Biomedical subjects

H Brandis

Publications and source records attributed to H Brandis.

At least 19 recordsLinked to original sources

PubMed1988

A comparison between methods of identification and serotyping of encapsulated strains of Haemophilus influenzae.

Seven methods of serotyping of Haemophilus influenzae were evaluated. Comparing slide agglutination, staphylococcal coagglutination, latex agglutination, counterimmunoelectrophoresis, immunofluorescence, capsular swelling, and cultivation on antiserum agar the commercial coagglutination test was most reliable, most rapid, and easiest to perform. To identify all six serotypes this coagglutination test had to be combined with slide agglutination. With most methods best results were achieved by using cultures incubated at 37 degrees C for 6 h. As nonencapsulated strains often agglutinated unspecifically, selection of probably typeable strains was useful. Differentiation with help of colonial morphology and opalescent growth was facilitated by cultivation on Brain Heart Infusion (BHI) Chocolate Agar and testing of growth factor requirements on translucent BHI Agar with strips containing the growth factors V, X, and VX, respectively. In broth turbid growth was a hint for encapsulation. Nigrosin staining, a negative capsule staining, proved to be useful if specific antisera are not available. From 252 clinical isolates of H. influenzae 216 were not typeable. 36 strains could be serotyped. 27 (75%) belonged to serotype b, 6 (16.6%) were serotype e, 3 (8.3%) were serotype f. Serotype e and f were most difficult to identify. Spectrum of patients and diseases were corresponding to the findings of other authors. Less well-known infections like cellulitis (erysipelas of the cheeks) and arthritis were observed, too. Rapid identification of at least H. influenzae type b could render treatment in some cases more effective by early application of a suitable antibiotic.

Agglutination Tests↗

PubMed1987

Correlation between enterotoxigenicity, tested by different ELISA-techniques, antibiotic resistance patterns and phage groups of Staphylococcus aureus strains.

A group of 596 Staphylococcus aureus strains isolated from various clinical sources or implicated in food poisoning was investigated for enterotoxins A and B (SEA and SEB) production. The conventional ELISA techniques (competitive and sandwich ELISA) were compared with a newly developed avidin-biotin ELISA in their ability to detect the enterotoxins. The avidin-biotin system was not remarkably influenced by SPA up to 10 micrograms/ml. A semi-quantitative competitive ELISA for the detection of staphylococcal protein A (SPA) in culture supernatants was carried out in parallel. The strains isolated in cases of food poisoning showed different antibiotic resistance patterns, whereas the strains from clinical sources were selected for either methicillin or penicillin resistance only. The strains isolated in food poisoning outbreaks (FP strains) were enterotoxin A positive in 22%, enterotoxin B positive in 11%, and SEA + SEB positive in 9% of cases. The strains with resistance to penicillin only (PER strains) produced SEB in 26%, SEA in 14%, and both toxins in 7% of the cases. The methicillin-resistant strains (MCR strains) produced SEA in 59% of cases, whereas SEB was produced in 6% only (SEA + SEB: 20%). 37% of the SEA producers belonged to phage group III (SEB: 30%; SEA + SEB: 25%) and 12% (SEB: 11%; SEA + SEB: 9%) to phage group I. 26% of the SEA-producing and 37% of the SEB-producing strains (SEA + SEB: 23%) were non-typable.

Anti-Bacterial Agents↗

PubMed1987

Biotyping, serotyping and phage typing of Streptococcus faecalis isolated from dental plaque in the human mouth.

Thirty Streptococcus faecalis isolates from mixed dental plaque samples were classified into four groups on the basis of biotype, tetracycline susceptibility, phage type and serotype combinations. The organisms were from patients on haemodialysis, from staff of the dialysis unit, and from controls. Three biotypes were distinguished by seven biochemical tests: production of acid from inositol, sucrose and xylose; rapid or delayed production of acid from sorbitol; gelatin liquefaction; and production of alkaline phosphatase and beta-galactosidase. With a set of eight typing antisera for S. faecalis, 15 strains were non-typable, 12 were serotype 1 and three were serotype 19. With a set of 17 bacteriophages specific for S. faecalis, all of the oral isolates were typable; 40% were lysotype I1 and the remainder lysotype V6b. On the basis of biotype-serotype-phage-type combinations, indications of possible spread of strains between haemodialysis patients and dialysis unit staff were obtained. Biotyping and serotyping of 13 German isolates of S. faecalis of phage type I1 from four clinical sources and tripartite typing of three control strains provided additional evidence for the potential of biotyping in distinguishing between strains of identical serotype and phage type. One oral isolate of S. faecium was of phage type XX. None of the oral isolates of S. faecalis, of which 14 exhibited delayed sorbitol fermentation, reacted with group-G streptococcal grouping reagents or antiserum. Slow sorbitol fermentation does not appear to be a definitive phenotypic marker for S. faecalis strains possessing antigens that react with both group-D and group-G grouping reagents.

