DNA fingerprinting of Shiga-toxin producing Escherichia coli O157 based on Multiple-Locus Variable-Number Tandem-Repeats Analysis (MLVA).
BACKGROUND
The ability to react early to possible outbreaks of Escherichia coli O157:H7 and to trace possible sources relies on the availability of highly discriminatory and reliable techniques. The development of methods that are fast and has the potential for complete automation is needed for this important pathogen.


METHODS
In all 73 isolates of shiga-toxin producing E. coli O157 (STEC) were used in this study. The two available fully sequenced STEC genomes were scanned for tandem repeated stretches of DNA, which were evaluated as polymorphic markers for isolate identification.


RESULTS
The 73 E. coli isolates displayed 47 distinct patterns and the MLVA assay was capable of high discrimination between the E. coli O157 strains. The assay was fast and all the steps can be automated.


CONCLUSIONS
The findings demonstrate a novel high discriminatory molecular typing method for the important pathogen E. coli O157 that is fast, robust and offers many advantages compared to current methods.
Lindstedt
Bjørn-Arne
BA
Norwegian Institute of Public Health, Department of Infectious Disease Control, Oslo, Norway. bjorn-arne.lindstedt@fhi.no
Heir
Even
E
Gjernes
Elisabet
E
Vardund
Traute
T
Kapperud
Georg
G