Diversity of Cervical Microbiota in Asymptomatic Chlamydia trachomatis Genital Infection: A Pilot Study

Abstract

<i>Chlamydia trachomatis</i> genital infection continues to be an important public health problem worldwide due to its increasing incidence. <i>C. trachomatis</i> infection can lead to severe sequelae, such as pelvic inflammatory disease, obstructive infertility, and preterm birth. Recently, it has been suggested that the cervico-vaginal microbiota may be an important defense factor toward <i>C. trachomatis</i> infection as well as the development of chronic sequelae. Therefore, the investigation of microbial profiles associated to chlamydial infection is of the utmost importance. Here we present a pilot study aiming to characterize, through the metagenomic analysis of sequenced 16s rRNA gene amplicons, the cervical microbiota from reproductive age women positive to <i>C. trachomatis</i> infection. The main finding of our study showed a marked increase in bacterial diversity in asymptomatic <i>C. trachomatis</i> positive women as compared to healthy controls in terms of Shannon's diversity and Shannon's evenness (<i>P</i> = 0.031 and <i>P</i> = 0.026, respectively). More importantly, the cervical microbiota from <i>C. trachomatis</i> positive women and from healthy controls significantly separated into two clusters in the weighted UniFrac analysis (<i>P</i> = 0.0027), suggesting that differences between the two groups depended entirely on the relative abundance of bacterial taxa rather than on the types of bacterial taxa present. Furthermore, <i>C. trachomatis</i> positive women showed an overall decrease in <i>Lactobacillus</i> spp. and an increase in anaerobes. These findings are part of an ongoing larger epidemiological study that will evaluate the potential role of distinct bacterial communities of the cervical microbiota in <i>C. trachomatis</i> infection.