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Abdallah M.,University Of Lille1 Science Et Technologies | Abdallah M.,Laboratoire SCIENTIS | Benoliel C.,Laboratoire SCIENTIS | Ferreira-Theret P.,Laboratoire SCIENTIS | And 3 more authors.
Biofouling | Year: 2015

The relationship between the environmental conditions of biofilm formation and resistance to disinfectants was studied. Anti-biofilm assays were performed against biofilms grown at 20, 30 and 37°C on stainless steel and polycarbonate, over 24 and 48 h. A rise in growth temperature increased the resistance of 24 h biofilms to disinfectants containing didecyldimethylammonium chloride and decreased it to a disinfectant containing alkyldimethylbenzylammonium chloride. The increase in growth temperature coupled with an incubation time of 24 h promoted increases in both matrix production and the membrane rigidity of sessile cells. An increase in incubation time also increased both matrix production and the membrane rigidity of sessile cells. Such phenomena resulted in an increased resistance to disinfectants of biofilms grown at 20 and 30°C. The resistance of 48 h biofilms to disinfectants decreased with an increase in growth temperature despite the increase in matrix production and the membrane rigidity of sessile cells. © 2015, © 2015 Taylor & Francis.


PubMed | Ecole Nationale Supérieure de Chimie de Lille, Laboratoire SCIENTIS and Lille University of Science and Technology
Type: Journal Article | Journal: Journal of food protection | Year: 2014

This study investigated the effect of growth temperature changes (20, 30, and 37C) on the adhesion behavior of Pseudomonas aeruginosa and Staphylococcus aureus to stainless steel and polycarbonate. Adhesion assays were performed under static conditions at 20C. In addition, the validity of the thermodynamic and extended Derjaguin, Landau, Verwey, and Overbeek theories as predictive tools of bacterial adhesion were studied. The surface properties of the bacterial cells and the substrates of attachment were characterized, and atomic force microscopy was used to analyze the surface topography. The results indicated that the highest adhesion rate of P. aeruginosa and S. aureus on both surfaces was observed when the cells were grown at 37C. The bacterial adhesion to stainless steel was found to be two times higher than to polycarbonate for both bacteria, whatever the condition used. The present study underlined that the thermodynamic and the extended Derjaguin, Landau, Verwey, and Overbeek theories were able to partially predict the empirical results of P. aeruginosa adhesion. However, these theories failed to predict the adhesion behavior of S. aureus to both surfaces when the growth temperature was changed. The results of the microbial adhesion to solvent indicated that the adhesion rate to abiotic surfaces may correlate with the hydrophobicity of bacterial surfaces. The effect of surface topography on bacterial adhesion showed that surface roughness, even on the very low nanometer scale, has a significant effect on bacterial adhesion behavior.


Abdallah M.,Laue Langevin Institute | Abdallah M.,Laboratoire SCIENTIS | Benoliel C.,Laboratoire SCIENTIS | Drider D.,Laue Langevin Institute | And 2 more authors.
Archives of Microbiology | Year: 2014

The biofilm formation on abiotic surfaces in food and medical sectors constitutes a great public health concerns. In fact, biofilms present a persistent source for pathogens, such as Pseudomonas aeruginosa and Staphylococcus aureus, which lead to severe infections such as foodborne and nosocomial infections. Such biofilms are also a source of material deterioration and failure. The environmental conditions, commonly met in food and medical area, seem also to enhance the biofilm formation and their resistance to disinfectant agents. In this regard, this review highlights the effect of environmental conditions on bacterial adhesion and biofilm formation on abiotic surfaces in the context of food and medical environment. It also describes the current and emergent strategies used to study the biofilm formation and its eradication. The mechanisms of biofilm resistance to commercialized disinfectants are also discussed, since this phenomenon remains unclear to date. © 2014 Springer-Verlag.


Abdallah M.,Lille University of Science and Technology | Abdallah M.,Laboratoire SCIENTIS | Chataigne G.,Lille University of Science and Technology | Ferreira-Theret P.,Laboratoire SCIENTIS | And 4 more authors.
Applied Microbiology and Biotechnology | Year: 2014

The goal of this study was to investigate the effect of the environmental conditions such as the temperature change, incubation time and surface type on the resistance of Staphylococcus aureus biofilms to disinfectants. The antibiofilm assays were performed against biofilms grown at 20°C, 30°C and 37°C, on the stainless steel and polycarbonate, during 24 and 48 h. The involvement of the biofilm matrix and the bacterial membrane fluidity in the resistance of sessile cells were investigated. Our results show that the efficiency of disinfectants was dependent on the growth temperature, the surface type and the disinfectant product. The increase of growth temperature from 20°C to 37°C, with an incubation time of 24 h, increased the resistance of biofilms to cationic antimicrobials. This change of growth temperature did not affect the major content of the biofilm matrix, but it decreased the membrane fluidity of sessile cells through the increase of the anteiso-C19 relative amount. The increase of the biofilm resistance to disinfectants, with the rise of the incubation time, was dependent on both growth temperature and disinfectant product. The increase of the biofilm age also promoted increases in the matrix production and the membrane fluidity of sessile cells. The resistance of S. aureus biofilm seems to depend on the environment of the biofilm formation and involves both extracellular matrix and membrane fluidity of sessile cells. Our study represents the first report describing the impact of environmental conditions on the matrix production, sessile cells membrane fluidity and resistance of S. aureus biofilms to disinfectants. © Springer-Verlag 2014.


