Team:Nevada

Project Description

Lysesavers: A New Approach to Fighting Bacterial Diseases

Current methods of treating bacterial pathogens in both plant and animal systems all have their disadvantages. For instance, popular methods for controlling diseases in major crop plants include the use of antibiotics, harsh chemical treatments such as copper sprays, and complete removal of infected plants. An increasing number of deleterious bacteria are developing resistance to antibiotic treatment. In the case of pathogens such as Erwinia amylovora, which targets members of the Rosaceae family such pear and apple trees, bacteria have also been shown to develop resistance to chemical treatments.

A more recent approach to combating bacterial disease takes advantage of naturally occurring viruses that are toxic to the specific bacteria which are targeted as hosts for lysis. Bacteriophage technology has been approved for uses ranging from agriculture to food safety, possessing advantages over other treatments including a lack of resistance formation and relatively little disruption to native flora. However, there are still concerns about the use of phages as antibacterial treatments including the possible immunogenic effects of using self-replicating biological agents that can potentially evolve; the low virulence of many phages due to poor adsorption properties, poor replication characteristics, etc.; and the very narrow host range of all bacteriophages.

To address these disadvantages, our team plans to develop an antibacterial treatment that uses only the phage proteins involved in bacterial cell wall degradation rather than the entire phage. It has been demonstrated that these muralytic enzymes known as endolysins can lyse specific bacterial cells when applied as a purified protein product. The target range of several endolysins that target gram-negative bacteria has also been broadened through the use of chemicals that degrade the outer lipid membrane, allowing the endolysins to attack the peptidoglycan layer, which is highly conserved across most gram-negative bacteria.

Our project aims to create bactericides that can effectively control a wide range of gram-negative pathogens by coupling purified endolysins with a method of permeabalizing the outer membrane of target bacterial cells that is less harmful than the detergents and chaotropes typically used in vitro. We will also develop a system that uses fluorescence to easily detect outer membrane permeabilization. This new system will be critical in ensuring the success of our project, which focuses on three endolysins which naturally target E. amylovora, Xanthamonas campestris, or Pseudomonas aeruginosa, as well as any future studies on the efficacy of gram-negative endolysins.