摘要
为了解大熊猫粪源大肠杆菌的耐药性、整合子-基因盒的分布特性,分析整合子对细菌耐药性的影响,采用Kirby-Bauer（K-B）纸片法进行了50株大肠杆菌对13种抗菌药物的药物敏感性试验;PCR-测序法检测了1、2、3型整合酶基因,进一步对阳性菌株可变区的基因盒序列鉴定分析。结果显示,菌株对13种抗菌药物表现出不同的耐药性,其中对氨苄西林、头孢唑林、四环素和复方新诺明表现出较高耐药性（耐药率为30%-68%）,对其余药物耐药性较低（耐药率低于14%）;50株菌中有15株（30%）含有1型整合子,未发现2型和3型整合子;15株1型整合子阳性菌中,有6株（40%）扩增出1200-2000 bp的基因盒,主要介导氨基糖苷类和磺胺-甲氧苄啶耐药的aad A和dfr A基因家族。以dfr A27＋aad A2为主（检出率83.33%）,1株为aac A4＋aad A1＋cat B2。以上说明本次检测的大熊猫粪源大肠杆菌对多种抗菌药物呈低水平耐药;1型整合子在大肠杆菌中广泛分布,整合子-基因盒是造成整合子阳性菌株耐氨基糖苷类、磺胺-甲氧苄啶类、氯霉素的主要原因。
To investigate the antimicrobial resistance,distribution of integron-gene cassettes of Escherichia coli that isolated from the feces of giant pandas,as well as determine the correlation between resistance and integron-gene cassette,KirbyBauer method was used to test the susceptibility of 50 E. coli isolates against 13 antimicrobial agents. PCR-sequencing was established to detect the integrons（ class 1,2,3） and gene cassettes that were harbored in E. coli isolates. The results showed that the isolates had different resistant levels to the 13 tested antimicrobials： high resistant level was observed in ampicillin,cefazolin,tetracycline and SMZ-TMP（ resistant rates ranged from 30% to 68%）; 30% of the isolates were found to harbor the class 1 integron,and no class 2 or class 3 integron was detected; gene cassettes with length of 1200- 2000 bp were amplified from 40% of the 15 int I1-positive isolates,and the main resistant gens were identified as encoding aminoglycoside adenyltransferase（ aad A） and dihydrofolate reductase（ dfr A）. The main arrays of gene cassettes were dfr A27 ＋ aad A2（ detection rate was 83. 33%）,moreover,1 isolate was found to harbor the gene cassettes aac A4 ＋ aad A1 ＋ cat B2 discovered. In conclusion,the E. coli isolates from the feces of giant pandas were sensitive to majority of the tested antimicrobial agents. Class l integron was widely distributed in E. coli strains from giant pandas,and integron-gene cassettes were responsible for resistant to aminoglycosides,sulfonamides-TMP and chloramphenicol.
出处
《四川动物》
北大核心
2015年第4期489-493,共5页
Sichuan Journal of Zoology
基金
国家科技支撑计划项目(2012BAC01B06)
关键词
大熊猫
粪源大肠杆菌
耐药性
整合子-基因盒
giant panda
fecal Escherichia coli
resistance
integron-gene cassette
