Fig. 6

L. crispatus inhibits growth of N. gonorrhoeae. a, b Unbuffered RPMI or (c) L. crispatus CM was adjusted to pH 5.5 and placed under transwells. Relevant explants were inoculated with L. crispatus. After 48 h, relevant explants were inoculated with N. gonorrhoeae. Experiments were performed under aerobic conditions and the pH of media below explants was monitored over time. a RPMI under uncolonized controls (CNTL) and those colonized with N. gonorrhoeae (NG) alone remained at pH 5.5 while RPMI under explants colonized with L. crispatus (LC) alone or co-colonized with both organisms (LC + NG) was reduced to pH 4.5 (N = 4, n = 1). b The presence of L. crispatus inhibited 48 h N. gonorrhoeae growth. Asterisk indicates significant difference in growth between the two groups shown (p < 0.002). c CM under CNTL or NG remains at pH 5.5 while CM under explants colonized with LC alone or co-colonized with both organisms (LC + NG) was reduced to pH 4.0 (N = 3, n = 1). d While N. gonorrhoeae did exhibit a growth defect over NYC + RPMI media (the background media for CM) it was completely killed by aerobic or anaerobic CM at pH 5.5, even in the absence of a L. crispatus co-infection. Asterisks indicate significant difference from inoculum (p < 0.0001). For (b) and (d), dotted lines represent NG inocula