The Use of Multiplex PCR to Determine the Prevalence of Enterotoxigenic Staphylococcus aureus Isolated from Raw Milk, Feta Cheese, and Hand Swabs

Abstract

Staphylococcus aureus (S. aureus) can cause mastitis in cattle and, therefore, can be present in milk. This study was undertaken to determine the prevalence of coagulase positive S. aureus and its enterotoxin genes sea, seb, and sec in isolates recovered from raw milk, feta cheese, and human hand swabs of milk and cheese handlers in Beni-Suef province, Egypt. A total of 100 samples of raw milk and 50 samples of pasteurized-milk feta cheese were collected. In addition, 50 hand swabs from milk handlers and 25 hand swabs from cheese handlers were examined for the presence of coagulase positive S. aureus. The isolates were characterized by multiplex PCR for detection of sea, seb, and sec genes, and for resistance to 5 classes of commonly used antibiotics. Twelve (12/100), 12 (6/50), and 17% (13/75) of milk, cheese, and hand swab samples, respectively, were positive for coagulase positive S. aureus. One isolate was obtained from each positive sample (31 isolates), and none contained genes for SEA or SEC production. Twenty-five percent, 33%, and 31%, respectively, of the isolates contained the genes for SEB, resulting in 3%, 4%, and 5% of samples being positive for toxin producing coagulase positive S. aureus, respectively. At least one isolate was resistant to each of the antibiotics tested. Despite the low potential for SEB production shown, preventative measures, such as maintenance of the cold-chain and good hygienic practices should be implemented to further reduce the potential risk to public health from SEB, and to reduce the spread of antimicrobial resistance.

Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Workers in the Food Industry

“…However, in both studies enterotoxins A and C were most predominant. In contrast to these results Zeinhom et al (2015) investigated skin swaps from 75 milk and cheese handlers in Egypt and reported a carriage rate among individuals of only 17% with 5% of food handlers carrying enterotoxin B positive isolates.…”

Molecular detection of Staphylococcus aureus enterotoxin genes isolated from mastitic milk and humans in El-Behira, Egypt

“…Our results are very similar to those of Kirkan et al [29] who confirmed that S. aureus was the major pathogen causing bovine mastitis, being identified from 23.1% of the inspected farms, and from 28.3% of the milk samples studied in Turkey. Zeinhom et al and Mansour et al [30,31] reported that 12% and 16.3% of tested milk samples were S. aureus positive, respectively. Jahan et al [32] reported that the prevalence of S. aureus was 25.53%, and Pexara et al [33] reported that the overall occurrence of S. aureus in milk was 24.3%, and Ameen et al [34] found a prevalence of 30%.…”

Comparative meta-analysis of antimicrobial resistance from different food sources along with one health approach in the Egypt and UK

“…Out of 220 eligible studies related to pathogens carrying AMR in Egypt from 2013 to 2022, 34 full-text articles were included for further examination [ 37 – 70 ]. Out of 9,751 samples, 3205 (32.87%) found positive prevalence of which samples included beef 204 (28.73%), chicken 1315 (41.42%), raw meat 239 (24.26%), ready to eat food 239 (41.57%), fish 137 (24.46%), milk 484 (30.42%), other dairy products 608 (42.13%), vegetables 51 (9.46%), and water 44 (25.43%) showed positive prevalence for various pathogens including E. coli 1725 (17.69%), Staphylococcus 643 (6.59%), Salmonella spp.…”