Quantal Microbiology: a stressed cell phenomenon

The Antiinfluenza Virus Activity of Hydroalcoholic Extract of Olive Leaves

     The influenza viruses are major etiologic agents of human respiratory infections, and inflict a sizable health and economic burden. This study examines the antiinfluenza virus activity of hydroalcoholic extract of olive leaves (OLHE). Olive leaves were collected from gardens around the city of Shiraz, characterized, dried, ground to powder, and its hydroalcoholic extract was prepared. The ...

Effects of Dietary Vitamin C, E and Fat on CD4 to CD8 T Cell Ratios in Peripheral Blood of Heat-stressed Broiler Chicks

The importance of epigenetic modifications in cancer progression

Epigenetics are dynamic and inherited changes in the genome that occur independently of DNA sequencing. This phenomenon requires coherent interaction with various enzymes and other molecular components. Abnormal epigenetic changes can lead to the onset of improper gene expression and the promotion of tumorigenesis. Because epigenetic changes are prone to external and reversible factors, they ar...

Genetic mechanisms underlying the pathogenicity of cold-stressed Salmonella enterica serovar typhimurium in cultured intestinal epithelial cells.

Salmonella encounters various stresses in the environment and in the host during infection. The effects of cold (5°C, 48 h), peroxide (5 mM H2O2, 5 h) and acid stress (pH 4.0, 90 min) were tested on pathogenicity of Salmonella. Prior exposure of Salmonella to cold stress significantly (P < 0.05) increased adhesion and invasion of cultured intestinal epithelial (Caco-2) cells. This increased Sal...

Recovery of culturability of an HOCl-stressed population of Escherichia coli after incubation in phosphate buffer: resuscitation or regrowth?

An Escherichia coli population harvested in exponential phase at about 10(8) cells/ml was treated in phosphate buffer with HOCl at concentrations ranging from 0.4 to 1 mg/liter (7.7 to 19 microM). The HOCl stress resulted in the appearance of three cell subpopulations: a majority of dead (nonrespiring) cells, a few culturable cells (10(2) to 10(4)), and about 10(7) viable but nonculturable cell...