Model-based evaluation of Targeted-Antibacterial-Plasmids (TAPs) transfer kinetics and resensitization of pOXA-48 carbapenem-resistant Escherichia coli
- 1INSERM U1070, Universite de Poitiers, CHU de Poitiers
Abstract
Background Targeted-Antibacterial Plasmids (TAPs) are engineered mobile genetic elements that use bacterial conjugation to deliver selective CRISPR/Cas9 antibacterial activity against a specific target strain. Yet, the efficiency of TAPs is typically evaluated at a single time point, whereas the success of TAP-mediated resensitization critically depends on the dynamics of plasmid transfer and the complex interactions between bacterial subpopulations. This is the first study to evaluate the efficiency of a conjugation-based antibacterial approach at the subpopulation level, using an analytical framework analogous to that used for conventional antibiotics. Here, we investigate which process limits resensitization by TAPF-dCas9-OXA48: plasmid delivery, dCas9 activity, or the emergence of refractory and escape populations. Methods We fitted a mechanistic model of five interacting subpopulations (donors, recipients, transconjugants, escapers, and recusants) to 44 longitudinal conjugation experiments and used the fitted model to explore a range of biologically relevant scenarios. Results Using longitudinal conjugation data spanning 24 h, we show that up to 24% of recipients become recusants within 24h, refractory to further conjugation via entry exclusion, while secondary transconjugant emergence stays below 0.01%. Overall resensitization efficiency reaches up to 80%. Conclusion Plasmid transfer, rather than dCas9 repression, therefore appears to be the main bottleneck limiting the efficiency of TAPF-dCas9-OXA48 efficiency. These results identify plasmid delivery as a key engineering target for improving the performance of future TAPs.
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BibTeX
@misc{marolleau2026modelbased,
title = {{Model-based evaluation of Targeted-Antibacterial-Plasmids (TAPs) transfer kinetics and resensitization of pOXA-48 carbapenem-resistant Escherichia coli}},
author = {S. Marolleau and J. Moreau and J. M. Buyck and S. Bigot and C. Lesterlin and N. Gregoire and V. Aranzana-Climent},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.01.748484},
url = {https://www.biorxiv.org/content/10.64898/2026.09.01.748484v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Model-based evaluation of Targeted-Antibacterial-Plasmids (TAPs) transfer kinetics and resensitization of pOXA-48 carbapenem-resistant Escherichia coli
AU - S. Marolleau
AU - J. Moreau
AU - J. M. Buyck
AU - S. Bigot
AU - C. Lesterlin
AU - N. Gregoire
AU - V. Aranzana-Climent
PY - 2026
DA - 2026/09/01
PB - bioRxiv
DO - 10.64898/2026.09.01.748484
UR - https://www.biorxiv.org/content/10.64898/2026.09.01.748484v1
AB - Background Targeted-Antibacterial Plasmids (TAPs) are engineered mobile genetic elements that use bacterial conjugation to deliver selective CRISPR/Cas9 antibacterial activity against a specific target strain. Yet, the efficiency of TAPs is typically evaluated at a single time point, whereas the success of TAP-mediated resensitization critically depends on the dynamics of plasmid transfer and the complex interactions between bacterial subpopulations. This is the first study to evaluate the efficiency of a conjugation-based antibacterial approach at the subpopulation level, using an analytical framework analogous to that used for conventional antibiotics. Here, we investigate which process limits resensitization by TAPF-dCas9-OXA48: plasmid delivery, dCas9 activity, or the emergence of refractory and escape populations. Methods We fitted a mechanistic model of five interacting subpopulations (donors, recipients, transconjugants, escapers, and recusants) to 44 longitudinal conjugation experiments and used the fitted model to explore a range of biologically relevant scenarios. Results Using longitudinal conjugation data spanning 24 h, we show that up to 24% of recipients become recusants within 24h, refractory to further conjugation via entry exclusion, while secondary transconjugant emergence stays below 0.01%. Overall resensitization efficiency reaches up to 80%. Conclusion Plasmid transfer, rather than dCas9 repression, therefore appears to be the main bottleneck limiting the efficiency of TAPF-dCas9-OXA48 efficiency. These results identify plasmid delivery as a key engineering target for improving the performance of future TAPs.
ER -