Infectious Diseases in Obstetrics and Gynecology Age Race White African American Hispanic (2 missing) Time since HIV diagnosis On ART CD4 Count (median, IQR) cells/mL Plasma viral load (median, IQR) copies/mL Vaginal ﬂuid cells (cells/cc) Nucleated cells RBCs Monocytes Lymphocytes Eosinophils Log-transformed bacterial 16S rDNA copies/mL (mean ± SD) Lactobacillus genus Lactobacillus crispatus Gardnerella vaginalis Megasphaera Leptotrichia/Sneathia BVAB1 BVAB2 BVAB3 BV + (N = 24) 35.7 ± 8.6 11 (46) 8 (33) 5 (21) 7.4 ± 4.8 9 (38) 393 (246–582) 3250 (800–44,500) 961 ± 1296 39 ± 41 2.9 ± 5.4 0.8 ± 1.6 1.2 ± 1.8 6.93 ± 1.74 2.36 ± 3.05 7.21 ± 1.82 3.56 ± 3.66 5.82 ± 3.59 2.06 ± 3.51 4.22 ± 3.61 2.38 ± 3.15 BV − (N = 27) 38.2 ± 6.5 9 (33) 11 (41) 7 (26) 6.8 ± 4.0 13 (46) 437 (209–619) 4800 (320–41,000) 752 ± 1034 676 ± 2458 0.2 ± 0.6 0.5 ± 1.3 0.3 ± 1.0 6.71 ± 2.08 2.43 ± 3.30 3.70 ± 3.04 0.56 ± 1.71 2.12 ± 3.23 0.50 ± 1.85 0.48 ± 1.50 0.50 ± 1.50 Table 1: Characteristics of the study population (N = 51§). §For individuals who contributed more than one sample, only data from the ﬁrst visit are included in this table. ∗Tests are chi-square for categorical variables, and t-test or Mann-Whitney for continuous variables. Data presented as mean ± SD for continuous variables or n(%) for categorical variables unless otherwise noted. for analysis. All other samples had detectable DNA extracted, and no evidence of PCR inhibition. Sixty (94%) of the 64 samples had any lactobacilli detected by genus speciﬁc PCR, but only 23 (37%) had Lactobacillus crispatus detected. Gardnerella vaginalis was detected in 84% of samples, Megasphaera in 31%, Lep- totrichia/Sneathia in 59%, BVAB1 in 19%, BVAB2 in 41%, and BVAB3 in 27%. As in previous studies, not all bacteria were detected in all women with BV, and the novel bacteria BVAB1, BVAB2, and BVAB3 were detected in some women without BV though at a lower prevalence. Furthermore, the concentrations of Leptotrichia/Sneathia, Megasphaera, BVAB1, BVAB2, and BVAB3 were signiﬁcantly lower in women without BV compared to women with BV (Table 1). After controlling for plasma viral load there were no signiﬁcant associations between HIV-1 RNA in the genital tract and detection of any individual bacteria; however there were trends toward increased HIV shedding in subjects with BVAB 1, 2, and 3 (OR 2.59–3.07, p = .14–.17) irrespective of BV diagnosis (Table 2). The largest odds ratio, while still not signiﬁcant, was for an association of vaginal HIV-1 RNA with detection of Gardnerella vaginalis (OR 17.2, 95% CI 0.48,619). There were no signiﬁcant diﬀerences in the quantities of individual bacteria between women with CD4 counts >500 cells/mL, 200–500 cells/mL, and <200 cells/mL (data not shown). Novel bacteria in the Clostridiales order-designated BVAB1, BVAB2, and BVAB3 remain highly speciﬁc indicators of BV in HIV infected women, with speciﬁcities of 89%– 93% (Table 3). However, BVAB2 is a more sensitive indicator of BV (63%) and when detection of either BVAB2 or Megasphaera is used as a diagnostic criterion sensitivity improves to 71%. As has been established in other studies [21], high concentrations of Gardnerella vaginalis are also sensitive for the diagnosis of BV and more speciﬁc than the mere presence of the organism. Higher concentrations of Lactobacillus crispatus were associated with a lower vaginal pH. Higher concentrations of Gardnerella vaginalis, Leptotrichia/Sneathia, Megasphaera, BVAB1, BVAB2, and BVAB3 were all associated with an increase in vaginal pH (Table 4). In a multivariate model, quantities of Lactobacillus crispatus, Gardnerella vaginalis, and BVAB2 are most independently predictive of vaginal pH ( p = .004, p = .047, and p < .001, resp.). The presence of any Lactobacillus species was associated with a signiﬁcant decrease in number of nucleated cells (primarily epithelial 3 P value .23 .83 .59 .42 .74 >.99 .53 .21 .012 .50 .04 .69 .94 <.001 <.001 <.001 .045 <.001 .007