sodium-dodecyl-sulfate and Staphylococcal-Infections

The combination of levulinic acid (LVA) and sodium dodecyl sulfate (SDS) in recent years has shown a considerable potential to use as an antimicrobial intervention. The objectives of this study were to evaluate the antimicrobial efficacy of the combination against Staphylococcus aureus in both planktonic and biofilm states and to investigate the transcriptional changes in S. aureus biofilms coincubated with sublethal concentrations of LVA and/or SDS. The minimum inhibitory concentrations (MICs) of LVA and SDS determined by the microdilution method were 3.125 and 0.039 mg/mL, respectively. An additive bacteriostatic interaction (fractional inhibitory concentration index = 1) between the two compounds was observed by the checkerboard assay, whereas a synergistic bactericidal activity was displayed by the time-kill assay. The biomass and viable cells in the biofilms were reduced by both antimicrobials either alone or in combination in a dose-dependent manner. Transcriptomics indicated that more differentially expressed (DE) genes were observed in the biofilm treated with SDS (103 up- and 205 downregulated DE genes) and LVA + SDS (187 up and 162 down) than that coincubated with LVA (34 up and 32 down). The SDS and LVA + SDS treatments mainly affected the expression of genes responsible for cell surface proteins, virulence factors, adhesins, and capsular polysaccharides. Both the antibiofilm assay and the transcriptomics indicated that SDS, not LVA, was the major chemical contributing to the antibacterial efficacy of the combination. This study reveals the behavioral responses and protective mechanisms of S. aureus to LVA and SDS applied individually or in combination.

Topics: Anti-Bacterial Agents; Biofilms; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Sodium Dodecyl Sulfate; Staphylococcal Infections; Staphylococcus aureus; Transcriptome

Mixture based synthetic combinatorial libraries offer a tremendous enhancement for the rate of drug discovery, allowing the activity of millions of compounds to be assessed through the testing of exponentially fewer samples. In this study, we used a scaffold-ranking library to screen 37 different libraries for antibacterial activity against the ESKAPE pathogens. Each library contained between 10000 and 750000 structural analogues for a total of >6 million compounds. From this, we identified a bis-cyclic guanidine library that displayed strong antibacterial activity. A positional scanning library for these compounds was developed and used to identify the most effective functional groups at each variant position. Individual compounds were synthesized that were broadly active against all ESKAPE organisms at concentrations <2 μM. In addition, these compounds were bactericidal, had antibiofilm effects, showed limited potential for the development of resistance, and displayed almost no toxicity when tested against human lung cells and erythrocytes. Using a murine model of peritonitis, we also demonstrate that these agents are highly efficacious in vivo.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Cell Line; Drug Discovery; Guanidines; Humans; Mice; Small Molecule Libraries; Staphylococcal Infections; Staphylococcus aureus

Extracellular antigens as well as cell wall extracts of 4 S. aureus strains isolated from different kinds of infection were analysed by Western-Blott technique. Materials obtained in two systems of bacteria cultivation (with and without aeration) were compared. Four systems of PAGE (native conditions, with 8.0 M urea, with SDS and SDS after previous reduction of the material with 2-mercaptoethanol) were compared in order to get the best differentiation of proteins and antigens. Immunological reactivity of the antigens mixture with two human sera: highly positive (with three S. aureus antigens in ELISA) from patient with staphylococcal sepsis and negative (from blood donor) were analysed. The best results were obtained after reduction of the cell wall extracted material in SDS-PAGE. The different protein patterns depending on the strain and the method of bacteria cultivation were observed. The standardisation of Western-Blott technique was performed, including titration of the sera to get the best differentiation of the antigens. The difference in immunological reactivity of the positive and negative sera with staphylococcal antigens mixture showed rather quantitative than qualitative character.

Topics: Air; Antigens, Bacterial; Blotting, Western; Culture Media; Electrophoresis, Polyacrylamide Gel; Humans; Immune Sera; In Vitro Techniques; Mercaptoethanol; Sepsis; Sodium Dodecyl Sulfate; Staphylococcal Infections; Staphylococcus aureus

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: Anti-Bacterial Agents; Cadmium; Cross Infection; Ethidium; Microbial Sensitivity Tests; Proflavine; R Factors; Sodium Dodecyl Sulfate; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Anti-Bacterial Agents; Chloramphenicol; Mice; Oxytetracycline; Penicillin Resistance; Penicillins; R Factors; Sodium Dodecyl Sulfate; Staphylococcal Infections; Staphylococcus aureus; Suppuration; Transduction, Genetic

Topics: Child; Demeclocycline; Erythromycin; Humans; Sodium Dodecyl Sulfate; Staphylococcal Infections