Resumo

Over the last two decades, many β-lactam antibiotics have been developed that were specifically designed to be resistant to the action of β-lactamases. β-lactamases form a large group of enzymes that hydrolyze antibiotics that exhibit the β-lactam ring in their structure which gives to the bacteria that produce this enzyme a strong resistance to this group of antibiotics. In recent years there has been an increased incidence and prevalence of extended-spectrum β-lactamases (ESBLs). Different factors may explain the quick spread of these multidrug resistant (MDR) microorganisms, such as acquisition by food, person-to-person transmission from fecal carriers, and dissemination in the environment, carriage by domestic and wild animals. Resistance to β-lactams has emerged as a great problem in both human and veterinary medicine. Some food-producing animals maybe have been considered as potential sources of these bacteria that cause community-acquired diseases. The aim of this study was to describe the presence of ESBL-producing E. coli isolated from a fecal sample collected from a piglet without enteric signs in Botucatu city, located in Sao Paulo state, Brazil. E. coli was identified using biochemical and molecular tests. The isolate was submitted to the disc diffusion method and double disc approximation test according to CLSI criteria. PCR analyses were performed to determine the resistant genes carried by isolate. This strain was phenotypically resistant to aminopenicillins, cephalosporins, chloramphenicol, fluorquinolones and tetracycline. The double disc test was positive from ESBL-producing. PCR revealed that the E. coli strain possessed AmpC, Cat 1, flor, tetA and B, strB, bla-CTX-M, cmy and blaTEM type β-lactamases in addition to sulI,sulII and dfrX. The multi resistance might be explained by the intensive use to therapeutic or growth promotion purpose in pig production in Brazil. The use of β-lactams and cephalosporins in veterinary medicine could be one reason to the high ESBL occurrence and that may occur because of the selective pressure exerted by drugs on the microorganisms. The spread of ESBL-producing microorganism has been rapid, indicating that continuous monitoring studies are necessary, mainly in isolates from food animals, because of the possibility of their transfer to products of animal origin.