Prospective screening for carbapenemase-producing gram-negative bacteria in rectal swabs of ICU patients

Abstract

Aim: In recent years, carbapenem-resistant enteric gram-negative bacilli in intensive care units and their emergence as an important pathogen causing morbidity and mortality have been remarkably increasing. Considering that colonisation occurs primarily in Intensive Care Unit patients, we decided to perform a prospective surveillance study to investigate carbapenemase-producing Enterobacteriaceae in rectal swab samples. Methods: The patients were enrolled on admission to Intensive Care Units from the 1st of February to the 15th of May 2014. The rectal swabs were taken within the first 48 hours and then weekly during hospitalization. Rectal swab samples were plated on chromID CARBA (bioM & eacute;rieux) chromogenic agar plates. The next day detected colonies were named according to their colors. At the same time, VITEK2 automated system identification was performed, and MIC values for carbapenems were determined by the E-test method. During the study period, 204 samples from 104 patients were evaluated. Results: Only 2 of the patients (1.9%) had initial rectal swab samples positive for carbapenemase-producing Enterobacteriaceae. Overall, during the hospitalization period, 6 patients (5.8%) were screened as carbapenem-resistant Enterobacteriaceae. One of the isolates (16.7%) was identified as E.coli, the others were Klebsiella pneumoniae (83.3%). Urine cultures of 2 patients were also detected as carbapenemase-producing Enterobacteriaceae. As a result, 2% of patients followed up in our Intensive Care Units had carbapenemase-producing Enterobacteriaceae in rectal swab cultures on admission. Conclusion: Screening Intensive Care Units with rectal swabs for colonization will provide us with early infection control and appropriate empiric therapies.