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F Massaria

Publications and source records attributed to F Massaria.

11 recordsLinked to original sources
PubMed1996

Uptake and killing of Lyme disease and relapsing fever borreliae in the perfused rat liver and by isolated Kupffer cells.

In situ-perfused rat livers were infused with a single dose of 1.5 x 10(7) radiolabeled borreliae. Significant (P < 0.00005) differences in the liver uptake of the agents of Lyme borreliosis, Borrelia burgdorferi IRS, Borrelia afzelii VS461, and Borrelia garinii PBi, and that of the agents of relapsing fever, Borrelia hermsii, Borrelia parkeri, and Borrelia turicatae, were observed. The liver uptakes ranged between 65.9% for B. burgdorferi IRS and 40.5% for B. turicatae. Neither relapsing fever nor Lyme disease borreliae were recovered from infected livers when the livers were cultured in Barbour-Stoenner-Kelly II medium. The in vitro uptake of B. burgdorferi IRS by isolated rat Kupffer cells was rapid, and within 30 min of the infection, large intracellular aggregates of amorphous material were detectable by immunofluorescence with specific anti-B. burgdorferi antibody. The reculturing of B. burgdorferi IRS from Kupffer cells incubated for 24 h in RPMI medium before inoculation with bacteria was negative. The results obtained in this study indicated that borreliae are efficiently taken up and killed by rat hepatic macrophages in the absence of serum factors.

Animals↗
PubMed1995

Functional activities of antibodies directed against surface lipoproteins of Borrelia hermsii.

Enriched preparations for mouse polyclonal immunoglobulin G (IgG) antibodies reactive with surface-exposed epitopes (Ab-SEE) of the 22-kDa and 24-kDa membrane lipoproteins of living Borrelia hermsii (HS 1 strain) cells were obtained by an antibody absorption technique using living spirochetes. In vitro, the antibody preparations both inhibited spirochetal growth and were borreliacidal in the presence of complement. The monovalent Fab antibody fragments, prepared from antibody-enriched preparations, did not inhibit the growth of the bacteria, whereas they killed the bacteria in the presence of complement. The two-dimension gel electrophoresis of B. hermsii cells showed that 3H-labeled fatty acids incorporated into the 22-kDa and 24-kDa lipoproteins were resolved into one and three compact spots, respectively. The spots were recognized by the Ab-SEE preparations reactive with the 22-kDa and 24-kDa proteins, by Western blotting.

Animals↗
PubMed1993

Glycoprotein patterns in Borrelia spp.

The presence of glycoproteins in several Borrelia species was investigated by the digoxigenin labelling technique. The outer surface proteins A and B of seven isolates of the Lyme disease spirochete B. burgdorferi showed to be major glycosylated proteins. Few minor polypeptides with variable molecular masses were also present, at variance, in B. burgdorferi strains. Minor glycosylated proteins with varying molecular masses have been detected in the relapsing fever borreliae B. hermsii, B. turicatae and B. parkeri. B. turicatae showed also a major glycosylated protein with a molecular mass of approximately 40 kDa. Animal pathogenic borreliae B. anserina and B. coriaceae presented only minor glycosylated proteins with variable molecular masses.

Antigens, Bacterial↗
PubMed1993

Adherence of Borrelia burgdorferi and Borrelia hermsii to mammalian cells in vitro.

This study investigated the ability of Borrelia burgdorferi and Borrelia hermsii to attach the surface of several types of in vitro-cultured mammalian cells. Borreliae showed different adhesion efficiencies depending on cell type and temperature. Temperatures both lower and higher than 33 degrees and 37 degrees C respectively, decreased the adhesion of borreliae which preferentially adhere to human fibroblast-like cells. The adhesion process, mediated by structures exposed onto the surface of the microorganisms, also proved to be sensitive to the treatment of mammalian cells with hyaluronidase and sialidase, confirming that carbohydrate receptors are involved in the adhesion of borreliae to eukaryotic cells.

Animals↗
PubMed1992

Complement-mediated in vitro bactericidal activity of monoclonal antibodies reactive with outer-surface-protein OspB of Borrelia burgdorferi.

Murine monoclonal antibodies (mAbs) were obtained against the outer-surface-protein OspA and OspB and against the 41-kDa flagellar antigen of Borrelia burgdorferi. The specificity of mAb was determined by the Western blotting technique and the surface association of the antigens was inferred by immunofluorescence of living bacteria. In an in vitro assay in the presence of complement, two mAbs reactive with the Ospa were able to kill borreliae, whereas several mAbs reactive with the OspA as well as with the 41-kDa flagellar protein were not.

