Microbiological Quality, Transmission of Resistant Bacteria, and Genetic Characterization in Fish Sold in Town Fairs in the Recôncavo da Bahia Region, Brazil

Abstract

Informal fish marketing is an important source of food and income for many families. However, it is also a public health issue, since the quality of fish can be compromised during marketing. The microbiological quality of fish sold in town fairs in the municipalities of the Bahia Reconcavo region, Brazil, was assessed to characterize isolates based on antimicrobial susceptibility and to investigate gene virulence. Samples of mullets ( Mugil sp.), mussels ( Mytella sp.), and mollusks ( Anomalocardia brasiliana ) were collected in town fairs in the municipalities of Cachoeira, Cruz das Almas, and Santo Ant ônio de Jesus. The presence of mesophylls, molds and yeasts, total coliforms, Escherichia coli , and Staphylococcus aureus was evaluated. E. coli and S. aureus isolates were subjected to antimicrobial susceptibility tests and the presence of the gene stx in E. coli isolates was investigated. Total coliforms and S. aureus ranged between 0 and 9.50 log CFU/g, while high counts of mesophylls, molds, and yeasts were detected. E. coli had greater resistance (76.8%) to amoxicillin and S. aureus had greater sensitivity to gentamicin. The stx gene was not identified in any of the samples studied. Results showed that some fish sold in the town fairs of the three municipalities possessed unsatisfactory microbiological quality, which may pose risks to consumer health, and may be vectors for the dissemination of bacteria resistant to different antimicrobial agents.