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Minimal Inhibitory Concentration of Ceftazidime and Co-trimoxazole for Stenotrophomonas Maltophilia using E-test
Firoozeh Jamali1, Mohammad Ali Boroumand, Farzad Yazdani
1Department of Pathology, Vali-asr Hospital, Tehran, Iran.
Background:
Stenotrophomonas maltophilia, previously named as Pseudomonas or Xanthomonas maltophilia, is an important nosocomial pathogen
Aim:
The purpose of the present study was to investigate the prevalence of S. maltophilia in Iranian hospitals and its susceptibility to available antimicrobial agents.
Setting And Design:
A cross-sectional study in Imam Khomeini Hospital affiliated to Tehran University of Medical Sciences.
Materials And Methods:
All blood specimens were sent to the laboratory for blood culture and biochemical analysis. One hundred samples were positive for S. maltophilia. We used disk diffusion and E-test in order to determine minimal inhibitory concentration (MIC) of ceftazidime and co-trimoxazole as the first line antibiotics for S. maltophilia. The tests were performed and interpreted according to the guidelines of Clinical Laboratory Standards Institute (CLSI).
Statistical Analysis:
Chi-square test and Kappa measurement of agreement were applied as appropriate.
Results:
S. maltophilia was the most frequent pathogen (895 specimens; 38.9%) isolated from the samples which were mostly from emergency ward (780 specimens; 33.9%). Ceftazidime MIC(50) and MIC(90) were 2 and 32 μg/ml, respectively (sensitive ≤8 μg/ml and resistant ≥32 μg/ml according to CLSI guideline). MIC(50) and MIC(90) for co-trimoxazole were 0.5 and 2 μg/ml, respectively (sensitive ≤2 μg/ml and resistant ≥4 μg/ml according to CLSI guideline).
Conclusion:
S. maltophilia is the most frequent pathogen in our hospital with a high susceptibility to both ceftazidime and co-trimoxazole.
Insights
Stenotrophomonas maltophilia is a frequent nosocomial pathogen. This study found high susceptibility to ceftazidime and co-trimoxazole in Iranian hospitals, indicating effective treatment options.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Stenotrophomonas maltophilia, a significant nosocomial pathogen, poses a growing threat in healthcare settings.
- Understanding its prevalence and antimicrobial susceptibility is crucial for effective infection control.
Purpose of the Study:
- To determine the prevalence of Stenotrophomonas maltophilia in Iranian hospitals.
- To assess the susceptibility of S. maltophilia isolates to key antimicrobial agents.
Main Methods:
- A cross-sectional study was conducted at Imam Khomeini Hospital.
- Blood cultures were analyzed, and 100 S. maltophilia isolates were identified.
- Disk diffusion and E-test were used to determine antimicrobial susceptibility according to CLSI guidelines.
Main Results:
- Stenotrophomonas maltophilia was the most frequent pathogen identified (38.9% of isolates).
- High susceptibility was observed for co-trimoxazole (MIC50=0.5 μg/ml, MIC90=2 μg/ml).
- Ceftazidime also showed significant susceptibility (MIC50=2 μg/ml, MIC90=32 μg/ml).
Conclusions:
- Stenotrophomonas maltophilia is a prevalent pathogen in the studied hospital.
- The findings support the use of ceftazidime and co-trimoxazole as effective treatments for S. maltophilia infections.
