Implication of Mn-cofactored superoxide dismutase in the tolerance of swarmer Pseudomonas aeruginosa to polymixin, ciprofloxacin and meropenem antibiotics.

The protective role of superoxide dismutase (Sod) against oxidative stress, resulting from the common antibiotic pathway of action, has been studied in the wild type and mutant strains of swarmer Pseudomonas aeruginosa, lacking Cytosolic Mn-Sod (sodM), Fe-Sod (sodB) or both Sods (sodMB).Our results showed that inactivation of sodB genes leads to significant motility defects and tolerance to meropenem. This resistance is correlated with a greater membrane unsaturation as well as an effective intervention of Mn-Sod isoform, in antibiotic tolerance.

Swarmer Cells Adaptation Toward UVc Radiations.

Swarming is the most rapid surface motility allowing bacteria to rapidly colonize new surfaces. However, swarming behavior is affected by environmental factors like ultraviolet irradiation (UVc). UVc radiation is the most disinfection technology usually applied for wastewater and proven to be effective to inactivate microorganisms.

Antioxidant Defense Mechanisms in Pseudomonas aeruginosa: Role of Iron-Cofactored Superoxide Dismutase in Response to UV-C Radiations.

The role of SOD gene in response to UV-C radiations was studied in Pseudomonas aeruginosa. Firstly, our results showed that the inactivation of sodM and/or sodB genes decreases the resistance of P. aeruginosa after exposure to UV-C rays.

Antioxidant enzymes expression in Pseudomonas aeruginosa exposed to UV-C radiation.

It was well known that, UV-C irradiation increase considerably the reactive oxygen species (ROS) levels in eukaryotic and prokaryotic organisms. In the enzymatic ROS-scavenging pathways, superoxide dismutase (SOD), Catalase (CAT), and peroxidase (POX) were developed to deal with oxidative stress. In this study, we investigated the effects of UV-C radiations on antioxidant enzymes (catalase, superoxide dismutase, and peroxidases) expression in Pseudomonas aeruginosa.

Fatty Acids Composition and Biofilm Production of Attenuated Salmonella typhimurium dam and seqA Mutants After Exposure to UV-C.

The goal of this work was the investigation of correlation between some peculiarities of membrane fatty acids composition, biofilm formation, and motility of dam and/or seqA mutants in Salmonella typhimurium bacterial cells and UV-C radiations. The exposure changed the fatty acids composition of dam and seqA/dam strains. Significant increase of unsaturated fatty acids was observed.

UV-C pre-adaptation of Salmonella: effect on cell morphology and membrane fatty acids composition.

The present study was carried out to evaluate the effects of ultraviolet radiations (UV-C) on the fatty acids composition of three serovars of Salmonella: S. typhimurium, S. hadar and S.

Allelic polymorphisms of human platelets-specific alloantigens in South Tunisian population.

Objectives: Human platelet-specific alloantigens (HPA) are polymorphic epitopes which vary among ethnic groups.

Background: In Tunisia, HPA frequencies were determined in North and centre; however, the pattern of HPA in South Tunisian population is not been studied yet. The aim of this work was to determine allelic frequencies of HPA-1, -3, and -5 systems in south Tunisian population, in order to estimate the risk of anti-platelet allo-immunization and to create a register of HPA-typed blood donors.

Prevalence of factor V Leiden in south Tunisian blood donors.

Venous thrombosis (VT) is a common disease with multifactorial pathogenesis. Factor V Leiden mutation (G1691A) (FVL) is the most common risk factor in venous thrombosis. The prevalence of FVL varies according to geography and ethnicity.