Combined resistance to penicillin and gentamicin in community-acquired bacteraemia in Copenhagen County, 1991–2000

Abstract number: 1134_04_117

Bangsborg J.M., Jarløv J.O., Scheibel J.

Objectives:  

For several years, a combination of penicillin and gentamicin has been our recommendation for the initial treatment of community-acquired septicemia with an unknown focus, supplemented with metronidazole if an abdominal or genital focus is suspected. We sought to verify if this regime is still valid according to resistance patterns and mortality over a recent period of ten years.

Methods:  

From results registered in our laboratory database (ADBakt), we analysed 6476 cases of community-acquired bacteraemia (CAB), excluding contaminants, during Jan 1, 1991 to Dec 31, 2000 from the County of Copenhagen (three hospitals, 2400 beds) for resistance patterns and clinical information (initial antibiotic treatment given, follow-up treatment and patient survival).

Results:  

Resistance to both penicillin and gentamicin were found in 239 isolates, of which 191 were anaerobes sensitive to metronidazol, and 48 isolates from 46 patients were facultative or aerobic bacteria [Enterobacteriaceae (23), enterococci (8), Staphylococcus aureus (1), coagulase-negative staphylococci (10), Pseudomonas spp (2), Stenotrophomonas maltophilia (1), Streptococcus pneumoniae (1), Mycobacterium fortuitum (1), and Haemophilus influenzae (1)]. There was no increase in the occurrence of microorganisms with resistance to both penicillin and gentamicin over the years. Most notably, the incidence of gentamicin-resistant Enterobacteriaceae remained low (0–5/year). Forty-two of the 46 patients survived, 31 receiving irrelevant or no antibiotic treatment until diagnosis. Treatment according to our recommendations was relevant in 99% of cases if strict adherence to the guidelines, also with respect to the addition of metronidazole, is presumed.

Conclusion:  

The incidence of CAB with aerobic and facultative bacteria resistant to both penicillin and gentamicin remains low in our county. Our recommendations for the initial antibiotic treatment of community-acquired sepsis will remain unchanged.