Inter-laboratory comparison of multi-locus variable-number tandem repeat analysis (MLVA) for verocytotoxin-producing Escherichia coli O157 to facilitate data sharing.
Multi-locus variable number tandem repeat analysis (MLVA) is used in clinical and reference laboratories for subtyping verocytotoxin-producing Escherichia coli O157 (VTEC O157). However, as yet there is no common allelic or profile nomenclature to enable laboratories to easily compare data. In this study, we carried out an inter-laboratory comparison of an eight-loci MLVA scheme using a set of 67 isolates of VTEC O157. We found all but two isolates were identical in profile in the two laboratories, and repeat units were homogeneous in size but some were incomplete. A subset of the isolates (n = 17) were sequenced to determine the actual copy number of representative alleles, thereby enabling alleles to be named according to international consensus guidelines. This work has enabled us to realize the potential of MLVA as a portable, highly discriminatory and convenient subtyping method.
Scottish Escherichia coli O157/VTEC Reference Laboratory, Royal Infirmary of Edinburgh, Edinburgh,UK.
A
A
Holmes
Gastrointestinal Bacterial Reference Unit, Public Health England, London,UK.
N
N
Perry
Gastrointestinal Bacterial Reference Unit, Public Health England, London,UK.
G
G
Willshaw
Scottish Escherichia coli O157/VTEC Reference Laboratory, Royal Infirmary of Edinburgh, Edinburgh,UK.
M
M
Hanson
Scottish Escherichia coli O157/VTEC Reference Laboratory, Royal Infirmary of Edinburgh, Edinburgh,UK.
L
L
Allison
D005838:Genotype; D033181:Information Dissemination; D018598:Minisatellite Repeats; D058889:Molecular Typing / Q000379:methods* / Q000592:standards*; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification* / Q000235:genetics