authors: G
authors: Walcher
authors: Chamber for Agriculture Vorarlberg Bregenz, Austria.
authors: Othmar
authors: O
authors: Bereuter
authors: Department of Pathobiology, Functional Microbiology, Institute of Microbiology, University of Veterinary Medicine Vienna, Austria.
authors: Martina
authors: M
authors: Fricker
authors: Department of Pathobiology, Functional Microbiology, Institute of Microbiology, University of Veterinary Medicine Vienna, Austria.
authors: Tom
authors: T
authors: Grunert
authors: Department for Farm Animals and Herd Management, Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna, Austria.
authors: Martin
authors: M
authors: Wagner
authors: Department of Pathobiology, Functional Microbiology, Institute of Microbiology, University of Veterinary Medicine Vienna, Austria.
authors: Monika
authors: M
authors: Ehling-Schulz
keywords: FTIR spectroscopy; Staphylococcus aureus; dairy chain; food safety; mastitis; metabolic fingerpriting; subtyping