Determinación de Beta-lactamasas de Espectro Extendido en Escherichia coli y Klebsiella pneumoniae a través de pruebas moleculares en urocultivos provenientes de pacientes ambulatorios con infecciones de vías urinarias

摘要

The increase of Enterobacteriaceae’s resistance to β-lactam antibiotics has led them to become an epidemiological problem worldwide. The main mechanism of resistance– And clinical importance – is the enzymatic inactivation through Beta-lactamases. Due to their rapid dissemination, these enzymes have provoked an increase in the morbidity rate and the cost of clinical services besides reducing the offer of helpful medical drugs. New types of resistance have originated because of the high rate of modifications in these enzymes. In Ecuador, the ones with greater clinical value are: TEM, SHV, OXA and CTX-M (usual in the community); being the genes that encode these enzymes, the ones that are analyzed in this investigation. Urinary infection is the most common bacterial infection in outpatients; it affects 150 million people per year (Mireles, Walker y Hultgren, 2015). In Ecuador, these infections are located in the eighth position of the main causes of morbidity and mortality (INEC). Among the main pathogens causing urinary infections, we have Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae); these Gram- negative bacillus belong to the family Enterobacteriaceae. The latest data published by the Instituto Nacional de investigación en Salud Pública (INSPI) reported that in E. coli strains, the incidence of resistance to cefotaxime (CTX) and ceftazidime (CAZ) exceeds 28%; and in K. pneumoniae it exceeds 60%. (INSPI, 2015). Likewise, in this investigation, the Polymerase Chain Reaction (PCR) technique was used for the detection of different genes that codify the main types of Beta-lactamases in urineculture samples from outpatients with urinary tract infection. The prevalence of the Beta-lactamases genes was CTX-M: 96,67%, TEM: 28,89%, SHV: 2,22% and OXA:0%.