Fecal carriage of carbapenem resistant Enterobacteriaceae among the intensive care unit patients

ABSTRACT

Background: The war against multidrug-resistant bacteria is challenging and of global concern. Hospitals are increasingly plagued by resistant gram negative pathogens. Bacteria of the family Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae are part of the normal human intestinal flora but are also often responsible for community- and healthcare-associated infections. These bacteria are prone to acquiring resistance genes.Methods: Rectal swabs/swabs from the peri-anal area of the patients who were admitted in the Intensive Care Unit (ICU) of the accident and emergency department of this teaching hospital. Swabs were collected first on day 1 of admission, then day 4, and thereafter weekly during the period of stay in the ICU. All the swabs were immediately inoculated into trypticase soy broth with one 10μg  meropenem disc and were incubated overnight at 35±2ºC, ambient air. Next day, the broth was vortexed, and then sub-cultured onto a MacConkey agar plate. On the third day, MacConkey agar plates were examined for lactose fermenting (pink-coloured) colonies. The representative isolated colonies were subjected to conventional antimicrobial susceptibility testing by the Kirby Bauer Disc diffusion method following the CLSI guidelines to know the susceptibility to carbapenem and other antimicrobial agents. Carbapenemase production was done by a Modified Hodge Test (MHT) and Imipenem-EDTA test.Results: Out of 89 patients, carbapenem resistant Klebsiella pneumoniae and E. coli isolates were recovered from 35 (39.3%) patients i.e. Klebsiella pneumoniae isolates from fifteen patients and carbapenem resistant E. coli isolates from twenty patients. Prevalence of carbapenemase producing isolates was found to be 1.42%.  Conclusions: Surveillance for CRE can definitely help reduce rates of healthcare associated infections.