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Biomedical subjects

S R Coates

Publications and source records attributed to S R Coates.

14 recordsLinked to original sources

Seroreactive recombinant herpes simplex virus type 2-specific glycoprotein G.

The herpes simplex virus type 2 (HSV-2) genome codes for an envelope protein, glycoprotein G (gG), which contains predominantly type 2-specific epitopes. A portion of this gG gene has been expressed as a fusion protein in Escherichia coli. Expression was regulated by a lambda phage pL promoter. The 60,000-molecular-weight recombinant protein was purified by ion-exchange chromatography. Amino acid sequence analysis confirmed the N terminus of the purified protein. Mice immunized with recombinant gG developed antibodies reactive with native HSV-2 protein, but not with HSV-1 protein, in an indirect immunofluorescence assay. The serological activity of this purified recombinant gG protein was evaluated by immunoblot assay. This protein was reactive with an HSV-2 gG monoclonal antibody. It was also reactive with HSV-2 rabbit antiserum but not with HSV-1 rabbit antiserum. Of 15 patient serum samples known to have antibody to HSV-2, 14 were reactive with this recombinant type 2-specific gG protein, and none of 15 HSV antibody-negative patient serum samples showed reactivity. In agreement with the expected prevalence of HSV-2 infection, 27.6% of 134 serum samples from random normal individuals had antibodies reactive with recombinant gG. This recombinant gG protein may be of value in detecting HSV-2-specific antibody responses in patients infected with HSV-2.

Adult↗

Serological evaluation of Escherichia coli-expressed human T-cell leukemia virus type I env, gag p24, and tax proteins.

Three proteins (env, gag, and tax) encoded by the human T-cell leukemia virus type I (HTLV-I) genome were cloned and expressed in Escherichia coli. The env protein contained a substantial part of the gp46 domain and a majority of the p21e domain. The gag protein contained all of p24 and portions of p19 and p15. In addition to these two structural proteins, a full-length tax (p40X) construct was obtained. All three recombinant proteins were purified to near homogeneity. When used in an immunoblot assay, the three recombinant proteins detected antibodies in more HTLV-I antibody-positive patient sera than did the corresponding native proteins. Antibodies to at least two of these three different gene products were detected in 98.4% of adult T-cell leukemia patients, 100% of HTLV-I-associated myelopathy patients, 97.4% of asymptomatic carriers, and 94% of uncharacterized HTLV-I-positive patients. Antibody to recombinant tax was found in 4.9% of adult T-cell leukemia patients, whereas antibody to recombinant env could not be detected. These recombinant proteins from three different gene products may be useful in detecting or confirming the presence of antibodies to HTLV-I.

Adult↗

Direct detection of Mycoplasma pneumoniae antigen in clinical specimens by a monoclonal antibody immunoblot assay.

Throat swabs from patients with pharyngitis and sputum specimens from patients with atypical pneumonia were tested for the presence of a Mycoplasma pneumoniae polypeptide with a molecular weight of 43,000 with the use of an M. pneumoniae species-specific monoclonal antibody in an immunoblot assay. This 43,000-dalton polypeptide was detectable in 33 of 33 throat swabs from patients with pharyngitis that were positive for M. pneumoniae by conventional culture as well as a culture-amplified enzyme immunoassay. The 43,000-dalton polypeptide was also detected in three of three M. pneumoniae culture-positive sputum specimens. It was not detected in 3 sputum specimens culture-confirmed for Legionella pneumophila, 10 sputum specimens from normal persons, or 25 throat swabs also from normal persons. This immunoblot assay could be completed within five hours and may be an alternative method for detecting M. pneumoniae antigen directly in sputum or throat swab specimens.

Adult↗

The simultaneous direct detection of Mycoplasma pneumoniae and Legionella pneumophila antigens in sputum specimens by a monoclonal antibody immunoblot assay.

An immunoblot (Western) assay was developed employing a species-specific monoclonal antibody to a 43 kDa Mycoplasma pneumoniae membrane polypeptide and a species-specific monoclonal antibody to 29 kDa Legionella pneumophila outer membrane protein. This assay could simultaneously detect these two different antigens directly in sputum. The 43 kDa M. pneumoniae antigen was detected by this assay in each of three M. pneumoniae culture-confirmed sputum specimens. In addition, the 29 kDa L. pneumophila antigen was detected in three of three L. pneumophila culture-confirmed sputum specimens. Neither of these two specific antigens were detected in induced sputum specimens from ten normal individuals.

Antibodies, Monoclonal↗

Serological characterization and gene localization of an Escherichia coli-expressed 37-kilodalton Treponema pallidum antigen.

