Identificação e perfil de resistência antimicrobiana de enterobactérias isoladas de moluscos bivalves e água em dois estuários da Região do Baixo Sul, Bahia

Abstract

Among those species of bacteria capable of causing infections in humans stand strains Escherichia coli and Salmonella spp. The ability of these microorganisms in causing human gastroenteritis associated with consumption of shellfish raw or lightly cooked, has increased its importance in food outbreaks becoming an alert to public health. Based on this, this study aimed to evaluate the presence of Escherichia coli and Salmonella spp. Two estuaries (cultivation of oysters and extraction) Southern Lowlands, Bahia and check the profile of antimicrobial susceptibility of isolates. For this, there were six collections of oysters and water in an area of cultivation and extracted natural oyster banks. For antimicrobial susceptibility were employed 15 drug six families. The production of β-lactamase enzymes (βLs) was verified by phenotypic and genotypic tests (blaTEM-1, blaCTX-M and blaSHV). In the cultivation area the water samples had microbial density coliforms at 35°C (2.85 log MPN / 100ml) and 45°C (2.50 MPN / 100 ml) higher than the oyster samples (35°C - 2.65 log MPN / 100g 45°C - 2.30 log MPN / 100g). For the extraction of oysters density of coliforms at 35°C was 3.30 log MPN / 100 g at 45°C of 3.15 log MPN / 100 g. Escherichia coli was isolated in 50% of water samples and 67% of the samples for extraction of oysters. It was observed the presence of Salmonella in any of the samples. Strains of Escherichia coli from Torrinhas estuary growing water showed only antimicrobial resistance intermediate profile (57.14%). Isolates of extraction of oysters showed antimicrobial resistance of 60% and 20% intermediate resistance with greater resistance checked to β-lactam (71.42%). Multiresistant profile (40%) was only observed for Escherichia coli isolated from the extraction of oysters, with multiple resistance index (MAR) ranging from 0.13 to 0.20. Regarding the type of antimicrobial resistance, 50% showed resistance mediated by plasmids and 50% Chromosome, and the strains of the water showed a higher percentage of plasmid resistance (62.50%). Phenotypically was not observed the production of β-lactamase enzymes. The presence of blaTEM-1 and blaCTX-M genes was observed at 83.33% and 8.33% of the strains of Escherichia coli, respectively. It was observed the presence of the gene blaSHV. The presence of Escherichia coli containing resistance genes in the estuaries of Taperoá and Torrinhas, Bahia, shows that the extracted bivalves or collected in the region must go through a purification process before undergoing marketing to minimize the presence of bacterial strains shellfish containing genes antimicrobial resistance. The presence of isolates of Escherichia coli with resistance genes blaTEM-1 and blaCTX-M type, draws attention as the spread of these bacteria to the estuarine environment.