Identificação e resistência a antimicrobianos de espécies de Aeromonas móveis isoladas de peixes e ambientes aquáticos

Abstract

This experiment was done with the objective to verify the diversity of motile Aeromonas species and their antibiotic susceptibility profiles. A total of eight commercial producers of tilapia located in the Alto Rio Grande region of Minas Gerais state were selected for this experiment. The collected samples were three fish, one sample of pond water and one sample of water used in filling the pond. Suitable dilutions of the washed surface of the fish and water samples were scattered in TSA supplemented with ampicilin (10mg/l). Kidney samples were streaked in Horse Blood Agar. Isolated colonies oxidase positive, were submitted of tests for identification of the species of Aeromonas (presumptive and biochemical tests). The antibiogram profile of the isolated samples was obtained through a diffusion test of antibiotic disks in Mueller Hinton Agar. Were obtained 75 different isolates in nine species of Aeromonas: A. jandaei, A. hydrophila, A. trota, A. caviae, A. sobria, A. eucrenophila, A. veronii bv veronii, A. schubertii, A. media, and samples classified like atypical Aeromonas. Of the total isolations, eight samples were taken from the corporal surface of the fish, 14 from the water source and 53 from the pond water. There was no isolation of the renal tissue. In relation to the resistance profile, 93% of the isolated samples were resistant to erythromycin, 36% to tetracycline, 13% to nalidixic acid, 9% to gentamicin, 8% to nitrofurantoin, 8% to kanamycin, 5% to norfloxacin, 4% to chloramphenicol and 3% to sulfonamides. Among the isolated samples analyzed, 42,66% presented a MAR index (Multiple Antibiotic Resistance Index) equal to or superior to 22,2%. It was concluded that the isolation of potentially pathogenic bacterial species, with multiresistant antibiotic traits may be a risk to human food chain.