Isolation and characterization of pathology in case of massive mortality by Photobacterium damselae subsp. piscicida in Rachycentron canadum

  • Marina T. Shimada Unesp
  • Jefferson Yunis Aguinaga UNESP http://orcid.org/0000-0002-1959-4350
  • Victor A. Cueva-Quiroz Unesp
  • Gustavo S Claudiano Unesp
  • Jair R. Engrácia Filho Pontifical Catholic University of Paraná (PUCPR)
  • Jose L. P. Mouriño Federal University of Santa Catarina (UFSC)
  • Flávio Ruas de Moraes Unesp
  • Julieta R. Engrácia de Moraes Unesp
Keywords: Cages, pseudotuberculosis, granulomas, antibiotic resistance, Neobenedenia melleni

Abstract

This study aimed to investigate outbreak with high mortality in cultured juvenile cobia occurred in Southeast Brazil in 2011. Fish displayed retarded growth rates, lethargy, fin ulceration, skin depigmentation, corneal opacity, and physical deformities. Internally, livers were increased in volume and pale in different degrees. Firm whitish nodules were disseminated in the liver, kidney and spleen. A moderate number of parasites identified as Neobenedenia melleni were recovered from the body surface. Microscopically, severe hepatic steatosis and extensive granulomatous lesion were identified in all fish sampled. Microbiological analysis of moribund fish revealed the presence in pure culture of a Gram-negative bacterium identified as Photobacterium damselae subsp. piscicida using biochemical and molecular characteristics. Analysis of the partial 16S rRNA sequences confirmed the results demonstrating high identity (98%). The isolates were sensitive to chloramphenicol and enrofloxacin and resistant to ciprofloxacin, florfenicol, doxycycline hydrochloride, norfloxacin, oxytetracycline, and tetracycline. Chronic pasteurellosis was considered as the main problem in the farm, while hepatic steatosis and parasitic infestation may have contributed to the development of the process.

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Published
2020-06-20
How to Cite
Shimada, M. T., Yunis Aguinaga, J., Cueva-Quiroz, V. A., Claudiano, G. S., Engrácia Filho, J. R., Mouriño, J. L. P., Ruas de Moraes, F., & Engrácia de Moraes, J. R. (2020). Isolation and characterization of pathology in case of massive mortality by Photobacterium damselae subsp. piscicida in Rachycentron canadum. Bioscience Journal , 36(5). https://doi.org/10.14393/BJ-v36n5a2020-41745
Section
Agricultural Sciences