Aeromonas hydrophila in Rhamdia quelen: macroscopIc and microscopIc aspect of the lesions and antibiotic resistence profiles


  • Leonardo José Gil BARCELLOS Professores do Curso de Medicina Veterinária da Universidade de Passo Fundo, RS
  • Luiz Carlos KREUTZ Professores do Curso de Medicina Veterinária da Universidade de Passo Fundo, RS
  • Laura Beatriz RODRIGUES Professores do Curso de Medicina Veterinária da Universidade de Passo Fundo, RS
  • Luciana Ruschel dos SANTOS Professores do Curso de Medicina Veterinária da Universidade de Passo Fundo, RS
  • Adriana Costa da MOTTA Professores do Curso de Medicina Veterinária da Universidade de Passo Fundo, RS
  • Filipe RITTER Acadêmicos do Curso de Medicina Veterinária da Universidade de Passo Fundo, RS
  • Alexandra Calliari BEDIN Acadêmicos do Curso de Medicina Veterinária da Universidade de Passo Fundo, RS
  • Leonardo Bolognesi da SILVA Médico Veterinário, Mestrando CPG Zootecnia -  UFRGS


aeromonoses, bacteriosis, jundiá, ichthyopathology


With the intensification of fish culture in Rio Grande do Sul, the incidence and severity of pathologies increased significantly; fish raised under inappropriate management conditions are prone to stress related pathologies, such as that caused by Aeromonas hydrophila. Herein, the isolation, antibiotic sensibility and macroscopic and microscopic lesions caused by A. hydrophila are described. The identification of A. hydrophila was confirmed following inoculation on blood agar and biochemical assays. Macroscopic lesions were initially observed as ulcers in the caudal peduncle that became disseminated through the body and barbs, exposing muscle tissue. Histopathological lesions were characterized by degeneration, necrosis, hyperplasia, mononuclear cell infiltration and the presence of bacteria colonies. All samples of A. hydrophila were susceptible to chloramphenicol, polymyxin B, kanamycin, sulfonamides and neomycin; 81.25% of the samples were susceptible to doxycyclin and 18.75% had intermediate susceptibility. Cefoxitin was effective against 75% of the samples, but 18.75% of the samples had intermediate susceptibility and 6.25% were resistant. The susceptibility to erythromycin observed among 50% of the samples, but 31.25% and 18.75% of the samples has intermediate susceptibility or were completely resistant, respectively. Thus, to know the resistance profiles of the bacteria and to prescribe an effective treatment when recommended, it is necessary to perform antibiotic susceptibility test to each outbreak of this disease.



Altwegg, M.; Geiss, H.K. 1989. Aeromonas as a human pathogen. Critical Reviews in Microbiology,16 :253-286.

Aoki, T. 1999 Motile Aeromonads (Aeromonas hydrophila). In: Woo, P.T.K, Bruno, D.W. Fish Diseases and disorders. CAB INTERNATIONAL,p.427-476.

Barcellos, L.J.G.; Kreutz, L.C.; Quevedo, R.M.; Fioreze, I.; Rodrigues, L.B.; Soso,
A.B.; Ritter, F.; Conrad, J.; Cericato, L.;Fagundes, M.; Lacerda, L.A. e erra, S.
2004 Hematological changes in jundiá (Rhamdia quelen Quoy & Gaimard Pimelodidae) provocked by usual aquaculture practices, with empahsis
on immunossupressive effects. Aquaculture Amsterdan, 237(1-4), 229-236.

Belém-Costa, A.; Cyrino, J.E.P. 2006 Antibiotic resistence of Aeromonas hydrophila isolated from Piaractus mesopotamicus (Holmberg, 1887) and Oreochromis niloticus (Linnaeus, 1758). ScientiaAgricola, 36(3):281-284.

