Biofilm Development and Sanitizer Inactivation of Listeria monocytogenes and Salmonella typhimurium on Stainless Steel and Buna-n Rubber

1993 ◽  
Vol 56 (9) ◽  
pp. 750-758 ◽  
Author(s):  
AMY B. RONNER ◽  
AMY C. L. WONG

Biofilm formation by seven strains of Listeria monocytogenes and one strain of Salmonella typhimurium on stainless steel and Buna-n rubber was examined under two nutrient conditions. The type of surface, nutrient level, and organism influenced biofilm development and production of extracellular materials. Buna-n had a strong bacteriostatic effect on L. monocytogenes, and biofilm formation on Buna-n under low nutrient conditions was reduced for four of the seven strains tested. Buna-n was less bacteriostatic toward S. typhimurium. It inhibited the growth of several other pathogens to varying degrees. An ethylene propylene diamine monomer rubber was less inhibitory than Buna-n, and Viton rubber had no effect. The effectiveness of sanitizers on biofilm bacteria was examined. Biofilms were challenged with four types of detergent and nondetergent sanitizers. Resistance to sanitizers was strongly influenced by the type of surface. Bacterial biofilm populations on stainless steel were reduced 3–5 log by all the sanitizers, but those on Buna-n were resistant to these sanitizers and were reduced less than 1–2 log. In contrast, planktonic (suspended) bacteria were reduced 7–8 log by these sanitizers. Chlorine and anionic acid sanitizers generally removed extracellular materials from biofilms better than iodine and quaternary ammonium detergent sanitizers. Scanning electron microscopy demonstrated that biofilm cells and extracellular matrices could remain on sanitized biofilm cells and extracellular matrices could remain surfaces from which no viable cells were recovered.

2018 ◽  
Vol 12 (3) ◽  
pp. 179-188
Author(s):  
Hossein Tajik ◽  
Mehran Moradi ◽  
Mosatafa Alipour ◽  
Hadi Ghasemmahdi ◽  
◽  
...  

2017 ◽  
Vol 80 (3) ◽  
pp. 368-375 ◽  
Author(s):  
Yuejia Lee ◽  
Chinling Wang

ABSTRACT Listeria monocytogenes, a lethal foodborne pathogen, has the ability to resist the hostile food processing environment and thus frequently contaminates ready-to-eat foods during processing. It is commonly accepted that the tendency of L. monocytogenes' to generate biofilms on various surfaces enhances its resistance to the harshness of the food processing environment. However, the role of biofilm formation in the transferability of L. monocytogenes EGDe remains controversial. We examined the growth of Listeria biofilms on stainless steel surfaces and their effect on the transferability of L. monocytogenes EGDe. The experiments were a factorial 2 × 2 design with at least three biological replicates. Through scanning electron microscopy, a mature biofilm with intensive aggregates of cells was observed on the surface of stainless steel after 3 or 5 days of incubation, depending on the initial level of inoculation. During biofilm development, L. monocytogenes EGDe carried out binary fission vigorously before a mature biofilm was formed and subsequently changed its cellular morphology from rod shaped to sphere shaped. Furthermore, static biofilm, which was formed after 3 days of incubation at 25°C, significantly inhibited the transfer rate of L. monocytogenes EGDe from stainless steel blades to 15 bologna slices. During 7 days of storage at 4°C, however, bacterial growth rate was not significantly impacted by whether bacteria were transferred from biofilm and the initial concentrations of transferred bacteria on the slice. In conclusion, this study is the first to report a distinct change in morphology of L. monocytogenes EGDe at the late stage of biofilm formation. More importantly, once food is contaminated by L. monocytogenes EGDe, contamination proceeds independently of biofilm development and the initial level of contamination when food is stored at 4°C, even if contamination with L. monocytogenes EGDe was initially undetectable before storage.


Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 103
Author(s):  
Rodrigo Jiménez-Pichardo ◽  
Iriana Hernández-Martínez ◽  
Carlos Regalado-González ◽  
José Santos-Cruz ◽  
Yunny Meas-Vong ◽  
...  

Biofilms on food-contact surfaces can lead to recurrent contamination. This work aimed to study the biofilm formation process on stainless steel plates used in the dairy industry: 304 surface finish 2B and electropolished; and the effect of a cleaning and disinfection process using alkaline (AEW) and neutral (NEW) electrolyzed water. Milk fouling during heat processing can lead to type A or B deposits, which were analyzed for composition, surface energy, thickness, and roughness, while the role of raw milk microbiota on biofilm development was investigated. Bacteria, yeasts, and lactic acid bacteria were detected using EUB-338, PF2, and Str-493 probes, respectively, whereas Lis-637 probe detected Listeria sp. The genetic complexity and diversity of biofilms varied according to biofilm maturation day, as evaluated by 16S rRNA gene sequence, denaturing gradient gel electrophoresis, and fluorescence in situ hybridization microscopy. From analysis of the experimental designs, a cleaning stage of 50 mg/L NaOH of AEW at 30 °C for 10 min, followed by disinfection using 50 mg/L total available chlorine of NEW at 20 °C for 5 min is a sustainable alternative process to prevent biofilm formation. Fluorescence microscopy was used to visualize the effectiveness of this process.


