Removal of Bacterial Biofilm Matrix Using Novel Anti-Biofilm Compounds to Enhance the Antimicrobial Susceptibility of Bacteria Causing Chronic Infections
Faculty Mentor
Thomas Inzan
Area of Research
Veterinary Biomedical Sciences
Major
Veterinary Medicine
Description
INTRODUCTION: Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni are three primary bacterial pathogens responsible for Bovine Respiratory Disease. Each etiological agent produces a biofilm that enhances their resistance to antibiotics due to the extracellular matrix (ECM) surrounding the bacteria, especially H. somni. H. somni produces a prominent biofilm matrix and also causes infections that include myocarditis, arthritis, and thrombotic meningoencephalitis.
METHOD: Initially, 5000 compounds were screened for the capability to remove the H. somni biofilm and 2 successful compounds were selected for further study. Planktonic H. somni was added to 96-well plates and incubated statically for three days to form biofilms. The compounds were then added to the wells along with positive and negative controls and incubated overnight. The wells were then stained with 0.1% crystal violet, rinsed, and solubilized with 30% acetic acid. The amount of biofilm removed was measured by absorbance at 600 nm and graphed.
RESULTS: Compound B was slightly more effective at removing the H. somni biofilm compared to compound A. In contrast, compound A was more effective at removing the ECM of P. multocida and M. haemolytica. Because of compound A’s broader efficacy in removing biofilm ECM, the study was expanded to determine the efficacy of compound A in removing the ECM of Enterococcus faecalis and Pseudomonas aeruginosa, which are responsible for causing potential systemic infections. Compound A was also found to be effective at removing the ECM of E. faecalis and P. aeruginosa.
DISCUSSION/CONCLUSION: Neither compound A or B were toxic for bovine epithelial or endothelial cells at concentrations used for ECM removal. Due to compound B’s efficacy at disrupting the biofilm ECMs of several pathogenic species, one or a combination of these compounds may be useful as a supplement to enhance the efficacy of antibiotics used for treating biofilm infections.
Removal of Bacterial Biofilm Matrix Using Novel Anti-Biofilm Compounds to Enhance the Antimicrobial Susceptibility of Bacteria Causing Chronic Infections
INTRODUCTION: Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni are three primary bacterial pathogens responsible for Bovine Respiratory Disease. Each etiological agent produces a biofilm that enhances their resistance to antibiotics due to the extracellular matrix (ECM) surrounding the bacteria, especially H. somni. H. somni produces a prominent biofilm matrix and also causes infections that include myocarditis, arthritis, and thrombotic meningoencephalitis.
METHOD: Initially, 5000 compounds were screened for the capability to remove the H. somni biofilm and 2 successful compounds were selected for further study. Planktonic H. somni was added to 96-well plates and incubated statically for three days to form biofilms. The compounds were then added to the wells along with positive and negative controls and incubated overnight. The wells were then stained with 0.1% crystal violet, rinsed, and solubilized with 30% acetic acid. The amount of biofilm removed was measured by absorbance at 600 nm and graphed.
RESULTS: Compound B was slightly more effective at removing the H. somni biofilm compared to compound A. In contrast, compound A was more effective at removing the ECM of P. multocida and M. haemolytica. Because of compound A’s broader efficacy in removing biofilm ECM, the study was expanded to determine the efficacy of compound A in removing the ECM of Enterococcus faecalis and Pseudomonas aeruginosa, which are responsible for causing potential systemic infections. Compound A was also found to be effective at removing the ECM of E. faecalis and P. aeruginosa.
DISCUSSION/CONCLUSION: Neither compound A or B were toxic for bovine epithelial or endothelial cells at concentrations used for ECM removal. Due to compound B’s efficacy at disrupting the biofilm ECMs of several pathogenic species, one or a combination of these compounds may be useful as a supplement to enhance the efficacy of antibiotics used for treating biofilm infections.