Agricultural College, Guangdong Ocean University, Zhanjiang, China.
Curr Microbiol. 2011 Feb;62(2):623-7. doi: 10.1007/s00284-010-9753-8. Epub 2010 Sep 19.
Thirty-six strains, numbered from PY01 to PY36, were isolated from six moribund Oreochromis niloticus. The biochemical characteristics of all strains conformed to the species description of Aeromonas sobria on the basis of API 20E and Biolog GN system. Furthermore, gyrB sequence of strain PY36 was sequenced and showed high similarity (99.8%) with A. sobria in Genbank. Antibiotic-resistance of strain PY36 was assessed by the Kirby-Bauer disk diffusion method, and the results showed it was susceptible and moderately susceptible to 12 and 3 of the 19 antimicrobials tested. Virulence of strain PY36 to juvenile tilapia was also tested, and we found that LD₅₀ was about 4.17 × 10³ CFU per fish in intraperitoneal injection. This is the first article to report that A. sobria was the pathogenic agent of tail-rot disease in juvenile tilapia. A. sobria was multi-resistant to the most frequently used antimicrobial drugs in China, so the antimicrobial resistance test should be carried out when these bacteria are isolated from biological samples in order to avoid therapeutic failures and spread of the pathogenic organisms in the environment.
从 6 尾濒死的尼罗罗非鱼中分离到 36 株编号为 PY01 至 PY36 的菌株。所有菌株的生化特性均符合 API 20E 和 Biolog GN 系统中温和气单胞菌的种描述。此外，菌株 PY36 的 gyrB 序列测序结果与 Genbank 中的温和气单胞菌高度相似（99.8%）。采用 Kirby-Bauer 纸片扩散法评估菌株 PY36 的抗生素耐药性，结果表明其对 19 种测试抗生素中的 12 种和 3 种呈敏感和中度敏感。还测试了菌株 PY36 对幼罗非鱼的致病性，发现腹腔注射时 LD₅₀约为每尾鱼 4.17×10³ CFU。这是第一份报道温和气单胞菌是幼罗非鱼尾鳍腐烂病的病原体的文章。温和气单胞菌对中国最常用的抗菌药物具有多重耐药性，因此在从生物样本中分离这些细菌时应进行抗菌药物敏感性测试，以避免治疗失败和病原体在环境中的传播。
