Incidence and susceptibility of aerobic Gram-negative bacilli from 20 Canadian intensive care units: 1989-1993.

OBJECTIVE

To assess the prevalence of antibiotic resistance in Canadian intensive care units.

DESIGN

The antimicrobial profiles of 1939 Gram-negative bacilli isolated in 20 Canadian intensive care units were analyzed using a custom designed MicroScan panel.

SETTING

The majority of the hospitals were tertiary care institutions, but some community hospitals were included.

PATIENTS: Adult intensive care unit patients were the sources of isolates.

MAIN

RESULTS

Pseudomonas aeruginosa was the most frequently isolated microorganism overall, with Escherichia coli the most common initial isolate. Comparison of initial and repeat isolates showed that P aeruginosa readily acquired resistance to all antibiotic classes except the aminoglycosides. Enterobacter aerogenes developed resistance to ciprofloxacin and Enterobacter cloacae demonstrated resistance to all beta-lactam antibiotics except for imipenem on repeat isolation. Other Enterobacteriaceae remained susceptible. Historical comparison with data derived four years previously from 15 of the centres showed increased resistance of P aeruginosa and Acinetobacter species to ciprofloxacin while other susceptibility patterns remained stable.

CONCLUSIONS

The prevalence of Gram-negative resistance in Canadian hospitals is less than that reported in surveys done in some other countries, and was relatively stable over four years.