Risk factors for drug resistant gram negative bacilli infections in hospitalized burned patients and their in- vitro colistin susceptibilily in Sina hospital of Tabriz

Abstract

Burning as the 4th injury event involves 11 million people annually, in a way that medical help is needed. Infectious complications is the most common cause of death in these patients. Gram negative bacilli are the dominant isolated micro-organism in most of the centers, whereas, their expanding resistance to antibiotics are one of the major challenges in the clinic. Methods: This study was conducted in ICU or wards of the Sina hospital, and patients with the clinical evidence of infections, after sampling for culture and anti-bio-gram, entered the study in case of the isolation of gram negative bacteria. Control group involved patients with isolated organisms from their wounds other than resistant gram negative bacilli, resistant gram positive cocci including MRSA and VRE, and fungi. Firstly, the existence of 14 possible risk factors was evaluated and was compared between the group of infection with resistant gram negative bacilli and control group. Also, the sensitivity in resistant gram negative bacilli to Colistin using disk-diffusion and E-test was evaluated. Results: within 200 included patients, 100 were in the control group and the other 100 were in the case group. In the case group, the means of intensity and percent of burning, respiratory rate, heart rate, body temperature, respiratory tract involvement, history of antibiotics consumption in the past 2 months and past 5 days, ICU duration, being under mechanical ventilation and having central vein catheter and Foley catheter were significantly higher than control group (P<0.05). However, there were no significant difference between two groups regarding age, gender, anogenital involvement, diastolic and systolic blood pressure at the time of diagnosis, times of debridement and scarotomy, and skin graft (p>0.05). the most common isolated gram negative bacilli were Pseudomonas aeruginosa, Acinetobacter, Klebsiella pneumoniae, E.coli, and enterobacter species. Only one resistant Acinetobacter to Colistin was reported, and the resistance was confirmed by both the Disk-diffusion and E-test methods. On the other hand, two resistant cases and two intermediate cases were reported by disk-diffusion that were not confirmed by E-test.