scholarly journals Evaluation of chimeric proteins for serological diagnosis of brucellosis in cattle

2021 ◽  
pp. 2187-2196
Author(s):  
Aitbay K. Bulashev ◽  
Bakytkali K. Ingirbay ◽  
Kanatbek N. Mukantayev ◽  
Alfiya S. Syzdykova
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Cross Reactivity ◽  
Accurate Diagnosis ◽  
Expression Vectors ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chimeric Proteins ◽  
Serum Samples ◽  
Serological Tests

Background and Aim: An accurate diagnosis of Brucella-infected animals is one of the critical measures in eradication programs. Conventional serological tests based on whole-cell (WC) antigens and detecting antibodies against pathogen-associated lipopolysaccharide might give false-positive results due to the cross-reactivity with other closely related bacteria. This study evaluated the serological potential of Brucella spp. chimeric outer membrane proteins (Omps) as antigens in an indirect enzyme-linked immunosorbent assay (i-ELISA). Materials and Methods: The chimeric gene constructs of the most immunodominant regions of Brucella Omps 25+31, 25+19, and 19+31 were cloned into the pET28a expression vectors and transformed into Escherichia coli BL21 (DE3). The serological potential of chimeric proteins compared with single recombinant Omps (rOmps)19, 25, and/or 31 were studied on blood serum samples of (i) a rabbit immunized with killed Brucella abortus 19WC, (ii) mice immunized with single rOmps, (iii) cows seropositive for brucellosis by rose Bengal test, and (iv) cattle naturally and/or experimentally infected with brucellosis. Results: E. coli BL21 actively produced Brucella chimeric rOmps, the concentration of which reached a maximum level at 6 h after isopropyl-β-D-1-thiogalactopyranoside stimulation. Target proteins were antigenic and expressed in an active state, as recognized by rabbit anti-B. abortus antibodies in an i-ELISA and western blotting. Murine antibodies against the single rOmps reacted with chimeric antigens, and conversely, antichimeric antibodies found their epitopes in single proteins. Brucella chimeric rOmps showed higher antigenicity in blood sera of seropositive cattle kept in the hotbed of the infection and/or experimentally challenged with brucellosis than single proteins. Conclusion: Brucella chimeric recombinant outer membrane proteins could be a potential antigen candidate for developing an ELISA test for accurate diagnosis of bovine brucellosis.

scholarly journals Evaluation of a Western Blot Method for the Detection of Yersinia Antibodies: Evidence of Serological Cross-Reactivity between Yersinia Outer Membrane Proteins and Borrelia burgdorferi

2005 ◽  
Vol 12 (11) ◽  
pp. 1269-1274 ◽  
Author(s):  
Mindy L. Rawlins ◽  
Cecilia Gerstner ◽  
Harry R. Hill ◽  
Christine M. Litwin
Keyword(s):  
Membrane Proteins ◽  
Borrelia Burgdorferi ◽  
Western Blot ◽  
Outer Membrane ◽  
Sensitivity And Specificity ◽  
Reactive Arthritis ◽  
Outer Membrane Proteins ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Western Blot Assay