A recombinant plasmid containing a 5.6-kilobase-pair DNA fragment of the Treponema pallidum genome was characterized by endonuclease mapping, and the encoded proteins were expressed in Escherichia coli and analyzed by use of in vitro transcription and translation. One of the proteins, identified as having a molecular weight of 37,000 (37K protein), was selected for further study. Initially, the seroreactivity of the partially purified 37K antigen was demonstrated by immunoblotting. After its purification to near homogeneity, the cloned T. pallidum protein was assessed for diagnostic significance by radioimmunoassay. Although first identified as seroreactive by screening with secondary syphilitic sera (T. E. Fehniger, A. M. Walfield, T. M. Cunningham, J. D. Radolf, J. N. Miller, and M. A. Lovett, Abstr. Annu. Meet. Am. Soc. Microbiol. 1985, B156, p. 44), the antigen was shown to be serologically reactive with antibodies in serum from all stages of syphilis but was not recognized by serum from controls by both immunoblotting and radioimmune assay. Further, a monospecific polyclonal rabbit antiserum generated to the 37K antigen recognized a polypeptide of the same molecular weight from T. pallidum but did not efficiently recognize proteins from five nonpathogenic treponemes tested. Therefore, because of reactivity with and specificity for T. pallidum antibodies, the 37K antigen may be of serodiagnostic value in the detection of syphilis.

Animals↗

Serospecificity of a cloned protease-resistant Treponema pallidum--specific antigen expressed in Escherichia coli.

We evaluated the serological reactivity of a protease-resistant antigen designated 4D which was encoded by Treponema pallidum DNA and was expressed in Escherichia coli from recombinant plasmid pAW329. This 19,000-molecular-weight antigen was purified in its native, non-protease-treated form from E. coli sonic extracts by molecular sieving and ion-exchange chromatography. Antibody binding to antigen 4D was detected by a radioimmunoassay. Antigen 4D-specific antibody was detected in 95% of the sera in a Centers for Disease Control syphilis serum panel. It was also detected in 55% of 121 primary syphilis patients, whereas syphilis antibody was detected in 83% of the sera by a fluorescent treponemal antibody absorption test and in 88% of the sera by a T. pallidum microhemagglutination test. In tests of 118 normal sera, less than 3% demonstrated antibody to antigen 4D; these results are similar to microhemagglutination and fluorescent treponemal antibody absorption test results. Rabbit antisera against Treponema phagedenis, Treponema refringens, Treponema denticola, and Treponema vincentii did not react with antigen 4D.

Antibody Specificity↗

Identification of Mycobacterium tuberculosis antigens in Seibert fractions by immunoblotting.

Seibert fractions prepared from Mycobacterium tuberculosis culture filtrates were evaluated by immunoblotting with a serum pool from patients with active pulmonary tuberculosis. Antibody activity was observed primarily with antigens in the polysaccharide II and A protein fractions; these fractions were further evaluated by immunoblotting with sera from individual patients with tuberculosis, from individuals without tuberculosis and positive for the purified protein derivative antigen skin test, and from individuals negative for the purified protein derivative antigen skin test. The antigens identified in the protein A fraction, a 32,000-molecular-weight antigen and a heterogeneous high-molecular-weight antigen, reacted with antibody found in sera from all patients with tuberculosis and with antibody from over 25% of the control individuals. A 10,000-molecular-weight antigen, a 30,000- to 44,000-molecular-weight antigen, and a heterogeneous high-molecular-weight antigen were observed in the polysaccharide II fraction; these antigens reacted with serum antibody from 70% or more of the patients with tuberculosis and with antibody from 20 to 70% of the control individuals. One of the antigens, with a molecular weight ranging from 17,000 to 28,000 in the polysaccharide II fraction, reacted with antibody in 64% of the sera from patients with tuberculosis but with only 1 of 15 control normal sera. This antigen may elicit an antibody response specifically associated with tuberculosis.

Antigens, Bacterial↗

Species-specific monoclonal antibody to a 43,000-molecular-weight membrane protein of Mycoplasma pneumoniae.

A murine immunoglobulin G1 monoclonal antibody was produced that binds to a protease-sensitive, periodate-insensitive epitope on a 43,000-molecular-weight Mycoplasma pneumoniae membrane polypeptide. The 43,000-molecular-weight polypeptide appeared to be a major antigenic component of M. pneumoniae, as determined by immunoblot analysis. This monoclonal antibody reacted with 33 different clinical isolates of M. pneumoniae, but not with normal-flora Mycoplasma species or 18 other microorganisms potentially inhabiting the normal or diseased human respiratory tract. This apparent species-specific monoclonal antibody may have application for the detection of M. pneumoniae antigen in clinical specimens.

Animals↗

Enzygnost-Rubella: an enzyme immunoassay for screening and quantitation of antibodies to rubella virus.

