An optimized electrotransformation protocol for Lactobacillus jensenii

PLoS One. 2023 Feb 17;18(2):e0280935. doi: 10.1371/journal.pone.0280935. eCollection 2023.

Abstract

Engineered bacteria are promising candidates for in situ detection and treatment of diseases. The female uro-genital tract presents several pathologies, such as sexually transmitted diseases or genital cancer, that could benefit from such technology. While bacteria from the gut microbiome are increasingly engineered, the use of chassis isolated from the female uro-genital resident flora has been limited. A major hurdle to implement the experimental throughput required for efficient engineering in these non-model bacteria is their low transformability. Here we report an optimized electrotransformation protocol for Lactobacillus jensenii, one the most widespread species across vaginal microflora. Starting from classical conditions, we optimized buffers, electric field parameters, cuvette type and DNA quantity to achieve an 80-fold improvement in transformation efficiency, with up to 3.5·103 CFUs/μg of DNA in L. jensenii ATCC 25258. We also identify several plasmids that are maintained and support reporter gene expression in L. jensenii. Finally, we demonstrate that our protocol provides increased transformability in three independent clinical isolates of L. jensenii. This work will facilitate the genetic engineering of L. jensenii and enable its use for addressing challenges in gynecological healthcare.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / genetics
  • Female
  • Humans
  • Lactobacillus*
  • Plasmids / genetics
  • Vagina* / microbiology

Supplementary concepts

  • Lactobacillus jensenii

Grants and funding

JB acknowledges support from the INSERM Atip-Avenir program (https://www.inserm.fr/en/about-us/atip-avenir-program) and the Bettencourt-Schueller Foundation (https://www.fondationbs.org). GC acknowledges support from the CNRS Atip-Avenir program (https://www.insb.cnrs.fr/fr/atip-avenir). The CBS acknowledges support from the French Infrastructure for Integrated Structural Biology (FRISBI, https://frisbi.eu/; ANR-10-INSB-05-01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.