Effect of Photodynamic Treatment on Survival of Legionella Pneumophila
Grade Level at Time of Presentation
Senior
Major
Biology and Chinese
Minor
Chemistry
Institution 25-26
Western Kentucky University
KY House District #
17
KY Senate District #
32
Faculty Advisor/ Mentor
Simran Banga, PhD
Department
Department of Biology
Abstract
Legionella pneumophila is a gram-negative aerobic bacterium first identified during a fatal outbreak at an American Legion Convention in Philadelphia. It is known as a causative agent of respiratory illnesses such as Legionnaires’ disease and Pontiac fever. In the past two years, Legionella pneumophila outbreaks have appeared in both Louisville and Lexington through contaminated water. This study investigated the effectiveness of Photodynamic Treatment (PDT) in inhibiting the growth of L. pneumophila in a water environment. Photodynamic Treatment is the method of using light-sensitive drugs also known as Photosensitizers combined with light to induce bacterial cell destruction. In this study, the photosensitizer that was used was Methyl Blue.
The first part of this project is to test two different strains of L. pneumophila which were Lp02 and Lp03. The main difference between them was that Lp02 is a wild-type strain and is capable of infecting human and protozoan cells while Lp03 lacks the ability to infect. We exposed these strains to PDT treatment with Methylene Blue and tested the difference in the growth in comparison to the untreated control L. pneumophila. With the data from standard plate counts using colony-forming units, it was determined that this treatment is highly effective in inhibiting the growth of Legionella pneumophila.
The second part of the project involved determining the time period for PDT treatment exposure that can effectively limit the amount of growth of Legionella pneumophila in water. It is determined that 6 minutes or over can reduce the majority of the bacteria colonies forming units.
In future works, we will perform infection assays to determine if the bacteria that was treated with PDT will have reduced capability to infect human and amoeba cells in comparison to untreated bacteria.
Effect of Photodynamic Treatment on Survival of Legionella Pneumophila
Legionella pneumophila is a gram-negative aerobic bacterium first identified during a fatal outbreak at an American Legion Convention in Philadelphia. It is known as a causative agent of respiratory illnesses such as Legionnaires’ disease and Pontiac fever. In the past two years, Legionella pneumophila outbreaks have appeared in both Louisville and Lexington through contaminated water. This study investigated the effectiveness of Photodynamic Treatment (PDT) in inhibiting the growth of L. pneumophila in a water environment. Photodynamic Treatment is the method of using light-sensitive drugs also known as Photosensitizers combined with light to induce bacterial cell destruction. In this study, the photosensitizer that was used was Methyl Blue.
The first part of this project is to test two different strains of L. pneumophila which were Lp02 and Lp03. The main difference between them was that Lp02 is a wild-type strain and is capable of infecting human and protozoan cells while Lp03 lacks the ability to infect. We exposed these strains to PDT treatment with Methylene Blue and tested the difference in the growth in comparison to the untreated control L. pneumophila. With the data from standard plate counts using colony-forming units, it was determined that this treatment is highly effective in inhibiting the growth of Legionella pneumophila.
The second part of the project involved determining the time period for PDT treatment exposure that can effectively limit the amount of growth of Legionella pneumophila in water. It is determined that 6 minutes or over can reduce the majority of the bacteria colonies forming units.
In future works, we will perform infection assays to determine if the bacteria that was treated with PDT will have reduced capability to infect human and amoeba cells in comparison to untreated bacteria.