Adolescent↗

PubMed1986

An avidin-biotin ELISA for the detection of staphylococcal enterotoxins A and B.

The avidin-biotin system was incorporated into the enzyme-linked immunosorbent assay (ELISA) to establish a new detection method for staphylococcal enterotoxins A and B in culture supernatants. Staphylococcal protein A (SPA) does not interfere significantly with the procedure. The test shows good sensitivity for the toxins and the ease and rapidity with which the assay can be performed make it a valuable tool for the routine detection of enterotoxins.

Alkaline Phosphatase↗

PubMed1985

Contribution of immune interferon (IFN-gamma) in lymphokine-induced anti-toxoplasma activity: studies with recombinant murine IFN-gamma.

Recombinant E. coli-derived murine interferon gamma (cDNA IFN-gamma) per se induced resident mouse peritoneal macrophages (MPM) and mouse embryo cells to exert marked antitoxoplasma activity. This capacity of cDNA IFN-gamma was abrogated by a specific antiserum to cDNA IFN-gamma which could only neutralize the antiviral activity mediated by this product, whereas a rabbit antiserum directed against murine IFN-alpha/beta proved ineffective in neutralizing these functions. It has been found that rabbit antiserum to cDNA IFN-gamma could also neutralize IFN-gamma-mediated antiviral activity present in crude lymphokine-enriched supernatants of antigen-stimulated toxoplasma-sensitized spleen cells (Toxo-LK) but proved ineffective in abolishing the capacity of Toxo-LK to trigger macrophage anti-toxoplasma activity. The data obtained suggest that macrophage anti-toxoplasma activity induced by Toxo-LK may be an interplay of multiple factor(s) and that Toxo-LK preparations contain soluble factor(s) other than IFN-gamma, which can induce macrophages to kill intracellular Toxoplasma. Experiments in which crude Toxo-LK preparations were incubated with lectin concanavalin A (Con A) showed that this treatment resulted in a block of anti-toxoplasma arming factor(s) activity, as well as a significant reduction of IFN-gamma-mediated antiviral activity present in Toxo-LK. By contrast, no significant difference was observed in the macrophage anti-toxoplasma activity mediated by Con A or untreated cDNA-IFN-gamma.

Animals↗

PubMed1985

Species distribution of coagulase-negative staphylococci isolated from clinical sources.

The distribution of coagulase-negative staphylococcal species from clinical material was investigated in order to detect possible tropisms. 398 strains of staphylococci (336 coagulase-negative and 62 coagulase-positive strains) and 3 micrococcus strains were isolated. Differentiation between the two genera was achieved by testing sensitivity to lysostaphin and anaerobic growth in thioglycolate. Four S. hominis strains reacted like micrococci in these tests. Staphylococci were classified according to the Kloos and Schleifer biotyping scheme in a modified way on microtitre plates. Additionally coagulation and reduction of methylene blue milk were determined and the test proved to be useful. Identified coagulase-negative species included S. epidermidis (205 strains), S. hominis (64), S. haemolyticus (35), S. warneri (15), S. capitis (5), S. simulans (6), S. saprophyticus (5), and S. species (1). A high predominance of S. epidermidis was found among isolates from nasopharyngeal (91%) and tracheobronchial (80%) tracts and most other localizations. A different distribution of species was observed in urine and vaginal swabs where non-S. epidermidis species accounted for over 50% of identified strains. The majority of S. hominis and S. haemolyticus strains was isolated from these sources. S. simulans, like S. saprophyticus was found in urine specimens only and occurred predominantly in women of the sexually active age.

