<i>Edwardsiella tarda</i> in Tambaqui (<i>Colossoma macropomum</i>): A Pathogenicity, Antimicrobial Susceptibility, and Genetic Analysis of Brazilian Isolates
Francisco Yan Tavares Reis,
Victória Pontes Rocha,
Peter Charrie Janampa-Sarmiento,
Henrique Lopes Costa,
Renata Catão Egger,
Naísa Cristine Passos,
Carlos Henrique Santos de Assis,
Sarah Portes Carneiro,
Ágna Ferreira Santos,
Brendhal Almeida Silva,
Fernanda Alves Dorella,
Márcia Pimenta Leibowitz,
Ronald Kennedy Luz,
Felipe Pierezan,
Sílvia Umeda Gallani,
Guilherme Campos Tavares,
Henrique César Pereira Figueiredo
Affiliations
Francisco Yan Tavares Reis
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Victória Pontes Rocha
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Peter Charrie Janampa-Sarmiento
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Henrique Lopes Costa
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Renata Catão Egger
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Naísa Cristine Passos
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Carlos Henrique Santos de Assis
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Sarah Portes Carneiro
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Ágna Ferreira Santos
Department of Veterinary Clinics and Surgery, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Brendhal Almeida Silva
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Fernanda Alves Dorella
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Márcia Pimenta Leibowitz
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Ronald Kennedy Luz
Department of Animal Science, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Felipe Pierezan
Department of Veterinary Clinics and Surgery, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Sílvia Umeda Gallani
Postgraduate Program in Aquaculture, Nilton Lins University, Manaus 69058-030, AM, Brazil
Guilherme Campos Tavares
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Henrique César Pereira Figueiredo
Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
Edwardsiella tarda is a crucial pathogenic bacterium in tropical aquaculture. This bacterium was recently isolated from tambaqui (Colossoma macropomum), a commercially important fish species in Brazil. This study assessed the antimicrobial susceptibility, pathogenicity, and genetic diversity of the tambaqui-derived E. tarda isolates. Fourteen bacterial isolates isolated from tambaqui were identified as E. tarda by using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry and dnaJ gene sequencing. Antimicrobial susceptibility tests were conducted against seven drugs using the disc diffusion assay. The pathogenicity test conducted by intraperitoneal injection of 2.4 × 107 colony-forming units (CFU) fish−1 of E. tarda (ED38-17) into tambaqui juveniles eventually revealed that neither clinical signs nor death were present. However, splenomegaly and whitish areas in the spleen and kidneys were observed. The histological investigation also revealed granulomatous splenitis, nephritis, and hepatitis occurring internally. Repetitive extragenic palindromic-PCR fingerprinting separated the 14 isolates into three genetic groups. The antibiogram revealed that all E. tarda isolates were wild-type (WT) to florfenicol (FLO), norfloxacin (NOR), neomycin (NEO), erythromycin (ERY), and oxytetracycline (OXY); however, some were non-wild-type to sulfamethoxazole/trimethoprim (7.1%) and amoxicillin (21.4%). Therefore, through experimental infection, E. tarda ED38-17 could induce pathogenic effects in C. macropomum. Additionally, three distinct genetic types were found, and the E. tarda isolates were WT to FLO, NOR, NEO, ERY, and OXY. These findings raise awareness of a bacteria causing unseen lesions, a pathogen that will potentially impact tambaqui aquaculture in the future.
