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El abed S.,Laboratoire Of Biotechnologie Microbienne | El abed S.,University Sidi Mohammed Ben Abdellah | Ibnsouda S.K.,Laboratoire Of Biotechnologie Microbienne | Ibnsouda S.K.,University Sidi Mohammed Ben Abdellah | And 4 more authors.
World Journal of Microbiology and Biotechnology | Year: 2012

Initial microbial adhesion to surfaces is a complicated process that is affected by a number of factors. An important property of a solution that may influence adhesion is pH. The surface properties of the cedar wood were characterized by the sessile drop technique. Moreover, the interfacial free energy of surface adhesion to the cedar wood was determined under pH values (2, 3, 5, 7, 9 and 11). The results showed that cedar wood examined at different pH levels could be considered hydrophobic ranged from Giwi = -13. 1 mJ/m2 to Giwi = -75 mJ/m2. We noted that the electron-donor character of cedar wood was important at both basic and limit acidic conditions (pH 11 and pH 3) and it decreased at intermediate pH (pH 5). The cedar wood substratum presents a weak electron acceptor under various pH's. In addition, the adhesion of conidia from Penicilllium expansum to the cedar wood surfaces at different pH values (2, 3, 5, 7, 9 and 11) was investigated using Environmental Scanning Electron Microscopy and image analysis was assessed with the Mathlab® program. The data analysis showed that the conidia from P. expansum were strongly influenced by the pH. The maximum adhesion occurs in the pH 11 and pH 3 and decreased to 24% at pH 5. © 2011 Springer Science+Business Media B.V.

Soumya E.A.,Laboratoire Of Biotechnologie Microbienne | Saad I.K.,Laboratoire Of Biotechnologie Microbienne | Saad I.K.,University Sidi Mohammed Ben Abdellah | Hassan L.,Laboratoire Of Valorisation Et Of Securite Des Produits Agroalimentaires | And 3 more authors.
African Journal of Microbiology Research | Year: 2011

Pseudomonas aeruginosa has a high propensity to develop biofilms that are resistant to exogenous deleterious agents. The aim of this study was to investigate whether carvacrol and thymol can interfere with adherence phenomena as well as acting on biofilm formation. Tests of P. aeruginosa strains showed that carvacrol and thymol interferes with the starting phases of adherence as well as with P. aeruginosa biofilms. Carvacrol and thymol (2MIC) inhibition was 97±8.5 and 89±6.3% for P. aeruginosa (ATCC 27853) and 72±4.6 and 69±6.8% for P. aeruginosa (CIP A22) adherence respectively. Carvacrol (2MIC) inhibition exceeds 90% for P. aeruginosa (ATCC 27853) and P. aeruginosa (IL5) biofilm. Thymol (2MIC) inhibition is 86±2.1, 54±5.9 and 70±4.3% for P. aeruginosa (ATCC 27853) P. aeruginosa (CIP A22), P. aeruginosa (IL5), respectively. © 2011 Academic Journals.

Zineba G.,Institute Pasteur du Maroc | Zineba G.,Laboratoire Of Biotechnologie Microbienne | Hassan L.,Laboratoire Of Valorisation Et Of Securite Des Produits Agroalimentaires | Mostafa M.,Laboratoire Of Valorisation Et Of Securite Des Produits Agroalimentaires | And 3 more authors.
Water Resources | Year: 2014

Potable water piping has been demonstrated to serve as a reservoir for opportunistic pathogens bacteria such as Pseudomonas aeruginosa. In this report, we describe the characterization of P. aeruginosa strains isolated from water intended for human consumption by the presence of virulence factors. These strains expressed their suitability for adhesion and the formation of biofilms on polyethylene (PE). Also in this work, we were able to elucidate the factors intervening in adhesion and biofilm formation by showing the role of the substrate, the environment and bacteria. Strong correlation was observed between physicochemical properties especially the electron donor property and the surface percentage covered by cells. These results indicate that this property plays a crucial role in Pseudomonas aeruginosa adherence on the PE surface. In addition, if no relationship was found between the adhesion results and hydrophobicity, it means that this property was not involved in the adhesion process of Pseudomonas aeruginosa on the PE surface. © 2015, Pleiades Publishing, Ltd.

