Influence of Peroxyacetic Acid and Nisin and Coculture with Enterococcus faecium on Listeria monocytogenes Biofilm Formation

Abstract

Biofilm formation is a matter of concern in food industries because biofilms facilitate the survival of pathogenic bacteria such as Listeria monocytogenes, which may contaminate food-processing equipment and products. In this study, nisin and two Enterococcus faecium strains were evaluated for their effect on biofilm formation by L. monocytogenes cultured in brain heart infusion broth and on stainless steel coupons. Elimination of preformed L. monocytogenes biofilms by peroxyacetic acid also was tested. Adhesion control experiments were performed with pure cultures of L. monocytogenes after swab collection of adhered cells, which were then enumerated on PALCAM agar plates and visualized by scanning electron microscopy. Formation of a biofilm was recorded when the number of adhered cells was at least 10(3) CFU/cm2. When L. monocytogenes was cocultured with E. faecium bac-, the number of adhered L. monocytogenes cells was 2.5 log lower (P = 0.002) when initially compared with the control culture, but after 6 h of incubation a biofilm was again detected. However, in coculture on stainless steel coupons, E. faecium bac+ inhibited L. monocytogenes adherence and did not allow biofilm formation for up to 48 h (P < 0.001). In the presence of nisin or after treatment with peroxyacetic acid, bacterial growth was reduced (P < 0.001) up to 4.6 and 5.6 log CFU/cm2, respectively, when compared with L. monocytogenes cultures on untreated coupons. However, after these treatments, cells were still present, and after 24 h of incubation, a renewed biofilm was detected in L. monocytogenes cultures treated with nisin. Although all tested conditions reduced L. monocytogenes growth to some extent, only coculture with E. faecium bac+ efficiently reduced biofilm formation, suggesting a potential control strategy for this pathogen.

Differential Biofilm Formation and Chemical Disinfection Resistance of Sessile Cells of Listeria monocytogenes Strains under Monospecies and Dual-Species (with Salmonella enterica) Conditions

“…Evidently, bacterial pathogens, such as L. monocytogenes and S. enterica, can be entrapped in multispecies sessile communities formed on such surfaces. In addition, attachment and biofilm formation by these two species have been shown to be influenced by either the natural in situ presence of other species or just their metabolic by-products (8,10,11,24,26,27,29,32,33,37,38,39,46,58,77). For instance, the presence of Staphylococcus xylosus and Pseudomonas fragi affected the numbers of L. monocytogenes biofilm cells on stainless steel (51), while compounds present in Hafnia alvei cell-free culture supernatant inhibited the early stage of S. enterica serovar Enteritidis biofilm formation on the same material (10).…”

Fermentation Processes Using Lactic Acid Bacteria Producing Bacteriocins for Preservation and Improving Functional Properties of Food Products

“…They have generally focused on the effects of pH, temperature, composition of the culture medium, and general microbial growth conditions (in vitro as well as in natural fermentations) on maximal bacteriocin production (FAO-WHO, 2002;ANVISA, 2010;Cruz et al, 2009;Silveira et al, 2009;Minei et al, 2008;Galvez et al, 2008). By supplementing the medium with growth limiting factors, such as carbohydrates, nitrogen, vitamins and potassium phosphate, or by adjusting the medium pH, levels of bacteriocin production is often increased.…”

Análise da expressão gênica, formação de biofilmes e adesão/invasão a célula Caco-2 por Listeria monocytogenes em diferentes condições encontradas no trato gastrintestinal, em alimentos e em presença de bacteriocinas

“…A utilização de peptídeos antimicrobianos denominados bacteriocinas apresenta grande potencial para o controle de biofilmes na indústria de alimentos (AMMOR et al, 2006;GUERRIERI et al 2009;MINEI et al, 2008;WINKELSTROTER et al, 2011 monocytogenes em superfícies abióticas (CHANG et al, 2012).…”

“…Grande número de sistemas modelos para se estudar a formação e o desenvolvimento dos biofilmes in vitro têm sido empregados e em sua grande maioria a quantificação é feita pelo método convencional de contagem em placa (DONLAN; COSTERTON, 2002;MINEI et al, 2008;PEETERS, NELIS, COENYE;2008;SHAKERI et al, 2007). Entretanto, diferentes estudos têm quantificado os biofilmes em placa de microtitulação baseando-se na quantificação de biomassa, de viabilidade e da matriz dos biofilmes (CHANG et al, 2012;HARVEY;KEENAN;GILMOUR, 2007;PEETERS, NELIS, COENYE;2008;SHAKERI et al, 2007, TAKAHASHI et al, 2009.…”

“…Tabela 9. Valores de ΔCt utilizados para avaliação da expressão gênica de inlA em L. monocytogenes quando incubados em caldo BHI suplementado com: NaCl 5%, sacarose 2%, Oxgall 0,3%, ácido clorídrico 4mol/L (pH4,5), caldo BHI 5ºC, extratos semipurificado obtidos da cultura de L. sakei 1, extratos semi-purificado obtidos da cultura de L. mesenteroides A11 e extratos semipurificado obtidos da cultura de E. faecium 130. bactérias láticas e seu potencial uso no controle de contaminação por patógenos em alimentos e formação de biofilmes (AMMOR et al, 2006;GHRAIRI et al, 2008;MINEI et al, 2008;TRIAS et al, 2008;WINKELSTROTER et al, 2011;ZHAO;DOYLE;ZHAO, 2004). monocytogenes, tanto quando incubados a 30ºC ou 20ºC.…”