青海湖斑头雁粪便细菌分离鉴定与耐药性分析

Isolation, Identification and Antimicrobial Susceptibility of Fecal Bacteria from Bar-headed Geese Anser indicus from Qinghai Lake

为了解斑头雁(Anser indicus)粪便中携带细菌多样性及其耐药情况,对青海湖斑头雁粪便细菌进行分离培养、生化鉴定、16S r RNA基因PCR扩增和序列分析,并进行细菌耐药性试验。结果显示:从30份斑头雁粪便中共分离到123株细菌,可分为10类细菌,分别从每类细菌中挑出一株代表性菌株进行鉴定,鉴定结果显示这10株细菌分别为大肠埃希菌(Escherichia coli)、水生拉恩氏菌(Rahnella aquatilis)、蒙氏肠球菌(Enterococcus mundtii)、枯草芽孢杆菌(Bacillus sublitis)、柠檬节杆菌(Arthrobacter citreus)、腐败希瓦氏菌(Shewanella pulrefaciens)、河生肠杆菌(Enterobacter amnigenus)、成团泛菌(Pantoea agglomerans)、杀鲑气单胞菌(Aeromonas salmonicida)和产酸克雷伯菌(Klebsiella oxytoca)。选取氨苄西林、哌拉西林、阿莫西林/克拉维酸、头孢唑林、头孢他啶、氨曲南、庆大霉素、卡那霉素、阿米卡星、四环素、氯霉素、环丙沙星、诺氟沙星药敏纸片,对分离菌株进行耐药性分析,发现水生拉恩菌、杀鲑气单胞菌和成团泛菌表现为多重耐药性;其他细菌对氨苄西林和四环素有一定的耐药性,对其余受试药物都有不同程度的敏感性。野鸟携带耐药性的条件致病菌,可能会对野生动物健康造成威胁,本研究对斑头雁粪便中携带的条件致病菌及其耐药性进行探究,以期为野鸟携带细菌的耐药机制提供研究理论依据,同时也对野生动物疫病的监测与防控有重要意义。

To investigate the diversity and antibiotic susceptibility of bacteria from Bar-headed Geese（Anser indicus）, we collected their feces in Qinghai Lake area during July, 2015. Bacteria were isolated and identified by colonial morphology observation, biochemical properties tests, amplification of 16 S r RNA genes by PCR and sequences analysis. A total of 123 bacteria strains belonging to 10 genus were isolated from 30 feces samples. One strain from each of the 10 genus was further cultured and identified. The growth statuses of 10 strains on nutrition agar medium were shown in Fig. 1. The results of gram dyeing, culture shape and detection rate of isolated bacterial strains were shown in Table 1. The biochemical analysis results and Phylogenetic analysis were presented in Table 2 and Fig. 3. The results indicated that 10 isolated strains were Escherichia coli, Rahnella aquatilis, Enterococcus mundtii, Bacillus sublitis, Arthrobacter citreus, Shewanella pulrefaciens, Enterobacter amnigenus, Pantoea agglomerans, Aeromonas salmonicida, and Klebsiella oxytoca, respectively. The resistance of isolates to 13 drugs（Ampicillin, Piperacillin, Amoxicillin/Clavulanic Acid, Cefazolin, Ceftazidime, Aztreonam, Gentanicin, Kanamycin, Amikacin, Tetracyline, Chloramphenicol, Ciprofloxacin, Norfloxacin） was evaluated and shown in Table 3. Among these bacteria, R. aquatilis, A. salmonicida and P. agglomerans were multidrug resistant, while other bacteria were resistant to ampicillin and tetracycline and showed varying degrees of sensitivity to the rest drugs. The results obtained from this study indicate that Bar-headed Geese carry amounts of pathogens which exhibit antibiotic resistance. This would provide references to study the antibiotic resistance mechanisms of bacteria in wild birds, and is of great value to the surveillance of wildlife disease.