Food contaminated with Shiga toxin-producing Escherichia coli (STEC) represents a hazardous public health problem worldwide. Therefore, the present study was performed to elucidate the virulent and antimicrobial resistance characteristics of STEC isolated from milk and dairy products marketed in Egypt. A total of 125 samples (raw market milk, bulk tank milk, Kareish cheese, white soft cheese, and small scale-produced ice cream, 25 each) were collected for determination the prevalence and antimicrobial resistance profiling of STEC. Thirty-six STEC isolates were recovered from milk and dairy products. Serological analysis illustrated that three isolates were E. coli O157:H7 and 33 isolates belonged to different serotypes. Molecular examination indicated that all isolates harboured stx1 and/or stx2 genes, 14 isolates expressed eaeA gene and 3 isolates possessed rfbE gene. Antimicrobial resistance profiling of the isolates was both phenotypically and genetically examined. Interestingly, 31 out of 36 (86.11%) isolates were multidrug-resistant and harboured the extended-spectrum β-lactamase encoding genes, namely, blaCTX-M-15, blaSHV-12 and blaCTX-M-14. Moreover, 12 isolates (33.33%) harboured plasmid-mediated quinolone resistant gene, qnrS. The overall conclusion of the current investigation indicated insufficient hygienic measures adopted during milking, handling, and processing leading to development of pathogenic and multidrug-resistant STEC.

中文翻译：

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在埃及的牛奶和乳制品中，产生志贺毒素的大肠杆菌的患病率和抗药性。

产生志贺毒素的大肠杆菌（STEC）污染的食品在全球范围内代表着危害公共健康的问题。因此，进行本研究是为了阐明从埃及销售的牛奶和乳制品中分离出的STEC的毒性和抗微生物特性。总共收集了125个样品（原料牛奶，散装罐装牛奶，Kareish奶酪，白色软奶酪和小规模生产的冰淇淋，每个25个），以测定STEC的患病率和抗菌素谱。从牛奶和乳制品中回收了36种STEC分离物。血清学分析表明三种分离株是大肠杆菌O157：H7，其中33种分离株属于不同的血清型。分子检查表明，所有分离株均带有stx1和/或stx2基因，14株表达eaeA基因，3株具有rfbE基因。对分离物的抗菌素耐药性进行了表型和遗传学检查。有趣的是，在36个分离株中，有31个（占86.11％）具有多药耐药性，并且具有广谱β-内酰胺酶编码基因，即blaCTX-M-15，blaSHV-12和blaCTX-M-14。此外，有12个分离株（33.33％）带有质粒介导的喹诺酮抗性基因qnrS。当前调查的总体结论表明，在挤奶，处理和加工过程中采取的卫生措施不足，导致了病原性和多药耐药性STEC的发展。11％）分离株具有多重耐药性，并带有广谱β-内酰胺酶编码基因，即blaCTX-M-15，blaSHV-12和blaCTX-M-14。此外，有12个分离株（33.33％）带有质粒介导的喹诺酮抗性基因qnrS。当前调查的总体结论表明，在挤奶，处理和加工过程中采取的卫生措施不足，导致了病原性和多药耐药性STEC的发展。11％的分离株具有多重耐药性，并带有广谱β-内酰胺酶编码基因，即blaCTX-M-15，blaSHV-12和blaCTX-M-14。此外，有12个分离株（33.33％）带有质粒介导的喹诺酮抗性基因qnrS。当前调查的总体结论表明，在挤奶，处理和加工过程中采取的卫生措施不足，导致了病原性和多药耐药性STEC的发展。