Abstract
Objectives: The aim of this work was to study the formation of biofilm on glass and wood coupons at refrigeration and room temperatures, different incubation periods and to assess the efficacy of hydrogen peroxide (HP), Para Acetic Acid (PAA), Sodium hypochlorite (SH) and mixture of PAA + SH against the biofilm. Method: 200 µL of 108 suspension E. coli ATCC 29922 was inoculated on the coupons inside petri dishes containing 20 ml of tryptic soy broth, incubated at 10 and 270 C for 24, 48, 72 and 168 hours. Biofilm developed at each hour above was quantified by bead-vortex followed by agar plating. The action of disinfectants was tested on 168 hours biofilm. The surfaces were exposed to the disinfectants and incubated at 270 C for 10 minutes, followed by deactivation for 5 minutes. Cells that resisted disinfectants effect were vortexed and enumerated by agar plating. Results: The results showed that E. coli can form high biofilm on wood in addition to glass. After disinfection treatment, HP had the highest efficacy at 270 C followed by PAA then SH, whilst PAA + SH had the least. Conclusion: it can be concluded that HP and PAA can be good disinfectants agents against E. coli biofilm.
Key words: Biofilm, E. coli, Log Reduction, Survival Fractions
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