Chlamydia trachomatis is the most prevalent sexually transmitted bacterium worldwide and the causative agent of trachoma. Its strains are classified according to their ompA genotypes, which are strongly linked to differential tissue tropism and disease outcomes ocular disease, urogenital disease and lymphogranuloma venereum LGV. While the genome-based species phylogenetic tree presents four main clades correlating with tropismprevalence, namely ocular, LGV, urogenital T1 more prevalent genotypes and urogenital T2 less prevalent genotypes, inter-clade exchange of ompA is considered a rare phenomenon probably mediating marked tropism alterations. An LGV epidemic, associated with the clonal expansion of the L2b genotype, has emerged in the last few decades, raising concerns particularly due to its atypical clinical presentation ulcerative proctitis and circulation among men who have sex with men MSM. Here, we report an LGV outbreak, mostly affecting human immunodeficiency virus-positive MSM engaging in high-risk sexual practices, caused by an L2b strain with a rather unique non-LGV ompA signature that precluded the laboratory notification of this outbreak as LGV. C. trachomatis whole-genome capture and sequencing directly from clinical samples was applied to deeply characterize the genomic backbone of this novel LGV outbreak-causing clone. It revealed a chimeric genome structure due to the genetic transfer of ompA and four neighbouring genes from a serovar DDa strain, likely possessing the genomic backbone associated with the more prevalent urogenital genotypes T1 clade, to an LGV L2b strain. The hybrid L2bD-Da strain presents the adhesin and immunodominant antigen MOMP major outer membrane protein encoded by ompA
Journal Article - Open Access
Microbial Genomics , 5, 11, 01 Jan 0001, 01 Jan 0001, [ 1 ] Natl Inst Hlth, Dept Infect Dis, Bioinformat Unit, Lisbon, Portugal[ 2 ] Natl Inst Hlth, NRL Curable Sexually Transmitted Infect STIs, Lisbon, Portugal [ 3 ] Cent Lisbon Univ Hosp Ctr CHULC, Dermatovenereol Dept, Sexually Transmitted Dis Clin, Lisbon, Portugal[ 4 ] Lapa Hlth Ctr, Sexually Transmitted Dis Clin, Lisbon, Portugal[ 5 ] CheckpointLX, Grp Ativistas Tratamentos, Lisbon, Portugal[ 6 ] Natl Inst Hlth, Dept Human Genet, Innovat and Technol Unit, Lisbon, Portugal This is an open-access article distributed under the terms of the Creative Commons Attribution NonCommercial License.