The aim of this work was the genetic characterization of cefotaxime-resistant enterobacteria from animals (53 samples), the surface water of rivers (17 samples), and wastewater treatment plants (43 samples) in Tunisia. A total of 48 (42.4%) cefotaxime-resistant isolates were recovered. An extended spectrum beta-lactamase (ESBL) phenotype with a positive double-disk synergy test (DDST) was exhibited by 34 (70.8%) and 14 (29.1%) isolates from water and animal origins, respectively. Isolates from water were identified as: Escherichia coli (n = 17), Hafnia spp. (n = 13), Citrobacter spp. (n = 1), Enterobacter cloacae (n = 1), Klebsiella pneumoniae (n = 1), and K. oxytoca (n = 1). Animal isolates were identified as: E. coli (n = 11), E. cloacae (n = 1), Hafnia spp. (n = 1), and K. pneumoniae (n = 1). PCR investigation of blaCTX-M, blaTEM, and blaSHV genes showed that amongst the 48 isolates with a positive DDST, 41 (87.5%) carried the blaCTX-M gene, 1 isolate harbored the blaSHV gene, and 1 isolate coharbored blaCTX-M with blaSHV genes. The class 1 and 2 integrons were detected in 27 (56.2%) and 1 (2%) isolates, respectively. Our study showed a significant occurrence of ESBL-producing enterobacteria in animals and aquatic environments with a predominance of blaCTX-M genes.

中文翻译：

---

动物和水源性广谱产生β-内酰胺酶的肠杆菌科细菌的多重耐药性和blaCTX-M优势。

这项工作的目的是从突尼斯的动物（53个样品），河流地表水（17个样品）和废水处理厂（43个样品）中对头孢噻肟耐药肠杆菌进行遗传表征。总共回收了48种（42.4％）耐头孢噻肟耐药菌株。分别从水和动物来源分离出的34个（70.8％）和14个（29.1％）分离物表现出具有阳性双盘协同试验（DDST）的超广谱β-内酰胺酶（ESBL）表型。从水中分离出的细菌被鉴定为：大肠埃希菌（n = 17），Hafnia spp。（n = 13），柠檬酸杆菌属。（n = 1），阴沟肠杆菌（n = 1），肺炎克雷伯菌（n = 1）和产氧假丝酵母（n。1）。动物分离株鉴定为：大肠杆菌（n = 11），阴沟肠杆菌（n = 1），Hafnia spp。（n = 1）和肺炎克雷伯菌（n = 1）。blaCTX-M，blaTEM，blaSHV和blaSHV基因显示，在DDST阳性的48个分离株中，有41个（87.5％）携带blaCTX-M基因，其中1个分离株带有blaSHV基因，另外1个分离株与blaSHV基因共携带blaCTX-M。分别在27（56.2％）和1（2％）分离物中检测到1类和2类整合素。我们的研究表明，在动物和水生环境中，以blaCTX-M基因为主的ESBL产肠细菌的发生率很高。