Quantification of plasmid copy number as surrogate marker of virulence among different invasive and non-invasive genotypes of Chlamydia trachomatis

• Published in: Diagnostic microbiology and infectious disease 2022-04, Vol.102 (4), p.115610-115610, Article 115610
• Main Authors: López-Pintor, José María, Martínez-García, Laura, Maruri, Ainhize, Menéndez, Blanca, Puerta, Teresa, Rodríguez, Concepción, González-Alba, José María, Rodríguez-Domínguez, Mario, Galán, Juan Carlos
• Format: Article
• Language: English
• Subjects: Chlamydia trachomatis; Lymphogranuloma venereum; Plasmid copy number; Virulence factors
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2021.115610

•Plasmid copy number (PCN) was higher in symptomatic than asymptomatic patients.•Plasmid copy number among L-genotypes showed higher values than non-L genotypes.•Symptomatic patients infected by non-L genotypes yielded PCN similar to L-genotypes.•PCN varies depending on anatomical sites revealing the impact of micro-environment.•Chlamydia PCN could be used a surrogate marker in C. trachomatis infections. The population dissemination of invasive genotypes of C. trachomatis and an increase of urogenital infections cases by non-invasive genotypes have been observed in many countries. In this epidemiological context, the descriptions of a high proportion of infections related to L-genotypes in asymptomatic patients, but also to infections caused by non-L genotypes in symptomatic patients have been unexpected finding. The plasmid copy number (PCN) has been proposed as a surrogate marker of virulence. We quantified the PCN in 233 samples and 179 samples carrying L-genotype and non-L genotypes respectively. A significant difference in the median of PCN was detected between symptomatic/asymptomatic patients (P < 0.001), independently of the genotype. Moreover, PCN could vary, in the same strain, among different anatomical sites suggesting that micro-environmental changes could affect virulence. These findings suggest that the quantification of PCN in clinical samples could improve the management of patients.