Department of Microbiology and Veterinary Public Health, Faculty of Veterinary Medicine, Chittagong Veterinary and Animal Sciences University, Chittagong, Khulshi, Bangladesh.
Department of Genetics and Animal Breeding, Faculty of Veterinary Medicine, Chittagong Veterinary and Animal Sciences University, Chittagong, Khulshi, Bangladesh.
Vet Med Sci. 2022 Nov;8(6):2616-2622. doi: 10.1002/vms3.935. Epub 2022 Sep 12.
Shiga toxin-producing Escherichia coli (STEC) are zoonotic foodborne pathogens and a significant concern with the emergence of antibiotic resistance. Close human contact might have a higher chance of being transmitted to humans from sheep if the sheep population is a potential reservoir of antimicrobial-resistant STEC. Therefore, this study aimed to examine the sheep population in rural Bangladesh for antimicrobial-resistant STEC.
We screened 200 faecal samples collected from sheep in three Upazilas from the Chattogram district. Randomisation of sampling was not performed due to the smaller flock size (two to six animals per smallholding). Phenotypically positive E. coli isolates were examined for two Shiga toxin-producing genes - stx1 and stx2. PCR-positive STEC isolates were investigated for the presence of antimicrobial resistance (AMR) genes - bla , sul1 and sul2.
In total, 123 of the 200 tested samples were confirmed positive E. coli using culture-based methods. PCR results show 17 (13.8%) E. coli isolates harboured ≥ one virulent gene (stx1 or/and stx2) of STEC. The AMR profile of STEC isolates was determined utilising the disc diffusion method. Of the STEC isolates, 82, 76, 71 and 71% were susceptible to chloramphenicol, gentamicin, ciprofloxacin and ampicillin. In contrast, 47% of isolates were resistant to trimethoprim-sulfamethoxazole, and 41% were resistant to amoxicillin. In addition, six of the tested STEC isolates exhibited the bla gene; eight STEC isolates had the sul1 gene, and the sul2 gene was detected in ten STEC isolates.
To our knowledge, this study is the first to reveal a substantial percentage of STEC isolated from sheep in rural Bangladesh harbouring AMR genes.
产志贺毒素大肠杆菌（STEC）是一种人畜共患的食源性病原体，由于其出现抗生素耐药性，因此备受关注。如果绵羊种群是具有抗微生物耐药性 STEC 的潜在储库，那么与绵羊的密切人类接触可能会增加从绵羊传播给人类的机会。因此，本研究旨在检测孟加拉国农村地区的绵羊种群中是否存在具有抗微生物耐药性的 STEC。
我们从吉大港地区的三个 Upazilas 采集了 200 份绵羊粪便样本。由于羊群规模较小（每个小农场有两到六只动物），因此没有进行随机抽样。用基于培养的方法检测到 200 个测试样本中的 123 个为阳性大肠杆菌。PCR 结果显示，17（13.8％）大肠杆菌分离株携带≥一种产志贺毒素基因（stx1 和/或 stx2）的 STEC。利用纸片扩散法确定 STEC 分离株的 AMR 图谱。STEC 分离株中，82％、76％、71％和 71％分别对氯霉素、庆大霉素、环丙沙星和氨苄西林敏感。相比之下，47％的分离株对复方磺胺甲噁唑耐药，41％对阿莫西林耐药。此外，6 株测试的 STEC 分离株携带 bla 基因；8 株 STEC 分离株携带 sul1 基因，10 株 STEC 分离株携带 sul2 基因。
据我们所知，本研究首次揭示了从孟加拉国农村地区的绵羊中分离出的大量 STEC 携带 AMR 基因。
