Networks of Co-Abundant Bacteria that Increase Prior to Incident Bacterial Vaginosis
Christopher M Taylor1, Omar Aldibasi1,2, Vincent Maffei1, Eugene Blanchard IV1, David H Martin1,3, Jane R Schwebke4, Christina A Muzny4
1Louisiana State University Health Sciences Center; New Orleans, LA, USA; 2King Abdullah International Medical Research Center; Riyadh, Saudi Arabia; 3Tulane University; New Orleans, LA, USA; 4University of Alabama at Birmingham; Birmingham, AL, USA
Bacterial vaginosis (BV) is the most common vaginal infection and its etiology remains unknown. This study aims to determine co-abundant vaginal bacteria leading up to incident BV (Nugent score of 7-10 for at least 2 consecutive days). A cohort of African American women who have sex with women, with normal vaginal flora (Nugent 0-3 and no Amsel criteria), were prospectively enrolled and followed for 90 days with daily self-collected vaginal swabs to determine the sequence of microbiological events occurring prior to incident BV (iBV) [a]. We analyzed 176 vaginal specimens from 14 participants who developed iBV during the study using SParse InversE Covariance Estimation for Ecological ASsociation Inference (SPIEC-EASI) [b] in order to assess microbial networks arising in the 14 days leading up to iBV. A robust network of 3 bacteria was identified, consisting of Gardnerella vaginalis, Atopobium vaginae, and Aerococcus christensenii, which increased in abundance prior to iBV (p-value < 0.01). Aerococcus christensenii is particularly interesting due to its role as a pathogen in the female genital tract [c] and involvement in a case of severe polymicrobial chorioamnionitis [d], likely due to an ascending vaginal infection.
a) Muzny CA, Blanchard E, Taylor CM, et al. Identification of Key Bacteria Involved in the Induction of Incident Bacterial Vaginosis: A Prospective Study. J Infec Dis. 2018 Apr
b) Kurtz ZD, Muller CL, Miraldi ER, et al. Sparse and compositionally robust inference of microbial ecological networks. PLoS Comput Biol. 2015 May
c) Rasmussen M. Aerococcus: an increasingly acknowledged human pathogen. Clin Microbiol Infect. 2016 Jan
d) Carlstein C, Marie Soes L, Jorgen Christensen J. Aerococcus christensenii as Part of Severe Polymicrobial Chorioamnionitis in a Pregnant Woman. Open Microbiol J. 2016 Mar
Funding is provided through NIH awards K23 AI106957 to CAM and R01 AI118860 to CMT.
Funding was also provided through NIH awards U54 TR001368 and P20 GM103424 for CMT.