scholarly journals Recombinant Multiepitope Protein for Diagnosis of Leptospirosis

2008 ◽  
Vol 15 (11) ◽  
pp. 1711-1714 ◽  
Author(s):  
Xu'ai Lin ◽  
Yin Chen ◽  
Jie Yan
Keyword(s):  
Outer Membrane Proteins ◽  
Agglutination Test ◽  
Accurate Diagnosis ◽  
Immunoglobulin M ◽  
Severe Illness ◽  
Enzyme Linked Immunosorbent Assay ◽  
Promising Alternative ◽  
Immunity Reaction ◽  
Gene Recombinant ◽  
Immunodominant Epitopes

ABSTRACT Leptospirosis is an emerging infectious disease and is considered to be the most widespread zoonotic disease in the world. It can be misdiagnosed because manifestations of this febrile disease vary from mild flu-like symptoms to severe illness involving vital organs such as the liver and lungs. Therefore, accurate diagnosis for differentiation of leptospirosis from other pyrogenic infections prevailing in the same locality is imperative for proper treatment. Here, we report a customized recombinant leptospirosis multiepitope protein (r-LMP) that can specifically detect the immunoglobulin class of anti-leptospirosis antibodies in patient sera. Immunodominant epitopes from leptospire outer membrane proteins OmpL1, LipL21, and LipL32 were predicted and confirmed using phage display and immunity reaction. On the basis of the sequences of the identified epitopes, five major immunodominant epitopes were selected to construct a synthetic gene, recombinant lmp. The recombinant lmp gene was doubled and expressed in Escherichia coli. The recombinant protein was purified and used as an antigen to develop an enzyme-linked immunosorbent assay for detection of special immunoglobulin M (IgM) or IgG in sera from patients with leptospirosis or other febrile illnesses and healthy subjects. The results showed that the r-LMP protein recognized IgG and IgM in all the sera that were microscope agglutination test positive, and there were no cross-reactions with other patient sera. This approach of creating customized antigens coupled to overexpression and simple purification offers a promising alternative option for leptospirosis diagnosis, with the potential to circumvent the drawbacks of whole-leptospirosis-antigen-based assays.

scholarly journals Limited Diagnostic Capacities of Two Commercial Assays for the Detection of Leptospira Immunoglobulin M Antibodies in Laos

2006 ◽  
Vol 13 (10) ◽  
pp. 1166-1169 ◽  
Author(s):  
Stuart D. Blacksell ◽  
Lee Smythe ◽  
Rattanaphone Phetsouvanh ◽  
Michael Dohnt ◽  
Rudy Hartskeerl ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Immunosorbent Assay ◽  
Gold Standard ◽  
Agglutination Test ◽  
Immunoglobulin M ◽  
Microscopic Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diagnostic Utility

ABSTRACT The diagnostic utility of immunochromatographic (Leptotek) and enzyme-linked immunosorbent assay (ELISA; Panbio) tests for the detection of Leptospira immunoglobulin M antibodies was assessed in febrile adults admitted in Vientiane, Laos. Both tests demonstrated poor diagnostic accuracy using admission serum (Leptotek sensitivity of 47.3% and specificity of 75.5%: ELISA sensitivity of 60.9% and specificity of 65.6%) compared to the Leptospira “gold standard” microscopic agglutination test.

scholarly journals Technical viability of the YF MAC-HD ELISA kit for use in yellow fever-endemic regions

2021 ◽  
Vol 15 (6) ◽  
pp. e0009417
Author(s):  
Christin H. Goodman ◽  
Maurice Demanou ◽  
Mick Mulders ◽  
Jairo Mendez-Rico ◽  
Alison Jane Basile
Keyword(s):  
South America ◽  
Yellow Fever ◽  
Accurate Diagnosis ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa Kit ◽  
Wash Buffer ◽  
Antibody Capture ◽  
Vaccination Campaigns ◽  
Arboviral Disease

Yellow fever (YF), an arboviral disease, affects an estimated 200,000 people and causes 30,000 deaths per year and recently has caused major epidemics in Africa and South America. Timely and accurate diagnosis of YF is critical for managing outbreaks and implementing vaccination campaigns. A YF immunoglobulin M (IgM) antibody-capture (MAC) enzyme-linked immunosorbent assay (ELISA) kit, the YF MAC-HD, was successfully introduced starting in 2018 to laboratories in Africa and South America. The YF MAC-HD kit can be performed in 3.5 hours, test up to 24 samples, and includes all reagents necessary to perform the test, except for water used to dilute wash buffer. In 2018 and 2019, a total of 56 laboratory personnel from 39 countries in Africa and South America were trained to use the kit during workshops, followed by take-home YF IgM proficiency testing (PT) exercises. Participants received either a 10- or 20-sample YF PT panel and performed testing using the YF MAC-HD kit. All countries obtained 90% or higher correct results. These results verified the technical viability and transferability of YF MAC-HD kit use for laboratories in YF-endemic countries.

scholarly journals Comparison of a Dipstick Assay for Detection of Brucella-Specific Immunoglobulin M Antibodies with Other Tests for Serodiagnosis of Human Brucellosis

