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Sabbahi S.,Institute National Of Recherche En Genie Rural Eaux Et Forets Inrgref | Ben Ayed L.,Institute National Agronomique Of Tunis | Boudabbous A.,Laboratoire Microorganismes et Biomolecules Actives
Journal of Water and Health | Year: 2013

The aim of this study was to evaluate the photobactericidal effect of four photosensitizers (PSs) with different structural and physico-photochemical properties, namely mesotetracationic porphyrin (T4MPyP), dianionic rose Bengal (RB), monocationic methylene blue (MB) and neutral red (NR). Their photokilling activity was tested in vitro on pathogenic bacteria such as Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) suspended in nutrient broth (NB) and in phosphate buffered saline (PBS) through following their influence on the PSs antimicrobial efficacy. Photodynamic inactivation (PDI) experiments were performed using visible light (L) and different PSs concentrations (20-70 μM). The ability of these PSs to mediate bacterial photodynamic inactivation was investigated as a function of type of PS and its concentrations, spectral and physico-chemical properties, bacterial strain, irradiation time and suspending medium. Indeed, they showed antibacterial effects against S. aureus and P. aeruginosa with significant difference in potency. Staphylococcus aureus suspended in NB showed 0.92 log units reduction in viable count in the presence of T4MPyP at 20 μM. Changing the suspending medium from NB to PBS, S. aureus was successfully photoinactivated by T4MPyP (20 μM) when suspended in PBS at least time exposure (10 and 30 min), followed by MB and RB. © IWA Publishing 2013. Source

Sabbahi S.,Institute National Of Recherche En Genie Rural Eaux Et Forets | Sabbahi S.,Laboratoire Microorganismes et Biomolecules Actives | Alouini Z.,Institute National Of Recherche En Genie Rural Eaux Et Forets | Ayed L.B.,Institute National Of Recherche En Genie Rural Eaux Et Forets | And 2 more authors.
Desalination and Water Treatment | Year: 2010

The high inactivation of faecal indicators [faecal coliforms (FC), E. coli and faecal streptococci (FS)] using a combination of methylene blue (MB) with natural sunlight or artificial visible light determined on a small scale, was dependent mainly on the MB concentration, its application process and pH. In order to avoid primarily leaching of the compound into the environment and to further understand the MB photosensitization mechanisms, MB should be properly immobilized within resin. The FC and FS were found to be susceptible to the photodynamic action of MB fixed to the support. The mechanism of faecal bacteria inactivation by MB also seems to be a combination of Type I and Type II processes, and the relative efficiency of each of them depends notably on the experimental conditions. In parallel, the MB stability under light "photobleaching" has been studied by optical absorption spectroscopy. It has been shown that it was dependent essentially on pH, nature of the medium (distilled water and secondary wastewater effluent) and time exposure to light. Practically, all of the MB (10 μM) disappeared from effluent, exposed to sunlight, by the end of a 12 h experiment with a bleaching rate from 92 at neutral pH. Kinetic data indicate that the dye photobleaching efficiency can be approximated by pseudo-first-order reaction. © 2010 Desalination Publications. Source

Slama K.B.,Laboratoire Microorganismes et Biomolecules Actives | Gharbi S.,Laboratoire Microorganismes et Biomolecules Actives | Jouini A.,Laboratoire Microorganismes et Biomolecules Actives | Maarouf M.,Laboratoire Microorganismes et Biomolecules Actives | And 3 more authors.
African Journal of Microbiology Research | Year: 2011

Ninety four clinical isolates of Pseudomonas aeruginosa cultured from patients admitted to the Intensive Care Unit (ICU) (N= 37) and Otolaryngology (ORL) (N= 57) during one year (2001-2002) at the Rabta hospital (Tunisia) have been investigated by using serotyping, pyocintyping, drug susceptibility, M13-PCR and PFGE typing. Result shown that most of the isolates at the ICU belonged to serotyp e O:12 (11/37) that showed high resistance to commonly used antimicrobials (β-lactamins, aminosids, and quinolone) and a predominance for pyocinotype P10. Despite the frequent occurrence of identical serotypes and pyocinotypes, most of the isolates represent unique RAPD-M13 genotype (88/94). PFGE typing detected three distinct clusters amongst the O12 isolates, suggesting a clonal relatedness among multiresistant O12 isolates. This study illustrates the importance of phenotypic and genotypic epidemiological surveillance of predominant O12 serotype clones in such service in local hospital. © 2011 Academic Journals. Source

Essghaier B.,Laboratoire Microorganismes et Biomolecules Actives | Abdelhak J.,Universite Ibn Tofail | Naouar A.,Laboratoire Microorganismes et Biomolecules Actives | Toukebri N.,Laboratoire Microorganismes et Biomolecules Actives | And 2 more authors.
Journal of Chemical Sciences | Year: 2015

Tetraaqua bismaleato iron(II) [Fe(C4H3O4)2(H2O)4], (1) is a new synthetic antimicrobial agent. Thermal analysis shows that the dehydration of the compound occurs in agreement with the structure. The single crystal salt crystallizes in the triclinic space group P-1 with a = 5.171(2) Å, b = 7.309(3) Å, c = 9.731(3) Å, α = 109.15(2)°, β = 115.02(2)°, γ = 92.42(1)°, V = 313.6(3) Å3 and Z = 1. Three dimensional network is formed by strong intermolecular O - H ...O hydrogen bonds. Magnetic susceptibility measurements of 1 in the range 2-300 K exhibited paramagnetic behavior at high temperature. However, at low temperature, the susceptibility data showed weak antiferromagnetic interactions between the local spins. Antimicrobial activity of 1 was tested. It showed high response against gram-positive and gram-negative bacteria as well as fungi and the MIC and IC50 values ranged from 8 to 256 μg.mL-1 and from 1.38 to 22.19 μg.mL-1, respectively. © 2015 Indian Academy of Sciences. Source

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