PREVALENCE OF PLASMID-MEDIATED RESISTANCE GENES IN MULTIDRUG-RESISTANT Escherichia coli ISOLATED FROM PIGS AND SOILS FROM BRAZIL

Escherichia coli belong to the commensal microbiota and may act as an opportunistic pathogen, mainly in immunocompromised patients. E. coli is an important pathogen able to survive in different environments, in which it acquires several and important genes for their survival, such as resistance genes. The inadequate use of antimicrobials increases the selective pressure and favors the emergence of resistant bacteria, which can spread among different sources, such as humans, animals and environment. In food-producing animals, the acquisition of resistant bacteria may occur along the chain of food production. The bacterial resistance is a frequent problem and the increased resistance among different genera and bacterial species has resulted in the emergence of multidrug-resistant bacteria, which represent a major public health problem. This study aimed to investigate the antimicrobial resistance profile, the presence of plasmid-mediated resistance genes and the different plasmid families in E. coli isolated from pigs and soils from Brazil. The fecal and soil samples were obtained from a Brazilian pig farm. The bacterial isolation was performed using MacConkey agar and, then, the genomic DNA was extracted. The identification was performed using the sequencing of 16S rRNA gene. The resistance profile was performed using the disc diffusion method. PCR reactions were performed for detection of different plasmid-mediated resistance genes, integrons and plasmid families. Eighteen isolates were obtained, being 11 from pigs and 7 from soils. A total of 37 antibiotics belonging to nine different classes were used to determine the resistance profile of the isolates. These isolates were non-susceptible (resistant or intermediate) mainly to penicillins, cephalosporins, aminoglycosides, tetracyclines and sulfonamides and all isolates were classified as multidrug-resistant. Among the plasmid-mediated resistance genes researched, the blaOXA-1-like and tetA were detected in all isolates, followed by blaCMY, blaSHV and tetB (17), aac(6′)-lb (8), aph(3′)-la and sul3 (4), sul2 (5) and sul1 (1). The class 1 integron was detected in 17 isolates. Among the plasmid families, the IncFrepB and IncY were detected in all isolates, followed by IncFIB (14), IncHI1 (9), ColE-like (8), IncI1 (3), IncFIA (2) and IncFIC (1). These results indicate that plasmid-mediated resistance genes have high potential to spread in different sources.