Analysis of Cross-Transmission and Antimicrobial Resistance of Pseudomonas aeruginosa and Acinetobacter baumannii Isolates Causing Nosocomial Infection in an Intensive Care Unit

Abstract

Pseudomonas aeruginosa and Acinetobacter baumannii ciddi hastane enfeksiyonlarına neden olur. Bu çalışmada, Üçüncü basamak bir hastanenin, yoğun bakım ünitesinde bu bakterilerin hastalar arasında çapraz geçişini ve antibiyotik duyarlılığını araştırdık. GGeerreeçç vvee YYöönntteemmlleerr

Pseudomonas aeruginosa and Acinetobacter baumannii cause nosocomial in— fections in intensive care units. We investigated the antimicrobial susceptibility and cross—transmis— sion of these bacteria amongst patients in an intensive care unit. Material and Methods: Thirty—three P. aeruginosa (from 26 patients) and 48 A. baumannii isolates (from 41 patients) responsible for noso— comial infections were isolated from patients between October 2009 and June 2010. Pulsed field gel electrophoresis was used to investigate clonal relationship among isolates. Susceptibility to amikacin, ceftazidime, gentamycin, imipenem, cefepime, piperacillin/tazobactam, aztreonam, and meropenem was examined using the disk diffusion method. Results: P. aeruginosa isolates formed 18 pulsotypes; five of these were clusters including or more strains having indistinguishable PFGE patterns and the re— maining 13 were unique. After excluding the repeated samples of the same patients, the clustering rate was estimated as 38.5%. The 48 A. baumannii isolates formed 13 pulsotypes; eight pulsotypes were clusters including totally 41 strains of which five were from repeated samples of five patients. The clustering rate was 87.8% for the isolates obtained from 41 different patients. The antimicrobial resis— tance rates of P. aeruginosa ranged from 27—39%, but were 45.5—91% for A. baumannii isolates. Conclusion: Despite an implemented infection control program, P. aeruginosa and A. baumannii isolates showed cross—transmission among patients, and the antimicrobial resistance rate of A. bau— mannii isolates was very high. These findings indicate that the current infection control programs should be reassessed and modifications should be made according to the specific hospital and staffing conditions.