ABSTRACT
BACKGROUND: Metallo-beta-lactamase (MBL) producing Pseudomonas aeruginosa in the burn patients is a leading cause of morbidity and mortality and remains a serious health concern among the clinicians. OBJECTIVES: The aim of this study was to detect MBL-producing P. aeruginosa in burn patients and determine multidrug-resistant (MDR) strains, and respective resistance patterns. PATIENTS AND METHODS: In this cross-sectional study, 270 strains of P. aeruginosa were isolated from the burn patients referred to Ghotbeddin Burn Hospital, Shiraz, Iran. Among them, 55 MBL-producing P. aeruginosa strains were isolated from 55 patients hospitalized in burn unit. Minimum inhibitory concentrations (MICs) and MBLs were determined by the E-test method. RESULTS: Of the 55 burn cases, 29 (53%) were females and 26 (47%) males. Injured burn patients' ages ranged from 16 to 87 years, with maximum number of cases in the age group of 16 to 36 years (n, 40; 72.7%). Overall, 32 cases were accidental (60%), and 22 were suicidal burns (40%). Of the 55 burn patients, 17 cases were expired (30%). All deaths were due to chemical exposures. In antibiotic susceptibility testing by E-test method, ceftazidime was the most effective one and 35 isolates (63.5%) were resistant to all the 11 tested antibiotics. CONCLUSIONS: Routine microbiological surveillance and careful in vitro testing of antibiotics prior to prescription and strict adherence to hospital antibiotic policy may help to prevent, treat, and control MDR and pandrug-resistant (PDR) P. aeruginosa strains in burn units.
ABSTRACT
BACKGROUND: Failure in the treatment of burn patients infected with Pseudomonas aeruginosa could happen as a result of the acquisition of antibiotic resistance, including carbapenems. OBJECTIVES: The aim of the present study was to investigate the phenotypic and genotypic characteristics of the Pseudomonas aeruginosa strains, isolated from burn patients. PATIENTS AND METHODS: During a 12 month period, in this cross-sectional study, two hundred seventy strains of Pseudomonas aeruginosa were isolated from the burn patients in Ghotbeddin Burn Hospital, Shiraz, Iran. Screening for the carbapenem resistance in the isolates was carried out by the E test method. Sensitivity patterns of metallo-ß-lactamase (MßLs) producing strains of pseudomonas to eleven antibiotics were determined by the mentioned method. The epidemiological associations of these strains were determined by Pulsed-field gel electrophoresis (PFGE). RESULTS: Of the 270 strains, 60 (22.2%) were resistant to imipenem and meropenem, classified as MßLs producing. MßLs producing strains of pseudomonas were completely resistant to five tested antibiotics while their sensitivities to the three most effective antibiotics including ceftazidime, amikacin and ciprofloxacin were 23.4%, 6.7 % and 1.7%, respectively. In PFGE, 37 patterns from the genome of Pseudomonas aeruginosa were observed. Majority of the strains (43; 71.6%) exhibited more than 80% similarity, based on the drawn dendrogram. CONCLUSIONS: According to the results, none of the tested antibiotics is safe to prescribe. As PFGE revealed, a limited number of Pseudomonas aeruginosa types are predominant in the hospitals which infect the burn patients.
