ABSTRACT
Background: trimethoprim/sulfamethoxazole [['MPISMX] has been the antimicrobial of choice for treatment of Stenotrophomonas malt philia [S. malt philia] infections. Several reports have shown that the prevalence of strains resistant to TMP/SMX is increasing. We investigated prevalence, risk factors and sulfamethoxazole resistance determinants of TMPISMX resistant S. malt philia in our geographic location
Methods: this study was conducted from January, 2009 till March, 2010 on 625 patients admitted to intensive care units [ICUs] in Mansoura University Hospitals [MUHs]. Nosocomial S. malt philia infections were detected in 90 samples. Antimicrobial susceptibilities were determined using the disk diffusion method. PCR was. Conducted for the detection of sull and sul2
Results: out of 90 S. malt philia isolates, 22 [24.4%] revealed resistances to TMPISMX Significant risk factors were: duration of ICU stay [P = 0.018], antibiotic treatment [P = 0.002] specifically Carbapenems [P = 0.035] and fluoroquinolones [P < 0.001] and duration of antibiotic treatment. All TMPISMX resistant S. malt philia isolates were positive for sull gene. None of the isolates carried sul2
Conclusion: the isolation of TMP/SMX resistant S. malt philia at our geographic location is alarming. Strategies to prevent S. malt philia infection should be encouraged. The resistance of S. malt philia isolates to TMP/SMX is due to sull rather than to sul2