PROPAGATION OF ANTIMICROBIAL RESISTANT Salmonella spp. IN BIVALVE MOLLUSKS FROM ESTUARY AREAS OF BAHIA, BRAZIL

• Published in: Caatinga 2016-06, Vol.29 (2), p.450-457
• Main Authors: SILVEIRA, CARLA SILVA DA, SOUSA, OSCARINA VIANA DE, EVANGELISTA-BARRETO, NORMA SUELY
• Format: Article
• Language: English
• Subjects: Acid resistance; AGRICULTURE, DAIRY & ANIMAL SCIENCE; AGRONOMY; Ampicillin; Antiinfectives and antibacterials; Antimicrobial agents; Antimicrobial resistance; Bacterial diseases; Bivalvia; Estuaries; Estuarine environments; FISHERIES; Fluoroquinolones; FOOD SCIENCE & TECHNOLOGY; FORESTRY; Livestock; Livestock production; Microorganisms; Minimum inhibitory concentration; Mollusca; Mollusks; Multidrug resistance; Mussels; Nalidixic acid; Oysters; Quinolones; Salmonella; Shellfish; Strains (organisms); Tetracyclines; VETERINARY SCIENCES
• ISSN: 1983-2125; 0100-316X; 1983-2125
• DOI: 10.1590/1983-21252016v29n222rc

In recent years, the emergence of resistant pathogens has complicated the treatment of bacterial infections in livestock production as well as in the medical field, due to the development of resistance mechanisms by microorganisms. The objective of this study was to delineate the antimicrobial resistance profile of Salmonella spp. strains isolated from bivalve mollusks (oysters and mussels) and from estuarine environment water of two regions of Bahia, Brazil. Twenty-seven strains, 12 isolated from bivalve mollusks and 15 from estuarine water, were tested. Eight antimicrobial agents (phenicol, beta-lactams, tetracyclines, quinolones and fluoroquinolones classes) were used for a susceptibility test, Minimum Inhibitory Concentration (MIC) and extended-spectrum beta-lactamases (ESBLs) production. Isolates showed high susceptibility to the classes of antimicrobial agents tested, with resistance only to nalidixic acid (27%), ampicillin (25%) and tetracycline (25%). Bacterial resistance was of chromosomal origin and the multidrug resistance index (MAR) among isolates of shellfish (mussels in natura) was 0.25. The MIC was found to be 100 µg/mL, 500 µg/mL and 350 µg/mL to nalidixic acid, ampicillin and tetracycline, respectively. None of the isolates presented ESBLs production. The presence of multidrug-resistant and high MIC Salmonella spp. is being conveyed in extraction areas of bivalve mollusks in the State of Bahia, Brazil. RESUMO: Nos últimos anos o surgimento de patógenos resistentes tem dificultado o tratamento de infecções bacterianas, tanto na produção animal como na área médica, em decorrência do desenvolvimento de mecanismos de resistência pelos micro-organismos. O objetivo deste estudo foi traçar o perfil de resistência antimicrobiana em cepas de Salmonella spp. isoladas de moluscos bivalves (ostras e sururu) e da agua de áreas estuarinas em duas regiões da Bahia, Brasil. Um total de 27 cepas previamente isoladas foram testadas, sendo 12 provenientes de moluscos bivalves e 15 de amostras de água. Para o teste de suscetibilidade foram utilizados oito agentes antimicrobianos (classes fenicóis, betalactâmicos, tetraciclina, quinolonas e fluoroquinolonas), Concentração Inibitória Mínima (CIM) e a produção de Betalactamases de Espectro Ampliado (ESBL). Os isolados apresentaram alta suscetibilidade as classes de antimicrobianos testadas, com resistência apenas ao ácido nalidíxico (27%), ampicilina (25%) e tetraciclina (25%). A resistência bacteriana era de o