【摘要】 为研究近年来禽致病性大肠杆菌(APEC)的耐药性,本研究室于2018年～2019年对江苏北部及周边地区228份水禽组织病料样品(鸭头、鸭肝样品;鹅头、鹅肝样品)进行了细菌分离培养和APEC的PCR鉴定。对分离到的APEC菌株采用K-B纸片法进行药敏试验;同时对其碳青霉烯类、β-内酰胺类、氨基糖苷类、磺胺类、粘菌素类、喹诺酮类、四环素类7大类共计16种耐药基因进行了PCR检测。结果显示,在分离到的细菌中,共鉴定出50株APEC菌株。药敏试验结果显示,APEC分离菌株对四环素、氨苄西林、氟苯尼考耐药性较强,耐药菌株分别占100%、96%、86%;对头孢噻肟、恩诺沙星、链霉素、氧氟沙星中等耐药,耐药菌株分别占76%、70%、58%、36%;对美罗培南、呋喃妥因、丁胺卡那霉素的耐药性较低,耐药菌株仅分别占4%、4%、6%。其中多重耐药性较严重,耐4、5、6、7种抗生素的现象较普遍。在对其β-内酰胺类的耐药基因检测中,CTX-M、TEM、SHV的检出率分别为60%、58%、20%;氨基糖苷类:ant(3’’)-I a、aac(3’)-I b的检出率分别为0,50%(25/50);磺胺类sul I的检出率为82%(41/50);粘菌素类mcr-1的检出率为6%(3/50);喹诺酮类:qnrB、parC的检出率分别为68%(34/50)、98%(49/50);四环素类:tetA、tetB的检出率分别为66%(33/50)、10%(5/50)。值得注意的是,从50株APEC分离菌中,鉴定出3株携带粘菌素类耐药基因mcr-1和2株携带碳青霉烯类耐药基因NDM的APEC,进一步经改良Hoge试验检测该2株菌均产碳青霉烯酶。表明这两株菌均耐美罗培南等碳青霉烯类抗生素,也进一步表明分离的APEC耐药情况的严重性。本研究为养禽场相关疫病的用药提供了参考依据。更多还原

【Abstract】 The purpose of this experiment is to study the drug resistance of avian pathogenic Escherichia coli(APEC) isolated in recent years. The bacteria were isolated and identified from 228 waterfowl samples(head and liver samples from ducks and geese) in northern Jiangsu and surrounding areas in 2018-2019. The K-B disk method was used to evaluate the drug sensitivity of the APEC isolates. At the same time, 16 drug resistance genes for seven species, i.e., carbapenems, beta-lactamides, aminoglycosides,sulfonamides, polycolistin, quinolones and tetracycline were detected by PCR amplification. Results showed that a total of 50 APEC strains were identified from the isolated bacteria. The results of drug sensitivity test showed that APEC isolates had strong resistance to tetracycline, ampicillin and florfenicol, and the resistant strains accounted for 100%, 96% and 86% respectively; the isolates of APEC were moderately resistant to cefotaxime, enoxacin, streptomycin and ofloxacin, accounting for 76%, 70%, 58% and 36%respectively; the isolates of APEC were less resistant to meropenem, furantoin and amikacin, and the resistant strains accounted for4%, 4% and 6% respectively. The multi-drug resistance was serious and the resistance to 4, 5, 6 or 7 antibiotics was common. In the detection of beta-lactam resistance genes, the detection rates of CTX-M, TEM, SHV was 60%, 58%, 20% respectively; the detection rates of aminoglycosides: ant(3’’)-I a and aac(3’)-I b were 0, 50%(25/50), respectively; the detection rates of sulfonamides: sul I was82%(41/50); the detection rates of colistin: mcr-1 was 6%(3/50); the detection rates of quinolones: qnr B and par C were 68%(34/50) and 98%(49/50), respectively; the detection rates of tetracycline: tet A and tet B were 66%(33/50) and 10%(5/50), respectively. It is noteworthy that three strains carry the mcr-1 gene and two strains carry the NDM gene from the isolated APEC. The drug resistance genes of meropenem and colistin were detected from APEC isolated in this study, which combined with the "last line of defense" against gram-negative bacterial infection, further indicating the seriousness of drug resistance of these APEC isolates. In this study, the results showed that the isolated APEC drug resistance was severe and the multiple drug resistance was serious, which provided a reference for the drug use of related diseases in poultry farms.更多还原