ABSTRACT Yersinia enterocolitica and Yersinia pseudotuberculosis have been identified as causative organisms of reactive arthritis in humans. We evaluated a Western blot assay which uses Yersinia outer membrane proteins as antigens for the detection of Yersinia antibodies as a replacement for the complement fixation (CF) assay. Clinical agreement, sensitivity, and specificity were determined by testing 19 positive and 21 negative serum samples by the CF assay, Western blot assay, and enzyme-linked immunosorbent assay (ELISA). The CF assay and ELISA were compared to the Western blot assay, which was the reference method used in this study. Sera with antibodies that could potentially cross-react with Yersinia were also tested by the Western blot assay. The agreement, sensitivity, and specificity of the CF method were 61%, 26%, and 95%, respectively; and those for the ELISA were 89%, 95%, and 82%, respectively. The prevalences of Yersinia antibodies in 50 healthy donors were 6% for immunoglobulin G (IgG), 2% for IgA, and 2% for IgM. Sera positive for Bartonella henselae, Brucella, Chlamydia pneumoniae, and Rickettsia rickettsii antibodies showed cross-reactivity by the Western blot assay. The highest cross-reactivity was observed with Borrelia burgdorferi; 5 of 11 (45%) specimens were cross-reactive by the IgM-specific assay. Overall, the Western blot assay performs acceptably and is more sensitive than the CF assay, warranting replacement of the CF assay in the laboratory. Due to the evidence of cross-reactivity, particularly with B. burgdorferi, which can cause an oligoarthritis similar to reactive arthritis, the diagnosis of reactive arthritis should be based on clinical findings and complete serologic analysis of the potential causative infectious pathogens.

scholarly journals Use of recombinant Brucella outer membrane proteins 19, 25, and 31 for serodiagnosis of bovine brucellosis

2020 ◽  
Vol 13 (7) ◽  
pp. 1439-1447
Author(s):  
Aitbay Bulashev ◽  
Orken Akibekov ◽  
Alfiya Syzdykova ◽  
Zhanbolat Suranshiyev ◽  
Bakytkali Ingirbay
Keyword(s):  
Outer Membrane ◽  
Single Injection ◽  
Outer Membrane Proteins ◽  
Enzyme Linked Immunosorbent Assay ◽  
Post Inoculation ◽  
Serological Testing ◽  
Bovine Brucellosis ◽  
Serum Samples ◽  
Serological Tests ◽  
Time Point

Background and Aim: Brucellosis remains one of the most common zoonoses. The current anti-brucellosis measures are largely deemed ineffective due to a lack of specificity of conventional serological tests. This study evaluated the use of Brucella outer membrane protein (Omp)19 for serodiagnostic testing. Materials and Methods: The antigenicity of recombinant Brucella Omp19, Omp25, and Omp31 was examined in serum samples from mice and rabbits immunized with Omp19 or Brucella abortus 19 whole cell (WC) and 12 and 152 cows experimentally or naturally infected with brucellosis, respectively. Serum samples were collected from 151 cows that were vaccinated with B. abortus 19 and 12 unvaccinated heifers that were maintained on a brucellosis-free farm. Results: Immunization with Omp19 resulted in antibody production in mice after a single injection without the use of adjuvant. Serum antibodies obtained from rabbits immunized with inactivated B. abortus strain 19 WC targeted Omps by enzyme-linked immunosorbent assay (ELISA) and Western blot. Antibodies targeting Omp19 were identified in all B. abortus strain 544 experimentally infected cows at day 14 post-inoculation (p.i.); Omp25 was detected by ELISA at day 28 p.i., while an ELISA targeting Omp31 was negative for 25% of cows at this time point. Omp19 and Omp25 were readily detected by sera from cows from a new epizootic focus. Antibodies recognizing Omps were also detected in >50% of the animals maintained in a brucellosis-free herd at 10 months after vaccination. Conclusion: Brucella Omp19 in combination with Omp25 and Omp31 may be utilized as target antigens in an ELISA designed for serological testing of unvaccinated cattle.

scholarly journals Evaluation of the Serologic Cross-Reactivity between Transmissible Gastroenteritis Coronavirus and Porcine Respiratory Coronavirus Using Commercial Blocking Enzyme-Linked Immunosorbent Assay Kits

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Ronaldo Magtoto ◽  
Korakrit Poonsuk ◽  
David Baum ◽  
Jianqiang Zhang ◽  
Qi Chen ◽  
...  
Keyword(s):  
Culture Medium ◽  
Large Deletion ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Transmissible Gastroenteritis Virus ◽  
Serum Samples ◽  
Serological Tests ◽  
Transmissible Gastroenteritis ◽  
Respiratory Coronavirus ◽  
Porcine Respiratory

