Extended-spectrum β-lactamases (ESBL) TEM and SHV in intensive care unit patients with Health-care associated infections, silenced genes?

Abstract

Background:The extended-spectrum ␤-lactamases (ESBL) Ambler's class A are capable of hydrolyze broad spectrum penicillin and cephalosporins, and mostly are codified by plasmidial genes. Health-care associated infections (HAI) are a group of entities with a high frequency worldwide, specially in critical adult patients and children in Intensive Care Units (ICU). The frequency of ESBL in this kind of patients is unknown nowadays in ICU in Cartagena de Indias D.T., Bolívar Colombia.Methods & Materials: The goal of this project was to describe the epidemiology of ESBLS type TEM and SHV in the city of Cartagena de Indias D.T state of Bolívar in Colombia. Clinical samples (blood, urine, LRT secretion, surgical site secretion) were collected from adult patients under HAIs diagnosis (Ventilator Associated Pneumonia, Bloodstream Infection, Urinary Tract Infection, Surgical Site Infection). Phenotypic identification, susceptibility test and antibiotic profile was performed with an automatized method according the current CLSI standards, following of genotypic identification with molecular biology methods as PCR and sequencing to confirm the presence of TEM and SHV genes in susceptible and resistant bacteria.Results: The presence of ESBLS type TEM and SHV was frequent in the samples collected, finding that the presence of TEM/SHV at the same time was found in 43.3% of the samples and TEM ESBL was the most frequent, these findings were observed in susceptible and resistant bacteria. K pneumoniae was the most frequent bacteria (33.3%) follow by P. aeruginosa (28,9%) with TEM and SHV genes in susceptible and resistant samples at the same time. Conclusion:The presence of ESBL type TEM and SHV in susceptible and resistant bacteria in Health-care associated infections (HAI) in Intensive Care Units (ICU) patients has an importance in antibiotic therapy and prognosis of this kind of patients worldwide. Silenced genes in susceptible strains has been described in this kind of isolates, in Cartagena, Colombia this kind of findings are new, and could be part of the reason of the negative outcome on these patients.