【摘要】 从患病锦鲤体内分离得到1株细菌ML1,经人工感染后发现ML1具有较高的致病性,临床症状与自然发病症状一致,96 h的LD50为5.0×107cfu/m L。ML1菌株革兰染色呈阴性,杆状。16S rRNA基因序列分析结果显示,序列片段长度为1 419 bp,ML1菌株在系统发育树上与嗜水气单胞菌聚类,相似性达到100%。综合VITEK 2 Compact全自动微生物鉴定仪的生理生化特征分析、形态学观察、人工感染以及16S rRNA基因序列分析,将ML1菌株鉴定为嗜水气单胞菌。ML1菌株的最适生长p H为7~9,最适生长温度为28℃。在28℃200 r/min条件下的生长周期是:0~4 h为生长延迟期,4~10 h为对数生长期,10~24 h为稳定期,24~48 h为衰亡期。药敏试验表明,ML1菌株对多黏霉素B、环丙沙星、诺氟沙星等高度敏感,对磺胺异恶唑中度敏感,对麦迪霉素、氨苄西林、林可霉素等不敏感。研究结果为指导临床合理用药提供了科学依据。更多还原

【Abstract】 One bacterial strain named ML1 was isolated from diseased carp. The artificial infection assay showed ML1 had a high virulence,and clinical symptoms of the artificially infected fish were similar to those in naturally infected fish. The LD50 was 5. 0x107 CFU / m L.The 16 S rRNA gene sequence analysis showed that ML1 has a similarity of 100% with Aeromonas hydrophila. The best growth p H and temperature of strain ML1 were between 7 and 9 and 28 ℃,respectively. Its growth curve under the condition of 28℃ and 200 r / min was as follows: the lag phase was 0 h ~ 4 h,the log phase was 4 h ~ 10 h,the stationary phase was 10 h ~ 24 h,and the decline phase was 24 h ~ 48 h. The antibiotic sensitivity test showed that the strain ML1 had hypersensitivity to polymixin B,hydrochloric and norfloxacin; medium sensitivity to sulfafurazole; nonsensitivity to midecamycin,ampicillin and cillimycin. This study is of guiding significance for the use of drugs in aquaculture.更多还原