2012 ◽  
Vol 75 (8) ◽  
pp. 1411-1417 ◽  
Author(s):  
ANTÓNIO LOURENÇO ◽  
FRANCISCO REGO ◽  
LUISA BRITO ◽  
JOSEPH F. FRANK

The contamination of ready-to-eat products with Listeria monocytogenes has been related to the presence of biofilms in production lines, as biofilms protect cells from chemical sanitizers. The ability of L. monocytogenes to produce biofilms is often evaluated using in vitro methodologies. This work aims to compare the most frequently used methodologies, including high-throughput screening methods based on microplates (crystal violet and the Calgary Biofilm Device) and methods based on CFU enumeration and microscopy after growth on stainless steel. Thirty isolates with diverse origins and genetic characteristics were evaluated. No (or low) correlations between methods were observed. The only significant correlation was found between the methods using stainless steel. No statistically significant correlation (P > 0.05) was detected among genetic lineage, serovar, and biofilm-forming ability. Because results indicate that biofilm formation is influenced by the surface material, the extrapolation of results from high-throughput methods using microplates to more industrially relevant surfaces should be undertaken with caution.


2020 ◽  
Author(s):  
Oliver Handorf ◽  
Viktoria Isabella Pauker ◽  
Thomas Weihe ◽  
Uta Schnabel ◽  
Eric Freund ◽  
...  

Abstract Plasma-generated compounds (PGCs) such as plasma-processed air (PPA) or plasma-treated water (PTW) offer an increasingly important alternative for the treatment of microorganisms in hard-to-reach areas found in several industrial applications including the food industry. To this end, we studied the antimicrobial capacity of plasma-treated water on the vitality and biofilm formation of Listeria monocytogenes, a common food spoilage microorganism. Using a microwave plasma (MidiPLexc), 10 ml of deionized water was treated for 100 s, 300 s and 900 s (pretreatment time) and the bacterial biofilm was subsequently exposed to the PTW for 1 min, 3 min and 5 min (posttreatment time) for each pretreatment time separately. Colony-forming units (CFU), metabolic activity, and cell vitality were reduced for 4.7 log10, 47.9%, and 69.5%, respectively. Live/dead staining and fluorescence microscopy showed a positive correlation between treatment and incubation times and reduction in vitality. Atomic force microscopy indicated a change in the plasticity of the bacteria. These results suggest a promising antimicrobial impact of plasma-treated water on Listeria monocytogenes, which may lead to more targeted applications of plasma decontamination in the food industry in the future.


2020 ◽  
Vol 63 (5) ◽  
pp. 1401-1407
Author(s):  
Bog Eum Lee ◽  
Youngsang You ◽  
Won Choi ◽  
Eun-mi Hong ◽  
Marisa M. Wall ◽  
...  

HighlightsNanoporous superhydrophobic surfaces were fabricated using electrochemical etching and Teflon coating.Adhesion of Listeria monocytogenes to the nanoengineered stainless steel surfaces was reduced.Self-cleanable food-contact surfaces prevent bacterial attachment and subsequent biofilm formation.Abstract. Bacterial attachment on solid surfaces and subsequent biofilm formation is a significant problem in the food industry. Superhydrophobic surfaces have potential to prevent bacterial adhesion by minimizing the contact area between bacterial cells and the surface. In this study, stainless steel-based superhydrophobic surfaces were fabricated by manipulating nanostructures with electrochemical etching and polytetrafluoroethylene (PTFE) film. The formation of nanostructures on stainless steel surfaces was characterized by field emission scanning electron microscopy (FESEM). The stainless steel surfaces etched at 10 V for 5 min and at 10 V for 10 min with PTFE deposition resulted in average water contact angles of 154° ±4° with pore diameters of 50 nm. In addition, adhesion of Listeria monocytogenes was decreased by up to 99% compared to the bare substrate. These findings demonstrate the potential for the development of antibacterial surfaces by combining nanoporous patterns with PTFE films. Keywords: Electrochemical etching, PTFE, Nanoengineered surface, L. monocytogenes, Superhydrophobic.


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