ABSTRACTThis study compared the performances of three commercial transmissible gastroenteritis virus/porcine respiratory coronavirus (TGEV/PRCV) blocking enzyme-linked immunosorbent assays (ELISAs) using serum samples (n = 528) collected over a 49-day observation period from pigs inoculated with TGEV strain Purdue (n = 12), TGEV strain Miller (n = 12), PRCV (n= 12), or with virus-free culture medium (n = 12). ELISA results were evaluated both with “suspect” results interpreted as positive and then as negative. All commercial kits showed excellent diagnostic specificity (99 to 100%) when testing samples from pigs inoculated with virus-free culture medium. However, analyses revealed differences between the kits in diagnostic sensitivity (percent TGEV- or PRCV-seropositive pigs), and all kits showed significant (P < 0.05) cross-reactivity between TGEV and PRCV serum antibodies, particularly during early stages of the infections. Serologic cross-reactivity between TGEV and PRCV seemed to be TGEV strain dependent, with a higher percentage of PRCV-false-positive results for pigs inoculated with TGEV Purdue than for TGEV Miller. Moreover, the overall proportion of false positives was higher when suspect results were interpreted as positive, regardless of the ELISA kit evaluated.IMPORTANCECurrent measures to prevent TGEV from entering a naive herd include quarantine and testing for TGEV-seronegative animals. However, TGEV serology is complicated due to the cross-reactivity with PRCV, which circulates subclinically in most swine herds worldwide. Conventional serological tests cannot distinguish between TGEV and PRCV antibodies; however, blocking ELISAs using antigen containing a large deletion in the amino terminus of the PRCV S protein permit differentiation of PRCV and TGEV antibodies. Several commercial TGEV/PRCV blocking ELISAs are available, but performance comparisons have not been reported in recent research. This study demonstrates that the serologic cross-reactivity between TGEV and PRCV affects the accuracy of commercial blocking ELISAs. Individual test results must be interpreted with caution, particularly in the event of suspect results. Therefore, commercial TGEV/PRCV blocking ELISAs should only be applied on a herd basis.

scholarly journals Mutagenesis and Functional Reconstitution of Chlamydial Major Outer Membrane Proteins: VS4 Domains Are Not Required for Pore Formation but Modify Channel Function

2001 ◽  
Vol 69 (3) ◽  
pp. 1671-1678 ◽  
Author(s):  
E. S. Hughes ◽  
K. M. Shaw ◽  
R. H. Ashley
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Single Channel ◽  
Outer Membrane Proteins ◽  
Host Cells ◽  
Chimeric Proteins ◽  
Functional Differences ◽  
And Function ◽  
Bacterial Porins ◽  
Medical Interest

ABSTRACT Chlamidial organisms are obligate intracellular pathogens containing highly antigenic porin-like major outer membrane proteins (MOMPs). MOMP epitopes are of substantial medical interest, and they cluster within four relatively short variable (VS) domains. If MOMPs adopt a β-barrel fold, like bacterial porins, the VS domains may form extramembranous loops and the conserved regions of the protein may correspond to predicted membrane-located β-strands. However, molecular studies on native MOMPs have been hampered by the need to culture chlamydiae in eukaryotic host cells and purification and reconstitution remain problematic. In addition, the organisms are difficult to manipulate genetically, and it has also been difficult to functionally reconstitute recombinant MOMPs. To help overcome these problems and improve our understanding of MOMP structure and function, we cloned and expressed C. trachomatis and C. psittaci MOMPs and functionally reconstituted them at the single-channel level. We measured significant functional differences between the two proteins, and by removing and exchanging VS4, we tested the hypothesis that the largest variable domain forms an extramembranous loop that contributes to these differences. Proteins in which VS4 was deleted continued to form functional ion channels, consistent with the idea that the domain forms an extramembranous protein loop and incompatible with models in which it contributes to predicted membrane-located β-strands. Additionally, the properties of the chimeric proteins strongly suggested that the VS4 domain interacts closely with other regions of the protein to form the channel entrance or vestibule. Our approach can be used to probe structure-function relationships in chlamydial MOMPs and may have implications for the generation of effective antichlamydial vaccines.

