Subject(s)
Burkholderia Infections/epidemiology , Burkholderia cepacia/classification , Cystic Fibrosis/complications , Adolescent , Adult , Burkholderia Infections/microbiology , Burkholderia cepacia/drug effects , Burkholderia cepacia/genetics , Burkholderia cepacia/isolation & purification , Case-Control Studies , Child , Child, Preschool , Cystic Fibrosis/microbiology , Electrophoresis, Gel, Pulsed-Field , Female , Genotype , Humans , Infant , Italy/epidemiology , Male , Microbial Sensitivity Tests , Phenotype , Risk Factors , SerotypingABSTRACT
BACKGROUND: Acinetobacter baumannii has become an increasingly important nosocomial pathogen, particularly in intensive care units (ICUs). The aim of this investigation was to study the molecular epidemiology of A baumanii in a university hospital in Italy. METHODS: All A baumanii isolates were collected and typed with phenotypic and genotypic methods during a 7-month period. A 1-year prospective surveillance of ICU-acquired infections was performed by using the National Nosocomial Infections Surveillance methodology. RESULTS: A baumanni accounted for 28.4% of all infections and 46.7% of all pneumonia acquired in the ICU, with a nosocomial infection rate of 12.4% or 8 infections per 1000 patient-days. Risk factors for A baumannii acquisition in the ICU were mechanical ventilation and previous use of broad-spectrum antibiotics, whereas administration of carbapenems showed a significant protective effect. Pulsed-field gel electrophoresis of genomic Apa I digests identified at least 5 outbreaks in the ICU caused by 5 different clones, one replacing the other in a well-defined temporal order. CONCLUSIONS: Whereas the sequential temporal cluster of epidemic clones in the ICU is intriguing and requires further research, the clear evidence of cross-contamination of A baumannii isolates involved with infections in the ICU demands extensive preventive efforts.
