Mohammad Rahbar; Hadi Mehragan; Negar Haji Ali Akbari
Volume 5, Issue 2 , March 2010, , Pages 90-96
Abstract
Background and Objectives: Non-fementer gram-negative bacilli (NFGB) are ubiquitous pathogen that has emerged as a major cause of health care associated infections. The aim of this study was to determine the prevalence and antimicrobial susceptibility of NFGB in an Iranian hospital. ...
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Background and Objectives: Non-fementer gram-negative bacilli (NFGB) are ubiquitous pathogen that has emerged as a major cause of health care associated infections. The aim of this study was to determine the prevalence and antimicrobial susceptibility of NFGB in an Iranian hospital. Materials and Methods: FromJuly 2005 to November 2006 a total of 257 strains of NFGB including 109 (42.41%) strains of Pseudomonas aeruoginosa, 88 (34.24%) strains of Acinetobacter baumannii, 48 (18.67%) stains of Stenotrophomonas maltophilia and 12 (4.66%) strains of Burkholderia cepacia were isolated from clinical specimens taken from patients hospitalized in an Iranian 1000–bed tertiary care hospital[d1] . Conventional bacteriological methods were used for identification and susceptibility testing of NFGB. Susceptibility testing was performed by method as recommended by Clinical Laboratory Standard Institute (CLSI). Data were analyzed using SPSS 11.5 for Windows (SPSS Inc., Chicago, IL) Results: A total of 257 non-duplicating of NFGB strains were isolated from 234 hospitalized patients. The most effective antibiotic against P. aeruginosa and A. baumannii was imipenem followed by tobramycin. Fluoroquinolones had moderate activity against P. aerugunosa. Most isolates of A.baumannii were multi-drug resistant. Susceptibility of S. maltophila to ticarcillin- clavuanic, ofloxacin and ceftazidim was 96%, 94% and 81%, respectively. Thirty three percent of this bacterium isolates were resistant to co-trimoxazole. Conclusion: In our study, imipenem was the most effective antibiotic against P. aeruginosa and A. baummannii isolates. Previous history use of antibiotics, longer duration of hospital stay and mechanical ventilation were the major risk factors for resistance acquisition in NFGB especially in P. aeruginosa and A. baumannii.
Mohammad Rahbar; Nooshafarin Safadel
Volume 1, Issue 4 , September 2006, , Pages 145-148
Abstract
Background and Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial and community acquired infections. Detection of MRSA in laboratories is very important for treatment and appropriate infection control. The aim of this study was to evaluate cefoxitin disk diffusion ...
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Background and Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial and community acquired infections. Detection of MRSA in laboratories is very important for treatment and appropriate infection control. The aim of this study was to evaluate cefoxitin disk diffusion method for detection of MRSA and comparison of this method with other conventional methods. Methods: A total of 175 clinical isolates of S. aureus isolated from clinical specimens were studied. The isolates were identified by conventional laboratory methods. In this respect, E-test MIC, cefoxitin and oxacillin disk diffusion methods, and MAST ID Methicillin strips were used for detection of MRSA. All disk diffusion methods were performed as recommended by NCCL and manufacturers’ guidelines. Results: Using E-test MIC, 53 out of 175 strains of S. aureus were resistant to methicillin. In addition, disk diffusion method using oxacillin disk showed that 52 strains are resistant to methicillin. In this respect, 8 strains had intermediate resistance to methicillin. For cefoxitin disk diffusion method, 52 strains were resistant to methicillin. This method had a good correlation with E-test MIC method. Meanwhile, MAST ID methicillin strips detected 47 strains that were resistant to mehicillin. Sensitivity and specificity for both cefoxitin and oxacillin disk diffusion methods were 98%and 100% respectively. However cefoxitin was better than oxacillin for detecting intermediate resistant strains of S. aureus. Sensitivity and specificity for MAST ID methicillin strips were 91% and 100% respectively. Conclusion: This study revealed that cefoxitin disk diffusion method is a good alternative for oxacillin disk diffusion method for detection of MRSA. This method is more reliable for identification of intermediate resistant strains of S. aureus.