Anti-Bacterial Agents↗

PubMed1985

Interaction of the staphylococcin-like peptide Pep 5 with cell walls and isolated cell wall components of Gram-positive bacteria.

Unlike bacteriocins of Gram-negative bacteria, the strongly basic staphylococcin-like peptide Pep 5 lacked specific receptor mediated binding to sensitive Gram-positive bacteria. Studies with whole cells, purified cell walls, teichoic acids, and lipoteichoic acids strongly suggested that it binds reversibly via electrostatic interaction to negatively charged groups. Thus, Pep 5 binding could be reversed by sufficiently high concentrations of monovalent (K+, 150-250 mM) and divalent (Ca2+, 15-30 mM) cations (Fig. 1, 2) and by low pH (pH 2), where Pep 5 binding groups are protonated. Cells of Staphylococcus cohnii 22 with a reduced teichoic acid content showed a reduced Pep 5 binding capacity (Fig. 3). The results indicate that teichoic, teichuronic, and lipoteichoic acids are the unspecific cell wall binding sites for Pep 5.

Adsorption↗

PubMed1985

Screening of clinical S. aureus-isolates for the production of exfoliative toxin. A methodological study.

Screening S. aureus-isolates for the production of exfoliative toxin (ET) and discrimination between its two known variants (ETA, ETB) by immunodiffusion (ID), isoelectric focusing (IEF) and animal experiment were assessed methodologically using isolates from a patient with bullous impetigo and a patient with Ritter von Rittershain's disease. Only by animal assay one of the isolates could be identified as ET-producer. ID was used for the discrimination between ETA and ETB. It is concluded that the in-vivo assay for ET-production using live staphylococci can not yet be replaced by ID and IFE and that in patients with staphylococcal scalded skin syndrome swabs should be taken from multiple lesions und all S. aureus isolates obtained should be screened for ET-production to prevent false-negative results. Lysotyping alone gives no proof of ET-production since types II 55/71 and II 3A/3C do not produce ET in all cases and toxinogenic S. aureus strains of phage groups I and III have been described.

Adolescent↗

PubMed1985

Purification and properties of LIQ 4, an antibacterial substance produced by Streptococcus faecalis var. liquefaciens K4.

An antibacterial substance (LIQ 4) produced by Streptococcus faecalis var. liquefaciens K 4 was isolated in extracellular and cell associated form. It markedly inhibited the growth of Gram-positive bacteria, whereas only a few Gram-negative bacteria were susceptible. LIQ 4 was purified by hydrophobic chromatography (Servachrome XAD-2; octyl-Sepharose CL-4B; Sephadex LH 60) and Sephacryl S-200. TLC yielded a fluorescent spot as the active component and several inactive ninhydrin-positive substances. These contaminating peptides strongly adsorbed to LIQ 4 and could only be removed by repeated reversed phase HPLC. Furthermore, HPLC separated LIQ 4 into seven closely related substances. All showed strong fluorescence under UV light, stained yellow with ninhydrin, and contained aspartate and lysine after acid hydrolysis. The molecular weight was estimated by Amicon ultrafiltration to be less than 2000. LIQ 4 was stable at 80 degrees C (30 min) and pH 2, but considerably inactivated above pH 8. It was apparently affected by proteolytic enzymes, but the activity could be fully restored upon heating.

Anti-Bacterial Agents↗

PubMed1985

Structural similarities of the staphylococcin-like peptide Pep-5 to the peptide antibiotic nisin.

The staphylococcin-like peptide Pep-5 was shown to be a complex mixture of closely related and strongly basic peptides. Five peptides were purified by high-pressure liquid chromatography on reversed-phase and gel filtration columns and further characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and amino acid analysis. Four peptides have molecular weights of ca. 3,500, whereas one is of double size. All contain the thioether amino acid lanthionine and a large number of lysine residues per molecule. The amino terminus of the main active peptide is blocked; the carboxy-terminal end is formed by a lysine residue. The data obtained for Pep-5 suggest striking structural similarities to the peptide antibiotics nisin and subtilin.

Alanine↗

PubMed1985

[Significance of Clostridium septicum as a cause of gas edema].

