Antibiotic resistance in intensive care unit areas

Abstract

The incidence of nosocomial infections and antimicrobial resistance rates of nosocomial pathogens vary considerably among countries and even among intensive care units (ICUs) within one hospital. Such differences might be partly due to the selection pressure exerted by certain antibiotics, since intensive care patients are given more antimicrobials than any other group of patients. We therefore compared resistance rates of four important nosocomial pathogens (Staphylococcus aureus, E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) isolated from patients in general wards and ICUs. There were few trends toward higher resistance of ICU isolates, and most differences were found with Klebsiella pneumoniae. We also tried to relate antibiotic use in ICUs and frequency of antibiotic resistance of five selected nosocomial pathogens. The ampicillin and cephalosporin resistance of E. coli and Klebsiella pneumoniae arose along with an increase in usage of both drugs. Decreasing prescription of cotrimoxazole was not reflected by decrease in resistance of Staphylococcus aureus and Staphylococcus epidermidis. Increasing prescriptions of tetracyclines were followed by an increasing resistance of E. coli, but not of Staphylococci. The oxacillin resistance of Staphylococcus epidermidis almost paralleled the consumption, the opposite was true for Staphylococcus aureus. There seemed to be a rather close relationship between the incidence of resistant Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa strains and the quantities of gentamicin, tobramycin and azlocillin prescribed. The increase or decrease of prescriptions of certain antimicrobials increased or decreased their resistance rate to the respective drugs of only certain bacterial strains in one ICU, but not in the other. The findings in our hospital cannot necessarily be applied to other hospitals.(ABSTRACT TRUNCATED AT 250 WORDS)