Incidence of Staphylococcus aureus and its enterotoxins in yoghurt

Abstract

A total of 50 samples of balady and automatically packaged plain yoghurt (25 of each) were collectedfrom different dairy shops, groceries and supermarkets at Kalubia Governorates. The collected sampleswere transferred immediately to the laboratory in an ice box for detection of Staph.aureus,itsenterotoxins produced and detection of virulent genes responsible for enterotoxins production. Theobtained results revealed that, Staph. aureus could be detected in three samples (12%) and two samples(8%) of examined balady and automatically packaged plain yoghurt, respectively. Isolated strains weretested for detection of enterotoxins producing genes by using PCR. The obtained results showed thatone strain belonged to each of balady and automatically packaged plain yoghurt proved to have genetype (A) and (D), respectively. Also detection of enterotoxins by using ELISA revealed that one strainof both balady and automatically packaged plain yoghurt was enterotoxigenic, types (A) and (D)production at percentage of (33.33% and 50%), respectively. The public health importance and hygienicsignificance of the isolated Staph. aureus and their entertoxins as well as the suggested measures forimproving the quality and safety of the yoghurt was discussed