Selective Action of Sodium Cholate-MgCl2 Broth and its Possible Use in Isolation of Salmonellae and Other Enteric Pathogens.

Numerous chemical and biological compounds were screened for possible use as selective inhibitors in Salmonella enrichment broths. Efforts were directed primarily at certain strains of Enterobacter which often interfere with isolation of Salmonella from some food products. Tests of various bile compounds showed that sodium cholate had such a potential and that its selective qualities were enhanced when used in conjunction with MgCl2. Studies were conducted with various proportions of the two compounds in tryptic-soy broth, using pure cultures and mixed cultures in broth alone and in the presence of food material. In general, Salmonella , Arizona , and Shigella were less inhibited that other Enterobacteriaceae . Levels of cholate-MgCl2 which strongly inhibited other organisms also prevented growth of some strains of Salmonella when only a few cells were inoculated into the medium. When the concentrations of sodium cholate and magnesium chloride were adjusted to permit growth of the very low inocula of all 39 test strains of Salmonella , the selectivity was reduced; however, growth and inhibitory results still compared favorably with those of other presently recommended selective broths. In tests using chicken and ground beef as typical food products materials, the need for more than one selective medium was reaffirmed.

Observations on brilliant green agar with H2S indicator.

Several formulations of brilliant green agar with an added H2S indicator were evaluated. Results were optimum with variations of a basic formula consisting of 40 g of tryptic soy agar (Difco), 8 g of lactose, 8 g of sucrose, 80 mg of phenol red, 1 g of sulfanilamide, 1.5 g of ferric ammonium citrate, 5 g of sodium thiosulfate pentahydrate, and 7 mg of brilliant green dye per liter. Brilliant green dye was added after sterilization of the other components This formulation supported good growth of all of 39 strains of Salmonella tested. Normal biochemical types formed pink colonies with black centers, and an H2S-negative S. choleraesuis formed pink colonies without black centers. Of other bacteria tested, only Enterobacter, Klebsiella, and a few Citrobacter strains showed significant growth in 24 h. When lactose was omitted from the formulation, a lactose-fermenting strain formed pink colonies with black centers, and differentiation of Salmonella from the Enterobacter-Klebsiella groups was equally good. Addition of xylose (4.0 g) and L-lysine hydrochloride (5.4 g) to the above formulation improved differentiation between Salmonella and the few Citrobacter strains that grew and produced more intense blackening in Salmonella colonies. Addition of an H2S indicator to brilliant green agar formulations aided in identification of Salmonella colonies, especially in mixtures with other bacteria. These media were judged to give better differentiation of salmonellae from other bacteria than Hektoen agar with added novobiocin (10 mg/liter).

Factors affecting selectivity of brilliant green-phenol red agar for salmonellae.

Commercial brilliant green (BG)-sulfa agar was found to be nonselective toward a test series of Enterobacteriaceae. Various formulations of BG were prepared by using Trypticase soy agar (BBL) as a base. Results were more reproducible when BG dye was added after sterilization than before. Sulfonamides improved selectivity as compared with brilliant green alone. Sulfanilamide (SN) was slightly more selective for salmonellae than other sulfonamides tested. Bile salts and sodium dodecyl sulfate markedly reduced the toxicity of BG to all the test bacteria. Enterobacter strains were most difficult to inhibit. A combination of 5 mg of BG and 1 g of SN/liter prevented growth of Proteus mirabilis and Escherichia coli and retarded growth of Enterobacter strains. The BG-SN agars were superior in selectivity to a series of commercial agars tested, and numbers of salmonellae recovered on BG-SN agar and Trypticase soy agar (BBL) were the same. Brilliant green agars with various degrees of selectivity are described.

The health care safety net: money matters but savvy leadership counts.

The nation's health care safety net--heavily reliant on external funding and support--is uniquely vulnerable to shifting and often adverse market and policy conditions. While adequate funding is essential to ensuring safety net providers can care for low-income people, the Center for Studying Health System Change (HSC) has identified a number of other factors key to building and maintaining viable community safety nets. Throughout the four rounds of HSC's Community Tracking Study (CTS) site visits, researchers have found that strong political and organizational leadership, community support, collaboration and business acumen have helped safety net providers build capacity and improve care coordination for low-income and uninsured people. These characteristics and business strategies have strengthened many community safety nets, better preparing them to weather current economic problems and providing a road map for the potentially tougher times ahead.

