Capacity of Escherichia coli and Staphylococcus aureus to produce biofilm on stainless steel surfaces in the presence of food residues

摘要

This study analyzed biofilms composed of Escherichia coli and Staphylococcus aureus on a stainless steel surface, in the presence of food residues (milk and meat exudate), at 25 and 35 ℃, with the objective of simulating the real conditions of industrial processing of these foods. The biofilm formed on the surface was determined by quantifying the colonies and scanning electron microscopy. In addition to milk and meat exudate, three different culture media were used, one specific for each bacterium and a common environment for the growth of both bacteria (Mueller Hinton agar, MH). Such conditions were favorable for the biofilm formation of both bacteria, with predominance of the Gram-negative species in the multispecies biofilm. The food residues favored the formation of the biofilm in both temperatures, especially the meat exudate at 35 ℃, when compared to the MH broth. Therefore, substrate and temperature directly influenced the microbial composition of the biofilm.