Infectio (Sep 2011)
Resistencia a los antibióticos en Escherichia coli con beta-lactamasas de espectro extendido en un hospital de la Orinoquia colombiana Antimicrobial resistance of Escherichia coli with extended spectrum beta -lactamase in a hospital at the Colombian Orinoquia
Abstract
Objetivo. Analizar la resistencia de Escherichia coli a los antibióticos de acuerdo con la presencia de beta-lactamasas de espectro extendido (BLEE). Materiales y métodos. Estudio descriptivo y de corte transversal, en el Hospital Departamental de Villavicencio, centro de atención de mediana y alta complejidad. La población de estudio fueron los pacientes con cultivos positivos para E. coli. La variable de estudio fue la resistencia a ceftazidima, cefotaxima y clavulanato. Se confirmó la presencia de BLEE y la resistencia a otros antibióticos. Resultados. Se tamizaron 29.451 estudios de microbiología, de los cuales 26,7 % fueron positivos. Se identificaron 77,6 % como Gram negativos y 2.551 (41,8 %) como E. coli. De los cultivos, 65,1 % se obtuvieron de orina; 9,5 % fueron resistentes a ceftazidima y 8,7 % a cefotaxime. En los aislamientos de orina, la resistencia de E. coli a ceftazidima fue de 6,5 %, mientras que, en aspirados traqueales, fue de 35,0 % (OR=7,98; pObjective: To analyze antimicrobial resistance of Escherichia coli according to the presence of extended spectrum beta-lactamase. Design: A cross sectional descriptive study. Setting: Hospital Departamental de Villavicencio, a State center of second and tertiary care. Study population: Positive cultures for E. coli were analyzed between September 2005 and November 2009. Interventions: None. Study variable: Ceftazidime and cefotaxime resistance with and without clavulanate. Outcomes: Confirmation of ESBL test and resistance to other antimicrobials. Results: From the 29,451 microbiological samples that were screened, 26.7% were positive. 77.6% were identified as Gram negative and 2,551 (41.8%) were typified as E. coli. 65.1% isolations were from urine samples and 9.5 and 8.7% of them were resistant to ceftazidime and cefotaxime, respectively. 6.5% of urine samples were resistant to ceftazidime, but it raised to 35% for tracheal aspirate (OR 7.98 p<0.05). Three hundred and fifteen confirmatory tests for ESBL were performed with Vitek® and 506 with AutoScan®. Most samples were ambulatory patients (34.0%) and a significant number of them were positive for ESBL (6.9%), but it was higher at the newborn ward (16.9%). Resistance was high for antimicrobials commonly used for infections by this microorganism such as ampicillin, cephalothin, ciprofloxacin, gentamycin and trimethoprim-sulfamethoxazole. Confirmatory ESBL test was 7.1%. Conclusions: The study demonstrates a 7.1% frequency of ESBL at this hospital but the samples from newborn ward showed a higher frequency of ESBL; nevertheless, the issue is not restricted to hospitalized patients. We also found a small number of isolations resistant to carbapenem.