[Experiences with a hydroxyapatite-coated, macroporous surface hip endoprosthesis]. / Erfahrungen mit einer Hydroxylapatit-beschichteten, makroporös strukturierten Hüftendoprothese.

INTRODUCTION: Cementless hip arthroplasty is not completely satisfactory--even with macroporous structured surface. Medium term results are sometimes disappointing because of insufficient secondary stability. Thus our aim was to improve fixation by additional coating with hydroxyapatite. METHODS: 200 consecutive patients who had hydroxyapatite-coated cementless hip replacement with a macroporous hip prosthesis (09/92-03/96) were studied prospectively. All patients were included in a prospective follow up schedule according to the criteria of Johnston et al. As measure of clinical outcome we calculated Harris Hip Score as well as Enghs Score to assess radiologic fixation and stability. RESULTS: 91% could be followed up regularly. No revision because of aseptic loosening had to be done. Analysis of clinical results showed almost painless patients from early after the operation--especially no thigh pain. Average HHS after 2 years was 97. Radiological evaluation showed early and complete osteointegration of all components. According to Engh-Score they are stable and well fixed. CONCLUSION: HA coated macroporous implants provide some striking advantages, which encouraged us to continue with this system. By early and secure bony ingrowth a fibrous interface is avoided and thereby also long-lasting thigh pain.

Effect of heat on the antimicrobial activity of brillant green dye.

Antimicrobial activity of brilliant green dye in Trypticase soy broth (BBL) is reduced and ultimately destroyed by prolonged autoclaving at 121 C. Loss of antimicrobial activity is accompanied by decolorization of the dye. This is consistent with other evidence that antimicrobial activity of brilliant green resides in the colored dye ion. The dye is not decolorized when heated in distilled water or peptone, but is decolorized by heating in glucose, glycine, or sodium dodecyl sulfate, showing that decolorization results from reaction with components of the medium. To ensure optimal results, it is recommended that bacteriological media be sterilized by heat prior to addition of brilliant green dye.

Bacteriological examination of commercial precooked Eastern-type turkey rolls.

Studies were conducted to ascertain the bacteriological condition of commercially cooked Eastern-type (foil-wrapped-oven roasted) turkey rolls during processing and storage. After 2 weeks at 5 C, numbers of aerobes on the surface of rolls, in slices, and in whole rolls reached levels of from 1 to 10 million per cm(2) or per g. In stored whole rolls, coliform and enterococcus counts ranged, respectively, from about 10,000 to more than 1 million per g and from < 100 to more than 1 million per g. Postcooking processing operations in two plants did not significantly affect the total count of turkey rolls. Eight of 28 rolls obtained after handling and packaging contained coagulase-positive staphylococci.

Mapping an antibody-binding site and a T-cell-stimulating site on the 1A protein of respiratory syncytial virus.

