title: Comparison of three genotyping methods to identify Chlamydia trachomatis genotypes in positive men and women.
abstract: Chlamydia trachomatis (Ct) comprises 3 serogroups and 19 serovars. Different genotyping methods are available to differentiate between the serovars. The aim of this study was to evaluate the sensitivity and discriminatory power of three genotyping methods, respectively Omp1 sequencing, the Ct Detection and genoTyping (DT) assay and the pmpH real-time PCR discriminating an LGV infection from a non-LGV infection. In total, 50 Aptima Combo 2 (AC2) Ct positive samples were selected and tested with the 3 genotyping methods. The Ct-DT assay detected 3 double Ct infections that caused a non interpretable result by Omp1 sequencing, while Omp1 sequencing has a higher discriminatory power that gave additional information about Ct genovariants. All three methods detected the 6 LGV samples. Although the pmpH real-time PCR detected all LGV infections, a substantial amount (24%) of non-LGV infections were missed. The sensitivity compared to AC2 Ct detection was 80% (95% CI 67-89%) for the Ct-DT assay, 72% (95% CI 58-83%) for Omp1 sequencing and 64% (95% CI 50-76%) for the pmpH real-time PCR. In conclusion, the Ct-DT assay is appropriate for serovar distribution studies, epidemiological studies and differentiation between an LGV and non-LGV Ct infection, while Omp1 sequencing is more appropriate for phylogenetic studies. The pmpH real-time PCR is suitable as second assay to differentiate between an LGV and non-LGV infection, but not as primary detection assay, due to its low sensitivity for non-LGV strains.
authors.affiliation: DDL Diagnostic Laboratory, Voorburg, The Netherlands. k.d.quint@gmail.com
authors.forename: K D
authors.initials: KD
authors.lastname: Quint
authors.forename: R J M
authors.initials: RJ
authors.lastname: Bom
authors.forename: S M
authors.initials: SM
authors.lastname: Bruisten
authors.forename: L J
authors.initials: LJ
authors.lastname: van Doorn
authors.forename: N
authors.initials: N
authors.lastname: Nassir Hajipour
authors.forename: W J G
authors.initials: WJ
authors.lastname: Melchers
authors.forename: H J C
authors.initials: HJ
authors.lastname: de Vries
authors.forename: S A
authors.initials: SA
authors.lastname: Morre
authors.forename: W G V
authors.initials: WG
authors.lastname: Quint
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D002692:Chlamydia trachomatis / Q000145:classification / Q000235:genetics*; D015342:DNA Probes; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008219:Lymphogranuloma Venereum / Q000175:diagnosis* / Q000382:microbiology; D008297:Male; D058889:Molecular Typing / Q000379:methods*; D009693:Nucleic Acid Hybridization / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods; D018272:Porins / Q000235:genetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D015342:DNA Probes; D004269:DNA, Bacterial; C410162:PmpH protein, Chlamydia trachomatis; D018272:Porins; C071677:omp1 protein, Chlamydia trachomatis