Trimethoprim/sulfamethoxazole resistance in clinical isolates of Burkholderia pseudomallei.

Abstract

OBJECTIVES:

Trimethoprim/sulfamethoxazole is commonly used to treat melioidosis. Antimicrobial susceptibility testing using the disc diffusion method is commonly used in melioidosis-endemic areas, but may overestimate resistance to trimethoprim/sulfamethoxazole.

PATIENTS AND METHODS:

We performed disc diffusion and Etest on isolates from the first positive culture for all patients presenting to Sappasithiprasong Hospital, Ubon Ratchathani, Thailand, with culture-confirmed melioidosis between 1992 and 2003.

RESULTS:

The estimated resistance rate for 1976 clinical Burkholderia pseudomallei isolates was 13% by Etest and 71% by disc diffusion. All isolates classed as either susceptible (n=358) or as having intermediate resistance (n=218) on disc diffusion were susceptible by Etest. Only 258 of the 1400 (18%) isolates classed as resistant on disc diffusion were resistant by Etest.

CONCLUSIONS:

Disc diffusion testing of B. pseudomallei may be useful as a limited screening tool in resource poor settings. Isolates assigned as 'susceptible' or 'intermediate' by disc diffusion may be viewed as 'susceptible'; those assigned as 'resistant' require further evaluation by MIC methodology.

• Authors: Vanaporn Wuthiekanun, Allen C Cheng, Wirongrong Chierakul, Premjit Amornchai, Direk Limmathurotsakul, Wipada Chaowagul, Andrew J H Simpson, Jennifer M Short, Gumphol Wongsuvan, Bina Maharjan, Nicholas J White, Sharon J Peacock
• Journal: The Journal of antimicrobial chemotherapy (J Antimicrob Chemother) Vol. 55 Issue 6 Pg. 1029-31 (Jun 2005) ISSN: 0305-7453 [Print] England
• PMID: 15886263 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Infective Agents
• Trimethoprim, Sulfamethoxazole Drug Combination

Topics

• Anti-Infective Agents (pharmacology)
• Burkholderia pseudomallei (drug effects)
• Diffusion
• Drug Resistance, Bacterial
• Humans
• Microbial Sensitivity Tests (methods)
• Trimethoprim, Sulfamethoxazole Drug Combination (pharmacology)