发布者：抗性基因网 时间：2020-04-23 浏览量：886
摘要
目标：
研究底泥分离的大肠杆菌、屎肠球菌和鱼类分离的garvieae乳球菌的耐药基因（ARGs）和重金属耐药基因（HMRGs）。
材料和方法：
通过16srRNA基因测序对分离的细菌进行鉴定。鉴定后，测定四环素（tetA，tetB，tetD）、红霉素（ereA，ereB）、磺胺类（sulI，sulII）、甲氧苄啶（dhfrA1）、β-内酰胺（blaTEM，blaCTX，ampC）、氟苯尼考（floR）和1类整合子（Int1）耐药基因。用聚合酶链反应（PCR）分析了HMRGs的存在，包括铜（copA）、汞（mer）、镉、锌、钴（czc）和镍、钴镉（ncc）。检查所有菌株的质粒上是否存在ARGs和/或HMRGs。
结果：
β-内酰胺类耐药基因频率最高，为49.7%～62.3%，其次是磺胺类、四环素类、非尼考类和大环内酯类耐药基因。网箱养鱼对底泥细菌ARG频率有显著影响，而对HMRGs频率无显著影响。在所有细菌中，最普遍的HMRG被确定为抗汞mer基因。四种HMRGs均位于质粒上，频率为1.20%～32.53%。质粒上ARGs的存在率在2.2%（Dhfr1）到75%（AmpC，blactx，tetB）之间，且不含tetD和ereB基因。
结论：
研究结果表明，养鱼对底泥细菌的耐药性有显著影响。
To characterize antibiotic resistance genes (ARGs) and heavy metal resistance genes (HMRGs) of Escherichia coli and Enterococcus faecium isolated from the sediment and Lactococcus garvieae isolated from fish.
The isolated bacteria were identified by sequencing 16S rRNA genes. After identification of the bacteria, tetracycline (tetA, tetB, tetD), erythromycin (ereA, ereB), sulfonamides (sulI, sulII), trimethoprim (dhfrA1), β-lactam (blaTEM, blaCTX, ampC), florfenicol (floR), and class 1 integron (Int1) resistance gene were then determined. The presence of HMRGs, including copper (copA), mercury (mer), cadmium, zinc, cobalt (czc), and nickel, cobalt cadmium (ncc), was also analyzed by PCR. All strains were checked for the presence of ARGs and/or HMRGs on the plasmid.
The frequency of the β-lactam resistance gene was highest and ranged from 49.7% to 62.3%, followed by sulfonamides, tetracyclines, phenicols, and macrolide resistance genes. The cage culture fish farming practice showed significant effects on ARG frequency of bacteria isolated from the sediment, whereas it had no effect on the frequency of HMRGs. The most prevalent HMRG was determined as mercury-resistant mer gene in all bacteria. All four of the HMRGs were located on plasmids with frequency ranging from 1.20% to 32.53%. The presence of ARGs on plasmids ranged between 2.2% (Dhfr1) and 75% (AmpC, blactx, tetB), and plasmids did not contain tetD and ereB genes.
The results of this study indicate that fish farming can significantly influence the antimicrobial resistance properties of bacteria isolated from sediment samples.