Streptococcus agalactiae, an Emerging Pathogen for Cultured Ya-Fish, Schizothorax prenanti, in China

作者：Yi Geng, K. Y. Wang, Xiaoli Huang, D. F. Chen, C. W. Li, Shuze Ren, Yi Liao, Z. Y. Zhou, Qiuning Liu, Zong‐Jun Du, Weiming Lai · 发表于：Transboundary and Emerging Diseases · 年份：2011 · DOI：10.1111/j.1865-1682.2011.01280.x · 被引用次数：109 · 研究领域：Neonatal and Maternal Infections、Aquaculture disease management and microbiota、Streptococcal Infections and Treatments

Streptococcus agalactiae (Group B streptococcus) has emerged as an important pathogen that affects humans and animals, including aquatic species. S. agalactiae infections are becoming an increasing problem in aquaculture and have been reported worldwide in a variety of fish species, especially those living in warm water. Recently, a very serious infectious disease of unknown aetiology broke out in ya-fish (Schizothorax prenanti) farms in Sichuan Province. A Gram-positive, chain-forming coccus was isolated from moribund cultured ya-fish. The goals of this study were to identify the bacterial strains isolated from diseased fish between 2009 and 2011 in Sichuan Province, China, to evaluate the pathogenicity of the pathogen in ya-fish, crucian carp (Carassius carassius) and the Nile tilapia (Oreochromis niloticus); and to determine the susceptibility of the pathogen strains to many currently available anti-microbial agents. The virulence tests were conducted by intraperitoneal injection of bacterial suspensions. In this study, four strains of a Gram-positive, chain-forming coccus were isolated from moribund cultured ya-fish (S. prenanti). The coccoid microorganism was identified as S. agalactiae using a commercial streptococcal grouping kit and 16S rDNA sequencing analysis. Susceptibility of the isolates to 22 antibiotics was tested using the disc diffusion method. All isolates showed a similar antibiotic susceptibility, which were sensitive to amoxicillin, ciprofloxacin, lomeflo...