State Key Laboratory of Organic Geochemistry, CAS Centre for PRD Environmental Pollution and Control Research, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Tianhe District, Guangzhou, China.
J Environ Sci Health B. 2013;48(11):999-1013. doi: 10.1080/03601234.2013.816611.
This study investigated antibiotic resistance profiles including antibiotic resistance frequencies, resistance genes and resistance patterns in Escherichia coli strains isolated from traditional and integrated aquaculture systems in South China by using antibiotic susceptibility testing and real time polymerase chain reaction (PCR) technique. The E. coli isolates were found to be resistant to at least one antibiotic among 12 antibiotics. Higher resistance frequencies to ampicillin, sulfamethoxazole, trimethoprime, streptomycin and tetracycline were found compared to the rest antibiotics. Among the 10 tetracycline resistance genes detected in the resistant isolates, the most prevalent tetracycline resistance genes were tetA, tetW and tetB with the frequency of 69.7%, 63.5% and 21.9%, respectively. Three sulfonamide resistance genes were detected in these resistant isolates, with their detection frequencies in the following order: sul2 (55.3%) > sul3 (28.2%) > sul1 (6.2%). Four resistance genes mainly encoding extended-spectrum β-lactamases (ESBLs) were detected in these resistant isolates, with the detection frequencies of blaTEM (28.4%) > blaOXA (9.7%) > blaCTX (9.3%) > blaCARB (5.2%) > blaSHV (0.0%). It was found that the integrated aquaculture system exhibited generally higher prevalence of antibiotic resistance than the traditional aquaculture system. An integrated aquaculture system could facilitate development of bacterial resistance and spread of the antibiotic resistance genes, and consequently become an important reservoir of resistance genes.
本研究通过抗生素药敏试验和实时聚合酶链反应（PCR）技术，调查了来自华南传统和综合水产养殖系统的大肠杆菌菌株的抗生素耐药谱，包括抗生素耐药频率、耐药基因和耐药模式。研究发现，大肠杆菌分离株对 12 种抗生素中的至少一种抗生素具有耐药性。与其他抗生素相比，它们对氨苄西林、磺胺甲恶唑、甲氧苄啶、链霉素和四环素的耐药频率更高。在耐药分离株中检测到的 10 种四环素耐药基因中，最常见的四环素耐药基因是 tetA、tetW 和 tetB，其频率分别为 69.7%、63.5%和 21.9%。在这些耐药分离株中检测到三种磺胺类耐药基因，其检出频率依次为 sul2（55.3%）>sul3（28.2%）>sul1（6.2%）。在这些耐药分离株中检测到 4 种主要编码超广谱β-内酰胺酶（ESBLs）的耐药基因，其检出频率依次为 blaTEM（28.4%）>blaOXA（9.7%）>blaCTX（9.3%）>blaCARB（5.2%）>blaSHV（0.0%）。研究发现，综合水产养殖系统的抗生素耐药性普遍高于传统水产养殖系统。综合水产养殖系统可能促进了细菌耐药性的发展和抗生素耐药基因的传播，因此成为了耐药基因的重要储存库。
