Suscetibilidade antimicrobiana de Salmonella spp. isoladas de moluscos bivalves no município de São Francisco do Conde, Bahia

Abstract

The indiscriminate use of antimicrobials has contributed to the rise of antibiotic-resistant bacteria, becoming harder the treatment of infections. The objective of this work was to determine the antimicrobial resistance profile of Salmonella strains isolated from bivalve molluscs commercialized in São Francisco do Conde, Bahia. Seventeen Salmonella strains isolated from in natura and processed mussels and in natura oysters were tested. For antimicrobial susceptibility testing were used the following antimicrobials: nalidixic acid, ampicillin, cephalothin, ceftazidime, chloramphenicol and sulfazotrim. Antimicrobial resistance was observed in 41,2% of Salmonella strains, and the multiple antibiotic resistance index was 33.3%. Cephalothin resistance was observed in 29,4% of the strains, followed by ampicillin in 17,6% and nalidixic acid in 5,9%. Some Salmonella strains showed subpopulations resistant to ampicillin and cephalothin. All strains were susceptible to ceftazidime, chloramphenicol and sulfazotrim. No isolates showed sensitivity after the treatment of bacterial cell to plasmid curing agent suggesting that the resistance gene can be present in the chromosome. The hightest values of the minimum inhibitory concentration were found to ampicillin and cephalothin >500 μg/mL. These results show the spread of Salmonella spp. resistant to antimicrobial commonly used as chemotherapeutic by population and transmitted by bivalve molluscs.