Calbiochem-Behring, Enzygnost-Rubella is an enzyme-linked immunosorbent assay (ELISA) for the determination of IgG antibodies to rubella virus. Two procedures, screening and quantitative, were used for the measurement of rubella antibodies in a characterized panel of sera and in random, premarital serum specimens. Using the screening procedure, no false-positive or false-negative results were observed in testing a panel of 40 sera previously characterized by human "O" cell and chick cell hemagglutination-inhibition (HI) tests. Additional testing of 323 random, premarital serum samples resulted in 99.4% agreement with HI tests in identifying positive and negative specimens. In the evaluation of the quantitative procedure, a coefficient of correlation (r) of 0.93 between ELISA titers and the geometric mean HI titers was obtained when testing the panel of 40 characterized sera. Furthermore, 100% agreement with HI test was obtained in the detection of titer rises in 20 pairs of acute and convalescent sera. The average within-run coefficients of variation for the screening and quantitative procedures were determined to be 11.2% and 15.6%, respectively. It is concluded that the Enzygnost-Rubella reagents are sensitive, specific, and provide objective means for assessing immunestatus and detecting rises in antibody titers to rubella virus.

Antibodies, Viral↗

Reactivity of nonsensitized control erythrocytes in rubella passive hemagglutination assays.

Two commercially available, nonsensitized control erythrocytes for use in rubella antibody passive hemagglutination assays detected nonspecific reactions in 10 of 600 (1.7%) and 9 of 500 (1.8%) sera tested. Reactive sera were positive with one or the other cell type, but not both. The probability of obtaining a false-positive result owing to a nonspecific passive hemagglutination reaction was estimated to be 0.17% for either cell type.

Erythrocytes↗

New passive hemagglutination assay kit that uses hemagglutinin-sensitized erythrocytes for detection of rubella antibodies.

A new passive hemagglutination assay for the detection of antibodies to rubella virus hemagglutinin (PHAST-Rubella) was compared with the hemagglutination inhibition (HI) test and another passive hemagglutination test that uses a soluble rubella virus antigen (SA-PHA). When the immune responses of vaccinated individuals were monitored, similar rises in antibody titer were detected by HI or PHAST-Rubella, whereas the rise in titer detected by SA-PHA was delayed. Early-phase vaccine-induced immunoglobulin M antibody analyzed by sucrose gradient fractionation was detected to the same degree by HI and PHAST-Rubella, but early-phase immunoglobulin G antibody reacted more strongly in the HI test. When acute and convalescent serum pairs from rubella-infected individuals were evaluated, a fourfold rise in titer was detected by PHAST-Rubella and HI in 15 of 15 pairs, whereas SA-PHA, which is not intended for detecting antibody titer rises in acute infections, detected a rise in titer in only 3 of 15 pairs. In studies to determine rubella immune status, testing of 1,078 premarital and random serum specimens resulted in 98.6% agreement among the three methods in identifying rubella antibody-positive and -negative individuals. For the quantitative PHAST-Rubella procedure, a coefficient of correlation of 0.93 was obtained, in comparison with HI, when a panel of 40 characterized sera were tested. These results indicate that PHAST-Rubella reagents can detect rubella antibodies as well as HI reagents and thus may be used as a fast and accurate means of determining rubella immune status and for the quantitation of rubella antibodies.

Antibodies, Viral↗

Sensitivities of Escherichia coli isolated from bovine and porcine enteric infections to antimicrobial antibiotics.

The antibiotic sensitivities of Escherichia coli isolated from 91 diarrheal pigs and 98 diarrheal calves were determined to 19 different microbials by the Kirby-Bauer method. Virtually all E coli isolated from pigs and calves were sensitive to amikacin, colistin, gentamicin, and polymyxin B. In vitro minimum inhibitory concentrations for these 4 antibiotics were determined for isolates from both pigs and calves.

Animals↗

The response of turkeys to varying doses of live oral Pasteurella multocida vaccine.

Groups of 30 turkeys were vaccinated by the drinking water route against fowl cholera with varying doses of the low virulence, CU strain, of Pasteurella mulocida. One group (heavy dose) received 1.2 x 107, another (medium dose) 1.5 x 105, and a third (light dose) 1.0 x 103 bacteria per ml. of drinking water. Two (6.7%) vaccine induced cholera deaths occurred in the heavy dose group. No deaths resulted in the other groups. Maximum serum antibody titers per group were; light dose 1:32, medium dose 1:128, and heavy dose 1:256. Three weeks after vaccination all turkeys were challenged with a large dose of virulent P. multocida (P-1059). Mortalities resulting from the challenge were 100% in the light group, 23% in the medium group, 4% in the heavy group, and 100% in the unvaccinated controls.

Administration, Oral↗