Biofilm Formation byMycobacterium bovis: Influence of Surface Kind and Temperatures of Sanitizer Treatments on Biofilm Control

Abstract

Mycobacterium boviscauses classic bovine tuberculosis, a zoonosis which is still a concern in Africa. Biofilm forming ability of twoMycobacterium bovisstrains was assessed on coupons of cement, ceramic, or stainless steel in three different microbiological media at 37°C with agitation for 2, 3, or 4 weeks to determine the medium that promotes biofilm. Biofilm mass accumulated on coupons was treated with 2 sanitizers (sanitizer A (5.5 mg L−1active iodine) and sanitizer B (170.6 g1alkyl dimethylbenzyl ammonium chloride, 78 g−1didecyldimethyl ammonium chloride, 107.25 g L−1glutaraldehyde, 146.25 g L−1isopropanol, and 20 g L−1pine oil) at 28 and 45°C and in hot water at 85°C for 5 min. Residual biofilms on treated coupons were quantified using crystal violet binding assay. The two strains had a similar ability to form biofilms on the three surfaces. More biofilms were developed in media containing 5% liver extract. Biofilm mass increased as incubation time increased till the 3rd week. More biofilms were formed on cement than on ceramic and stainless steel surfaces. Treatment with hot water at 85°C reduced biofilm mass, however, sanitizing treatments at 45°C removed more biofilms than at 28°C. However, neither treatment completely eliminated the biofilms. The choice of processing surface and temperatures used for sanitizing treatments had an impact on biofilm formation and its removal from solid surfaces.