Engineering a genome‐reduced bacterium to eliminate Staphylococcus aureus biofilms in vivo

Abstract

Bacteria present a promising delivery system for treating human diseases. Here, we engineered the genome‐reduced human lung pathogen Mycoplasma pneumoniae as a live biotherapeutic to treat biofilm‐associated bacterial infections. This strain has a unique genetic code, which hinders gene transfer to most other bacterial genera, and it lacks a cell wall, which allows it to express proteins that target peptidoglycans of pathogenic bacteria. We first determined that removal of the pathogenic factors fully attenuated the chassis strain in vivo . We then designed synthetic promoters and identified an endogenous peptide signal sequence that, when fused to heterologous proteins, promotes efficient secretion. Based on this, we equipped the chassis strain with a genetic platform designed to secrete antibiofilm and bactericidal enzymes, resulting in a strain capable of dissolving Staphylococcus aureus biofilms preformed on catheters in vitro , ex vivo , and in vivo . To our knowledge, this is the first engineered genome‐reduced bacterium that can fight against clinically relevant biofilm‐associated bacterial infections.

Bioengineered Probiotics: Synthetic Biology Can Provide Live Cell Therapeutics for the Treatment of Foodborne Diseases

“…Additionally, it lacks a cell wall and so has a limited ability to trigger an inflammatory response in mammalian hosts ( Sukhithasri et al, 2013 ). An M. pneumoniae with reduced virulence owing to deletion of the mpn133 and mpn372 genes was engineered to secrete dispersin B, a glycosyl hydrolase that can efficiently dissolve biofilms formed by S. aureus , and the bacteriocin lysostaphin ( Garrido et al, 2021 ). The engineered strain was effective in disrupting and reducing S. aureus biofilm development in a catheterized mouse model as well as eliminating biofilms formed ex-vivo ( Garrido et al, 2021 ).…”

Combating Infectious Diseases with Synthetic Biology

“…In another recent study, a genome-reduced Mycoplasma pneumoniae (namely CV2, lacking mpn372 and mpn133 genes) was engineered and tested for treatment of biofilm formation from Staphylococcus aureus . 11 Garrido et al first attenuated the bacterium to mediate its in vivo application and tested it in catheter-associated biofilms. Therapeutic elements dispersin B (DspB) and lysostaphin, a bacteriocin shown to be primarily active against methicillin-resistant S. aureus , 31 , 32 were introduced into the attenuated strain via a gene platform.…”

Erythrocyte membrane-enveloped molybdenum disulfide nanodots for biofilm elimination on implants via toxin neutralization and immune modulation

“…Among all the biofilm-positive strains, methicillin-resistant Staphylococcus aureus (MRSA) is well known for being resistant to nearly all the clinically used antibiotics. [8][9][10] Moreover, biofilms formed by MRSA create an immunosuppressive microenvironment by switching the infiltrating macrophages from a proinflammatory phenotype (M1) to an anti-inflammatory (M2) phenotype, which inhibits migration, impairs phagocytosis, and weakens the bactericidal ability of macrophages. 11 To this end, ideal antibiofilm strategies need to emphasize the immunomodulatory function of antibiofilm agents.…”