Molecular Detection and Genotyping

Genotyping of LGV Chlamydia serovars by real-time PCR and direct sequencing on confirmed C. trachomatis samples.

Chlamydia positive culture or positive rectal, endocervical, urethral, urine and other types of specimens including biopsies from Chlamydia positive patients, and specimens in GEN-PROBE APTIMA buffer. The minimum volume required is 1 mL.

Swab or cytobrush

Place cytobrushes or swabs in 2 mL of transport medium. Specimens may be stored and shipped refrigerated to NML within 48h of sample collection or must be stored and shipped frozen. Fresh biopsies must be stored frozen at all times and shipped on dry ice.

Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.

This service is offered for LGV suspected cases on positive C. trachomatis samples only. Specimens for C. trachomatis screening are not accepted unless part of pre-arranged collaborative study.

Completed "Viral STI, Polyoma and Herpesvirus Testing" requisition form including sender lab name, address and telephone number, patient identifier, date of birth or age, sex, specimen reference #, type of specimen, date collected, test requested, reason for testing and any other relevant clinical information.

N/A

Detection of LGV Chlamydia in Chlamydia positive specimens is performed by a multiplex qPCR assay (1). The analytical sensitivity for the detection of LGV is between 10 and 100 copies/reaction while the detection for the cryptic plasmid is about 100 copies/reaction. The serovar is confirmed by amplification and sequencing of the ompA gene. If the MOMP PCR is negative, the serovar cannot be determined. The precise C. trachomatis LGV serovar is reported. Please note that this method is less sensitive than diagnostic kits available and is not intended for Chlamydia trachomatis screening.

10 calendar days and 21 calendar days for LGV confirmation. Please contact lab to inquire about shorter turn around time.

1. Chen CY, Chi KH, Alexander S, Ison CA, Ballard RC. A real-time quadriplex PCR assay for the diagnosis of rectal lymphogranuloma venereum and non-lymphogranuloma venereum Chlamydia trachomatis infections. Sex Transm Infect. 2008 Aug;84(4):273-6.