Department of Bacteriology, Mycology, and Immunology, Faculty of Veterinary Medicine, University of Sadat City, Sadat City, Menoufia, Egypt.
Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, Benha University, Benha, Egypt.
BMC Microbiol. 2021 Sep 23;21(1):257. doi: 10.1186/s12866-021-02308-w.
The Shiga toxin-producing Escherichia coli (STEC) represented a great risk to public health. In this study, 60 STEC strains recovered from broiler and duck fecal samples, cow's milk, cattle beef, human urine, and ear discharge were screened for 12 virulence genes, phenotypic and genotypic antimicrobial resistance, and multiple-locus variable-number tandem-repeat analysis (MLVA).
The majority of strains harbored Shiga toxin 1 (stx) and stx, stx and stx, and ehxA genes, while a minority harbored stx subtype and eaeA. We identified 10 stx gene combinations; most of strains 31/60 (51.7%) exhibited four copies of stx genes, namely the stx, stx, stx, and stx, and the strains exhibited a high range of multiple antimicrobial resistance indices. The resistance genes blaCTX-M-1 and blaTEM were detected. For the oxytetracycline resistance genes, most of strains contained tetA, tetB, tetE, and tetG while the tetC was present at low frequency. MLVA genotyping resolved 26 unique genotypes; genotype 21 was highly prevalent. The six highly discriminatory loci DI = 0.9138 are suitable for the preliminary genotyping of STEC from animals and humans.
The STEC isolated from animals are virulent, resistant to antimicrobials, and genetically diverse, thus demands greater attention for the potential risk to human.
产志贺毒素大肠杆菌（STEC）对公众健康构成了巨大威胁。在本研究中，从肉鸡和鸭粪便样本、牛奶、牛肉、人尿和耳分泌物中回收了 60 株 STEC 菌株，对 12 种毒力基因、表型和基因型抗菌药物耐药性以及多位点可变数目串联重复分析（MLVA）进行了筛选。
大多数菌株携带志贺毒素 1（stx）和 stx、stx 和 stx、和 ehxA 基因，而少数菌株携带 stx 亚型和 eaeA。我们鉴定了 10 种 stx 基因组合；大多数菌株 31/60（51.7%）表现为 4 个 stx 基因拷贝，即 stx、stx、stx 和 stx，且菌株表现出广泛的多种抗菌药物耐药指数。检测到 blaCTX-M-1 和 blaTEM 耐药基因。对于四环素类抗生素耐药基因，大多数菌株含有 tetA、tetB、tetE 和 tetG，而 tetC 的存在频率较低。MLVA 基因分型确定了 26 个独特的基因型；基因型 21 非常普遍。6 个高度区分的基因座 DI=0.9138 适合初步对动物和人类来源的 STEC 进行基因分型。
从动物中分离出的 STEC 具有毒力、对抗菌药物耐药且遗传多样性丰富，因此对人类存在潜在风险，需要引起更大的关注。
