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Emergence of trimethoprim-sulfamethoxazole resistance in the AIDS era

J N Martin1, D A Rose, W K Hadley

  • 1Center for AIDS Prevention Studies and Department of Epidemiology and Biostatistics, University of California, San Francisco, USA. martin@psg.ucsf.edu

The Journal of Infectious Diseases
|November 24, 1999
PubMed

Insights

Trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis in HIV patients has led to increased bacterial resistance. This study observed significant TMP-SMX resistance in Staphylococcus aureus and E. coli among HIV-infected individuals.

Area of Science:

  • Infectious Diseases
  • Microbiology
  • Public Health

Background:

  • Trimethoprim-sulfamethoxazole (TMP-SMX) is a key prophylactic agent for Pneumocystis pneumonia in HIV-infected individuals.
  • The impact of widespread TMP-SMX use on antimicrobial resistance patterns in clinical isolates remains incompletely understood.

Purpose of the Study:

  • To investigate the emergence of TMP-SMX resistance in clinical bacterial isolates, particularly Staphylococcus aureus and Enterobacteriaceae, in relation to its prophylactic use in HIV patients.

Main Methods:

  • A serial cross-sectional study design was employed.
  • Clinical isolates of Staphylococcus aureus and seven genera of Enterobacteriaceae were collected and tested for TMP-SMX susceptibility.
  • Data were analyzed from 1979 to 1995 at San Francisco General Hospital.

Main Results:

  • Overall TMP-SMX resistance in clinical isolates increased from <5.5% (1979-1986) to 20.4% in 1995.
  • Resistance was markedly higher in HIV-infected patients, rising from 6.3% in 1988 to 53% in 1995.
  • Significant increases in TMP-SMX resistance were noted in Escherichia coli (24% to 74%) and Staphylococcus aureus (0% to 48%) from HIV-infected patients.

Conclusions:

  • The increased use of prophylactic TMP-SMX in HIV disease correlates with a substantial rise in TMP-SMX-resistant bacteria.
  • This resistance poses a potential challenge for future treatment and prophylaxis strategies in this patient population.

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