P1-172 Efficacy of Chemical Treatments for Control of Mycobacterium tuberculosis Biofilms on Various Surfaces

Monday, July 29, 2013
Exhibit Hall (Charlotte Convention Center)
Victoria Adetunji, University of Ibadan, Ibadan, Nigeria
Aderemi Kehinde, University of Ibadan, Ibadan, Nigeria
Olayemi Bolatito, University of Ibadan, Ibadan, Nigeria
Jinru Chen, The University of Georgia, Griffin, GA
Introduction: Tuberculosis is most commonly caused by Mycobacterium tuberculosis. Although the natural host of the pathogen is humans, occasional cases of M. tuberculosisinfections have been reported in animals which have had contact with infected humans.  The pathogen has potentials to form biofilms on surfaces commonly used in food processing environment.

Purpose: This study assessed biofilms formed by selected strains of M. tuberculosisand investigated the efficacy of three different treatments for biofilm control.

Methods: Two M. tuberculosis strains were inoculated separately in 150 ml Middlebrook 7H9-Tween 80 (0.1%) broth with 5% liver extract and 10% oleic albumin dextrose catalase (OADC), 5% liver extract alone, or 10% OADC alone in sterile jars containing 2 x 2 cm2 coupons of steel, cement or ceramic for biofilm development.  The jars were incubated at 37°C with agitation for 2, 3 and 4 weeks, respectively.  Biofilms on coupons were subsequently exposed to 10 ml of 2% Iodasteryl®, 0.5% Virocid®and sterile water at 28 and 45°C, respectively for 5 min.  Biofilm mass on treated and untreated coupons were assessed.

Results: Tested strains of M. tuberculosisformed biofilms on all three contact surfaces.  One tested strain formed more biofilms than the other strain.  More biofilms were formed in media containing both liver extract and OADC than media with only liver extract or OADC.  Biofilm mass increased as incubation time increased till the 3rd week of incubation.  More biofilms were formed on cement followed by ceramic and steel coupons.  Chemical treatments at 45°C removed more biofilms than those at 28°C.  Treatments with Iodasteryl® and Virocid®were equally effective in removing the biofilms on tested surfaces.  However, neither treatment completely removed the biofilms.

Significance: Results suggest that examined M. tuberculosis strains could form biofilms on tested surfaces, and chemical treatments used partially removed biofilms from the surfaces.