Molecular characterization of Aeromonas species isolated from farmed eels (Anguilla japonica)

Vet Microbiol. 2013 May 31;164(1-2):195-200. doi: 10.1016/j.vetmic.2013.02.006. Epub 2013 Feb 18.


Seventy Aeromonas strains were identified by phylogenetic analysis using housekeeping genes (gyrB and rpoD) in order to investigate etiological agents for aeromoniasis in farmed eels (Anguilla japonica). The phylogenetic analysis showed that Aeromonas aquariorum (n=22, 31.4%) was the predominant species among the investigated eel strains, followed by Aeromonas caviae (n=16, 22.9%), A. veronii (n=13, 18.6%), A. hydrophila (n=12, 17.1%), A. jandaei (n=4, 5.7%), A. media (n=2, 2.9%), and A. trota (n=1, 1.4%). The potential virulence of the present strains was estimated by performing PCR assays using the following seven virulence genes: cytotoxic enterotoxin (act), two cytotonic enterotoxins (alt and ast), glycerophospholipid:cholesterol acyltransferase (gcaT), DNase (exu), lipase (lip), and flagellin (fla). The detection rates of act, alt, ast, gcaT, exu, lip, and fla among all 70 strains were 91.4%, 55.7%, 27.1%, 97.1%, 95.7%, 100%, and 98.6%, respectively. In genotyping of enterotoxin genes, act(+)/alt(+)/ast(+), act(+)/alt(+)/ast(-), and act(+)/alt(-)/ast(-) genotypes were prevalent in A. hydrophila (8/12 strains), A. aquariorum (13/22 strains), and A. caviae (14/16 strains), respectively, suggesting a high heterogeneity among Aeromonas species. In this study, A. aquariorum, which has been an unrecorded species in Korea, can be an etiological agent for aeromoniasis of eel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aeromonas / classification*
  • Aeromonas / genetics
  • Aeromonas / isolation & purification*
  • Anguilla / microbiology*
  • Animals
  • Bacterial Proteins / genetics
  • DNA Gyrase / genetics
  • DNA-Directed RNA Polymerases / genetics
  • Enterotoxins / genetics
  • Fish Diseases / microbiology
  • Gram-Negative Bacterial Infections / microbiology
  • Gram-Negative Bacterial Infections / veterinary
  • Phylogeny
  • Polymerase Chain Reaction


  • Bacterial Proteins
  • Enterotoxins
  • DNA-Directed RNA Polymerases
  • DNA Gyrase