Soluble starch

Planktonic cells were grown in sBHI [Brain-heart infusion supplemented with 2% (wt/wt) gelatin (Liofilchem, Rosetodegli Abruzzi, Italy), 0.5% (wt/wt) yeast extract (Liofilchem) and 0.1% (wt/wt) soluble starch (Panreac, Barcelona, Spain)] for 24 h at 37 °C with 10% CO₂ (Shel Lab, Cornelius, Oregon, USA).²⁶ At this time, planktonic cells were still in the exponential growth phase. Thereafter, 18 mL of planktonic cells were harvested by centrifugation (20 min, 7197×g) and suspended in 1 mL of RNA protect [diluted 2:1 in phosphate-buffered saline (PBS); QIAGEN, Germany].

G. vaginalis strain UM241 was isolated from a woman diagnosed with BV [13 (link)]. Fifteen more bacterial species associated with BV were included in this study, namely: A. neuii, A. vaginae, B. ravenspurgense, C. amycolatum, C. tuscaniense, E. faecalis, N. ampullae, P. acnes, S. hominis, S. saprohyticus, S. simulans, S. warnerii, S. anginosus, M. mulieris, and P.bivia. More details on the species used here are found in Supplementary Table S1. The selection of these species was based on their feasibility to growth in vitro and the existence of previous phenotypic evidence of some key characteristics, including adhesion to HeLa cells, biofilm formation, cytotoxic assays as well as the determination of antimicrobial tolerance [22 (link), 23 (link), 41 (link), 42 (link)]. Each inoculum was grown in sBHI [Brain-heart infusion (Liofilchem, Rosetodegli Abruzzi, Italy) supplemented with 2% (wt/wt) gelatin (Liofilchem), 0.5% (wt/wt) yeast extract (Liofilchem), and 0.1% (wt/wt) soluble starch (Panreac, Barcelona, Spain)] for 24 h at 37 °C with 10% CO₂ (Shel Lab, Cornelius, Oregon, USA) [23 (link)]. The exceptions were with consortia with the strict anaerobes A. vaginae, M. mulieris, and P. bivia [43 (link)], which were grown in sBHI and incubated at 37 °C, under strict anaerobic conditions (AnaeroGen Atmosphere Generation system; Oxoid, United Kingdom).