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. zanzibar. Results obtained show that UV-C treatment increases significantly (P B 0.05) the percentage of cyclic fatty acids. The atomic force microscopy was used to study the morphology and cell surface of irradiated strains. Results show that UV-C rays induce morphological changes and alter the bacterial cell surfac

Survival and fatty acid composition of UV-C treated Staphylococcus aureus

Ultraviolet irradiation (UV-C) is proven to be effective to inactivate microorganisms. The present study investigates the effect of sublethal UV-C rays on the membrane fatty acid profile of four Staphylococcus aureus strains isolated from air, patient, food and animal. Our results show that S. aureus isolated from patients and air are the most sensitive to UV-C rays and that their inactivation achieves a greater than 2-log reduction after a UV-C exposure of 210 mJ cm−2. However, the strain isolated from food is the most resistant one. The fatty acid analysis indicates that this strain (food) reveals a decrease of branched chain fatty acids (BCFA iso and anteiso) and an increase of straight chain saturated fatty acids (SCFA)