El-Abed S.,Laboratoire Of Biotechnologie Microbienne | El-Abed S.,University Sidi Mohammed Ben Abdellah | Houari A.,Laboratoire Of Biotechnologie Microbienne | Latrache H.,Laboratoire Of Valorisation Et Of Securite Des Produits Agroalimentaires | And 3 more authors.
Research Journal of Microbiology | Year: 2011

Biofilm control has become an area of intense study. The effect of four Essential Oil Components (EOC's) on adherence and biofilms on two pathogenic Pseudomonas aeruginosa isolates were investigated in this study. The inhibitory activity was tested on polystyrene flat-bottomed microtitre plates using the Crystal Violet (CV) staining assay. The results showed that this activity was dependent on the terpenes concentration used to treat the adherence and biofilm. Treatment of Pseudomonas aeruginosa adherence with eugenol, carveol and carvone (0.5 Minimum Inhibitory Concentration), resulted 60, 45 and 54% inhibition for P. aeruginosa (CIP A22) and 69, 65 and 42% for P. aeruginosa (ATCC 27853), respectively. β-ionone shows a slight inhibitory effect for the two strains studied. The results also showed that eugenol (0.5 Minimum Inhibitory Concentration) was able to induce an inhibition>90% of P. aeruginosa biofilm (strain ATCC 27853) and a concentration of carvone and carveol of at least 0.5 Minimum Inhibitory Concentration (MIC) was required to obtain approximately 50% of biofilm inhibition. β-ionone (0.5 MIC) appeared as the least efficient against P. aeruginosahiofilm resulted only 43% reduction of the biofilm. This study demonstrated the anti-adherence and antibiofilm activity of terpenes and points out the exceptional efficiency of eugenol, carvone and carveol, which could represent candidates in the treatment of Pseudomonas aeruginosa biofilm. © 2011 Academic Journals Inc.

Soumya E.,Laboratoire Of Biotechnologie Microbienne | Soumya E.,University Sidi Mohammed Ben Abdellah | Saad I.K.,Laboratoire Of Biotechnologie Microbienne | Saad I.K.,University Sidi Mohammed Ben Abdellah | And 2 more authors.
Materials Science and Engineering C | Year: 2013

In this study, the adhesion of 4 Penicillium strains (Penicillium granulatum, Penicillium crustosum, Penicillium commune and Penicillium chrysogenum) on cedar wood was examined qualitatively and quantitatively by using the extended DLVO (XDLVO) approach and the environmental scanning electronic microscopy (ESEM) technique. A comparison between the XDLVO theories and the ESEM technique was also investigated. The adhesion tests revealed that P. chrysogenum was not able to adhere on the cedar wood substrata, as predicted by the XDLVO approach. We have also found by ESEM that the three Penicillium strains (P. granulatum, P. crustosum, P. commune) adhered on wood, as not predicted theoretically. Moreover, the time of adhesion (3 h and 24 h) was used not only to compare the capacity of adhesion according to contact time but also to explain the discrepancies between the XDLVO approach prediction and the adhesion experiments. A positive relationship between the XDLVO approach and adhesion experiments has been observed after 3 h of adhesion. In contrast, a contradiction between the XDLVO predictions and the adhesion test results has been noted after 24 h of adhesion of Penicillium strains to the wood surface. © 2013 Elsevier B.V. All Rights Reserved.

