Frequency of multi drug resistance and molecular charachteristics of resistance to colistin among Acinetobacter baumannii isolated from hospitalized patients in ICU of Qazvin& masih daneshvari hospital, with ventilator associated pneumoniae

Introduction and Objectives: Antibiotic resistance is increasing among bacterial agents causing hospital infection. Acinetobacter Baumannii has been considered as a pathogenic organism with multiple antibiotic resistance (MDR) . Acinetobacter is the most common cause of pneumonia in patients who have been using the respiratory duct for more than 5 days. Today, Acinetobacter Baumannii is considered as one of the major pathogens in the ICU, which can be life-threatening due to the high drug resistance of this organism. Therefore, in this study, we evaluated the frequency of multiple antibiotic resistance and molecular properties of Clistin resistance in Acinetobacter Baumannii isolated from patients with pneumonia associated with ventilator admitted to special intensive care units of Masih Daneshvari Hospitals and hospital. Materials and Methods: In this study, 200 isolates of Acinetobacter Baumanni I were collected from Bronchoalveolar lavage and aspiration tracheal of patients admitted to the ICU of Messiah Daneshvari and Qazvin hospital, with vap from 2011 to 2019. All isolated isolates were identified by conventional biochemical methods and then identified by the proliferation of the OXA-51 gene. Determination of susceptibility of strains to different antibiotics by disk diffusion method for imipenem, ciprofloxacin, colistin, TG cyclin, Gentamycin, Amikacin, co trimoxazol, Piperacillin, Piperacillin-tazobactam,Cefotaxim, Ceftazidim, Cefepim disks. determination of antibacterial sensitivity to colistin by broth microdilution ,sequenced for mutation analysis in the Pmr CAB,mcr1 gens. Result : Bacterial isolates were collected from clinical specimens of broncho alveolar lavage (32%) and tracheal (84%). Most of the samples in this study were isolated from Tehran (Mashhad Daneshvari Hospital), Among the 200 isolates of Acinetobacter baumannii 199 (99/5%) isolates were XDR, 1 (0/5%) isolates was PDR. According to our results the higher antimicrobial resistance rates were Imipenem, Ciprofloxacin, TG cyclin, Gentamycin, Trimetoprim –sulfometoxazol,Amikacin,Piperacillin, Piperacillin-Tazobactam, Cefotaxim, Ceftazidim, Cefepim (100%). In this study, MIC was reported at concentrations of 0.5-32.80% of the isolates were sensitive to 0.5 μg / ml concentration and responded to colistin antibiotic. Consequently. The result of sequencing of PCR products by matching the NCBI site and valid molecular databases on the genes studied shows, as shown, the confirmation of mutation in the PMR CAB gene. The result of sequencing of PCR products by matching the NCBI site and valid molecular databases on the genes studied shows, as shown, the confirmation of mutation in the PMR CAB gene & The presence of the plasmid MCR1 was not confirmed.Due to the presence of Colistin-resistant Acinetobacter isolates in the samples and its increased MIC level, it shows a change in the pattern of resistance of these strains to colistin. Therefore, more careful monitoring and administration of antibiotics along with improved infection control measures It is essential in health systems to prevent the spread of resistant strains. Therefore, greater monitoring and control over the administration and use of antibiotics along with the improvement of infection control measures in health systems is necessary to prevent the spread of resistant strains.