Boijink, C. L.; Brandão, D. A. 2001 Alterações histológicas e comportamentais provocadas pela inoculação de suspensão bacteriana (Aeromonas hydrophila) em juvenis de jundiá (Rhamdia quelen).Ciência Rural, 31(4): 687-694.

Dí­­az, R.A.J.; Pita, M.T.S.; Alemán, Z.W.; Rubalca,S.C.; González, M. I.; Rosa, O.E.D. e Salazar, M.C.R. 2006 Sensibilidad antimicrobiana en bacterias de origen ambiental. Higiene y Sanidad Ambiental, 6:150-159.

Graf, J. 1999 Diverse restriction fragment length polymorphism patterns of the PCR-amplified 16S rRNA genes in Aeromonas veronii strains and possible misidentification of Aeromonas species. Journal of Clinical Microbiology, 37(10):3194-3197.

Llobrera, A.T.; Gacutan, R.Q. 1987 Aeromonas hydrophila associated with ullcerative disease epizootic in Laguna de Bay, Philippines. Aquaculture Amsterdan, 7:273-278.

Miyazaki, T.; Kageyama, T.; Miura, M. e Yoshida, T. 2001 Histopathology of viremiaassociated ana-aki-byo in combination with Aeromonas hydrophila in color carp Cyprinus carpio in Japan. Diseases of Aquatic Organisms, 44:109-120.

NCCLS - National Committee for Clinical Laboratory Standards 2001 Performance Standards for Antimicrobial Susceptibility Testing, 11th Information Supplement. Approved Standard M2-A7 and M7-A5. Wayne, PA, U.S.A.

Palumbo, S. A. 1996 The Aeromonas hydrophila group in food. In: Austin, B., Altweeg, M., Gosling, P.J.,Joseph, P. The Genus Aeromonas. John Wiley and Sons. Chichester, p. 287 í  310.

Pavaneli, G.C.; Eiras, J.C. e Takemoto, R.M.1998 Doenças de Peixes. Profilaxia, Diagnóstico e tratamento. Editora da Universidade Estadual de Maringá. 264p.

Poletto, R.; Barcellos, L.J.G. e Kreutz, L.C. 2001 Diagnóstico de Aeromonas hydrophila em Jundiás (Rhamdia quelen) criados em gaiolas flutuantes,na região de Passo Fundo: relato de caso. In: XI MOSTRA DE INICIAÇÃO CIENTÍFICA E III MOSTRA INTERNA DE POS-GRADUAÇÃO, Passo Fundo. Anais...v.1, p.214-214.

Rodrí­­guez, L.A.; Ellis, A.E. e Nieto, T.P. 1993 Purification and characterisation of an extracellular metalloprotease, serineprotease and haemolysin of Aeromonas hydrophila strain B32: all are lethal for fish. Microbial Pathogenesis, 14:10-18.

Shama, S.; Brandão, D.A.; Vargas, A.C.; Costa,M.M. e Pedrozo, A.F. 2000 Ocorrência de bactérias com potencial patogênico em jundiás (Rhamdia quelen) cultivados em sistema semiintensivo. Ciência Rural, 30(2):293-298.

Stoskopf, M.K. 1993 Bacterial diseases of goldfish, koi and carp. In: Stoskopf, M.K. (ed.) Fish Medicine, pp. 473-475. Philadelphia: W.B. Saunders Company,882p.

Thune, R.L. 1993 Bacterial diseases of catfish. In: Stoskopf, M.K (ed.) Fish Medicine, pp. 511-520. Philadelphia: W.B. Saunders Company, 882p.

Thune, R.L.; Stanley, L.A.; Cooper, R.K. 1993 Pathogenesis of gran-negative bacterial infections in warmwater fish. Annual Reviews of Fish Diseases,3:37-68.

Wakabongo, M.; Bortey, E.; Meier, F. A.;Dalton, H. P. 1992 Rapid identification of motile Aeromonas. Diagnostic Microbiology and Infectious Diseases, 15:511-515.



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