Glycogen availability and pH variation in a medium simulating vaginal fluid influence the growth of vaginal Lactobacillus species and Gardnerella vaginalis

BMC Microbiology

Research

Stephany Navarro¹  Jane A. Colmer-Hamood²  Abdul N. Hamood³  Gary Ventolini⁴  Betsaida Delgado⁵  Habib Abla⁶ 

[1] Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA;Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA;Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX, USA;Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA;Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA;Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Center Permian Basin, Odessa, TX, USA;Honors College, Texas Tech University, Lubbock, TX, USA;Woody L. Hunt School of Dental Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA;School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA;

关键词: Lactobacillus jensenii;    Lactobacillus gasseri;    Lactobacillus crispatus;    Gardnerella vaginalis;    Medium simulating vaginal fluid;    pH;    Glycogen;    Glucose;   

DOI  :  10.1186/s12866-023-02916-8

 received in 2023-03-10, accepted in 2023-06-27,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundGlycogen metabolism by Lactobacillus spp. that dominate the healthy vaginal microbiome contributes to a low vaginal pH (3.5–4.5). During bacterial vaginosis (BV), strict and facultative anaerobes including Gardnerella vaginalis become predominant, leading to an increase in the vaginal pH (> 4.5). BV enhances the risk of obstetrical complications, acquisition of sexually transmitted infections, and cervical cancer. Factors critical for the maintenance of the healthy vaginal microbiome or the transition to the BV microbiome are not well defined. Vaginal pH may affect glycogen metabolism by the vaginal microflora, thus influencing the shift in the vaginal microbiome.ResultsThe medium simulating vaginal fluid (MSVF) supported growth of L. jensenii 62G, L. gasseri 63 AM, and L. crispatus JV-V01, and G. vaginalis JCP8151A at specific initial pH conditions for 30 d. L. jensenii at all three starting pH levels (pH 4.0, 4.5, and 5.0), G. vaginalis at pH 4.5 and 5.0, and L. gasseri at pH 5.0 exhibited the long-term stationary phase when grown in MSVF. L. gasseri at pH 4.5 and L. crispatus at pH 5.0 displayed an extended lag phase over 30 d suggesting inefficient glycogen metabolism. Glycogen was essential for the growth of L. jensenii, L. crispatus, and G. vaginalis; only L. gasseri was able to survive in MSVF without glycogen, and only at pH 5.0, where it used glucose. All four species were able to survive for 15 d in MSVF with half the glycogen content but only at specific starting pH levels – pH 4.5 and 5.0 for L. jensenii, L. gasseri, and G. vaginalis and pH 5.0 for L. crispatus.ConclusionsThese results suggest that variations in the vaginal pH critically influence the colonization of the vaginal tract by lactobacilli and G. vaginalis JCP8151A by affecting their ability to metabolize glycogen. Further, we found that L. jensenii 62G is capable of glycogen metabolism over a broader pH range (4.0–5.0) while L. crispatus JV-V01 glycogen utilization is pH sensitive (only functional at pH 5.0). Finally, our results showed that G. vaginalis JCP8151A can colonize the vaginal tract for an extended period as long as the pH remains at 4.5 or above.

【 授权许可】

CC BY   
© The Author(s) 2023

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