细鳞鱼气单胞茵的分离、鉴定及药敏试验

Isolation,identification and drug sensitive test of Aeromonas from lenok Brachymystax lenok

从患病细鳞鱼Brachymystax lenok体内分离出两种菌株（记为BAS和BAH），均属于革兰氏阴性短杆菌，无芽孢，元荚膜，多数呈单个排列，极端有单鞭毛。对两种菌株的菌落形态鉴定结果表明：BAS的菌落呈圆形，为浅黄色，半透明，无水溶性色素；BAH的菌落也呈圆形，中央微高，为灰白色。经API20NE细菌生化鉴定，BAS和BAH菌株分别为温和气单胞菌Aeromonas，sobria血和嗜水气单胞菌A．hydrophila，其鉴定率分别为98．1％和99．3％。注射剂量为1×10^7 CFU／mL时表现出较强的致病性，感染12d时，细鳞鱼的死亡率为100％。药物敏感试验结果表明：两种菌株对妥布霉素（TOB）、四环素（TET）、庆大霉素（GEN）、卡那霉素（KiN）、氟哌酸（NOR）、环丙沙星（CIP）、左氧氟沙星（LVX）高度敏感；对呋喃唑酮（FUR）、呋喃那斯、氯霉素（CHL）、复方新诺明（TST）中度敏感；对阿奇霉素（AZI）、红霉素（ERY）不敏感。

Two bacteria, BAS and BAH, were isolated from the dying lenok Brachymystax lenok, and were gramnegative, rods with polar single-flagella. The BAS colony was found to be round in shape, huff, and translucent, without water-solubility pigment,while BAH was round, hoar, and slight higher in the center. Thus the BAS and BAH were identified as Aerornonas sobria and Aeromonazhy hydrophila by bacteria certification with the identification percent of 98.1% in the BAS and 99.3% in the BAH by API 20NE. The injection at a dose of 1×10^7 CFU/ mL led to intense pathogenicity and 100% mortality in 12 days. The drug sensitive test showed that the stains had high sensitivity to tobramycin, tetracycline, gentamicin, kanamycin, norfloxacin, ciprofloxacin, and levofloxacin, and middle sensitivity to furaxone, furanace, chloramphenicol, trimethoprim and sulphame-thoxazole, and resistance to azithromycin and erythromycin.