Drug resistant enterococci: factors associated with gastrointestinal tract colonization

Abstract

Resistant enterococci are recognized as important h ospital acquired pathogens. They are generally sensitive to ampicillin but intrinsicall y resis tant to cephalosporins and aminoglycosides and are known to acquire high le vel resistance to these drugs. High level resistance has serious implications for treatment of patients infected with lhese organisms and for infection control activities. Colonis ation of the gastro­ intestinal tract is a prerequi,site to infection. A number of fa ctors a re known to contribute to acquiring colonisa tion by resistant enterococci according to studies conducted · in the West. The present s tudy determines the prevalence of resis tant enterococci on admission in a cohort of hospitalised patients, and identifies SOll1e risk factors that are significantly associated with acquiring resistant enterococci during hospital stay . A prospective s tudy conducted over three months, on 125 patien ts in orthopaedic units and the burns unit of the Nationa l Hospital of Sri Lanka, to determine colonisation showed that 5 .6 % were colonised on admission and 16.8% acquired ampicillin res istant ente rococci (ARE) during hospitalisation. No vancomycin res is tant enterococci (V RE) were isola led. Risk faclors 1. Senior Registrar i11 Microbiology that were s ignificantly associated w ith colonisation were empiric use of antibiotics, trealment with ampiCillin, multiple use of antibiotics, prior hospitalisa t ion and presence of diabetes mellitus. These features will be helpful in identifying pOSS ible patients for screening for resistant enterococci, with a view to implementing more sh'ingent infection conlrol measures La prevent spread of these organisms,