Abdallah M.,Lille University of Science and Technology | Abdallah M.,Laboratoire SCIENTIS | Benoliel C.,Laboratoire SCIENTIS | Jama C.,CNRS Materials and Transformations Unit of UMET | And 3 more authors.
Journal of Food Protection | Year: 2014

This study investigated the effect of growth temperature changes (20, 30, and 37°C) on the adhesion behavior of Pseudomonas aeruginosa and Staphylococcus aureus to stainless steel and polycarbonate. Adhesion assays were performed under static conditions at 20°C. In addition, the validity of the thermodynamic and extended Derjaguin, Landau, Verwey, and Overbeek theories as predictive tools of bacterial adhesion were studied. The surface properties of the bacterial cells and the substrates of attachment were characterized, and atomic force microscopy was used to analyze the surface topography. The results indicated that the highest adhesion rate of P. aeruginosa and S. aureus on both surfaces was observed when the cells were grown at 37°C. The bacterial adhesion to stainless steel was found to be two times higher than to polycarbonate for both bacteria, whatever the condition used. The present study underlined that the thermodynamic and the extended Derjaguin, Landau, Verwey, and Overbeek theories were able to partially predict the empirical results of P. aeruginosa adhesion. However, these theories failed to predict the adhesion behavior of S. aureus to both surfaces when the growth temperature was changed. The results of the microbial adhesion to solvent indicated that the adhesion rate to abiotic surfaces may correlate with the hydrophobicity of bacterial surfaces. The effect of surface topography on bacterial adhesion showed that surface roughness, even on the very low nanometer scale, has a significant effect on bacterial adhesion behavior. ©International Association for Food Protection.


Abdallah M.,Lille University of Science and Technology | Abdallah M.,Laboratoire SCIENTIS | Khelissa O.,Lille University of Science and Technology | Ibrahim A.,Iri Institute Of Recherche Interdisciplinaire | And 4 more authors.
International Journal of Food Microbiology | Year: 2015

Biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus on food-contact-surfaces represents a significant risk for the public health. In this context, the present study investigates the relationship between the environmental conditions of biofilm formation and the resistance to disinfectants. Therefore, a static biofilm reactor, called NEC-Biofilm System, was established in order to study the effect of growth temperature (20, 30 and 37. °C), and of the surface type (stainless steel and polycarbonate), on biofilm resistance to disinfectants. These conditions were selected to mimic the biofilm formation on abiotic surfaces of food processing industries. The antibiofilm assays were performed on biofilms grown during 24. h. The results showed that the growth temperature influenced significantly the biofilm resistance to disinfectants. These data also revealed that the growth temperature has a significant effect on the biofilm structure of both bacteria. Furthermore, the increase of the biofilm growth temperature increased significantly the algD transcript level in sessile P. aeruginosa cells, whereas the icaA one was not affected in S. aureus cells. Overall, our findings show that the biofilm structure and matrix cannot fully explain the biofilm resistance to disinfectant agents. Nevertheless, it underlines the intimate link between environmental conditions, commonly met in food sectors, and the biofilm resistance to disinfectants. © 2015 Elsevier B.V.


PubMed | Iri Institute Of Recherche Interdisciplinaire, Laboratoire SCIENTIS and Lille University of Science and Technology
Type: | Journal: International journal of food microbiology | Year: 2015

Biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus on food-contact-surfaces represents a significant risk for the public health. In this context, the present study investigates the relationship between the environmental conditions of biofilm formation and the resistance to disinfectants. Therefore, a static biofilm reactor, called NEC-Biofilm System, was established in order to study the effect of growth temperature (20, 30 and 37C), and of the surface type (stainless steel and polycarbonate), on biofilm resistance to disinfectants. These conditions were selected to mimic the biofilm formation on abiotic surfaces of food processing industries. The antibiofilm assays were performed on biofilms grown during 24 h. The results showed that the growth temperature influenced significantly the biofilm resistance to disinfectants. These data also revealed that the growth temperature has a significant effect on the biofilm structure of both bacteria. Furthermore, the increase of the biofilm growth temperature increased significantly the algD transcript level in sessile P. aeruginosa cells, whereas the icaA one was not affected in S. aureus cells. Overall, our findings show that the biofilm structure and matrix cannot fully explain the biofilm resistance to disinfectant agents. Nevertheless, it underlines the intimate link between environmental conditions, commonly met in food sectors, and the biofilm resistance to disinfectants.

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