Crystal Violet Binding Assay for Assessment of Biofilm Formation by Listeria monocytogenes and Listeria spp on Wood, Steel and Glass Surfaces

Abstract

Micro-organisms attach to surfaces and develop biofilms which are a concern in food and environmental safety. This study, quantified biofilms in 20 isolates viz: Listeria monocytogenes (14) and Listeria spp (6) from meat tables in Ibadan municipal abattoir, Nigeria on wood, glass and steel surfaces using crystal-violet binding assay. Listeria isolates formed biofilms on all three surfaces. At 24hours Listeria monocytogenes(SLM) formed more biofilms on wood(0.22±0.01) and glass(0.09±0.01) surfaces than Listeria spp(SLS) which was wood(0.17±0.02) and glass (0.06±0.01). But the reverse was the case on steel where Listeria spp (SLS) formed more biofilms (0.11±0.01) than Listeria monocytogenes (SLM) (0.10±0.00). A significant difference (P<0.01) exists between isolates for wood and glass at 24hours and (P<0.05) for wood at 72hours. Significant differences (P<0.05) occured in biofilms produced between 24hours and 72hours. It can be concluded that selection of suitable surfaces could reduce the ability of bacteria forming biofilms on meat contact-surfaces. This finding is very relevant in developing countries where wood is still in use as a major meat contact-surface in abattoirs.