Drug resistant enterococci: factors associated with gastrointestinal tract colonization

Resistant enterococci are recognized as important hospital acquired pathogens. They are generally sensitive to ampicillin but intrinsically resistant to cephalosporins and aminoglycosides and are known to acquire high level resistance to these drugs. High level resistance has serious implications for treatment of patients infected with these organisms and for infection control activities. Colonisation of the gastrointestinal tract is a prerequisite to infection. A number of factors are known to contribute to acquiring colonisation by resistant enterococci according to studies conducted in the West. The present study determines the prevalence of resistant enterococci on admission in a cohort of hospitalised patients, and identifies some risk factors that are significantly associated with acquiring resistant enterococci during hospital stay. A prospective study conducted over three months, on 125 patients in orthopaedic units and the burns unit of the National Hospital of Sri Lanka, to determine colonisation showed that 5.6% were colonised on admission and 16.8% acquired ampicillin resistant enterococci (ARE) during hospitalisation. No vancomycin resistant enterococci (VRE) were isolated. Risk factors that were significantly associated with colonisation were empiric use of antibiotics, treatment with ampicillin, multiple use of antibiotics, prior hospitalisation and presence of diabetes mellitus. These features will be helpful in identifying possible patients for screening for resistant enterococci, with a view to implementing more stringent infection control measures to prevent spread of these organisms, Key words: Colonization, enterococci, orthopaedic units, burns unit. DOI = 10.4038/cjms.v50i1.117 The Ceylon Journal of Medical Science 2007; 50: 9-1