title: Genotypic characterization by polymerase chain reaction of Staphylococcus aureus isolates associated with bovine mastitis.
abstract: Staphylococcus aureus is recognized worldwide as a pathogen causing many serious diseases in humans and animals, and is the most common aetiological agent of clinical and subclinical bovine mastitis. The importance of evaluating the combination of S. aureus virulence factors has been emphasized both in human and veterinary medicine, and knowledge about the genetic variability within different S. aureus populations would help in the design of efficient treatments. The aim of the present study was to determine the genetic profiles of S. aureus strains isolated from milk of cows suffering from clinical and subclinical mastitis in Belgium. The presence of about forty virulence-associated genes was investigated by specific polymerase chain reaction (PCR) amplification. A high number of genotypic subtypes were observed, demonstrating further the large variation in the presence of virulence genes in S. aureus isolates and the considerable diversity of strains populations that are able to cause mastitis in cows. In accordance with other studies, we showed that some genes are associated with mastitis-causing S. aureus isolates, whereas others are absent or rarely present. We also further highlighted the presence of conserved gene combinations, namely the enterotoxigenic egc-cluster and the bovine pathogenicity island SaPIbov. Importantly, the presence of isolates carrying genes coding for toxins involved in important human infections makes the milk of cows with mastitis a potential reservoir for these toxins, and therefore a potential danger in human health, which strengthens the importance to consider raw milk consumption and its processing very carefully.
authors.affiliation: Department of Infectious and Parasitic Diseases, Bacteriology, Faculty of Veterinary Medicine, University of Liège, Sart-Tilman, Bât B43a, B-4000 Liège, Belgium. iote@ulg.ac.be
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ote
authors.forename: Bernard
authors.initials: B
authors.lastname: Taminiau
authors.forename: Jean-Noël
authors.initials: JN
authors.lastname: Duprez
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dizier
authors.forename: Jacques G
authors.initials: JG
authors.lastname: Mainil
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics; D001530:Belgium; D002417:Cattle; D005260:Female; D005838:Genotype; D006460:Hemolysin Proteins / Q000235:genetics; D007956:Leukocidins / Q000235:genetics; D008414:Mastitis, Bovine / Q000382:microbiology*; D008892:Milk / Q000382:microbiology; D010447:Peptide Hydrolases / Q000235:genetics; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D007956:Leukocidins; D037521:Virulence Factors; D010447:Peptide Hydrolases