Microbiologic spectrum and susceptibility pattern of clinical isolates from the pediatric intensive care unit in a single medical center - 6 years' experience

Abstract

Background and purpose: Nosocomial infection contributes to the morbidity and mortality of patients in hospital. Timely microbiologic surveillance and assessment of antimicrobial resistance is important for dealing with nosocomial infections. This retrospective review was conducted to evaluate the microbiologic spectrum and susceptibility pattern in the pediatric intensive care unit from 2001 to 2006.

Methods: The microbiologic data and antimicrobial susceptibility of all clinical isolates in the pediatric intensive care unit between 2001 and 2006 were reviewed. The incidence and distribution of nosocomial infections and the associated pathogens were also analyzed.

Results: 1163 clinical isolates were analyzed. The frequencies of Gram-positive and Gram-negative bacteria were 30.4% and 56.2%, respectively. Staphylococcus aureus was the most common isolate among the Gram-positive organisms, while Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae were the 3 leading Gram-negative isolates. The proportion of methicillin-resistant S. aureus (MRSA) to all S. aureus was 65.2%. Six vancomycin-resistant enterococci were isolated in 2003. Extended-spectrum beta-lactamase (ESBL)-producing K. pneumoniae accounted for 20% of K. pneumoniae isolates since 2005. Carbapenem-resistant P. aeruginosa accounted for 34% of P. aeruginosa isolates. The nosocomial infection rate was not reduced after moving to a new hospital building in 2003. Urinary tract infection (30.2%) was the most common nosocomial infection, followed by bloodstream infection (26.5%) and lower respiratory tract infection (25.3%).

Conclusions: MRSA, carbapenem-resistant P. aeruginosa, and ESBL-producing K. pneumoniae were the major concerns in this study. Good hand hygiene and strict aseptic procedures remain the most important factors for infection control.