BACKGROUND Epidemiological studies suggested that determinants for antibiotic resistance have originated in aquaculture. Recently, the integrated agriculture-aquaculture system has been implemented, where fish are raised in ponds that receive agriculture drainage water. The present study aims to investigate the occurrence of β-lactamase and carbapenemase-producing Enterobacteriaceae in the integrated agriculture-aquaculture and the consequent public health implication. METHODS Samples were collected from fish, fishpond water inlets, tap water, outlet water, and workers at sites of integrated agriculture-aquacultures. Samples were also taken from inhabitants of the aquaculture surrounding areas. All samples were cultured on MacConkey agar, the Enterobacteriaceae isolates were tested for susceptibility to cephalosporins and carbapenems, and screened for blaCTX-M-15, blaSHV, blaOXA-1, blaTEM, blaPER-1, blaKPC, blaOXA-48, and blaNDM. Strains having similar resistance phenotype and genotype were examined for the presence of Incompatible (Inc) plasmids. RESULTS A major proportion of the Enterobacteriaceae isolates were resistant to cephalosporins and carbapenems. Among the 66 isolates from fish, 34 were resistant to both cephalosporin and carbapenem groups, 26 to carbapenems alone, and 4 to cephalosporins alone. Of the 15 isolates from fishpond water inlets, 8 showed resistance to both groups, 1 to carbapenems alone, and 5 to cephalosporins alone. Out of the 33 isolates from tap water, 17 were resistant to both groups, and 16 to cephalosporins alone. Similarly, of the 16 outlet water isolates, 10 were resistant to both groups, and 6 to cephalosporins alone. Furthermore, of the 30 examined workers, 15 carried Enterobacteriaceae resistant strains, 10 to both groups, and 5 to cephalosporins alone. Similar strains were isolated from the inhabitants of the aquaculture surrounding areas. Irrespective of source of samples, strains resistant to all examined antibiotics, carried predominantly the carbapenemase gene blaKPC either alone or with the β-lactamase genes (blaCTX-M-15, blaSHV, blaTEM, and blaPER-1). The isolates from fish, water, and workers harboured a wide-range of multi-drug-resistance Inc. plasmids, which were similar among all isolates. CONCLUSION The present findings suggest transmission of the resistance genes among Enterobacteriaceae strains from different sources. This reiterates the need for control strategies that focus on humans, animals, water, and sewage systems to solve the antibiotic resistance problem.

中文翻译：

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在综合养鱼场中产生β-内酰胺酶和碳青霉烯酶的肠杆菌科细菌的出现。

背景技术流行病学研究表明，抗生素耐药性的决定因素起源于水产养殖。最近，已经实施了农业－水产养殖综合系统，在接受农业排水的池塘中养鱼。本研究旨在调查在农业-水产养殖综合生产中产生β-内酰胺酶和碳青霉烯酶的肠杆菌科的发生及其对公共卫生的影响。方法从鱼类，鱼塘进水口，自来水，出水口以及农业综合养殖场的工人中采集样品。还从水产养殖周边地区的居民中取样。所有样品均在MacConkey琼脂上培养，测试了肠杆菌科细菌分离株对头孢菌素和碳青霉烯类药物的敏感性，并筛选了blaCTX-M-15，blaSHV，blaOXA-1，blaTEM，blaPER-1，blaKPC，blaOXA-48和blaNDM。检查具有相似抗性表型和基因型的菌株的不相容（Inc）质粒的存在。结果大部分肠杆菌科细菌对头孢菌素和碳青霉烯类耐药。在鱼类的66种分离物中，有34种对头孢菌素和碳青霉烯类均具有抗性，仅对碳青霉烯类有26种，对头孢菌素仅4种。在鱼塘进水口的15株分离物中，有8株对两组都有抗药性，仅对碳青霉烯类有1株，对头孢菌素有5株。在自来水的33株分离物中，有17株对两组都有抗药性，而16株仅对头孢菌素有抗药性。同样，在16个出口水分离株中，有10个对两组都有抵抗力，而对头孢菌素则有6个。此外，在接受检查的30名工人中，有15名携带抗肠杆菌科菌株，两组均为10例，头孢菌素则为5株。从水产养殖周边地区的居民中也分离出了类似的菌株。无论样品来源如何，对所有已检查抗生素均具有抗性的菌株主要单独或与β-内酰胺酶基因（blaCTX-M-15，blaSHV，blaTEM和blaPER-1）一起携带碳青霉烯酶基因blaKPC。来自鱼，水和工人的分离株带有多种耐药性的Inc.质粒，在所有分离株中都相似。结论目前的发现表明耐药基因在不同来源的肠杆菌科菌株之间的传播。重申需要针对人类，动物，水，