Periodic Reporting for period 1 - BactDrugConj (Bacteriocin-mediated Import of Active Molecules)
Reporting period: 2022-05-03 to 2024-05-02
The discovery and improvement of antibiotics has transformed human and veterinary medicine and saved millions of lives in the last decades. Nevertheless, the evolutionary pressure on bacteria during antibiotic treatment and the low genetic barrier to resistance has led to the appearance of bacterial strains insensitive to certain classes of antibiotics. Antibiotic resistant bacteria pose a severe threat to healthcare systems around the world. The situation is particularly urgent for multidrug resistant (MDR) Gram-negative bacteria, making some of these organisms untreatable in a near future. According to the recently published estimation from the European Centre for Disease Prevention and Control, about 33,000 people die every year due to infections with antibiotic-resistant bacteria within the European Union. The mortality associated with the MDR bacteria is now higher than in 2007 and 39 % of the burden is caused by infections against which the last-line antibiotics are inefficient. These data highlight the importance of developing new strategies to overcome the antibiotic resistance in pathogenic bacteria.
The opportunistic pathogen Pseudomonas aeruginosa is a major problem in hospitals. This Gram-negative bacterial pathogen causes ventilator-associated pneumonia, complicated urinary tract infection, and post-operative infections of soft tissues. These bacteria represent a threat for immunocompromised patients, where infections following surgery can be fatal.1 Besides, P. aeruginosa chronical infections are often deadly for patients suffering from rare diseases, such as cystic fibrosis (CF). P. aeruginosa colonises the lungs of CF patients resulting in higher rates of mortality than the disease itself. Some strains of P. aeruginosa are resistant to nearly all of the available antibiotics, both due to their capacity to acquire resistance genes via horizontal transfer and their intrinsic resistance mechanisms. This project will explore biotechnological approaches against antibioresistance in P.aeruginosa.
Bacteriocins are ribosomally synthesised antimicrobial peptides that are produced by various bacteria to kill or inhibit growth of their competitors during the fight for resources. They can be effective against antibiotic-resistant bacteria. Pyocins are bacteriocins secreted by P. aeruginosa to kill closely related Pseudomonas strains. They simply highjack the nutrient-import systems of vulnerable bacteria to make their way into the cell. However, their killing ¬potential is low compared to some chemically-synthesised antibiotics. Therefore, coupling the vector properties of bacteriocins and the cytotoxicity of synthetic drugs represents a novel and potentially revolutionary antibacterial chemotherapeutic approach following a Trojan Horse strategy.
The opportunistic pathogen Pseudomonas aeruginosa is a major problem in hospitals. This Gram-negative bacterial pathogen causes ventilator-associated pneumonia, complicated urinary tract infection, and post-operative infections of soft tissues. These bacteria represent a threat for immunocompromised patients, where infections following surgery can be fatal.1 Besides, P. aeruginosa chronical infections are often deadly for patients suffering from rare diseases, such as cystic fibrosis (CF). P. aeruginosa colonises the lungs of CF patients resulting in higher rates of mortality than the disease itself. Some strains of P. aeruginosa are resistant to nearly all of the available antibiotics, both due to their capacity to acquire resistance genes via horizontal transfer and their intrinsic resistance mechanisms. This project will explore biotechnological approaches against antibioresistance in P.aeruginosa.
Bacteriocins are ribosomally synthesised antimicrobial peptides that are produced by various bacteria to kill or inhibit growth of their competitors during the fight for resources. They can be effective against antibiotic-resistant bacteria. Pyocins are bacteriocins secreted by P. aeruginosa to kill closely related Pseudomonas strains. They simply highjack the nutrient-import systems of vulnerable bacteria to make their way into the cell. However, their killing ¬potential is low compared to some chemically-synthesised antibiotics. Therefore, coupling the vector properties of bacteriocins and the cytotoxicity of synthetic drugs represents a novel and potentially revolutionary antibacterial chemotherapeutic approach following a Trojan Horse strategy.
To this end, series of cytotoxic and non-cytotoxic mutants modified in C-ter of the selected bacteriocin have been produced in E.Coli by site directed mutagenesis, and a library of different classes of antibiotics coupled with various linkers have been synthesized. The soldiers (antibiotics) were then coupled to the Trojan Horse (bacteriocin) to invade Troy (P.aeruginosa)
Protein production and selective purification of protein which incorporated non natural amino acids. Synthesis of library of antibiotics and linker. The aim was to couple the antibiotics to the protein modified in C-ter by click chemistry and analyse the activity of the chimera on Pseudomonas aeruginosa.
The protein has been produced but the access to it hasn't be given by the previous supervisor or this fellowship. Therefore, no coupling has been achieved even though some antibiotics were available.
The protein has been produced but the access to it hasn't be given by the previous supervisor or this fellowship. Therefore, no coupling has been achieved even though some antibiotics were available.