这项研究调查了非O157产志贺毒素大肠杆菌(STEC)血清群的毒力潜力和抗生素敏感性分析,这是食源性疾病的重要原因。一项研究通过各种来源收集了800个奶牛原料奶样本,500来自牛奶店,200个来自奶牛场,26来自牛奶收集中心,和74来自街头小贩。使用标准方法,在收集的800个样品中的321个中检测到大肠杆菌。在分离出的321份大肠杆菌阳性样本中,148使用选择性培养基鉴定为STEC,特别是头孢克肟碲酸盐山梨醇MacConkey琼脂(CT-SMA)。148个阳性样本中,使用多重PCR确认40株为STEC非O157株,表明患病率为5%(800个样本中的40个)。对STEC分离株进行抗菌药物敏感性试验,并且所有分离株对通过圆盘扩散法测试的至少一种或多种抗微生物剂具有抗性,显示对阿莫西林100%的高耐药性,头孢曲松50%,青霉素44.5%,值得注意的是,44%的菌株表现出链霉素抗性,而恩诺沙星55%,氟苯尼考50%和诺氟沙星44%,表现出最高的易感性。在40个STEC非O157中,有12个通过IlluminaInc.MiSeq平台的下一代测序技术进行了多基因座序列分型(MLST)测序,美国。基因组研究证明了十二种血清型H4:O82,H30:O9a的持久性,H4:O82,H16:O187,H9:O9,H16:O113,H30:O9,H32:O,H32:O,H32,H32和H38:O187与人类的潜在感染有关。结论:STEC分离株对多种抗菌药物具有耐药性,由于这些药物在治疗和预防中的广泛使用,引起了对动物和公共卫生的关注。这项研究为监测生乳中的STEC提供了新的见解,强调全基因组测序(WGS)对不同分离株的基因分型和测序的关键作用。在理解STEC发病机制方面仍然存在不足,持续监测对于保障人类健康和增进对STEC遗传特征的了解至关重要.
This study investigated the virulence potential and antibiotic susceptibility analysis of non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups, which are significant cause of food borne diseases. A study collected 800 samples of dairy bovine raw milk through various sources, 500 from milk shops, 200 from dairy farms, 26 from milk collection centers, and 74 from street vendors. Using a standard method, E. coli was detected in 321 out of the 800 samples collected. Out of the 321 E. coli-positive samples isolated, 148 were identified as STEC using selective media, specifically Cefixime Tellurite Sorbitol MacConkey\'s Agar (CT-SMA). Out of the 148 positive samples, 40 were confirmed as STEC non-O157 strains using multiplex PCR, indicating a prevalence of 5% (40 out of 800 samples). STEC isolates were subjected to antimicrobial susceptibility testing, and all isolates were resistant to at least one or more antimicrobials tested through the disk diffusion method, revealed high resistance to Amoxicillin 100%, Ceftriaxone 50%, and Penicillin 44.5%, and notably 44% of the strains exhibited Streptomycin resistance, while Enrofloxacin 55%, Florfenicol 50% and Norfloxacin 44%, demonstrated the highest susceptibility. Out of 40 STEC non-O157, twelve were subjected to Multi Locus Sequence Typing (MLST) sequencing through Illumina Inc. MiSeq platform\'s next-generation sequencing technology, United States. The genome investigation evidenced the persistence of twelve serotypes H4:O82, H30:O9a, H4:O82, H16:O187, H9:O9, H16:O113, H30:O9, H32:O, H32:O, H32, H32, and H38:O187, linked to the potential infections in humans. Conclusion: STEC isolates showed resistance to multiple antimicrobials, raising concerns for both animal and public health due to widespread use of these drugs in treatment and prevention. The study contributes new insights into monitoring STEC in raw milk, emphasizing the critical role of whole genome sequencing (WGS) for genotyping and sequencing diverse isolates. Still a deficiency in understanding STEC pathogenesis mechanisms, ongoing surveillance is crucial for safeguarding human health and enhancing understanding of STEC genetic characteristics.