TypingChlamydia trachomatis: from egg yolk to nanotechnology

Abstract

A historical review is provided of the various methods used for half a century to differentiate and type Chlamydia trachomatis strains. Typing of C. trachomatis is an important tool for revealing transmission patterns in sexual networks, and enabling association with clinical manifestations and pathogenicity. Serotyping using the major outer membrane protein (MOMP) has been the mainstay of epidemiological work for several decades. However, the development of nucleic acid amplification techniques (NAAT) and easy access to sequencing have shifted the focus from MOMP serotypes to omp1 genotypes. However, insufficient epidemiological resolution is achieved by characterization of both MOMP and omp1. This calls for new high-resolution genotyping methods applying for example a multilocus variable number tandem repeat assay (MLVA) or multilocus sequence typing (MLST). The futuristic nanotechnology already seems at hand to further simplify and automate the high-resolution genotyping method based on NAAT and sequencing of various targets in the C. trachomatis genome. Thereby, a high throughput can be achieved and more epidemiological information can be obtained. However, it is important to realize that culture of C. trachomatis may still be needed to detect and characterize new variants of C. trachomatis.

Chlamydia trachomatis infection prevalence and serovar distribution in a high-density urban area in the north of Italy

“…The present finding is similar to many other surveys conducted in both high-risk and low-risk subjects (Petrovay et al, 2009;Weill et al, 2010;Yang et al, 2014;Veersteg et al, 2015;Giffard et al, 2016). Effectively, in many countries worldwide, serovars E, F, D, G and K represent the most common serovars among patients with urogenital infections, accounting for 60-80 % of positive patients (Millman et al, 2006;Pedersen et al, 2009;Lagerga rd et al, 2010;Veersteg et al, 2015).…”

“…As reviewed by Pedersen et al (2009) and Xia & Xiong (2014), many molecular methods, mainly based on omp1 or pmpH gene amplification and characterization, are nowadays available, showing different performances in terms of sensitivity, specificity and ability in the detection of mixed infections.…”

“…So far these assays have basically played a role in epidemiological and phylogenetic analysis or in the evolutionary surveillance of specific clones, but what is really needed in the near future is the advent of rapid and cost-saving methods for faster and reliable management of patients (Pedersen et al, 2009;Xia & Xiong, 2014).…”

“…In particular, serovars A to C are associated with trachoma, serovars D to K with typical urogenital infections and serovars L1 to L3 with LGV (Stevens et al, 2010). Since CT serotyping is time-and labour-consuming, nowadays genotyping methods are currently used and a variety of molecular techniques, such as PCR-RFLP, real-time PCR or nested-PCR, followed by sequencing, have been reported (Pedersen et al, 2009;de Vries et al, 2015).…”

Genotyping and prevalence of Chlamydia trachomatis infection among women in Belém, Pará, northern Brazil

“…The temporal and geographical distribution of strains throughout the world has significant implications for our understanding of the epidemiology of this infectious agent and for vaccine development [5]. Moreover, typing can be an important tool to reveal transmission pathways and associations with different tissue tropisms and pathogenicity [8].…”