Dejene Haileyesus, Abunna Fufa, Tuffa Ashenafi Chaka, Gebresenbet Girma
Department of Veterinary Epidemiology and Public Health, College of Veterinary Medicine and Animal Sciences, University of Gondar, Gondar, Ethiopia.
Department of Clinical Studies, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia.
Vet Med (Auckl). 2022 Jun 9;13:131-142. doi: 10.2147/VMRR.S366888. eCollection 2022.
Enterohemorrhagic (O157:H7) is the primary cause of bloody diarrhea or hemorrhagic colitis. The study was carried out with to determine the epidemiology and antimicrobial resistance pattern of O157:H7 along the dairy supply chains in Akaki Kaliti sub-city of Addis Ababa, Bishoftu and Sululta towns of central Ethiopia.
A cross-sectional study design with random sampling methods was employed. Thus, a total of 450 raw cow milk (294), milker hand swab (65) and water (91) samples were collected from dairy farms, milk collection centers and Cafeterias and processed according to the standards to isolate and identify O157:H7. The samples were initially enriched in buffered peptone water, then plated onto Sorbitol MacConkey agar. Consequently, the suspected non-sorbitol fermenting colonies were confirmed as biochemically and serological test using latex agglutination tests.
Out of the total 450 samples examined, 6.0% were found to be contaminated by O157:H7. Accordingly, 9.89% of water, 9.23% of milker hand swab and 4.08% of raw milk samples were contaminated by the pathogen. Furthermore, the prevalence of O157:H7 was 7.79%, 6.21% and 3.97% in Akaki kaliti sub-city, Sululta and Bishoftu towns, respectively. The result of Fisher exact analysis revealed a significant difference observed ( < 0.05) between the occurrence of the pathogen and the source of sample, sources of water used, sampled material and type of containers. The study also revealed that varying level of resistance of O157:H7 isolates against nine antimicrobial discs tested and 100% (n = 27) of the isolates showed multidrug-resistance comprising from two up to seven antimicrobial drugs.
In conclusion, this study has indicated the occurrence of O157:H7 and its multiple drug-resistant profiles in milk samples along the dairy supply chains and its risk to public health and food safety. Therefore, proper hygienic practices from dairy farms to fork and rational drug usage are recommended.
肠出血性大肠杆菌（O157:H7）是血性腹泻或出血性结肠炎的主要病因。本研究旨在确定埃塞俄比亚中部亚的斯亚贝巴的阿卡基卡利蒂次城、比绍夫图和苏卢尔塔镇乳制品供应链中O157:H7的流行病学特征和抗菌药物耐药模式。
采用随机抽样方法进行横断面研究设计。因此，从奶牛场、牛奶收集中心和食堂共采集了450份生牛奶（294份）、挤奶工手部拭子（65份）和水（91份）样本，并按照标准进行处理，以分离和鉴定O157:H7。样本首先在缓冲蛋白胨水中增菌，然后接种到山梨醇麦康凯琼脂平板上。随后，通过乳胶凝集试验进行生化和血清学检测，确认疑似非山梨醇发酵菌落为O157:H7。
在总共检测的450份样本中，发现6.0%被O157:H7污染。相应地，9.89%的水、9.23%的挤奶工手部拭子和4.08%的生牛奶样本被该病原体污染。此外，阿卡基卡利蒂次城、苏卢尔塔和比绍夫图镇的O157:H7患病率分别为7.79%、6.21%和3.97%。费舍尔精确分析结果显示，病原体的出现与样本来源、使用的水源、采样材料和容器类型之间存在显著差异（<0.05）。该研究还表明，O157:H7分离株对九种抗菌药物纸片的耐药水平各不相同，100%（n = 27）的分离株表现出对两种至七种抗菌药物的多重耐药性。
总之，本研究表明乳制品供应链中的牛奶样本中存在O157:H7及其多重耐药谱，对公众健康和食品安全构成风险。因此，建议从奶牛场到餐桌采取适当的卫生措施并合理使用药物。
