Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2024.02.13.579303

Thermally activated antibiotic production by probiotic bacteria for pathogen elimination

Dey, S.·Seyfert, C. E.·Fink-Straube, C.·Kany, A. M.·Mueller, R.·Sankaran, S.
View original source ↗Export metadata ↓

Abstract

Peptide drugs have seen rapid advancement in biopharmaceutical development, with over 80 candidates approved globally. Despite their therapeutic potential, the clinical translation of peptide drugs is hampered by challenges in production yields and stability. Engineered bacterial therapeutics is a unique approach being explored to overcome these issues by using bacteria to produce and deliver therapeutic compounds at the body site of use. A key advantage of this technology is the possibility to control drug delivery within the body in real time using genetic switches. However, the performance of such genetic switches suffers when used to control drugs that require post-translational modifications or are toxic to the host. In this study, these challenges were experienced when attempting to establish a thermal switch for the production of a ribosomally synthesized and post-translationally modified peptide antibiotic, darobactin, in probiotic E. coli. These challenges were overcome by developing a thermo-amplifier circuit that combined the thermal-switch with a T7 RNA Polymerase and its promoter that overcame limitations imposed by the host transcriptional machinery due to its orthogonality to it. This circuit enabled production of pathogen-inhibitory levels of darobactin at 40{degrees}C while maintaining leakiness below the detection limit at 37{degrees}C. More impressively, the thermo-amplifier circuit sustained production beyond the thermal induction duration. Thus, raised temperature for 2 h was sufficient for the bacteria to produce pathogen-inhibitory levels of darobactin even in the physiologically relevant simulated conditions of the intestines that include bile salts and low nutrient levels. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/579303v2_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@1cdb311org.highwire.dtl.DTLVardef@1a7523aorg.highwire.dtl.DTLVardef@77b68org.highwire.dtl.DTLVardef@136f52b_HPS_FORMAT_FIGEXP M_FIG C_FIG

Explore related subjects

bioengineeringPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Dey, S., Seyfert, C. E., Fink-Straube, C., Kany, A. M., Mueller, R., Sankaran, S.. 2024-02-15. Thermally activated antibiotic production by probiotic bacteria for pathogen elimination. https://doi.org/10.1101/2024.02.13.579303

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Single-Component Photo-Crosslinked Lipoic Acid Functionalized Mucin Hydrogels: Dynamic Mucus Mimetics for Antiviral Protection

Native mucus protects epithelial surfaces through viscoelastic networks of disulfide-linked mucins. However, commercially available mucins often fail to reconstitute comparable mechanical and barrier properties, while synthetic and hybrid mucus mimetics require polymeric crosslinkers that may alter mucus-like composition. Inspired by the native architecture, we directly functionalized porcine gastric and bovine submaxillary mucins with -lipoic acid to develop a single-component, photo-crosslinkable hydrogels. Upon UV irradiation (365 nm), the modified mucins rapidly form disulfide-crosslinked networks without added photo-initiator/ polymeric crosslinkers, two orders of magnitude faster as compared with PEG-SH approaches. The resulting mucin-lipoic acid (MUC-LA) hydrogels exhibit mucus-relevant properties, including tunable viscoelasticity, redox responsiveness, self-healing, and size-dependent restrictions on nanoparticle transport. In transwell-based infection models, MUC-LA hydrogels (2-3%) mimicking the healthy airway mucus (G' {approx} 10-20 Pa) suppress epithelial infection by SARS-CoV-2 and influenza A virus. Crosslinked MUC-LA provides greater protection against SARS-CoV-2 than the non-crosslinked, whereas both formulations suppress influenza A infection, suggesting distinct contributions from network formation and mucin-associated interactions. These findings establish a dynamic, mucus-mimetic platform integrating rapid photo-gelation, controllable mechanics, selective transport, and antiviral barrier functionality. MUC-LA hydrogels offer opportunities to investigate mucosal transport and host-pathogen interactions, with potential applications in drug delivery, and as biomaterials.

bioengineering↗
bioRxiv2026

A Fibrous Optofluidic Probe for Endovascular Sensing of Blood Oxygenation and Flow Velocity

Local hemodynamic information including blood oxygenation and flow velocity could guide vascular interventions, yet obtaining these parameters in deep, narrow vessels remains challenging. Here, we report a flexible, submillimeter-scale fibrous optofluidic probe for endovascular sensing of blood oxygenation and flow velocity. The probe integrates a polymer optical fiber for light transmission with a microfluidic tube for dye injection, enabling spectroscopic oximetry and fluorescence dilution-based velocimetry through a single device. Via vascular intervention, we demonstrate local hemodynamic sensing in rabbit arteries and angiography-guided deployment in canine carotid arteries. The probe captures local changes in blood oxygenation and flow velocity during vascular occlusion and reperfusion, revealing hemodynamic disturbances that are not reflected in peripheral monitors. These results illustrate the complementary information provided by local oximetry and velocimetry and establish a compact optofluidic platform for quantitative hemodynamic monitoring during vascular interventions.

bioengineering↗
bioRxiv2026

Broad-spectrum in situ genetic reprogramming of native microbiomes

Complex microbial communities are found throughout terrestrial, aquatic, and animal-associated ecosystems. Genetic modification of discrete microbial taxa within native communities represents a powerful tool to study and augment microbiome functions. Herein, we develop Synthetic Phage Assisted Reprogrammable and Targetable Addition (SPARTA) as a one-step strategy for packaging, delivering, and integrating large synthetic DNA into a broad range of native microbiomes. SPARTA leverages a broad-spectrum synthetic phage particle for in situ genome engineering within complex soil, freshwater, and mammalian fecal microbiomes, reprogramming 59 native species across 16 families. By modulating SPARTA components, we further demonstrated tunability of SPARTA towards targeted microbiome population. Additionally, we built a novel companion tool to quantitatively identify engineered taxa, named 16S crRNA-guided inference of bacterial engineering sequencing or ScRibe-seq. The SPARTA-ScRibe-seq pipeline delivered and validated functional synthetic gene clusters in diverse native microbiomes while preserving the original microbial community structure. Together, this novel genome engineering framework constitutes an end-to-end programmable platform for rational and customizable reprogramming of native microbiomes.

bioengineering↗