A synthetic peptide modeled on residues 45 to 60 of the 1A protein of respiratory syncytial (RS) virus [1A(45-60)] was constructed and used for immunization of mice and rabbits. The immunoglobulin G fraction of the resulting rabbit antibody, purified on protein A-Sepharose, immunoprecipitated from RS-infected HEp-2 cells a protein with a molecular size of approximately 9.5 kilodaltons, which corresponds to the previously published molecular size of the 1A protein (Y. T. Huang, P. L. Collins, and G. W. Wertz, Virus Res. 2:157-173, 1985). To investigate the T-cell-inducing properties of 1A(45-60), six strains of mice were immunized and their popliteal lymph node cells were tested for proliferation upon restimulation with peptide in vitro. The lymph node cells of all six strains of mice were responsive to restimulation with 1A(45-60) and showed high- and low-responder strain variation. These peptide-primed lymph node cells also proliferated upon in vitro restimulation with RS virus-infected cells. Correlation of proliferation with interleukin 2 production suggested that the responding lymphocytes were T-helper cells. The antibody-binding and T-cell-stimulating sites of 1A were mapped by constructing a series of overlapping synthetic peptides and testing each for ability to react with antiserum prepared by immunization of BALB/C mice with free peptide 1A(45-60) or for ability to restimulate proliferation in 1A(45-60)-primed lymph node cells of BALB/C mice. Human antibody, obtained during confirmed RS virus infection, was similarly tested with the truncated peptides. Antibody-binding activity was reduced after truncation from the carboxy terminus, and a binding site was mapped to residues 51 through 60, the smallest peptide tested. T-cell-stimulating activity in mice was relatively resistant to truncation from the carboxy terminus and sensitive to truncation from the amino terminus. The smallest region which retained significant T-cell-stimulating activity mapped to residues 46 through 56. However, addition of the naturally occurring Cys at residue 45 and extension of the C terminus to residue 62 resulted in maximum T-cell-stimulating activity of the peptide. These data define both a T-cell epitope and a B-cell epitope of the 1A protein of RS virus and suggest that the carboxy terminus of 1A contains a B-cell epitope, involving residues 51 through 60, which is recognized during natural human infection.

Isolation and characterization of native human renin derived from Chinese hamster ovary cells.

Transfection of Chinese hamster ovary (CHO) cells with a plasmid containing the cDNA for human preprorenin has provided cell lines that secrete 15 mg of native prorenin per liter of culture medium. Tryptic activation of the prorenin occurs by selective cleavage of the Arg66-Leu67 bond (numbering as in preprorenin). The renin product, purified in a single step and in high yield by affinity chromatography, is fully stable for as long as 8 months when stored in solution at 4 degrees C and pH 6.5. Purity of the renin was judged to be greater than 95% by gel electrophoresis, compositional and N-terminal sequence analyses, and specific enzyme activity. An important aspect of the present work is the development of a direct assay for renin which permits accurate and reproducible evaluation of enzyme units and kinetic parameters. Application of methods described herein, combined with appropriate scale-up fermentation capabilities, provides the means for generating gram quantities of human renin and its zymogen.

Production of an antibody to arterial fatty acid-binding protein (FABP) using a synthetic peptide as the antigen.

1. A procedure is described for the preparation of an antibody to arterial FABP using a synthetic peptide as an antigen. In order to locate a highly conserved region located on the outer surface of FABP, computer analysis of primary and secondary structures of several proteins from the FABP family was undertaken and a 24 amino acid sequence beginning at the fifth position from the N-terminus of rat heart FABP was chosen. 2. The synthetic peptide consisted of eight replications of the 24 amino acid sequence individually attached to the alpha and epsilon amino groups of each terminal lysine on an octalysine branched peptide. 3. Antibody to the synthetic antigen was raised in New Zealand rabbits. Western analysis was conducted and detection was accomplished by using goat-anti-rabbit second antibody conjugated to alkaline phosphatase. 4. The antibody produced from the previously described peptide, recognized purified rat heart FABP and demonstrated a high positive correlation (r = 0.96) when known concentrations of purified hFABP were plotted against densitometric measurement of the bands. 5. Additionally, the antibody recognized FABP from the 104,000 g supernates of rat atrial and arterial tissue fractionated by a Sephadex G-75 column. 6. Therefore, the antibody produced from this particular protocol employing a synthetic peptide can be utilized qualitatively and quantitatively in the analysis of the heart and arterial FABP content.

The chemical structure of prostaglandin X (prostacyclin).

The chemical structure of prostaglandin X, the anti-aggregatory substance derived from prostaglandin endoperoxides, is 9-deoxy-6, 6alpha-epoxy-delta5-PGF1alpha. The stable compound formed when prostaglandin X undergoes a chemical transformation in biological systems in 6-keto-PGF1alpha. Prostaglandin X is stabilized in aqueous preparations by raising the pH to 8.5 or higher. The trivial name prostacyclin is proposed for 9-deoxy-6, 9alpha-epoxy-delta5-PGF1alpha.