不同来源美人鱼发光杆菌美人鱼亚种菌株表型差异性分析

Studies on the phenotypic differences of different Photobacterium damselae subsp. damselae strains

美人鱼发光杆菌美人鱼亚种(Photobacterium damselae subsp. damselae)可感染多种海水养殖动物发病,为研究不同菌株之间的表型差异性,作者对不同来源的 25 株美人鱼发光杆菌美人鱼亚种菌株的溶血特性、生理生化特征、药物敏感性以及 5 种最敏感抗生素的最小抑菌浓度进行了分析。结果表明:(1)25 株菌株在 TSB 培养基上均为白色不透明圆形菌落, TCBS 培养基上菌落显绿色,直径为 1~2 mm,革兰氏染色均为阴性;(2)25 株菌对 3%胰胨水、无盐胰胨水、葡萄糖、肌醇、3% NaCl、ONPG 以及精氨酸双水解酶等 22 种生化反应呈现出高度一致性,对于丙二酸盐、赖氨酸脱羧酶、尿素酶以及西蒙氏枸橼酸盐表现出明显差异;(3)所有菌株中仅有 2 株菌表现出β溶血, 23 株菌表现出α溶血;(4)25 株菌对丁胺卡那、链霉素、复方新诺明、乙酰螺旋霉素以及苯唑青霉素 5 种抗生素均表现出耐药性;对萘啶酸、氟罗沙星、菌必治、头孢胺噻肟、盖伯斯林以及洛美沙星 6 种抗生素均表现敏感性;对恩诺沙星等 27 种抗生素的药物敏感性存在显著差异;(5)5 种抗生素的 MIC 检测结果表明, 25 株菌对萘啶酸以及环丙沙星的 MIC 基本一致,浓度分别是 2.5~10 μg/mL 以及低于 2.5 μg/mL,对多粘菌素 B、氧氟沙星以及洛美沙星 3 种抗生素差异较大。通过本研究证实不同来源的美人鱼发光杆菌美人鱼亚种菌株表型特征存在明显差异。

Photobacterium damselae subsp. damselae is an important pathogen to cause different kinds of marine animal disease. In this study, 25 strains of this bacterium which isolated from different host and region were se- lected to analyze their difference of physiology, biochemistry, drug resistance and MIC of 5 antibiotic. The results showed that different phenotypic characteristics existed among the 25 strains. They are:(1) All these strains formed whites and opaque colonies on TSB agar and green colonies on TCBS medium with diameter 1-2mm, and they were all Gram-negative (2) There were 22 biochemical reactions characteristics similar among the 25 strains, including 3% peptone water, salt-free peptone water, glucose, inositol, 3% NaCl, ONPG and arginine dihydrolase et al. The 4 biochemical reaction of malonate, urease, lysine decarboxylase and simmont citrate were different.(3) Only 2 strains showed beta hemolysis, the others 23 strains showed alpha hemolysis,.(4) All 25 strains showed resistance to 5 antibiotics of Amikacin, Streptomycin, SMZ-TMP, Acetylspiramycin and Oxacillin, and susceptivity to 6 antibiotics of Nalidixic acid, Fleroxacin, Cetriaxone Sodium, Cefotaxime, Ceftizoxime and Lomefloxacin. The differences of drug susceptivity existed in the others 27 antibiotics including Enrofloxacin and so on.(5)The MIC of these 25 strains were almost the same to 2 antibiotics of Nalidix acid and Ciprofloxacin, but significant difference to 3 antibiotics of Polymyxin B, Ofloxacin and Lomefloxacin. This study confirmed that the phenotypic characteristics of Photobacterium damselae subsp. damselae strains which isolated from different host and region were signifi- cantly different.