2.2. Biochemical tests
Twenty-six putative E. ictaluri isolates (whitish, pinpoint
colonies) were cultured on BHIA at 28 °C for 48 h and then subjected to
biochemical characterization. Gram staining was conducted and the
bacterial morphology was examined under a light microscope (Zeiss, Jena,
Germany). Oxidase and catalase tests were conducted on all 26 isolates,
as described by Crumlish et al. (2002). Other biochemical tests were
performed using the API 20E kit (bioMérieux, Marcy l’Etoile, France),
following the manufacturer’s instructions.