Gas gangrene caused by Clostridium septicum is relatively rare. In this paper 15 cases are described observed within the last 5 years. In 3 cases the gas gangrene was acquired exogenously. The other cases were endogenous infections. 9 of these cases were associated with colon carcinoma. C. septicum gas gangrene has a high lethality rate: 11 of the 15 patients died from the infection.

Aged↗

PubMed1985

[Typing of Streptococcus faecalis and Streptococcus faecium strains with bacteriophages].

With a set of 17 bacteriophages specific for Streptococcus faecalis and a set of 7 bacteriophages specific for Streptococcus faecium 441 strains of S. faecalis and 53 strains of S. faecium were typed. The species identification was done by means of the API 20 STREP system. For S. faecalis 22 and for S. faecium 12 lysotypes were found. Among S. faecalis strains lysotype V6b was most common (27%), followed by the lysotypes XV (9,5%), XIII1 (7%), II1 (5,7%), and I1 (4,3%). These 5 lysotypes comprised 54% of all 441 strains. 21% of the strains of S. faecalis and 6 from 53 strains of S. faecium were untypable. Strains of S. faecium were most frequently isolated from faeces and in rare cases from urine. To the contrary 50% of the S. faecalis strains were isolated from urine. There was no correlation between special lysotypes and age of the patients or the source of specimen. The results of phage typing of several strains from one patient, and especially of strains from mothers and their newborns suggest the usefulness of the typing system to clarify epidemiological questions.

Adolescent↗

PubMed1984

Topographical localization of distinct antigenic domains of Toxoplasma gondii with the aid of monoclonal antibodies.

In the present study, a panel of six individual hybridoma derived antibodies produced against the BK strain of Toxoplasma gondii were evaluated for their reactivity in an immunofluorescence test. Each of the six monoclonal antibodies demonstrated a unique pattern of fluorescence localized to distinctive regions on the toxoplasmas. Although all of the six detected antigenic determinants which were shared by at least four different T. gondii strains, monoclonal antibody TG-E4A17 has disclosed hitherto unrecognized population differences among the BK or PH strain parasites. The fact that some of the antigenic molecules are restricted to distinct regions of the toxoplasmas may have implications in the infections process/immune response.

Animals↗

PubMed1984

Analysis of Ia-antigen(s) positive macrophages in experimental murine toxoplasmosis.

The present study has demonstrated marked increase in the relative percentage of Ia-positive macrophages among the peritoneal macrophage population(s) of BALB/c mice infected intraperitoneally with Toxoplasma gondii or when chronically infected mice were rechallenged with Toxoplasma. The observed increase in Ia-positive peritoneal macrophage numbers coincided with the appearance of interferon-gamma (IFN-gamma) in the sera of infected mice. The appearance of elevated serum IFN-gamma titer was a temporary event but the increased percentage of Ia-positive macrophages persisted. The data presented have documented that antigen-specific proliferation response of vigorously purified Toxoplasma-sensitized T-cells is dependent upon Ia-bearing macrophages. This model is useful for future studies into various aspects of the interaction(s) between parasite antigens and Ia-antigen(s) at the macrophage surface for successful recognition of antigen-specific T-cells.

Animals↗

PubMed1984

Analysis of the roles of immune interferon (IFN-gamma) and colony-stimulating factor(s) in the induction of macrophage anti-toxoplasma activity.

Lymphokine-enriched, cell-free supernatants from specific antigen-stimulated spleen cells of toxoplasma-immune mice lacking detectable anti-toxoplasma antibody could generate effective anti-toxoplasma activity within normal (non-immune) murine peritoneal macrophages. Such supernatants also contained high levels of IFN-gamma as well as Ia-antigen(s) inducing activity. Supernatants from ConA stimulated normal (non-immune) spleen cells with high IFN-gamma, as well as CSF-containing supernatants from lung explants, lacked the capacity to induce anti-toxoplasma activity within peritoneal macrophages. ConA-stimulated spleen cell supernatants with high IFN-gamma titers but not CSF-enriched lung explant supernatants could induce the expression of macrophage cell surface Ia-antigen(s). Based on the results of our experiments, we have been able to eliminate the direct (by itself) role of IFN-gamma or CSF in generating macrophage anti-toxoplasma activity. However, the possibility that molecules like IFN-gamma or CSF synergize together with other immune spleen cell-derived factor(s) in the generation of effective macrophage anti-toxoplasma activity has not been ruled out.

