title: Effects of microwave (2.45 GHz) irradiation on some biological characters of Salmonella typhimurium.
abstract: The present study was carried out to evaluate the effects of sub-lethal doses of microwave radiation on some biological characteristics in Salmonella typhimurium. The aim was to show the relationship between this treatment and the development of radiotolerance in this pathogen because there is a need for more information on physiological responses of pathogens to sub-lethal doses of microwave radiation. So, the bacterial strain was treated with a dose of 3600J (40-s exposure with power P=90 W) to cause cellular damage. The results have shown that the exposure of bacteria to microwaves resulted in a significant inhibition of cellular growth. This treatment has notably increased the effectiveness of the most tested antibiotics by the amelioration or the appearance of sensitivity in exposed bacteria. Gas chromatography (GC) analysis was performed to demonstrate the modification of the fatty acids (FA) composition. Results obtained have shown that this treatment had a significant effect on the FA content with an increase of unsaturated FA percentage. The acquisition of sensitivity to the sodium deoxycholate and the significant increase in the amount of extracellular proteins in exposed bacteria has confirmed the weakening of the bacterial membrane by microwaves. This study represents one of the few demonstrating the modifications on the bacterial membrane as a cellular response to survive the non-ionising radiation stress.
authors.affiliation: Laboratoire de biochimie et biologie moléculaire, faculté des sciences de Bizerte, 7021 Zarzouna, Tunisia. nasrikaouther512@gmail.com
authors.forename: Kaouther
authors.initials: K
authors.lastname: Nasri
authors.forename: Douraid
authors.initials: D
authors.lastname: Daghfous
authors.forename: Ahmed
authors.initials: A
authors.lastname: Landoulsi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism; D001431:Bacteriological Techniques; D002849:Chromatography, Gas; D015169:Colony Count, Microbial; D003840:Deoxycholic Acid / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D005227:Fatty Acids / Q000378:metabolism; D005519:Food Preservation; D050356:Lipid Metabolism / Q000528:radiation effects; D008055:Lipids / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D008872:Microwaves; D012486:Salmonella typhimurium / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D005227:Fatty Acids; D008055:Lipids; D003840:Deoxycholic Acid
keywords: Biological characters; Caractères biologiques; Lipides totaux; Membrane; Membrane bactérienne; Micro-ondes; Microwaves; Salmonella typhimurium; Total lipids