Avaliação da formação de biofilmes de Escherichia coli e Staphylococcus aureus em superfície de aço inoxidável

Abstract

An important problem in the food industry is contamination of surfaces with biofilms, which can cause serious problems of contamination of the products when uncontrolled, can occur when the industry does not have the necessary hygienic and sanitizers conditions. The adhesion and biofilm formation harmful to human health has been the target of numerous studies, both as to its composition, the formation surface, the influence of intrinsic and extrinsic factors such as temperature, contact time, among others. This study had to determined the growth of monoespécie biofilm and multispecies consisting of Escherichia coli and Staphylococcus aureus on stainless steel surface AISI 304, represented by small coupons of this material in the presence of food waste such as milk and extract meat under controlled temperatures of 25 °C and 35 °C for periods of 24 and 48 hours. The method used was the quantification of the colonies on plates, activated were as bacteria and inoculated in substrates to be tested in the temperatures and contact times analyzed ; after plated were as subsequent dilutions and analyzed Growth to the biofilm varied conditions . The plating was Held in Three Distinct culture media, a specific paragraph Each bacterium and hum Part For Both Growth , the latter being the Miller Hinton ; The Specific Growth Medium of Escherichia coli was the Metin eosin blue and make Staphylococcus aureus was the Baird Parker. With such favorable conditions it was found the adhesion and biofilm formation of both bacteria, but with a predominance of Gram-negative species. Both food residues provided an adhesion and biofilm formation, however meat extract residue favored the development of multispecies biofilm at temperature of 35 °C, a situation that was not found in the milk residue in a period of 48 hours contact. The substrate and the temperature for the development of biofilm direct influence on their composition.