Serologic detection ofBrachyspira (Serpulina) hyodysenteriaeinfections

2001 ◽  
Vol 2 (1) ◽  
pp. 45-52 ◽  
Author(s):  
T. La ◽  
D.J. Hampson
Keyword(s):  
Cross Reactivity ◽  
Whole Cell ◽  
Brachyspira Hyodysenteriae ◽  
Serologic Tests ◽  
Cell Surface Structures ◽  
Outer Membrane Lipoprotein ◽  
Membrane Lipoprotein ◽  
Different Strains ◽  
Serologic Assay ◽  
Important Disease

AbstractSwine dysentery (SD) caused by the intestinal spirocheteBrachyspira hyodysenteriaeis an economically important disease in pig-producing countries throughout the world. To date, no specific serologic assay is commercially available for the diagnosis of pigs with SD. Several serologic techniques have been identified in the past; however, these tests have all used either whole-cell proteins or lipopolysaccharide (LPS) as the antigen. Whole-cell antigens are plagued with false-positive reactions due to cross-reactivity with common proteins shared with other spirochetes. LPS antigens produce fewer false-positives; however, false-negatives may result due to LPS components being serogroup-specific. Generally, these techniques are useful for detecting infected herds, but are unreliable for the detection of individual infected pigs. In order to develop improved serologic tests it will be necessary to identify suitable diagnostic antigens, in particular immunogenic cell-surface structures which are specific toB. hyodysenteriaebut common amongst different strains of the species. Recently, we identified and cloned a 30-kDa outer membrane lipoprotein (BmpB) which is specific toB. hyodysenteriaeand is recognized by experimentally and naturally infected pigs. In this review we summarize the available serologic tests for SD, and speculate on the use of recombinant BmpB as an antigen for future development of an improved serologic test for SD diagnosis.

scholarly journals Cross-Reactivity between Immune Responses to Helicobacter bilis and Helicobacter pylori in a Population in Thailand at High Risk of Developing Cholangiocarcinoma

2008 ◽  
Vol 15 (9) ◽  
pp. 1363-1368 ◽  
Author(s):  
Paola Pisani ◽  
Mark T. Whary ◽  
Ingrid Nilsson ◽  
Supannee Sriamporn ◽  
Torkel Wadström ◽  
...  
Keyword(s):  
High Risk ◽  
Immune Responses ◽  
Cross Reactivity ◽  
Surface Proteins ◽  
Massachusetts Institute Of Technology ◽  
Whole Cell ◽  
Serologic Tests ◽  
Helicobacter Bilis ◽  
Institute Of Technology ◽  
H Pylori

ABSTRACT Helicobacter bilis DNA has been detected in human tissue and is a candidate for etiologic investigations on the causes of hepatic and biliary tract diseases, but reliable serologic tests need to be developed in order to pursue such investigations. The scope of this study was to assess the specificity of two assays for H. bilis immune response allowing for H. pylori, and their cross-reactivity in a population in Thailand at high risk for cholangiocarcinoma. Plasma samples from 92 Thai volunteers were independently tested in two laboratories (Massachusetts Institute of Technology [MIT] and Lund). MIT performed three analyses of H. pylori and H. bilis based either on (i) outer membrane protein (OMP) with no preabsorption or on antigens derived from whole-cell sonicate before (ii) or after (iii) preabsorption with H. pylori sonicate protein. Lund used cell surface proteins from H. pylori and H. bilis as antigens. Testing for H. bilis was preabsorbed with a whole-cell lysate of H. pylori. More than 80% of the samples were positive for H. pylori in both laboratories. As tested by MIT, 58.7% (95% confidence interval, 47.9 to 68.9%) were positive for H. bilis by OMP and 44.5% (34.1 to 55.3%) were positive for H. bilis sonicate protein, but only 15.2% (8.6 to 24.2%) remained positive after preabsorption with H. pylori sonicate protein. Lund found 34.5% of the samples positive for H. bilis (22.0 to 41.0%), which was statistically compatible with all three MIT results. Serologic responses to OMPs of the two bacteria coincided in 66 and 45% of the samples in the MIT and Lund assays, respectively. We found high cross-reactivity between the immune responses to H. pylori and H. bilis antigens. More-specific H. bilis antigens need to be isolated to develop serologic tests suitable for epidemiological studies.

scholarly journals Automated Western immunoblotting detection of anti-SARS-CoV-2 serum antibodies

2021 ◽  
Author(s):  
Sophie Edouard ◽  
Rita Jaafar ◽  
Nicolas Orain ◽  
Philippe Parola ◽  
Philippe Colson ◽  
...  
Keyword(s):  
Negative Control ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Rt Pcr ◽  
Substantial Agreement ◽  
Western Immunoblotting ◽  
Elisa Kit ◽  
Line Test ◽  
Serologic Assay ◽  
Control Samples

