Antibiotics resistance of Stenotrophomonas maltophilia strains isolated from various clinical specimens.

BACKGROUND

A limited number of antibiotics are recommended for the therapy of Stenotrophomonas maltophilia infections due to therapy difficulties caused by its numerous mechanisms of resistance.

OBJECTIVES

In this study conducted over a period of approximately 5 years we aimed to determine resistance rates of S. maltophilia based on drug classification recommended by Clinical and Laboratory Standards Institute.

METHODS

A total of 118 S. maltophilia strains isolated from various clinical specimens between January 2006 and June 2012 were included in the study. BD Phoenixautomated microbiology system (Becton Dickinson, USA) was utilized for species level identification and antibiotic susceptibility testing.

RESULTS

Sixty seven of S. maltophilia strains were isolated from tracheal aspirate isolates, 17 from blood, 10 from sputum, 10 from wound and 14 from other clinical specimens. Levofloxacin was found to be the most effective antibiotic against S. maltophilia strains with resistance rate of 7.6%. The resistance rates to other antibiotics were as follows: chloramphenicol 18.2%, trimethoprim-sulfamethoxazole 20.3% and ceftazidime 72%.

CONCLUSION

The study revealed that S. maltophilia is resistant to many antibiotics. The treatment of infections caused by S. maltophilia should be preferred primarily as levofloxacin, chloramphenicol, and TMP-SXT, respectively.