Chlamydia Trachomatis: when the Virulence-Associated Genome Backbone Imports a Prevalence-Associated Major Antigen Signature
Abstract
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 tropism/prevalence, 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 D/Da strain, likely possessing the genomic backbone associated with the more prevalent urogenital genotypes (T1 clade), to an LGV (L2b) strain. The hybrid L2b/D-Da strain presents the adhesin and immunodominant antigen MOMP (major outer membrane protein) (encoded by ompA)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 07, 2019
- Accession Number
- AD1096711
Entities
People
- Ana I Salas (2)
- Ana M Rodrigues (3)
- Candida Fernandes (3)
- Cristina Correia (2)
- Dora Cordeiro (2)
- Jacinta Azevedo (4)
- Joana Isidro (1)
- Joao Alves (4)
- Joao P Gomes (1)
- Joao Roxo (5)
- Luis Vieira (6)
- Maria J Borrego (2)
- Miguel Rocha (5)
- Rita Corte-real (3)
- Victor Borges (1)
- Zohra Lodhia (2)
Organizations
- National Institute of Health Dr. Ricardo Jorge