Patterns of Causative Pathogens and Resistance in Nosocomial Pneumonia of Intensive Care Unit

Kim, Kyu Sik; Lim, Sung Chul; Jang, Il Gon; Hang, Jun Hwa; Kim, Yu Il; Park, Chang Min; Go, Kyung Haeng; Lim, Myung Su; Shin, Jong Hee; Ryu, Phil Youl; Park, Kyung Ok

Abstract

BACKGROUND
The most of nosocomial pneumonia in the intensive care unit (ICU)occurs usually in patients whose tracheally intubated and receiving mechanical ventilation. The pathogens causing pneumonia in ICU patients are Pseudomonas aeruginosa, Staphylococcus aureus, and mainly composed of Acinetobacter species. Today, the emergence of antimicrobial-resistant pathogens in the nosocomial pneumonia have been problematic and serious. We therefore, evaluated the prevalence of causative pathogens of hospital-acquired pneumonia in the ICU and analyzed the pathogens of their antibiotic-resistance
METHODS
Sixty-nine patients admitted to the ICU at Chonnam university Hospital were conducted retrospectively to the study for frequency of causative organisms and antibiotic resistance in the nosocomial pneumonia from January 1996 to December 1996. RESULT: Of the 69 patients, 24 patients(34.8%) were developed pneumonia 72 hours after admission and 45 patients had received antibiotics prior to entry into the study from first or second-line hospital. In the 69 patients with pneumonia, 67 microorganisms were detected in cultures obtained from tracheal aspirate and 2 microorganisms were cultured from PSB samples. The most frequent causative organisms were P. aeruginosa(33.3%, 23/69), S. aureus(33.3%, 23/69), Acinetobacter(15.9%, 11/69), Enterobacter(10.1%, 7/69). In S. aureus, antibiotic resistance showed 91.3% to methicillin, 82.6% to cefotaxime, 87% to ciprofloxacin. But MRSA resistant to vancomycin has not been reported. Cross-resistant pattern in P. aeruginosa infection represented 47% piperacilline-cefoperazone cross-reaction, 22% piperacilline-ceftazidime, 15.3% pileracilline-imipenem, 12.5% imipenem-ceftazidime, 30% gentamicinamikacin. There are no cross-reaction between imipenem and ciprofloxacin.
CONCLUSION
The extensive use of antibiotics in the community and hospitals has the crisis in antibiotic resistance. Mechanisms such as identification of causative organisms, antibiotic control program, and synthesis of agents with improved antimicrobial activity need to adopted in order to limit bacterial resistance.