title: Comparison of virulence and antibiotic resistance genes of food poisoning outbreak isolates of Staphylococcus aureus with isolates obtained from bovine mastitis milk and pig carcasses.
abstract: Staphylococcus aureus is the etiological agent in a variety of infections in humans and livestock and produces enterotoxins leading to staphylococcal food poisoning (SFP), one of the most prevalent foodborne intoxication diseases worldwide. Pork and bovine milk are considered  possible sources of SFP because pig skin is often colonized by S. aureus and bovine mastitis caused by S. aureus is common, but conclusive data are limited. The objective of the present study was to compare S. aureus isolates associated with cases of SFP with isolates  obtained from bovine mastitis milk and pig carcasses. DNA microarray analysis and spa gene typing were performed with 100 S. aureus isolates: 20 isolates related to outbreaks of SFP in humans, 39 isolates obtained from pig carcasses, and 41 isolates collected from bovine mastitis  milk. No overlap in spa types was observed for SFP isolates (t008, t015, t018, t024, t056, t084, t279, t377, t383, t648, t733, t912, t1239, t1270, t4802, and t6969) and isolates gathered from milk or pork. The porcine isolates were assigned to t034, t208, t337, t524, t899, t1939, t2922,  t2971, t4475, and t7006, and the bovine isolates belonged to t267, t524, t529, t1403, t2953, t7007, t7008, and t7013. Comparison of microarray profiles revealed similar virulence gene patterns for isolates collected from the same host (pigs or cattle) but few similarities between SFP isolate  profiles and the profiles of isolates obtained from bovine mastitis milk and pig carcasses. Although only some bovine and porcine isolates possessed the β-lactamase gene blaZ (milk, 24%; pork, 28%), significantly higher numbers of SFP isolates contained blaZ (90%). Investigations  of these isolates provided no evidence that pork or bovine mastitis milk represent common sources of SFP.
authors: Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Winterthurerstrasse 272, CH-8057 Zurich, Switzerland. sophia.johler@uzh.ch
authors: Sophia
authors: S
authors: Johler
authors: Franziska
authors: F
authors: Layer
authors: Roger
authors: R
authors: Stephan
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D006801:Humans; D008414:Mastitis, Bovine / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology*; D020411:Oligonucleotide Array Sequence Analysis; D013202:Staphylococcal Food Poisoning / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000472:pathogenicity*; D013552:Swine / Q000382:microbiology; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents