sodium-dodecyl-sulfate and Poultry-Diseases

Salmonella enterica subsp. enterica serovar Enteritidis is a leading causative agent of gastroenteritis in humans. This pathogen also colonizes the intestinal tracts of poultry and can spread systemically in chickens. Transfer to humans usually occurs through undercooked or improperly handled poultry meat or eggs. The bacterial twin-arginine transport (Tat) pathway is responsible for the translocation of folded proteins across the cytoplasmic membrane. In order to study the role of the Tat system in the infection and colonization of chickens by Salmonella Enteritidis, we constructed chromosomal deletion mutants of the tatB and tatC genes, which are essential components of the Tat translocon. We observed that the tat mutations affected bacterial cell morphology, motility, and sensitivity to albomycin, sodium dodecyl sulfate (SDS), and EDTA. In addition, the mutant strains showed reduced invasion of polarized Caco-2 cells. The wild-type phenotype was restored in all our Salmonella Enteritidis tat mutants by introducing episomal copies of the tatABC genes. When tested in chickens by use of a Salmonella Enteritidis Delta tatB strain, the Tat system inactivation did not substantially affect cecal colonization, but it delayed systemic infection. Taken together, our data demonstrated that the Tat system plays a role in Salmonella Enteritidis pathogenesis.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Caco-2 Cells; Chickens; Edetic Acid; Epithelial Cells; Ferrichrome; Gene Deletion; Genetic Complementation Test; Humans; Locomotion; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Sodium Dodecyl Sulfate; Virulence; Virulence Factors

The hepadnavirus reverse transcriptase binds cotranslationally to the viral pregenomic RNA. This ribonucleoprotein complex is then encapsidated into nascent viral core particles, where the reverse transcriptase copies the viral RNA into DNA. Here we report that 75% of the duck hepatitis B virus reverse transcriptase present in transfected LMH cells does not follow this well-known pathway but rather exists in the cell separate from the core protein or nucleocapsids. The nonencapsidated reverse transcriptase is also abundant in infected duck liver. The nonencapsidated reverse transcriptase exists as a complex set of isoforms that are most likely produced by posttranslational modification. Interestingly, only the smallest of these isoforms is encapsidated into viral core particles. The nonencapsidated reverse transcriptase is bound to a large cellular cytoplasmic structure(s) in a detergent-sensitive complex. The cellular distribution of the reverse transcriptase only partially overlaps that of the core protein, and this distribution is unaffected by blocking encapsidation. These observations raise the possibilities that the metabolic fate of the reverse transcriptase may be posttranscriptionally regulated and that the reverse transcriptase may have roles in the viral replication cycle beyond its well-known function in copying the viral genome.

Topics: Animals; Blotting, Western; Capsid; Cell Fractionation; Chickens; Cytoplasm; Detergents; Ducks; Fluorescent Antibody Technique; Hepadnaviridae Infections; Hepatitis B Virus, Duck; Liver; Microscopy, Confocal; Poultry Diseases; Precipitin Tests; RNA-Directed DNA Polymerase; Sodium Dodecyl Sulfate; Tumor Cells, Cultured

The properties of a complement fixing antigen, EbAg, extracted from erythroblastosis-affected chicken livers are described. The antigen in extracts freed of structural protein is strongly bound by bentonite, but not by barium sulphate. Strongly alkaline solutions of sodium dodecyl sulphate are required to release the antigen from bentonite. Acidification of the detergent solution precipitates the active solution precipitates the active protein. Extraction of heme from the acidified detergent precipitate by methyl-ethyl ketone further purifies the antigen. This acid detergent treatment eliminates the need to use bentonite as a purification step.

Topics: Adsorption; Alpharetrovirus; Animals; Antigens, Viral; Avian Leukosis; Avian Leukosis Virus; Barium Sulfate; Bentonite; Chickens; Liver; Poultry Diseases; Protein Binding; Sodium Dodecyl Sulfate

Topics: Animals; Centrifugation, Density Gradient; Chick Embryo; Electrophoresis, Disc; Electrophoresis, Polyacrylamide Gel; Female; Macromolecular Substances; Male; Muscle Development; Muscles; Muscular Dystrophies; Muscular Dystrophy, Animal; Polyribosomes; Poultry Diseases; Ribosomes; Sodium Dodecyl Sulfate