The effect of toluidine blue on the survival, dormancy and outer membrane porin proteins (OmpC and OmpF) of Salmonella typhimurium LT2 in seawater.
OBJECTIVE
To study the relationship between changes in the composition of the outer membrane proteins and the survival of Salmonella typhimurium LT2 in filtered autoclaved seawater containing Toluidine Blue (TB) dye as a photosensitizer.


RESULTS
In samples exposed to TB and excited by artificial visible light, the total viable (TVC) and respiring cell counts (RCC) showed that, although the TVC declined to an undetectable level in 6.5 h, the RCC showed that some cells were still capable of respiration. The porin protein composition changed gradually with OmpC and OmpF becoming undetectable by sodium dodecyl sulphate-polyacrylamide gel electrophoresis after 8 h of incubation. Hydrogen peroxide-pretreated cells survived longer compared with the control.


CONCLUSIONS
Oxidative pretreatment of Salm. typhimurium protects cells from some of the effects of sunlight in the presence of photosensitizers. The changes in porin proteins may play a role in this protection.


CONCLUSIONS
The study shows that the survival of bacteria under conditions of stress is the result of a linked series of reactions.
Ozkanca
R
R
Ondokuz Mayis University, Faculty of Arts and Sciences, Department of Biological Sciences, Kurupelit, Samsun, Turkey.
Sahin
N
N
Isik
K
K
Kariptas
E
E
Flint
K P
KP
D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D015169:Colony Count, Microbial; D004396:Coloring Agents / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress; D017319:Photosensitizing Agents / Q000494:pharmacology; D018272:Porins / Q000032:analysis*; D012486:Salmonella typhimurium / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development*; D012623:Seawater / Q000382:microbiology; D014048:Tolonium Chloride / Q000494:pharmacology*
D001425:Bacterial Outer Membrane Proteins; D004396:Coloring Agents; C113724:OmpC protein; C109237:OmpF protein; D016877:Oxidants; D017319:Photosensitizing Agents; D018272:Porins; D014048:Tolonium Chloride; D006861:Hydrogen Peroxide