Effect of Caffeine on Biofilm Formation and Capsule Size on Pseudomonas aeruginosa

HUB 302-#47

Caffeine is a stimulant naturally found in coffee beans and is consumed daily by millions of people. Pseudomonas aeruginosa (PA) is a gram-negative opportunistic microbe known to be the main cause for pneumonia in cystic fibrosis and is observed in many hospital-acquired infections. The ability of PA to form biofilms and capsules allows it to adhere to surfaces to survive in unfavorable environments. The objective of this study is to examine how caffeine affects the biofilm formation and capsule size of PA. To study the effect of caffeine on biofilm formation, a crystal violet biofilm assay was used and biofilm was quantified using a SpectraMax 190. To study the effect of caffeine on capsule size, Maneval’s capsule stain procedure was used. Bacteria and capsule sizes were measured using ImageJ and the differences between bacteria size, capsule size, and total size were tested for significance. All data was analyzed using a one sample T-test. The current findings represent triplicate runs and indicate that caffeine at high concentrations suppresses biofilm formation and decreased bacteria size; however, caffeine did not affect capsule size.