Structure of deposits formed by drying of droplets contaminated with Bacillus spores determines their resistance to rinsing and cleaning

Deleplace, Maureen; Dallagi, Heni; Dubois, Thomas; Richard, Elodie; Ipatova, Anna; Bénézech, Thierry; Faille, Christine

doi:10.1016/j.jfoodeng.2021.110873

Cited by 6 publications

(5 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Not only RH but also the physical characteristics of surfaces, microbes, and liquids can impact the kinetics of drying and may potentially alter the antibacterial properties of surfaces. (Grinberg et al 2019 , Lin and Marr 2020 , Majee et al 2021 , Deleplace et al 2022 , Cunliffe et al 2023 ).…”

Section: Resultsmentioning

confidence: 99%

Antibacterial activity of solid surfaces is critically dependent on relative humidity, inoculum volume, and organic soiling

Kaur,

Rosenberg,

Kook

et al. 2023

FEMS Microbes

View full text Add to dashboard Cite

Antimicrobial surface materials potentially prevent pathogen transfer from contaminated surfaces. Efficacy of such surfaces is assessed by standard methods using wet exposure conditions known to overestimate antimicrobial activity compared to dry exposure. Some dry test formats have been proposed but semi-dry exposure scenarios e.g., oral spray or water droplets exposed to ambient environment, are less studied. We aimed to determine the impact of environmental test conditions on antibacterial activity against the model species Escherichia coli and Staphylococcus aureus. Surfaces based on copper, silver, and quaternary ammonium with known or claimed antimicrobial properties were tested in conditions mimicking microdroplet spray or larger water droplets exposed to variable relative air humidity in the presence or absence of organic soiling. All the environmental parameters critically affected antibacterial activity of the tested surfaces from no effect in high-organic dry conditions to higher effect in low-organic humid conditions but not reaching the effect size demonstrated in the ISO 22169 wet format. Copper was the most efficient antibacterial surface followed by silver and quaternary ammonium based coating. Antimicrobial testing of surfaces using small droplet contamination in application-relevant conditions could therefore be considered as one of the worst-case exposure scenarios relevant to dry use surfaces.

show abstract

Section: Resultsmentioning

confidence: 99%

Antibacterial activity of solid surfaces is critically dependent on relative humidity, inoculum volume, and organic soiling

Kaur,

Rosenberg,

Kook

et al. 2023

FEMS Microbes

View full text Add to dashboard Cite

show abstract

“…The spore log reduction was around 1.13 ± 0.14 for water, showing that dipping the contaminated plates in water results in more than one log removal of spores. This result suggested that some of the hydrophilic spores deposited on the surface of the plates were not strongly adherent [ 4 ]. For the two APGs, the spores log reduction was similar with a spores log reduction of 1.33 ± 0.01 and 1.37 ± 0.05 for DG and LG, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, bacteria spores are of major concern to the food industry because a number of species are pathogenic, whereas others are associated with spoilage. Spores also have the capacity to adhere to materials of importance in the processing industries, such as stainless steel widely used in food equipment manufacturing [ 4 ]. The cleaning phase is the most important stage for minimizing microbial colonization and removing attached microorganisms.…”

Section: Introductionmentioning

confidence: 99%

Decontamination of Spores on Model Stainless-Steel Surface by Using Foams Based on Alkyl Polyglucosides

et al. 2023

Self Cite

View full text Add to dashboard Cite

In the food industry, the surfaces of processing equipment are considered to be major factors in the risk of food contamination. The cleaning process of solid surfaces is essential, but it requires a significant amount of water and chemicals. Herein, we report the use of foam flows based on alkyl polyglucosides (APGs) to remove spores of Bacillus subtilis on stainless-steel surfaces as the model-contaminated surface. Sodium dodecyl sulfate (SDS) was also studied as an anionic surfactant. Foams were characterized during flows by measuring the foam stability and the bubble size. The efficiency of spores’ removal was assessed by enumerations. We showed that foams based on APGs could remove efficiently the spores from the surfaces, but slightly less than foams based on SDS due to an effect of SDS itself on spores removal. The destabilization of the foams at the end of the process and the recovery of surfactant solutions were also evaluated by using filtration. Following a life cycle assessment (LCA) approach, we evaluated the impact of the foam flow on the global environmental footprint of the process. We showed significant environmental impact benefits with a reduction in water and energy consumption for foam cleaning. APGs are a good choice as surfactants as they decrease further the environmental impacts.

show abstract

“…Deleplace et al [37] recently demonstrated Bacillus spore distribution in dried droplet deposits on various substrates using confocal microscopy. Similarly, we used confocal microscopy to analyze fluorescently tagged Pseudomonas aeruginosa in our deposits.…”

Section: Confocal Microscopy Studymentioning

confidence: 99%

Unravelling the Dynamics of Bacterial-Laden Respiratory Droplets: Epidemiological Transfer from Fomites to Susceptible Host

Rasheed,

Parmar,

Poopady

et al. 2024

Preprint

View full text Add to dashboard Cite

This study provides the first comprehensive investigation into how pathogen-laden respiratory droplets transfer diseases via inanimate surfaces. Respiratory fluid ejections containing pathogens pose a significant health threat, especially in high-traffic areas like hospitals, public transport, restaurants, and schools. When these droplets dry on surfaces, they form deposits that can transfer pathogens to healthy individuals through contact and can be ingested via the oral or nasal route. The study examined the effects of varying salt and mucin concentrations in respiratory fluid droplets containingPseudomonas aeruginosa(PA). Results showed that PA viability increased tenfold at elevated mucin concentrations, while changes in salt concentration had minimal impact. Adhesive properties of the deposits were analysed using atomic force spectroscopy and scotch tape test. Pathogen transfer from the deposit to a fingerprint patterned model thumb at different relative humidity (RH) levels was assessed using confocal microscopy, showing significant pathogen transfer at elevated RH. Out of 106CFU/ml pathogens in deposits, 17% to 38% are potentially transferable, with most of the transfer occurring from the droplet’s edge deposits. The study also explored evaporation, internal flow, and precipitation dynamics, with deposit and pathogen distribution characterized by optical profilometry, scanning electron microscopy, and confocal microscopy.

show abstract

Structure of deposits formed by drying of droplets contaminated with Bacillus spores determines their resistance to rinsing and cleaning

Cited by 6 publications

References 26 publications

Antibacterial activity of solid surfaces is critically dependent on relative humidity, inoculum volume, and organic soiling

Antibacterial activity of solid surfaces is critically dependent on relative humidity, inoculum volume, and organic soiling

Decontamination of Spores on Model Stainless-Steel Surface by Using Foams Based on Alkyl Polyglucosides

Unravelling the Dynamics of Bacterial-Laden Respiratory Droplets: Epidemiological Transfer from Fomites to Susceptible Host

Contact Info

Product

Resources

About