2003 ◽  
Vol 10 (4) ◽  
pp. 612-615 ◽  
Author(s):  
Encarnación Clavijo ◽  
Ramón Díaz ◽  
Ángel Anguita ◽  
Antonio García ◽  
Alfonso Pinedo ◽  
...  
Keyword(s):  
Agglutination Test ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
Serological Response ◽  
Igm Elisa ◽  
Specific Immunoglobulin ◽  
History Of ◽  
Standard Serum ◽  
Serum Agglutination

ABSTRACT A dipstick assay for the detection of Brucella-specific immunoglobulin M (IgM) antibodies was evaluated by studying the serological response of 133 cultures and or serologically confirmed patients with brucellosis in its different stages along with those of 34 healthy controls. As regards patients with illness less than 3 months in duration, 93.1% tested positive by the dipstick assay, a percentage similar to that obtained in the standard serum agglutination test (SAT) (92.0%), somewhat lower than that obtained by culture (100%) and higher than that obtained by IgM enzyme-linked immunosorbent assay (ELISA) (80.5%). SAT was the most sensitive test (87.0%) for patients with illness more than 3 months in duration, followed by culture (50%), the dipstick assay (28.3%), and IgM ELISA (7.5%). The results demonstrate that the dipstick assay could well be used in the serodiagnosis of patients with acute brucellosis, as well as to identify patients with a long history of the illness. Under laboratory conditions this test has the advantage of being quick and IgM antibody-specific.

scholarly journals Macroscopic Agglutination Test for Rapid Diagnosis of Human Leptospirosis

1998 ◽  
Vol 36 (11) ◽  
pp. 3138-3142 ◽  
Author(s):  
Angela P. Brandão ◽  
Eide D. Camargo ◽  
Emilson D. da Silva ◽  
Marcos V. Silva ◽  
Rui V. Abrão
Keyword(s):  
Blood Donors ◽  
Agglutination Test ◽  
Immunoglobulin M ◽  
Screening Tests ◽  
Enzyme Linked Immunosorbent Assay ◽  
Initial Screening ◽  
Early Screening ◽  
Human Leptospirosis ◽  
Igm Elisa

A commercially available slide agglutination test (SAT) for the diagnosis of human leptospirosis was evaluated by comparing it to an immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) and to the microscopic agglutination test (MAT). For all 108 patients, leptospirosis was diagnosed on the basis of a fourfold or greater increase in titer by MAT (seroconversion), and all but 1 of 245 controls were MAT negative (titers, <1:100). Both SAT and the IgM ELISA failed to detect one case of infection (sensitivity, 99%). Only 3 of 145 blood donors and none of the 100 patients with other illnesses were SAT positive (specificity, 99%). The overall results were similar for the three tests; however, SAT and ELISA were statistically more sensitive as initial screening tests. For 22% of the patients, the diagnosis of leptospirosis was made earlier by SAT than by MAT. SAT detected 27 (44%) of 62 MAT-negative patients with the first serum sample. ELISA and SAT had very similar results. Follow-up of patients for 1 year after the onset of symptoms showed a decreasing rate of positivity by SAT from the third month on. The rate of positivity by ELISA decreased more slowly, to about 67% by the end of the study. By MAT all patients were persistently reactive. SAT and ELISA seem to be convenient methods for the rapid and early screening for leptospirosis and could replace the less sensitive MAT. ELISA gives less subjective results than SAT and provides information on IgM kinetics, but it can be performed only by the more sophisticated laboratories. SAT is inexpensive, can be performed more quickly and more easily than ELISA, and could be used by the less well equipped laboratories.

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 the Indirect Hemagglutination Assay for Diagnosis of Acute Leptospirosis

1998 ◽  
Vol 36 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Paul N. Levett ◽  
Carol U. Whittington
Keyword(s):  
Predictive Value ◽  
Venereal Disease ◽  
Agglutination Test ◽  
Immunoglobulin M ◽  
Microscopic Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Hemagglutination Assay ◽  
Serological Tests ◽  
Indirect Hemagglutination ◽  
Human Sera

Serology plays an important role in the diagnosis of leptospirosis. Few laboratories have the resources and expertise to perform the microscopic agglutination test. There is a need for rapid and simple serological tests which facilitate the early diagnosis of leptospirosis, while antibiotic therapy may be most effective. A commercially available indirect hemagglutination assay (IHA; MRL Diagnostics, Cypress, Calif.) was evaluated with multiple serum specimens from 107 patients being investigated for leptospirosis. By using a combination of enzyme-linked immunosorbent assay (ELISA) methods for immunoglobulin M (IgM) and IgG antibodies and the microscopic agglutination test, 54 patients were found to have leptospirosis and 53 were found not to have leptospirosis. The sensitivity of IHA for the detection of acute leptospirosis was 100%, the specificity was 94%, the positive predictive value was 95%, and the negative predictive value was 100%. IHA was negative when 13 antinuclear antibody-positive sera, 24 serum specimens from patients with syphilis, and 16 serum specimens false positive by the Venereal Disease Research Laboratory test were tested. IHA was shown to detect both IgM and IgG classes of antibodies in human sera. Serum specimens from 27 dogs investigated for leptospirosis were studied: 3 samples gave nonspecific hemagglutination, but for all remaining samples, the results of IHA and an IgM ELISA were concordant. Performance of IHA was simple, and IHA requires no specialized equipment. It represents a useful assay for laboratories which require a leptospiral diagnostic capability but lack the expertise to perform specialist investigations.

