Antibacterial Coating Effectiveness Against Gram Positive And Gram Negative Organisms

Abstract

Purpose: : To determine if polypropylene with alkyl halide has inhibitory or cidal activity against bacteria. The ultimate purpose is to develop polypropylene contact lens storage cases that will prevent contamination of lenses.

Methods: : Circles of polypropylene alkylated with alkyl halide (QPP/PP) will be exposed to suspensions of Pseudomonas aeruginosa and Staphylococcus aureus. The effect of QPP/PP on the bacteria will be compared to control of polypropylene alone, polypropylene with chlorine, and polypropylene with ethyleneimine. Microtiter Trays: Circles will be glued to the bottom of wells in 12 well-microtiter trays.. The trays will be wrapped individually and sterilized. Two trays will be used for each species, as well as a blood agar plate to verify the viability of the organisms. Inhibition: 24 hour broth cultures of P. aeruginosa and S. aureus will be prepared in tryptic soy broth. Two colonies will be added to the first vial of broth, and 0,1 ml of it to the next broth, diluting the bacteria four times. One ml of each concentration will be added to each well in a tray. The tray will be incubated for 18 hours at 35º C. The wells will be examined for turbidity the next day to indicate growth, or no turbidity to indicate no growth. Growth indicates lack of inhibitory activity. Cidal Activity: Every well will be subcultured to a blood agar plate, for each concentration of bacteria, and the plates will be incubated for 18-24 hours at 35º C. Growth indicates a lack of cidal action.

Results: : 24 hours after incubation we saw growth(turbidity) in all the controls and in the least concentrated amine(N1).Im the most concentrated amines(L1 and A4), there was a clear broth with no turbidity, indicating inhibition of growth for both pathogens.In the cidal activity test, 24 hours later, there was no growth on both plates for S.Aureus, indicating cidal activity, and growth on both plates for P. Aeruginosa, indicating only inhibition for this organism.

Conclusions: : The alkyl halide coating was successful in inhibiting the growth of both pathogens, and had a bactericidal effect on S. Aureus.

Keywords: antibiotics/antifungals/antiparasitics • contact lens