Animals↗

PubMed1984

Plasmid involvement in production of and immunity to the staphylococcin-like peptide Pep 5.

The staphylococcin-like peptide Pep 5 is produced by the penicillin resistant strain Staphylococcus epidermidis 5. This strain is immune to the peptide. Plasmid analysis of S. epidermidis 5 by agarose gel electrophoresis and electron microscopy demonstrated five plasmids with molecular weights ranging from 5.8 X 10(6) to 29 X 10(6). Variants of S. epidermidis 5 not producing Pep 5 or which had become penicillin sensitive were induced by various curing treatments. Strains lacking the 13.9 X 10(6) mol. wt plasmid (pED502) had lost penicillin resistance, and those lacking the 12.3 X 10(6) mol. wt plasmid (pED503) failed to produce Pep 5. pED503 is also responsible for the immunity of the producer cell to Pep 5. Plasmid pED502 could be transformed into S. aureus RN 981 which then became resistant to penicillin. pED503 could not be transformed into S. aureus RN 981, but could be transformed into S. epidermidis 5 variants previously cured of this plasmid; the transformants then regained the properties of Pep 5 production and immunity.

Bacteriocins↗

PubMed1984

Isolation and mode of action of a staphylococcin-like substance active against gram-positive and gram-negative bacteria.

Screening of non-phage group II Staphylococcus aureus strains for antagonistic substances revealed one particular strain, S. aureus D91, to excrete a substance with a wide spectrum of activity; both Gram-positive and Gram-negative bacteria were susceptible. The staphylococcin-like substance D91 produced by this strain was partially purified by column chromatography on Sephadex G-50, DEAE-cellulose, Phenyl Sepharose CL-4B and Sephadex G-200. A molecular weight of 76000 was estimated by gel filtration. The activity was heat sensitive but was not affected by hydrolytic enzymes except for pronase. The protein character of substance D91 was confirmed by gel electrophoresis and subsequent staining with Coomassie blue. The action exerted on sensitive bacteria was bacteriostatic rather than bactericidal. Biosynthesis of DNA, RNA, protein and polysaccharides were inhibited simultaneously in both Escherichia coli and Staphylococcus aureus. Active transport of glutamic acid was stopped in both S. cohnii and E. coli, whereas glucose uptake was inhibited in E. coli only. The substance induced a slow efflux of 86Rb+ from proloaded cells of S. cohnii and E. coli. The antagonistic activity of S. aureus D91 was eliminated by ethidium bromide at a rate of 47.6% suggesting that plasmids may be involved in its production.

Bacteriocins↗

PubMed1983

Hybridoma-derived monoclonal immunoglobulin M antibodies to Legionella pneumophila serogroup 1 with diagnostic potential.

Mouse hybridomas were isolated by fusing P3-X63-Ag 8.653 myeloma cells with spleen cells from mice that had been repeatedly immunized with Legionella pneumophila serogroup 1 organisms. In one fusion, three independent hybridoma cultures which secreted antibodies that reacted with the immunizing strain in the indirect immunofluorescent-antibody test were selected for cloning. Representative continuously growing clones, one of each hybridoma, which remained stable in producing high-titer antibodies were examined in detail. Extensive specificity tests revealed that these hybridoma-derived monoclonal antibodies were specifically directed against L. pneumophila serogroup 1 organisms and showed no cross-reactions in the indirect immunofluorescent-antibody test either with the other known serogroups of L. pneumophila or with other unrelated bacterial species. The three monoclonal antibodies F4/CB5/K18, F/4CB5/K104, and F4/JD3.8/K101 belonged to the immunoglobulin M class and were capable of agglutinating serogroup 1 organisms of L. pneumophila exquisitely. These monoclonal antibodies against L. pneumophila with defined fine specificity should enable purification and subsequent analysis of the corresponding antigenic determinant(s) and can also be used for the preparation of unlimited supplies of standard diagnostic reagents for the identification of L. pneumophila in the tissues and body fluids.

Animals↗