ABSTRACT

Virulent pathotypes of E. coli seriously affect the livestock regarding the misuse of antibiotics. All 180 samples collected from cow’s environment and dairy shops in Qena, Egypt were serologically and molecularly positive for coliforms. Enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli (STEC), Enteroinvasive E. coli (EIEC) and Enterotoxigenic E. coli (ETEC) pathotypes were isolated from water and milk-related samples. STEC serogroups O26, O55, O111, O113, O145 were also recovered. The non-O157 STEC serotypes were recovered from human diarrheagenic patients contacting cattle or consuming contaminated water/milk products. Bla_CTX-M and bla_TEM genes were detected in 25.5% and 100%, respectively. Disinfectants and algal extracts, identified by GC-MS, were evaluated in vitro for antibacterial activities. TH4+® disinfectant and methanol extract of Turbinaria decurrens reduced E. coli at 13 log10 at 1.5% and 3 mg/ml concentrations, respectively. Ag-NPs/T. decurrens showed 8–9 log10 reduction at concentration of 1.6 × 10⁵ NPs/ml. Examined water sources, milk and milk products were potential reservoirs for virulent antibiotic-resistant E.coli which may impose animal and public health threats.

Abbreviations: APEC: Avian pathogenic E. coli; bla_CTX-M: β-lactamase inhibitors-Cefotaximase gene; bla_TEM: β-lactamase inhibitors-Temoneira gene; CFU: Colony-forming unit; DAEC: Diffusely adherent E. coli; DEC: Diarrheagenic Escherichia coli; DEMSO: Dimethyl sulfoxide; eaeA: Intimin or E. coli attaching gene; EAEC: Enteroaggregative E. coli; EHEC: Enterohemorrhagic E. coli; EIEC: Enteroinvasive E. coli; EOSQC: Egyptian Organization for Standardization and Quality Control; EPEC: Enteropathogenic E. coli; ETEC: Enterotoxigenic E. coli; ExPEC: Extra-intestinal pathogenic E. coli; GC–MS: Gas chromatography–mass spectrometry technique; hly: Hemolysin gene; STEC: Shiga like producing E. coli; stx1: Shiga-toxin 1 gene; ESBLs: Extended-spectrum beta-lactamases.

摘要

大肠杆菌的毒性致病型严重影响牲畜滥用抗生素。从埃及 Qena 的奶牛环境和奶制品店采集的所有 180 个样本的大肠菌群在血清学和分子学上均呈阳性。 从水和牛奶相关样品中分离出致病性大肠杆菌( EPEC  )、产志贺毒素 大肠杆菌 (STEC)、侵入 性大肠杆菌 (EIEC) 和产肠毒素 大肠杆菌(ETEC) 致病型。还回收了 STEC 血清群 O26、O55、O111、O113、O145。非 O157 STEC 血清型是从接触牛或食用受污染的水/奶制品的人类腹泻患者中回收的。Bla _CTX-M和bla_TEM基因的检测率分别为 25.5% 和 100%。通过 GC-MS 鉴定的消毒剂和藻类提取物在体外进行了抗菌活性评估。Turbinaria decurrens的 TH4+® 消毒剂和甲醇提取物分别在 1.5% 和 3 mg/ml 浓度下以 13 log10减少大肠杆菌。Ag-NPs/ T. decurrens在浓度为 1.6 × 10 ⁵ NPs/ml 时显示 8-9 log10 减少。经过检查的水源、牛奶和奶制品是可能对动物和公众健康造成威胁的有毒耐抗生素大肠杆菌的潜在宿主。

缩写： APEC：禽致病性大肠杆菌；bla _CTX-M：β-内酰胺酶抑制剂-头孢噻肟基因；bla _TEM：β-内酰胺酶抑制剂-Temoneira 基因；CFU：菌落形成单位；DAEC：扩散粘附的大肠杆菌；DEC：腹泻性大肠杆菌；DEMSO：二甲基亚砜；eaeA：Intimin 或大肠杆菌附着基因；EAEC：肠聚集性大肠杆菌；EHEC：肠出血性大肠杆菌；EIEC：肠侵袭性大肠杆菌；EOSQC：埃及标准化和质量控制组织；EPEC：肠致病性大肠杆菌；ETEC：产肠毒素大肠杆菌；ExPEC：肠外致病性大肠杆菌；GC-MS：气相色谱-质谱技术；hly：溶血素基因；STEC：志贺喜欢生产大肠杆菌；stx1：志贺毒素 1 基因；ESBLs：超广谱β-内酰胺酶。