Determination of sensitivity of acinetobacter baumannii complex to chlorhexidine and colistin obtained from clinical samples at Hacettepe University Hospitals

Acinetobacter Baumannii Complex (ABC) covers all over the world soonafter the emergence of the first case occured as a wound site infection in 2006 andthe emergence of an mounting number of antimicrobial compound with which the pathogens concerned could fight, which enabled WHO (World Health Organization) to locate this pathogen on the first rank. The treatment of the infection has become complicated due to the resistance that was developed following the introduction of new treatment modalities. Therefore, after isolation and identification of the agent, it is vital to reveal an accurate antibiogram resistance profile, however another problemthat need to be overcome is that it is necessary to wait every other day for the antibiogram testing. We have been exposed to a highly skilled pathogen for years, given that both chromosomal and mobile genetic elements exploited. The aim of this study was to identify pathogen of interest, decipher susceptibility patterns to antimicrobials and elaborate if there was in exist a cross-resistance between the chlorhexidine and colistin in. ABC. Accordingly, The study was composed in the isolation of ABC that infects in part of the body such as blood culture, lavage fluid, tracheal aspirate material, on the detection of the susceptibility profile of colistin and chlorhexidine and determination of the diversity of clonal presence. The colistin and chlorhexidine resistance profiles were determined according to 100 isolates of A. baumannii, EUCAST clinical margin and broth microdilution guidelines. The colistin resistance was found in 15 isolates and chlorhexidine intermediate susceptibility was found in 17 isolates. In an isolate, both chlorhexidine intermediate sensitivity and colistin resistance were detected. According to in-vitro experiments thus far conducted to investigate pleiotropic resistance in other pathogensother than A. baumannii, it is stated that the colistin resistance in A. baumannii may befitness cost with exposure to chlorhexidine. Among the A. baumannii isolates showing resistance to colistin, the number of 7 different clones were detected by performing PFGE (Pulsed Field Gel Electrophoresis). These thesis is the first study to examine the relationship between chlorhexidine and colistin. In this thesis, it has been revealed that bacteria in especially the Internal Diseases Intensive Care Unit have decreased sensitivity to chlorhexidine and colistin resistance is higher than other inpatient care units one, and ones conferring resistance to colistin do not originate from a single clone, however from seven different clones.