Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa; Food and Agriculture Organisation of the United Nations, FAO Headquarters, Rome, Italy.
Sci Total Environ. 2024 Nov 15;951:175705. doi: 10.1016/j.scitotenv.2024.175705. Epub 2024 Aug 22.
Pathogenic Escherichia coli (PEC) are important foodborne bacteria that can cause severe illness in humans. The PECs thrive within the intestines of humans as well as animals and may contaminate multiple ecosystems, including food and water, via faecal transmission. Abattoir and farm employees are at high risk of PEC exposure, which could translate to community risk through person-to-person contact. To determine the epidemiology and resistome of PECs in Gauteng and Limpopo provinces of South Africa, 198 swine faecal samples, 220 poultry cloacal swabs, 108 human hand swabs, 11 run-off water samples from abattoirs and farms were collected from four swine and five poultry commercial abattoirs and two swine farms. One effluent sample each was collected from four wastewater treatment plants (WWTP) and a tertiary hospital setting. Phenotypic and genotypic techniques were used including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Results showed EHEC and EPEC prevalence was 4.1 % (22/542) and 20.8 % (113/542), respectively, with the O26 serogroup detected the most in PEC isolates. According to the PFGE dendrogram, isolates from poultry, human hand swabs and run-off water clustered together. Diverse virulence factors such as the novel stx2k subtype and eae genes were detected among the 36 representative PEC isolates according to WGS. The results showed that 66.7 % (24/36) of sequenced PECs presented with multi-drug resistance (MDR) to β-lactamase 13.9 % (5/36), aminoglycoside 61.1 % (22/36), tetracycline 41.7 % (15/36) and quinolones 38.9 % (14/36). No colistin nor carbapenem resistance was detected. Sequence types (STs) associated with MDR in this study were: ST752, ST189, ST206, ST10, ST48 and ST38. The findings highlight the threat of zoonotic pathogens to close human contacts and the need for enhanced surveillance to mitigate the spread of MDR foodborne PECs.
致病性大肠杆菌（PEC）是一种重要的食源性病原体，可以导致人类严重疾病。PEC 在人类和动物的肠道中大量繁殖，并可能通过粪便传播污染包括食物和水在内的多个生态系统。屠宰场和农场的员工面临着接触 PEC 的高风险，这可能会通过人与人之间的接触转化为社区风险。为了确定南非豪登省和林波波省的 PEC 的流行病学和耐药组，我们从四个生猪和五个家禽商业屠宰场和两个生猪农场采集了 198 份猪粪便样本、220 份家禽泄殖腔拭子、108 份人手部拭子、11 份屠宰场和农场的径流水样。从四个废水处理厂（WWTP）和一个三级医院各采集了一份废水样本。使用聚合酶链反应、脉冲场凝胶电泳（PFGE）和全基因组测序（WGS）等表型和基因型技术。结果显示，EHEC 和 EPEC 的流行率分别为 4.1%（22/542）和 20.8%（113/542），PEC 分离株中 O26 血清群检出率最高。根据 PFGE 聚类树，来自家禽、人手部拭子和径流水的分离株聚集在一起。根据 WGS，在 36 个代表性 PEC 分离株中检测到了多种毒力因子，包括新型 stx2k 亚型和 eae 基因。结果表明，测序的 PEC 中有 66.7%（24/36）对β-内酰胺酶表现出多药耐药（MDR），对 13.9%（5/36）的氨基糖苷类药物、61.1%（22/36）的四环素类药物、41.7%（15/36）的喹诺酮类药物和 38.9%（14/36）的药物耐药。未检测到粘菌素或碳青霉烯类药物耐药性。本研究中与 MDR 相关的序列类型（STs）为：ST752、ST189、ST206、ST10、ST48 和 ST38。这些发现突显了人畜共患病病原体对密切接触人类的威胁，需要加强监测以减轻食源性病原体 MDR-PEC 的传播。
