Identification and virulence of Aeromonas dhakensis, Pseudomonas mosselii and Microbacterium paraoxydans isolated from Nile tilapia, Oreochromis niloticus, cultivated in Mexico
Article first published online: 4 JUL 2013
© 2013 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 115, Issue 3, pages 654–662, September 2013
How to Cite
Soto-Rodriguez, S.A., Cabanillas-Ramos, J., Alcaraz, U., Gomez-Gil, B. and Romalde, J.L. (2013), Identification and virulence of Aeromonas dhakensis, Pseudomonas mosselii and Microbacterium paraoxydans isolated from Nile tilapia, Oreochromis niloticus, cultivated in Mexico. Journal of Applied Microbiology, 115: 654–662. doi: 10.1111/jam.12280
- Issue published online: 14 AUG 2013
- Article first published online: 4 JUL 2013
- Accepted manuscript online: 13 JUN 2013 01:11AM EST
- Manuscript Accepted: 6 JUN 2013
- Manuscript Revised: 5 JUN 2013
- Manuscript Received: 29 APR 2013
- Aquatic Animal Health Sinaloa State Committee (CESASIN in Spanish)
- Fundación Produce Sinaloa
- Aeromonas dhakensis ;
- cage culture;
- fish pathogen;
- Microbacterium paraoxydans ;
- Nile tilapia;
- Pseudomonas mosselii
To identify bacterial pathogens of diseased NiIe tilapia Oreochromis niloticus and determine their virulence.
Methods and Results
Sixteen bacterial isolates were recovered from diseased Nile tilapias (O. niloticus) reared in floating cages in Adolfo Lopez Mateos (ALM), Sanalona and Dique IV dams in Sinaloa, Mexico, from February to May 2009. The bacterial isolates were identified by phenotypic and molecular (rep-PCR and 16S rRNA sequencing) methods and were mostly isolated from the kidneys and the brain of tilapias. Bacterial cells and extracellular products (ECPs) of strains were characterized and used in experimental infections with sole Solea vulgaris and Mozambican tilapia Oreochromis mossambicus. The fish challenged with Aeromonas dhakensis sp. nov. comb nov, Pseudomonas mosselii and Microbacterium paraoxydans (3·1 × 106 CFU g−1) exhibited mortality between 40 and 100% starting at 6 h postinoculation. The ECPs displayed gelatinase, haemolytic and cytotoxic activity, causing the total destruction of the HeLa cell lines.
Aeromonas dhakensis and Ps. mosselii were virulent to O. mossambicus, whereas Mic. paraoxydans displayed virulence to S. vulgaris.
Significance and Impact of the Study
This the first time that Aeromonas dhakensis and Ps. mosselii are reported as pathogens to tilapia and Mic. paraoxydans was isolated from fish; then, these fish pathogens could be a threat to farmed Nile tilapia in Mexico.