Prevalence and Risk Factor Analysis of Faecal Carriage of Carbapenem Resistant Enterobacteriaceae in a Tertiary Care Hospital

Abstract

Introduction: Reduced susceptibility of carbapenems against enterobacterial strains have emerged as an important public health problem worldwide. Infection caused by Carbapenem Resistant Enterobacteriaceae (CRE) can affect severely ill patients, and their colonisation of human gut, endangers population at large in communities, and in hospitals. Aim: To determine the prevalence and risk factors associated with faecal carriage of CRE. Materials and Methods: A cross-sectional study was conducted on a total of 156 random stool samples collected from hospitalised patients of surgery wards. CRE were determined by antibiotic susceptibility testing against carbapenems as per Clinical Laboratory Standards Institute (CLSI) guidelines (2017) for a period of eight months from February to September, 2018, in a tertiary care hospital, Chidambaram, Tamil Nadu, India. Those strains appeared to be meropenem resistant were further tested with imipenem, a battery of biochemical test, modified Carbapenem Inactivation Method test (mCIM), Modified Hodge Test (MHT) and Epsilometer (E-test) to detect Extended Spectrum of β-Lactamases (ESBL). Confirmed carbapenem resistant isolates were also put through molecular analysis to detect the gene responsible for carbapenemase production. Risk factors associated with faecal carriage of CRE were comparatively analysed. Results: Out of a total 156 faecal samples, 222 Enterobacteriaceae isolates were obtained, and 21 isolates from 17 samples were CRE positive, with a prevalence of 10.89% phenotypically. Out of total phenotypically confirmed CRE, 23.8% (5/21) exhibited CRE gene. blaNDM-1 was the most frequent detection followed by blaVIM, blaOXA-48 and blaKPC, while no isolate was positive for blaIMP. One CRE isolate co-harboured blaNDM-1, blaOXA-48 and blaKPC and three CRE isolates co-harboured blaVIM and blaNDM-1. Length of hospital stay and haemorrhoids were discovered, as independent predisposing risk factors for CRE faecal carriage by multivariate regression analysis. Conclusion: We found high prevalence of faecal carriage of CRE during a non-outbreak situation from surgery wards. Hospitalised patients should be considered a population at risk. Enforcing robust surveillance system, antibiotic stewardship and maintaining unprecedented hygiene are the need of the hour to curb CRE.

Keywords

• genotypic methods
• modified hodge test
• resistance