Genotypic and phenotypic analysis of fish pathogen, Nocardia seriolae, isolated in Taiwan

• Published in: Aquaculture 2009-09, Vol.294 (3), p.165-171
• Main Authors: Shimahara, Yoshiko, Huang, Yun-Fen, Tsai, Ming-An, Wang, Pei-Chi, Yoshida, Terutoyo, Lee, Jian-Lin, Chen, Shih-Chu
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Alpha-glucosidase; Animal aquaculture; animal pathogenic bacteria; Animal productions; API ZYM; Aquaculture; bacterial infections; bass; beta-galactosidase; Biological and medical sciences; Brackish; Dicentrarchus labrax; disease surveillance; enzyme activity; Enzymes; epidemiological studies; Epidemiology; Epinephelus; Fish; fish culture; fish diseases; Fish pathogen; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; genetic variation; Genetics; Genotype & phenotype; Lateolabrax japonicus; Lutjanus erythropterus; Marine; Micropterus salmoides; Morone saxatilis; Mugil cephalus; mullet; Nocardia seriolae; Pathogens; PFGE; phenotypic variation; pulsed-field gel electrophoresis; Scatophagus argus; snapper; Taiwan; Terapon; Terapon jarbua; Trachinotus blochii; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2009.06.017

The phenotypic and genetic characterizations of 92 isolates of fish pathogen Nocardia seriolae from grey mullet ( Mugil cephalus), striped bass ( Morone saxatilis), crimson snapper ( Lutjanus erythropterus), sea bass ( Lateolabrax japonicus), largemouth bass ( Micropterus salmoides), grouper ( Epinephelus spp.), jarbua terapon ( Terapon jarbua), snubnose pompano ( Trachinotus blochii), and spotted scaf ( Scatophagus argus) isolated in Taiwan during 1997–2007 were examined to investigate the epidemiological relationship among isolates. The phenotypic and genetic characterizations were determined by API ZYM and pulsed-field gel electrophoresis (PFGE) analysis, respectively. In the API ZYM test, N. seriolae were divided into alpha-glucosidase-positive and alpha-glucosidase-negative strains. The alpha-glucosidase activity was also investigated by inoculating N. seriolae in a medium containing substrate 4-nitrophenyl-alpha- d-glucopyranoside. Results of the alpha-glucosidase activity obtained by both methods indicate that all the strains had positive reaction with some exception. In PFGE analysis, digestions with restriction enzymes Xba I and Ase I produced 12 and 9 restriction patterns, respectively. The alpha-glucosidase positive strains were assigned to pulsotypes X1–10 and A1–7. Predominant pulsotypes X1 and A1 were obtained from > 79% of strains (73 and 78 strains of 92 strains by Xba I and Ase I, respectively), demonstrating a clonal dissemination of N. seriolae in Taiwan. On the other hand, alpha-glucosidase-negative strains were assigned to X11–12 and A8–9, which differed from those of alpha-glucosidase-positive strains in Taiwan.