Hamida K.,Laboratoire Decologie Et Of Technology Microbienne | Faten K.,Laboratoire Decologie Et Of Technology Microbienne | Soumya E.A.,Center University Regional nterface | Saad I.K.,Center University Regional nterface | And 2 more authors.
Journal of Adhesion Science and Technology | Year: 2013

The initial microorganism adhesion on substrate is an important step for biofilm formation. The surface properties of the silicone and Bacillus cereus were characterized by the sessile drop technique. Moreover, the physicochemical properties (hydrophobicity; electron donor/electron acceptor) of surface adhesion and the impact of bio adhesion on the silicone were determined at different time of contact (3, 7, and 24 h). The results showed that the strain was hydrophilic (Giwi = 3.37 mJ/m2), whereas the silicone has hydrophobic character (Giwi =-68.28 mJ/m2). Silicone surface presents a weak electron-donor character (γ - = 2.2 mJ/m2) conversely to B. cereus that presents an important electron donor-parameter (γ - = 31.6 mJ/m2). The adhesion of B. cereus to silicone was investigated using environmental scanning electron microscope and image analysis was assessed with the Matlab® program. After 3 h of contact, the data analysis, confirmed the bio adhesion with an amount of 9.6105 cfu/cm2 adhered cells. After 24 h, the percentage of silicone covered reached 93%. Furthermore, despite the difference in hydrophohbicity, the interaction between B. cereus and substrata was favoured by the thermodynamic model of adhesion (ΔG adhesion < 0). The real time investigation of the effect of B. cereus adhesion on the physicochemical properties of silicone has revealed that the substrata becomes hydrophilic (θ° = 47.3, ΔGiwi = 23.7 mJ/m2), after 7 h of contact. This bio adhesion had also favoured the increase of electron donor/acceptor character of silicone (γ - = 53.1 mJ/m 2 and γ + = 5.3 mJ/m2). © 2013 Taylor & Francis Group, LLC.

Ksontini H.,CNRS Institute of Earth Sciences | Kachouri F.,CNRS Institute of Earth Sciences | El Abed S.,Center University Regional dInterface | Ibnsouda Koraichi S.,Center University Regional dInterface | And 3 more authors.
Journal of Adhesion Science and Technology | Year: 2013

Biofilms are the most common mode of bacterial growth in nature and the formation will occur on organic or inorganic solid surfaces in contact with a liquid. The aims of this study were, by combining numeration and sessile drop technique, (i) to characterize the structural dynamics of dairy biofilm growth and the physico chemical properties on silicone and stainless steel and (ii) to evaluate the impact of bio-adhesion on chemistry of surfaces at different times of contact (2, 7, 9 and 24 h). Significantly, greater biofilm volumes were observed after 48 h on two materials. Gram-positive bacteria and fungal population exhibited a significantly higher biofilm organization than gram-negative (43-64%). Elsewhere, after 48 h, results showed a slight difference on gram-negative adhered cells on stainless steel than silicone (2.6 × 107 cfu/cm2 and 4.7 × 105 cfu/cm2, respectively). Moreover, the physico chemical properties of the surfaces showed that the silicone and stainless steel have a hydrophobic character (Giwi = -68.28 mJ/m2 and -57.6 mJ/m2, respectively). Also, both the surfaces present a weak electron donor character (γ - = 2.2 mJ/m2 and 4.1 mJ/m2, respectively). The real-time investigation of the impact of dairy biofilm on the physico chemical properties of the materials has shown a decrease of hydrophobicity degree of the silicone surface that becomes hydrophilic (ΔGiwi = 11.47 mJ/m2) after 7 h and the increase of electron donor character (γ - = 75.8 mJ/m2). Elsewhere, bio-adhesion on stainless steel was accompanied with a decrease of hydrophobicity degree of the surface, which becomes hydrophilic after 7 h of contact (ΔGiwi = 6.62 mJ/m2) and the increase of the electron donor character (γ - = 44.8 mJ/m2). While, after 24 h of contact, results showed a decrease of the hydrophilicity degree and surface energy components of silicone and stainless steel that become hydrophobic (ΔGiwi = -21.2 mJ/m2 and ΔGiwi = -56.51 mJ/m2, respectively) and weak electron donor (γ - = 14.0 and 2.3 mJ/m2, respectively). © 2012 Taylor & Francis.

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