Detection of Leptospira DNA in Patients with Aseptic Meningitis by PCR

1998 ◽  
Vol 36 (5) ◽  
pp. 1453-1455 ◽  
Author(s):  
Eliete C. Romero ◽  
Ana E. C. Billerbeck ◽  
Valéria S. Lando ◽  
Eide D. Camargo ◽  
Candida C. Souza ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Aseptic Meningitis ◽  
Immunosorbent Assay ◽  
Agglutination Test ◽  
Immunoglobulin M ◽  
Microscopic Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay

Samples of cerebrospinal fluid from 103 patients with aseptic meningitis were tested by PCR for detection of leptospires, and the results were compared with those of the microscopic agglutination test (MAT) and an enzyme-linked immunosorbent assay for detection of immunoglobulin M (ELISA-IgM). Of these samples, 39.80% were positive by PCR and 8.74 and 3.88% were positive by MAT and ELISA-IgM, respectively.

scholarly journals Measurement of immunoglobulin M (IgM), IgG, and IgA antibodies against Yersinia enterocolitica by enzyme-linked immunosorbent assay: persistence of serum antibodies during disease

1979 ◽  
Vol 9 (3) ◽  
pp. 336-341 ◽  
Author(s):  
K Granfors
Keyword(s):  
Yersinia Enterocolitica ◽  
Immunosorbent Assay ◽  
Agglutination Test ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Antibodies ◽  
Heat Treated ◽  
Rabbit Igg ◽  
Iga Antibodies

An enzyme-linked immunosorbent assay for the detection and quantitation of human immunoglobulin M (IgM), IgG, and IgA antibodies against Yersinia enterocolitica is described. Formalinized or heat-treated bacteria were adsorbed onto specially designed microcuvettes, and antibodies were allowed to attach to the antigen-coated cuvettes. Rabbit anti-human mu, anti-human gamma, and anti-human alpha antisera were allowed to react with human antibodies, and these class-specific anti-immunoglobulins were detected by alkaline phosphatase-labeled swine anti-rabbit IgG. A total of 423 sera were tested. The results obtained with the enzyme-linked immunosorbent assay were compared with the results of the conventional tube agglutination test. Persistence of different antibodies was studied in six patients. Antibodies of the IgM class persisted only for 1 to 3 months after onset of the disease; thus the occurence of IgM-class Yersinia antibodies in a single sample indicates a recently acquired infection. The persistence of the IgG- and IgA-class antibodies was variable and not parallel with each other. Remarkably, all three patients in which the disease was complicated with arthritis had IgA-class Yersinia antibodies at the end of the follow-up period of 9 to 14 months, and in those without arthritis the IgA-class antibodies disappeared within 3 months after onset of the disease.

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

Production and immunological evaluation of epitope-based preventative pneumococcal candidate vaccine comprising immunodominant epitopes from PspA, CbpA, PhtD and PiuA antigens

2020 ◽  
Vol 22 ◽  
Author(s):  
Hesam Dorosti ◽  
Navid Nezafat ◽  
Reza Heidari ◽  
Mohammad Bagher Ghoshoon ◽  
Ahmad Gholami ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Pneumococcal Vaccine ◽  
Peptide Vaccine ◽  
Promising Alternative ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Serotype Replacement ◽  
Tnf Α ◽  
Immunological Evaluation ◽  
Immunodominant Epitopes

Background: Streptococcus pneumoniae is a leading cause of pneumonia, mostly in children less than five years and elderly people. Although the pneumoniae polysaccharide vaccine (PPV) and pneumonia conjugate vaccines (PCV) are the efficient pneumococcal vaccine in adult and children groups, but the serotype replacement of S. pneumoniae strains causes the reduction in the efficacy of PPV and PCV vaccines. Epitope-based vaccines are a promising alternative to the present capsular antigen vaccines. Methods: In this study, we evaluated cellular and humoral immune responses induced by our novel designed multi-epitope vaccine in BALB/c mice. CD8+ cytolytic T lymphocytes (CTLs) epitopes were selected from PspA and CbpA antigens, and CD4+ helper T lymphocytes (HTLs) epitopes were chosen from PhtD and PiuA antigens. PorB, the TLR2 agonist, as an adjuvant, was employed to increase the immunogenicity of the vaccine. Results and conclusion: The high levels of specific anti-peptide vaccine IgG and an increase in the level of IgG2 in the vaccinated group demonstrated our vaccine could elicit a robust antibody production. The significant increase in IFN-γ, IL-2, TNF-α, IL-4, IL-6, and decrease in IL-10 showed that, the designed vaccine could be proposed as the efficient preventative pneumococcal vaccine in the mouse model.

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