AbstractELISA and chemiluminescence serological assays for COVID-19 are currently incorporating only one or two SARS-CoV-2 antigens. We developed an automated Western immunoblotting as a complementary serologic assay for COVID-19. The JessTM Simple Western system, an automated capillary-based assay, was used, incorporating an inactivated SARS-CoV-2 lineage 20a strain as the source of antigen, and total immunoglobulins (IgG, IgM, IgA) detection. In total, 602 sera were tested including 223 from RT-PCR-confirmed COVID-19 patients, 76 from patients diagnosed with seasonal HCoVs and 303 from coronavirus-negative control sera. We also compared this assay with the EUROIMMUN® SARS-CoV-2 IgG ELISA kit. Among 223 sera obtained from RT-PCR-confirmed COVID-19 patients, 180/223 (81%) exhibited reactivity against the nucleocapsid and 70/223 (31%) against the spike protein. Nucleocapsid reactivity was further detected in 9/76 (14%) samples collected from patients diagnosed with seasonal HCoVs and in 15/303 (5%) coronavirus-negative control samples. In the subset of sera collected more than 2 weeks after the onset of symptoms, the sensitivity was 94% and the specificity 93%, the latter value probably reflecting cross-reactivity of SARS-CoV-2 with other coronaviruses. The automated Western immunoblotting presented a substantial agreement (90%) with the compared ELISA (Cohen’s Kappa=0.64). Automated Western immunoblotting may be used as a second line test to monitor exposure of people to HCoVs including SARS-CoV-2.

scholarly journals Antibodies produced by dogs successfully challenged with live Leptospira spp. did not cross-react to Brucella antigen in a commercial rapid slide agglutination test that detects antibodies to Brucella canis

2018 ◽  
Vol 31 (1) ◽  
pp. 83-85
Author(s):  
Matthew R. Krecic
Keyword(s):  
Cross Reactivity ◽  
Agglutination Test ◽  
Slide Agglutination ◽  
Serologic Tests ◽  
Experimental Infections ◽  
Negative Results ◽  
Brucella Canis ◽  
Slide Agglutination Test ◽  
Leptospira Spp ◽  
Canine Brucellosis

Brucella canis is a cause of canine infertility and abortion. Veterinarians and veterinary laboratorians screen for antibodies to B. canis with serologic tests including a rapid slide agglutination test (RSAT; D-Tec CB, Zoetis, San Diego, CA). False-positive results are possible because of cross-reactivity to antibodies to some gram-negative bacteria. Cross-reactivity has been reported between antibodies of Brucella abortus and Leptospira spp. with serologic tests for bovine brucellosis; however, this has not been documented with serologic tests for canine brucellosis, to the author’s knowledge. The RSAT was evaluated with the sera from dogs experimentally challenged with 1 of 4 serovars of Leptospira spp.: L. kirschneri serovar Grippotyphosa, or L. interrogans serovars Canicola, Icterohaemorrhagiae, or Pomona. Experimental infections were confirmed through results of microscopic agglutination testing and/or lateral flow immunochromatography testing. The sera of 32 dogs collected at day 0 and days 7, 10, and 14 yielded negative results with the RSAT. Antibodies produced through experimental infections to these 4 serovars of Leptospira spp. did not cross-react with Brucella antigen with the RSAT; therefore, cross-reactivity of anti-leptospiral antibodies may not be of concern for B. canis rapid slide agglutination testing of dogs.

scholarly journals Translation initiation in bacterial polysomes through ribosome loading on a standby site on a highly translated mRNA

2018 ◽  
Vol 115 (17) ◽  
pp. 4411-4416 ◽  
Author(s):  
Irena Andreeva ◽  
Riccardo Belardinelli ◽  
Marina V. Rodnina
Keyword(s):  
Ribosomal Proteins ◽  
Initiation Site ◽  
Start Codon ◽  
Translational Efficiency ◽  
Tight Coupling ◽  
Translation Elongation ◽  
Outer Membrane Lipoprotein ◽  
Rapid Formation ◽  
Membrane Lipoprotein ◽  
Early Recruitment

During translation, consecutive ribosomes load on an mRNA and form a polysome. The first ribosome binds to a single-stranded mRNA region and moves toward the start codon, unwinding potential mRNA structures on the way. In contrast, the following ribosomes can dock at the start codon only when the first ribosome has vacated the initiation site. Here we show that loading of the second ribosome on a natural 38-nt-long 5′ untranslated region oflppmRNA, which codes for the outer membrane lipoprotein fromEscherichia coli, takes place before the leading ribosome has moved away from the start codon. The rapid formation of this standby complex depends on the presence of ribosomal proteins S1/S2 in the leading ribosome. The early recruitment of the second ribosome to the standby site before translation by the leading ribosome and the tight coupling between translation elongation by the first ribosome and the accommodation of the second ribosome can contribute to high translational efficiency of thelppmRNA.

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