College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, People's Republic of China.
College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, People's Republic of China; Department of Nutrition and Food Science, University of Maryland, College Park, Maryland 20742, USA.
J Food Prot. 2014 Feb;77(2):331-4. doi: 10.4315/0362-028X.JFP-13-301.
Various ready-to-eat (RTE) foods are becoming increasingly popular in the world and could be easily contaminated with various microorganisms including certain pathogens. A total of 342 RTE food samples, including 32 cooked meats, 123 vegetable salads, 26 boiled peanuts, 109 cold noodles, and 52 dried tofu samples, were collected in Shaanxi Province, People's Republic of China, during the period of July to October 2012 and screened for Staphylococcus aureus. All S. aureus isolates were characterized by antimicrobial susceptibility and PCR for detecting nine enterotoxin genes (sea to sej). Overall, 25.4% of samples were positive for S. aureus, including 10 (31.3%) cooked meats, 34 (27.6%) salad vegetables, 6 (23.1%) boiled peanuts, 20 (18.3%) cold noodles, and 17 (32.7%) dried tofu samples. Of the isolated S. aureus organisms, 98.4% were resistant to at least one antimicrobial agent and 58.6% to three or more antimicrobials. Resistance to erythromycin (78.1%) and tetracycline (40.6%) was most frequently detected, while all isolates were sensitive to vancomycin and amikacin. Moreover, 55.5% of isolates were positive for one or more enterotoxin genes. The genes sed (25.8%) and sea (19.5%) were commonly detected among the isolates; seg, sei, and sej were not found. Our findings indicate that RTE foods in Shaanxi were contaminated with S. aureus isolates that harbored multiple toxin genes and exhibited multiple-drug resistance. Appropriated hygienic measures should be taken by producers, retailers, and consumers to reduce the risk posed by S. aureus in RTE foods.
在中国陕西省，2012 年 7 月至 10 月期间共采集了 342 份即食食品（RTE）样本，包括 32 份熟肉、123 份蔬菜沙拉、26 份煮花生、109 份冷面和 52 份干豆腐，以筛查金黄色葡萄球菌。所有金黄色葡萄球菌分离株均通过药敏试验和检测 9 种肠毒素基因（sea 至 sej）进行特征描述。总体而言，25.4%的样本呈金黄色葡萄球菌阳性，其中 10 份熟肉（31.3%）、34 份沙拉蔬菜（27.6%）、6 份煮花生（23.1%）、20 份冷面（18.3%）和 17 份干豆腐（32.7%）。分离出的金黄色葡萄球菌中，98.4%至少对一种抗菌药物耐药，58.6%对三种或更多种抗菌药物耐药。对红霉素（78.1%）和四环素（40.6%）的耐药性最常被检测到，而所有分离株均对万古霉素和阿米卡星敏感。此外，55.5%的分离株携带一种或多种肠毒素基因。sed（25.8%）和 sea（19.5%）基因在分离株中较为常见；seg、sei 和 sej 未被发现。研究结果表明，陕西省的 RTE 食品受到携带多种毒素基因且表现出多重耐药性的金黄色葡萄球菌的污染。生产者、零售商和消费者应采取适当的卫生措施，以降低 RTE 食品中金黄色葡萄球菌带来的风险。
