A single-center, six-year evaluation of the role of pulsed-field gel electrophoresis in suspected burn center outbreaks.

Abstract

Pulsed-field gel electrophoresis (PFGE) has been used as an adjunct to traditional hospital epidemiology in numerous outbreak investigations, including in burn centers. However, its most effective real-world application remains unclear, with few longitudinal descriptions of use. A 425 bed military tertiary hospital with a 40 bed burn center, from July 2007 to July 2013; retrospective evaluation of hospital infection prevention records was performed and results of PFGE where used in outbreak investigation. Twenty-two inquiries for suspected outbreaks were performed. 418 isolates were collected from 168 subjects during this time. 325 (78%) of the isolates originated from the burn intensive care unit. 17 inquiries were for gram-negative bacteria, comprised of 5 for Acinetobacter baumannii-calcoaceticus complex, 4 Klebsiella pneumoniae, 3 Stenotrophomonas maltophilia, 2 Pseudomonas aeruginosa, and 1 of each of the following: Enterobacter cloacae, Raoultella planticola, and Aeromonas hydrophila. The other 5 inquiries were specifically for Staphylococcus aureus. The majority of investigations revealed a combination of clonal and non-clonal isolates, and in no instance did PFGE contribute to targeting of interventions. PFGE contributed little to infection prevention interventions, and outbreaks resolved with increased focus on basic practices. Longitudinal studies including greater numbers of outbreaks in different settings are needed to clarify the utility of molecular typing in routine investigations.