Detection of Staphylococcus aureus enterotoxins in sheep cheese and dairy desserts by multiplex PCR technique.
The aim of this study was to investigate the presence of Staphylococcus aureus (S. aureus) and staphylococcal enterotoxins (SEs) genes in sheep cheese and dairy dessert samples by multiplex PCR (mPCR) technique. A total of 150 samples were analyzed consisting of 50 dairy dessert samples and 100 sheep cheese. Coagulase positive staphylococci (CPS) were found in 86 (57.3%) out of 150 analyzed samples. S. aureus were isolated from 60 (60%), 26 (52%) of sheep cheese and from of dairy desserts, respectively. Five suspected colonies were tested from each sheep cheese and dairy dessert samples for phenotypic and genotypic characterizations. A total of 430 isolates from the 86 positive samples were investigated in this study. Eighty (18.6%) isolates were characterized as S. aureus. The enterotoxin genes (sea, seb, sec, sed) were found in 13 (3.02%) out of 80 isolates. From cheese isolates, sea, seb and sed were detected in 5 (1.6%), 2 (0.6%), 1 (0.3%), respectively. From dairy dessert isolates, sea, sec and sed were detected in 3 (2.3%), 1 (0.76%), 1 (0.76%), respectively. The presence of SEs was identified in 12 (2.8%) out of 80 isolates by using ELISA technique. It was determined that these SEs had a distribution of 7 (1.6%) SEA, 2 (0.46%) SEB, 1 (0.23%) SEC, and 2 (0.46%) SED. SEs were found in 7 (2.3%) cheese and 5 (3.8%) dairy dessert isolates. In conclusion, S.aureus and their SEs were found to be present in sheep cheese and dairy desserts in this study. It is emphasized that the presence of S. aureus and their SEs genes in sheep cheese and dairy desserts may be regarded as a potential risk for human health.
Ertas
Nurhan
N
Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, University of Erciyes, Kayseri, Turkey. nertas@erciyes.edu.tr
Gonulalan
Zafer
Z
Yildirim
Yeliz
Y
Kum
Erhan
E
D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics*; D002611:Cheese / Q000032:analysis / Q000382:microbiology; D003611:Dairy Products / Q000382:microbiology*; D004768:Enterotoxins / Q000235:genetics*; D005506:Food Contamination / Q000032:analysis*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012756:Sheep; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*
D001427:Bacterial Toxins; D004768:Enterotoxins