Identificação molecular e antibiograma de Salmonella enterica encontrada em microbacia no noroeste do Rio Grande do Sul

Abstract

The quality of water resources used for agriculture, human consumption, the production chain and food processing and hygiene play an important role in the spread of diseases, especially those associated with the presence of contaminants such as thermotolerant coliforms and Salmonella sp. The presence of Salmonella in river and spring water can lead to serious food contamination problems, which can cause outbreaks of salmonellosis and infections associated with its genus. Another concern is microbial resistance, related to the strain's decreased sensitivity to an antimicrobial agent, leading to severe infections that are difficult to treat and control. In view of all these factors, the aim of this study was to verify the existence of the pathogen Salmonella enterica in the Lajeado do Pardo watershed in the rural area of the municipality of Frederico Westphalen, located in the northwestern region of the state of Rio Grande do Sul. The samples were collected at five different points along the course of the Lajeado do Pardo, after which they were analyzed at the Water Laboratory of the Federal University of Santa Maria - FW Campus, where they were tested for total coliforms and E. coli using the Colilert® test method. The Salmonella enterica strains were isolated using the modified ABNT NBR ISO 6579-1 methodology and identified using the PCR technique using SE Inv pri-mers. The antimicrobial resistance of the environmental strains found was checked using the disk-diffusion method for the following antibiotics: AMP (ampicillin) 10 µg/mL, CLO (chlorophenicol) 30 µg/mL, GEN (gentamicin) 10 µg/mL, CIP (ciprofloxacin) 5 µg/mL and AMC (amoxicillin/clavulanic acid) 30 µg/mL. The results obtained were positive for coliformes, E. coli and Salmonella enterica at all five collection points. All the Salmonella enterica strains evaluated showed resistance to the AMP antibiotic and 60% of the S. enterica strains showed resistance to the AMC antibiotic. S. enterica strains were susceptible to the other antibiotics tested (CLO, CIP and GEN).