“Determinación de betalactamasas de espectro extendido tipo AMPC en cepas de escherichia coli y su relación con la resistencia antimicrobiana”

Abstract

AmpC Betalactamasas are cephalosporinases produced by Enterobacterias and are considered clinically important because they can generate resistance to penicillin’s, cephalosporin’s, cefamycins and monobactams, and are poorly inhibited by clavulanic acid, which reduces therapeutic options and increases the chances of a Therapeutic failure during treatment. One of the main Enterobacteria is Escherichia coli which is the main agent of urinary tract infections in 95% of cases. The present investigation focused on determining Extended Spectrum Betalactamasas and AmpC Betalactamasas in patients with infections of the urinary tract that go to the Provincial General Hospital of Latacunga. The research focus was qualitative-quantitative, applying field, laboratory, descriptive and correlational research. Forty strains of Escherichia coli were isolated using urinecultures and biochemical tests. Antimicrobial susceptibility was established by the diffusion disc method on Muller Hinton agar by the Kirby Bauer technique and was considered as suspicious strains to Extended Spectrum Betalactamasas to all those that presented inhibition halos ≤ 27 mm to Aztreonam and Cefotaxime, ≤ 25 mm a Ceftriaxone, ≤ 22 mm to Ceftazidime and if there was deformation of halos in the form of "egg" or "fish tail". These strains were confirmed by CLSI recommendations with discs combined with inhibitors with Cefotaxime-Clavulanic acid and Cefotaxime and Ceftazidime-Clavulanic acid and Ceftazidime discs. On the other hand, for the detection of AmpC Betalactamasas was used the test by the method of double disc synergy and disc method combined with inhibitors. To ensure quality control, the instructions in the CLSI manual M100-S24 and the use of the strain Escherichia coli ATCC 25922 were followed. Statistical analysis was performed using descriptive statistics using the Microsoft Excel program, where the frequency of Escherichia coli with Extended Spectrum Betalactamasas was 15%, and Escherichia coli with AmpC Betalactamasas was 5%, most of which affected the female sex. It was concluded that there is a relationship between the determinations of Extended Spectrum Betalactamases type AmpC in strains of Escherichia coli with antimicrobial resistance.