Animals↗
PubMed1992

Surface immunofluorescence assay for diagnosis of Lyme disease.

A surface immunofluorescence assay (SIFA) was analyzed and compared with a conventional indirect immunofluorescence assay (IFA) and whole-cell enzyme-linked immunosorbent assay (ELISA) for detecting immunoglobulin G (IgG) antibodies to Borrelia burgdorferi in sera from patients with Lyme disease. Fifty-five patients with syphilis and 33 patients with rheumatoid arthritis were used as disease controls. The sensitivity of the SIFA was low during the acute phase of Lyme disease (sera from seven of nine patients presenting with erythema chronicum migrans were negative during the first 2 months of illness); later, seroconversion was observed in all patients at various times during convalescence. Sera from five patients with complicated Lyme disease were strongly positive. SIFA was found to be highly specific, since sera from all patients with secondary or latent syphilis and patients with rheumatoid arthritis did not react in the test. Strong cross-reactivity occurred when these sera were tested in conventional IFA and ELISA; sera from 38 (69%) patients with syphilis were positive by IFA and sera from 51 (93%) patients were positive by ELISA, whereas 7 (21%) and 12 (36%) of the serum samples from patients with rheumatoid arthritis were positive by IFA and ELISA, respectively. Immunoblot analysis of SIFA-positive sera showed that the 31- and 34-kDa outer surface proteins (proteins A and B, respectively) of B. burgdorferi were the major reactive antigens involved in the test. The results support a role for SIFA in the investigation of complicated Lyme disease as well as in the differentiation of Lyme disease from other diseases associated with B. burgdorferi cross-reactive antibodies.

Animals↗
PubMed1992

Differential cleavage of surface proteins of Borrelia burgdorferi by proteases.

The differential cleavage of surface proteins of Borrelia burgdorferi IRS strains by several proteases was examined. Proteinase K, trypsin, chymotrypsin and thermolysin all cleaved the outer surface protein B (OspB) to undetectable levels by Coomassie Brilliant Blue staining, whereas some residual protein was detected by immunoblotting with polyclonal and monoclonal antibodies. Not even antigenic fragments were detectable by immunoblotting with 1A8 monoclonal antibody reactive with OspB. Less effective or ineffective was the cleavage of OspB by V8 protease and proteinase A, respectively. The outer surface protein A was cleaved only by proteinase K. The effect of trypsin on borreliae viability and adhesion to cultured cells was also studied. The trypsin treatment of borreliae did not impair the viability of organisms which continued to synthesize the cleaved OspB. The attachment of B. burgdorferi to HEp-2 cells was reduced by 41% after treatment with trypsin, whereas preincubation of borreliae with monoclonal antibody 1A8 and guinea pig immune serum reduced the adhesion of borreliae to the cells by 32% and 87%, respectively.

Antibodies, Monoclonal↗
PubMed1991

Immunological characterization of a low molecular mass polypeptidic antigen of Borrelia burgdorferi.

The presence of a low molecular mass polypeptidic antigen in Borrelia burgdorferi was described. The protein was exposed at the bacterial surface since it was clearly identified by mAb 3H4 using the immunofluorescence test performed with living bacteria. This antigen was cleaved by proteinase K treatment, whereas it was resistant to the action of chymotrypsin, trypsin and thermolysin. Western blotting analysis of the immunological reactivity of this antigenic structure performed using monoclonal antibody, mouse-immune ascitic fluids raised against B. burgdorferi and other spirochetes, sera from patients with Lyme disease and other infirmities in which false positive results in serological tests for B. burgdorferi have been described, demonstrated that this protein expresses only species-specific epitopes which may be recognized during human B. burgdorferi infections.

Animals↗
PubMed1990

In-vitro susceptibility of Borrelia burgdorferi and Borrelia hermsii to ten antimicrobial agents.

The in-vitro activity of ten antimicrobial agents against four strains of Borrelia burgdorferi originating both in the United States and Europe and against one isolate of B. hermsii was investigated. Ceftriaxone, erythromycin and roxithromycin were the most active drugs against both Borrelia species studied, with minimum bactericidal concentrations ranging from 0.015 micrograms/ml to 0.125 micrograms/ml.

Anti-Bacterial Agents↗