Biofilms are often tolerant towards routine cleaning and disinfection processes. As they can grow on fabrics in household or healthcare settings, resulting in odors and serious health problems, it is necessary to contain biofilms through eradication strategies. The current study proposes a novel test model for the growth and removal of biofilms on textiles with Pseudomonas fluorescens and the opportunistic nosocomial pathogen Pseudomonas aeruginosa as model organisms. To assess the biofilm removal on fabrics, (1) a detergent-based, (2) enzyme-based, and (3) combined formulation of both detergent and enzymes (F1/2) were applied. Biofilms were analyzed microscopically (FE-SEM, SEM, 3D laser scanning- and epifluorescence microscopy), via a quartz crystal microbalance with mass dissipation monitoring (QCM-D) as well as plate counting of colonies. This study indicated that Pseudomonas spp. form robust biofilms on woven cellulose that can be efficiently removed via F1/2, proven by a significant reduction (p < 0.001) of viable bacteria in biofilms. Moreover, microscopic analysis indicated a disruption and almost complete removal of the biofilms after F1/2 treatment. QCM-D measurements further confirmed a maximal mass dissipation change after applying F1/2. The combination strategy applying both enzymes and detergent is a promising antibiofilm approach to remove bacteria from fabrics.

The use of lactic acid bacteria (LAB) in foods as biocontrol agents against foodborne pathogens has become increasingly known. Under the premise that controlling the adhesion of microorganisms to food contact surfaces is an essential step for meeting the goals of food processing, the aim of this work was to investigate the inhibitory and anti-biofilm effectiveness of Lactobacillus rhamnosus GG (ATCC 53103) and Lactobacillus casei (ATCC 393) against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. Lactobacillus strains (10⁸CFU/ml) and pathogens (10⁴CFU/ml) were evaluated to monitor LAB anti-adhesive and antibiofilm effect, in two main scenarios: (i) co-adhesion and (ii) pathogen incorporation to stainless steel surfaces with a protective biofilm of Lactobacillus cells. In (i) the predominant effect was observed in L. rhamnosus against S. enterica and L. monocytogenes, whereas in (ii) both LAB significantly reduced the number of pathogenic adherent cells. The effect of pre-established LAB biofilms was more successful in displacing the three pathogens than when they were evaluated under co-adhesion. These findings show that both LAB can be considered good candidates to prevent or inhibit the adhesion and colonization of L. monocytogenes, S. enterica and E. coli O157:H7 on surfaces and conditions of relevance for juice processing industries, offering alternatives for improving the safety and quality of fruit-based products.

Biofilms serve as a reservoir for pathogenic and spoilage microorganisms, and their removal from different surfaces is a recurring problem in the beverage industry. This study aimed to investigate the effect of a combination of natamycin (NAT, 0.1 mmol/l ) and farnesol (FAR, 0.6 mmol/l) against biofilms developed on ultrafiltration (UF) membranes and stainless steel (SS) surfaces. The biofilms were formed by Rhodotorula mucilaginosa, Candida tropicalis, C. krusei and C. kefyr (mixed yeast) with Listeria monocytogenes , Salmonella enterica or Escherichia coli O157:H7 (multi-species) in apple juice. In biofilms treated with NAT+FAR, inhibition of the filamentous/yeast forms, disruption of the tri-dimensional structure and a high detachment of yeast cells were observed. NAT+FAR affected the biofilms independently of the surfaces used and the presence (or not) of bacteria. L. monocytogenes was the most susceptible strain in multi-species biofilms, followed by E. coli O157:H7 on both surfaces, whereas the growth of S. enterica was slightly reduced in SS but not in UF-membranes. Since the combination NAT+FAR considerable affected the structure and viability of yeast strains and foodborne pathogens in multi-species biofilms developed on UF- membranes and SS surfaces, the combination proposed could be considered a promising control agent to prevent the formation of biofilms in juice processing plants.