Virulence factors, serogroups and antimicrobial resistance properties of Escherichia coli strains in fermented dairy products.
Virulence factors, serogroups and antimicrobial resistance properties of Escherichia coli strains in fermented dairy products.
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DOI：
10.1186/1756-0500-7-217
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发表时间：
2014-04-07
影响因子：
1.8
通讯作者：
Valizadeh Y
中科院分区：
文献类型：
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作者：
Dehkordi FS;Yazdani F;Mozafari J;Valizadeh Y
从临床角度来看，了解发酵乳制品的微生物安全性至关重要。 Doogh 和 kashk 是发酵乳制品。这些产品被数百万人使用，但其微生物质量尚不清楚。产生志贺毒素的大肠杆菌 (STEC) 是食物中毒和食源性疾病中最常见的病原体之一。本研究的目的是研究从发酵乳制品中分离出的 STEC 菌株的分子特征和抗菌特性。收集了六百份发酵乳制品样本并立即转移到实验室。所有样本均立即培养，并对大肠杆菌阳性样本进行分析，以确定是否存在 O157、O26、O103、O111、O145、O45、O91、O113、O121 和 O128 STEC 血清群、tetA、tetB、blaSHV、CITM、cmlA、cat1、aadA1、dfrA1、qnr、aac (3)-IV、sul1和ereA抗生素抗性基因以及stx1、stx2、eaeA、ehly、cnf1、cnf2、iutA、cdtB、papa、traT、sfaS和fyuA毒力因子使用PCR。抗菌药物敏感性测试也使用纸片扩散法和 Mueller-Hinton 琼脂进行。 600 个乳制品样本中有 50 个（8.33%）含有大肠杆菌。此外，酸奶是最常受污染的乳制品。 O157 (26%) 和 O26 (12%) 是最常检测到的血清群。附着和消失大肠杆菌与肠出血性大肠杆菌的发生频率存在显着性差异（P<0.05）。 Stx1 (44%)、eae (36%)、papA (32%)、stx2 (30%) 和 ehly (28%) 是最常检测到的毒力因子。最常见的是编码四环素（tetA 和 tetB）（分别为 76% 和 70%）、头孢噻吩 (blaSHV) (38%)、氨苄青霉素 (CITM) (36%) 和庆大霉素 (aac (3)-IV) (32%) 耐药性的基因。观察到对四环素（84%）、青霉素（46%）、氨苄青霉素（38%）和链霉素（36%）的高耐药性。发酵乳制品很容易被抗生素耐药性 STEC 菌株污染。我们的研究结果应该提高人们对伊朗抗生素耐药性的认识。临床医生在开抗生素处方时应谨慎行事，尤其是在兽医治疗中。
From a clinical perspective, it is essential to know the microbial safety of fermented dairy products. Doogh and kashk are fermented dairies. These products are used by millions of people but their microbial qualities are unknown. Shiga toxin producing Escherichia coli (STEC) is one of the most commonly detected pathogens in the cases of food poisoning and food-borne illnesses. The present investigation was carried out in order to study the molecular characterization and antimicrobial resistance properties of STEC strains isolated from fermented dairy products. Six hundred fermented dairy samples were collected and immediately transferred to the laboratory. All samples were cultured immediately and those that were E. coli-positive were analyzed for the presence of O157 , O26, O103, O111, O145, O45, O91, O113, O121 and O128 STEC serogroups, tetA, tetB, blaSHV, CITM, cmlA, cat1, aadA1, dfrA1, qnr, aac (3)-IV, sul1 and ereA antibiotic resistance genes and stx1, stx2, eaeA, ehly, cnf1, cnf2, iutA, cdtB, papA, traT, sfaS and fyuA virulence factors using PCR. Antimicrobial susceptibility testing was performed also using disk diffusion methodology with Mueller–Hinton agar. Fifty out of 600 (8.33%) dairy samples harbored E. coli. In addition, yoghurt was the most commonly contaminated dairy. O157 (26%) and O26 (12%) were the most commonly detected serogroups. A significant difference was found between the frequency of Attaching and Effacing E. coli and Enterohaemorrhagic E. coli (P <0.05). Stx1 (44%), eae (36%), papA (32%) stx2 (30%), and ehly (28%) were the most commonly detected virulence factors. The genes encode resistance against tetracycline (tetA and tetB) (76% and 70%, respectively), cephalothin (blaSHV) (38%), ampicillin (CITM) (36%) and gentamicin (aac (3)-IV) (32%) were the most commonly detected. High resistance levels to tetracycline (84%), penicillin (46%), ampicillin (38%) and streptomycin (36%) were observed. Fermented dairy products can easily become contaminated by antibiotic resistant STEC strains. Our findings should raise awareness about antibiotic resistance in Iran. Clinicians should exercise caution when prescribing antibiotics, especially in veterinary treatments.