Phenotypic and genotypic profile of Enterobacteria resistant to beta-lactams

Abstract Background: A serious emerging problem worldwide is increased antimicrobial resistance. Acquisition of coding genes for evasion methods of antimicrobial drug mechanisms characterizes acquired resistance. This phenomenon has been observed in several bacteria, including major species of Gram-negative bacteria such as the Enterobacteriaceae family. Among these, strains resistant to multiple classes of antibiotics were observed. Treatment for bacterial infections is performed with antibiotics and among the most used beta-lactams stand out. Resistance to this class of antimicrobials has also increased. The aim of this study was to correlate antimicrobial resistance profiles in Enterobacteriaceae by phenotypic methods and molecular identification of 14 beta-lactamase coding genes: blaOXA; blaIMP; blaNDM; blaSME; blaDHA; blaCMY, blaTEM, blaKPC, blaSPM, blaCTX-M, blaVIM, blaSIM, blaGIM, and blaSHV. Methods: The phenotypic methodologies used were the Antimicrobial Sensitivity Test for Disk-Diffusion, and complementary tests for the detection of resistance mechanisms of beta-lactamases (ESBL, MBL, AmpC and Carbapenemase). The molecular methodology used was Real Time PCR using the Sybr Green system. Results: Among the results found in the tests it was observed that 74.28% were resistant to ampicillin, 34.28% were resistant to aztreonam, 62.85% were resistant to amoxicillin associated with clavalunate, 51.42% were resistant to ceftazidime, 41.42% were resistant to cefoxitin, 54.28% were resistant to cefazolin, 44.28% were resistant to cefepime, 41.42% were resistant to cefuroxime, 8.57% were resistant to cefuroxime, 35.71% were resistant an imipenem and 41.42% were resistant to piperacillin associated with tazobactam. Among the total samples, the mechanism of resistance that presented the highest expression was ESBL (17.14%). The genes studied that were detected in a greater number of species were blaGIM and blaSIM (66.66% of the samples). The gene that was amplified in a smaller number of samples was blaVIM (16.66%). Conclusions: It is concluded that although there is a low correlation between the methodologies analyzed, the levels of antimicrobial resistance in enterobacteria are high and worrying, and a way to minimize the accelerated emergence of resistance includes the development or improvement of techniques that generate diagnoses with high efficiency and speed.