Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity
The reliability of the challenge test depends, among other parameters, on the spatial distribution of microorganisms in the matrix. The present study aims to quickly identify factors that are susceptible to impair a uniform distribution of inoculated bacteria in cosmetic matrices in this context. We...
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MDPI AG
2020-05-01
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Series: | Cosmetics |
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Online Access: | https://www.mdpi.com/2079-9284/7/2/32 |
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author | Samia Almoughrabie Chrisse Ngari Romain Briandet Valérie Poulet Florence Dubois-Brissonnet |
author_facet | Samia Almoughrabie Chrisse Ngari Romain Briandet Valérie Poulet Florence Dubois-Brissonnet |
author_sort | Samia Almoughrabie |
collection | DOAJ |
description | The reliability of the challenge test depends, among other parameters, on the spatial distribution of microorganisms in the matrix. The present study aims to quickly identify factors that are susceptible to impair a uniform distribution of inoculated bacteria in cosmetic matrices in this context. We used mosaic confocal laser scanning microscopy (M-CLSM) to obtain rapid assessment of the impact of the composition and viscosity of cosmetic matrices on <i>S.</i> <i>aureus</i> spatial distribution. Several models of cosmetic matrices were formulated with different concentrations of two thickeners and were inoculated with three <i>S.</i> <i>aureus</i> strains having different levels of hydrophobicity. The spatial distribution of <i>S.</i> <i>aureus</i> in each matrix was evaluated according to the frequency distribution of the fluorescence values of at least 1350 CLSM images. We showed that, whatever the thickener used, an increasingly concentration of thickener results in increasingly bacterial clustered distribution. Moreover, higher bacterial hydrophobicity also resulted in a more clustered spatial distribution. In conclusion, CLSM-based method allows a rapid characterization of bacterial spatial distribution in complex emulsified systems. Both matrix viscosity and bacterial surface hydrophobicity affect the bacterial spatial distribution which can have an impact on the reliability of bacterial enumeration during challenge test. |
first_indexed | 2024-03-10T19:55:28Z |
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id | doaj.art-5efa8094c6d147ac91c0d2c726bcddbe |
institution | Directory Open Access Journal |
issn | 2079-9284 |
language | English |
last_indexed | 2024-03-10T19:55:28Z |
publishDate | 2020-05-01 |
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series | Cosmetics |
spelling | doaj.art-5efa8094c6d147ac91c0d2c726bcddbe2023-11-20T00:00:53ZengMDPI AGCosmetics2079-92842020-05-01723210.3390/cosmetics7020032Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial HydrophobicitySamia Almoughrabie0Chrisse Ngari1Romain Briandet2Valérie Poulet3Florence Dubois-Brissonnet4Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, FranceLaboratoires Clarins, 5 Rue Ampère, 95300 Pontoise, FranceMicalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, FranceLaboratoires Clarins, 5 Rue Ampère, 95300 Pontoise, FranceMicalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, FranceThe reliability of the challenge test depends, among other parameters, on the spatial distribution of microorganisms in the matrix. The present study aims to quickly identify factors that are susceptible to impair a uniform distribution of inoculated bacteria in cosmetic matrices in this context. We used mosaic confocal laser scanning microscopy (M-CLSM) to obtain rapid assessment of the impact of the composition and viscosity of cosmetic matrices on <i>S.</i> <i>aureus</i> spatial distribution. Several models of cosmetic matrices were formulated with different concentrations of two thickeners and were inoculated with three <i>S.</i> <i>aureus</i> strains having different levels of hydrophobicity. The spatial distribution of <i>S.</i> <i>aureus</i> in each matrix was evaluated according to the frequency distribution of the fluorescence values of at least 1350 CLSM images. We showed that, whatever the thickener used, an increasingly concentration of thickener results in increasingly bacterial clustered distribution. Moreover, higher bacterial hydrophobicity also resulted in a more clustered spatial distribution. In conclusion, CLSM-based method allows a rapid characterization of bacterial spatial distribution in complex emulsified systems. Both matrix viscosity and bacterial surface hydrophobicity affect the bacterial spatial distribution which can have an impact on the reliability of bacterial enumeration during challenge test.https://www.mdpi.com/2079-9284/7/2/32clustered distributionregular distributionviscous matrixthickenerbacterial hydrophobicitychallenge test |
spellingShingle | Samia Almoughrabie Chrisse Ngari Romain Briandet Valérie Poulet Florence Dubois-Brissonnet Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity Cosmetics clustered distribution regular distribution viscous matrix thickener bacterial hydrophobicity challenge test |
title | Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity |
title_full | Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity |
title_fullStr | Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity |
title_full_unstemmed | Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity |
title_short | Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity |
title_sort | mosaic clsm assessment of bacterial spatial distribution in cosmetic matrices according to matrix viscosity and bacterial hydrophobicity |
topic | clustered distribution regular distribution viscous matrix thickener bacterial hydrophobicity challenge test |
url | https://www.mdpi.com/2079-9284/7/2/32 |
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