Multicenter evaluation of molecular and culture-dependent diagnostics for Shigella species and Entero-invasive Escherichia coli in the Netherlands.
An inter-laboratory collaborative trial for the evaluation of diagnostics for detection and identification of Shigella species and Entero-invasive Escherichia coli (EIEC) was performed. Sixteen Medical Microbiological Laboratories (MMLs) participated. MMLs were interviewed about their diagnostic methods and a sample panel, consisting of DNA-extracts and spiked stool samples with different concentrations of Shigella flexneri, was provided to each MML. The results of the trial showed an enormous variety in culture-dependent and molecular diagnostic techniques currently used among MMLs. Despite the various molecular procedures, 15 out of 16 MMLs were able to detect Shigella species or EIEC in all the samples provided, showing that the diversity of methods has no effect on the qualitative detection of Shigella flexneri. In contrast to semi quantitative analysis, the minimum and maximum values per sample differed by approximately five threshold cycles (Ct-value) between the MMLs included in the study. This indicates that defining a uniform Ct-value cut-off for notification to health authorities is not advisable.
Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands; Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands. Electronic address: maaike.van.den.beld@rivm.nl.
Maaike J C
MJC
van den Beld
Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Alexander W
AW
Friedrich
Certe, Medical Microbiology, Groningen, The Netherlands.
Evert
E
van Zanten
Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
Frans A G
FAG
Reubsaet
Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Certe, Medical Microbiology, Groningen, The Netherlands.
Mirjam A M D
MAMD
Kooistra-Smid
Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
John W A
JWA
Rossen
D015373:Bacterial Typing Techniques / Q000379:methods* / Q000592:standards; D004269:DNA, Bacterial; D003937:Diagnosis, Differential; D059026:Diagnostic Self Evaluation; D004405:Dysentery, Bacillary / Q000175:diagnosis* / Q000382:microbiology; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000175:diagnosis* / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D006801:Humans; D007753:Laboratories; D025202:Molecular Diagnostic Techniques / Q000379:methods* / Q000592:standards; D009426:Netherlands; D012760:Shigella / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D012763:Shigella flexneri / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification
D004269:DNA, Bacterial
Collaborative trial; Diagnostics; EIEC; Entero-invasive Escherichia coli; Inter-laboratory evaluation; Shigella