sodium-dodecyl-sulfate and Streptococcal-Infections

Streptococcus suis serotype 2 is an important zoonotic pathogen causing severe infections in pigs and humans. The pathogenesis of S. suis 2 infections, however, is still poorly understood. Spx proteins are a group of global regulators involved in stress tolerance and virulence. In this study, we characterized two orthologs of the Spx regulator, SpxA1 and SpxA2 in S. suis 2. Two mutant strains (ΔspxA1 and ΔspxA2) lacking the spx genes were constructed. The ΔspxA1 and ΔspxA2 mutants displayed different phenotypes. ΔspxA1 exhibited impaired growth in the presence of hydrogen peroxide, while ΔspxA2 exhibited impaired growth in the presence of SDS and NaCl. Both mutants were defective in medium lacking newborn bovine serum. Using a murine infection model, we demonstrated that the abilities of the mutant strains to colonize the tissues were significantly reduced compared to that of the wild-type strain. The mutant strains also showed a decreased level of survival in pig blood. Microarray analysis revealed a global regulatory role for SpxA1 and SpxA2. Furthermore, we demonstrated for the first time that Spx is involved in triggering the host inflammatory response. Collectively, our data suggest that SpxA1 and SpxA2 are global regulators that are implicated in stress tolerance and virulence in S. suis 2.

Topics: Animals; Bacterial Proteins; Blood; Cytokines; Female; Gene Deletion; Hydrogen Peroxide; Inflammation; Mice; Mice, Inbred BALB C; Oligonucleotide Array Sequence Analysis; Sodium Chloride; Sodium Dodecyl Sulfate; Streptococcal Infections; Streptococcus suis; Stress, Physiological; Swine; Transcription Factors; Transcription, Genetic

The targets for normal human serum antibodies that react with proteins c(alpha) and R4 isolated from group B streptococci (GBS; Streptococcus agalactiae) have been studied and compared with the targets for murine monoclonal and rabbit polyclonal antibodies raised against these proteins. The proteins were extracted by trypsin digestion and purified by precipitations and gel filtration and testing was based on enzyme immunoassays. The immune antibodies showed specificity for the corresponding protein, targeted that protein in Western blotting and recognized their targets after heat treatment (100 degrees C) of the proteins. Human antibodies in a commercial gammaglobulin preparation targeted a site(s) common to c(alpha) and R4. This target failed to bind the antibodies in Western blotting and was destroyed by heating. c(alpha)- and R4-reactive antibodies in sera from healthy pregnant women recognized the common, heat-labile determinant(s), but contained little or no antibodies against the heat-stable c(alpha)- or R4-specific determinants. These results are consistent with the notions that (i) the normal human antibodies and the immunization-induced animal antibodies targeted different sites on the c(alpha) and R4 proteins and that (ii) the natural human antibodies targeted conformational epitopes and the immune antibodies targeted linear epitopes. These findings are important for further clarification of GBS immunology and immunoprotection in humans.

Topics: Animals; Antibodies, Bacterial; Antibodies, Monoclonal; Antibody Specificity; Antigens, Bacterial; Bacterial Proteins; Blotting, Western; Enzyme-Linked Immunosorbent Assay; Epitopes; Female; Hot Temperature; Humans; Immune Sera; Mice; Mice, Inbred BALB C; Norway; Pregnancy; Pregnancy Complications, Infectious; Protein Denaturation; Rabbits; Sodium Dodecyl Sulfate; Streptococcal Infections; Streptococcus agalactiae; Zimbabwe

Two new teat dip formulations were evaluated against Streptococcus agalactiae and Staphylococcus aureus in half-udder, experimental challenge studies. The first product contained a combination of 1.9% linear dodecyl benzene sulfonic acid - .55% iodophor. Incidence of infection was reduced 52.7 and 70.7% for Streptococcus agalactiae and Staphylococcus aureus in dipped quarters compared to undipped controls. The second formulation was a barrier-type product consisting of milk protein solubilized with lauryl sulfate, a surface active detergent and 4.8% glycerin. Rates of infection were reduced 60.3 and 67.9% for Streptococcus agalactiae and Staphylococcus aureus.

Topics: Animals; Cattle; Disinfection; Fatty Alcohols; Female; Iodine; Iodophors; Mammary Glands, Animal; Mastitis, Bovine; Sodium Dodecyl Sulfate; Staphylococcal Infections; Staphylococcus aureus; Sterilization; Streptococcal Infections; Streptococcus agalactiae

Topics: Erythromycin; Humans; Liver; Pharyngitis; Sodium Dodecyl Sulfate; Streptococcal Infections