Comparative analysis of amplified fragment length polymorphism and pulsed field gel electrophoresis in a hospital outbreak and subsequent endemicity of ampicillin-resistant Enterococcus faecium.
Reliable molecular methods for determination of relatedness between bacterial isolates have become increasingly important to evaluate outbreaks and endemic situations with nosocomial pathogens. In the present study Simpson's index of diversity with calculated confidence intervals was used to compare amplified fragment length polymorphism (AFLP) and pulsed field gel electrophoresis (PFGE) analysis of a hospital outbreak of ampicillin-resistant Enterococcus faecium and subsequent endemicity. The outbreak, in a Norwegian tertiary hospital, of infections caused by these enterococci started in 1995 and increased in 1996 after which the situation turned endemic. The purpose of this study was to compare the two methods in this setting and to determine the length of time during an outbreak that these methods are sufficiently valid to be of value for hospital infection control efforts. One hundred and sixty clinical isolates from urine specimens collected during the period 1995-1999 were included. The findings indicate that PFGE and AFLP are equally discriminative and could in this setting be used for typing purposes over the whole 5-year period.
Jureen
Roland
R
Institute of Medicine, University of Bergen, 5021 Bergen, Norway. roland.jurren@med.uib.no
Harthug
Stig
S
Sørnes
Steinar
S
Digranes
Asbjørn
A
Willems
Rob J L
RJ
Langeland
Nina
N
D000667:Ampicillin / Q000494:pharmacology; D000668:Ampicillin Resistance; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D003627:Data Interpretation, Statistical; D004196:Disease Outbreaks / Q000517:prevention & control; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D019353:Endemic Diseases; D016984:Enterococcus faecium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D009664:Norway / Q000453:epidemiology; D012150:Polymorphism, Restriction Fragment Length
D001426:Bacterial Proteins; D000667:Ampicillin