scholarly journals Simultaneous detection of LipL32 and LipL21 genes of pathogenic leptospira from serum samples of bovines by multiplex PCR

2011 ◽  
Vol 1 (1) ◽  
pp. 15
Author(s):  
Timiri V. Meenambigai ◽  
Gopalakrishnan Ravikumar ◽  
Andy Srithar ◽  
Govindan Balakrishnan ◽  
Chidambaram Saranya ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Multiplex Pcr ◽  
Outer Membrane ◽  
Vaccine Development ◽  
Outer Membrane Proteins ◽  
Simultaneous Detection ◽  
Serum Samples ◽  
Pathogenic Leptospira ◽  
Annealing Conditions ◽  
Reference Strains

<p>Leptospirosis is a worldwide zoonotic disease of cattle associated with pathogenic leptospiral infection. This study focuses in the use of a molecular tool to detect pathogenic leptospiral infection in bovines by targeting the outer membrane proteins LipL32 and LipL21 simultaneously in a multiplex PCR. Sixteen pathogenic reference strains and 10 bovine serum samples were analyzed for simultaneous detection of both genes at appropriate annealing conditions. These findings are suggestive of the fact that multiplex PCR can be used to detect major outer membrane proteins of pathogenic leptospira from serum samples. Further it aided in the differentiation of pathogenic and non-pathogenic species of leptospires too. This study will definitely serve as a valuable tool, as it suggests the importance of <em>LipL32</em> genes as potential candidates for vaccine development to control animal Leptospirosis.</p>

scholarly journals Serum Antibody Responses in Ethiopian Meningitis Patients Infected with Neisseria meningitidis Serogroup A Sequence Type 7

2007 ◽  
Vol 14 (4) ◽  
pp. 451-463 ◽  
Author(s):  
Gunnstein Norheim ◽  
Abraham Aseffa ◽  
Mohammed Ahmed Yassin ◽  
Getahun Mengistu ◽  
Afework Kassu ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Acute Phase ◽  
Outer Membrane Proteins ◽  
Serum Antibody ◽  
Outer Membrane Vesicles ◽  
Sequence Type ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Complement ◽  
Convalescent Phase

ABSTRACT To elucidate critical components of protective immune responses induced during the natural course of serogroup A meningococcal disease, we studied acute-, early-convalescent-, and late-convalescent-phase sera from Ethiopian patients during outbreaks in 2002 to 2003. Sera were obtained from laboratory-confirmed patients positive for serogroup A sequence type 7 (ST-7) meningococci (A:4/21:P1.20,9) (n = 71) and from Ethiopian controls (n = 113). The sera were analyzed using an enzyme-linked immunosorbent assay to measure levels of immunoglobulin G (IgG) against serogroup A polysaccharide (APS) and outer membrane vesicles (OMVs) and for serum bactericidal activity (SBA) using both rabbit and human complement sources. Despite relatively high SBA titers and high levels of IgG against APS and OMVs in acute-phase patient sera, significant increases were seen in the early convalescent phase. Antibody concentrations returned to acute-phase levels in the late convalescent phase. Considering all patients' sera, a significant but low correlation (r = 0.46) was observed between SBA with rabbit complement (rSBA) using an ST-5 reference strain and SBA with human complement (hSBA) using an ST-7 strain from Ethiopia. While rSBA demonstrated a significant linear relation with IgG against APS, hSBA demonstrated significant linear relationships with IgG against both APS and OMV. This study indicates that antibodies against both outer membrane proteins and APS may be important in providing the protection induced during disease, as measured by hSBA. Therefore, outer membrane proteins could also have a role as components of future meningococcal vaccines for the African meningitis belt.

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