scholarly journals Kinetics and Magnitude of Antibody Responses against the Conserved 47-Kilodalton Antigen and the Variable 56-Kilodalton Antigen in Scrub Typhus Patients

2011 ◽  
Vol 18 (6) ◽  
pp. 1021-1027 ◽  
Author(s):  
Hua-Wei Chen ◽  
Zhiwen Zhang ◽  
Erin Huber ◽  
Elissa Mutumanje ◽  
Chien-Chung Chao ◽  
...  
Keyword(s):  
Scrub Typhus ◽  
Secondary Infection ◽  
Systematic Investigation ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Orientia Tsutsugamushi ◽  
Protein Antigens ◽  
Content Type ◽  
Molecular Sizes ◽  
Kinetics Of

ABSTRACTWestern blot analysis ofOrientia tsutsugamushiwhole-cell lysates with scrub typhus patient sera has identified at least five protein antigens ofO. tsutsugamushiwith molecular sizes of 22 kDa, 47 kDa, 56 kDa, 58 kDa, and 110 kDa. In this study, sera from serial bleedings of 108 patients were used to study the kinetics and the magnitude of specific antibody responses against the 47-kDa and 56-kDa antigens. Recombinant protein of the conserved 47-kDa antigen (r47b) or a mixture of truncated 56-kDa antigen (r56s) from three prototype strains was used as the antigen in an enzyme-linked immunosorbent assay (ELISA). Our results showed that 76% and 93% of these patients had elevated IgM and IgG against r47b, respectively, and 98% and 100% had elevated IgM and IgG against r56s, respectively. The kinetics of antibody responses against r47b and r56s can be grouped into three patterns. In the first type of response, IgM and IgG against r47b and r56s appeared about the same time. The IgM and IgG titers against r56s were much higher than those against r47b. In the second type of response, induction of IgM appeared to be similar to that in the first type. The major difference to the first type is that the IgG titers against r47b were induced at least 1 week later than those against the r56s. The third type showed strong IgG responses against both r47b and r56s, and low or no IgM responses indicated a secondary infection. This is the first systematic investigation of antibody response kinetics against the conserved 47-kDa antigen versus the variable 56-kDa antigen in scrub typhus patients.

scholarly journals Detection of Antibodies against Orientia tsutsugamushi Sca Proteins in Scrub Typhus Patients and Genetic Variation ofscaGenes of Different Strains

2012 ◽  
Vol 19 (9) ◽  
pp. 1442-1451 ◽  
Author(s):  
Na-Young Ha ◽  
Yuri Kim ◽  
Ji-Hye Choi ◽  
Myung-Sik Choi ◽  
Ik-Sang Kim ◽  
...  
Keyword(s):  
Scrub Typhus ◽  
Pcr Amplification ◽  
Febrile Illness ◽  
Immunofluorescence Assay ◽  
Antibody Responses ◽  
Diagnostic Methods ◽  
Orientia Tsutsugamushi ◽  
Content Type ◽  
Asian Pacific Region ◽  
Different Strains

ABSTRACTScrub typhus, caused byOrientia tsutsugamushiinfection, is one of the main causes of acute febrile illness in the Asian-Pacific region. Although early diagnosis and immediate antibiotic treatment are critical for reducing disease severity and mortality, current diagnostic methods using serological and molecular approaches have some limitations in sensitivity and applicability in clinical laboratories. In this study, we identified and characterizedO. tsutsugamushisurface cell antigen (sca) family genes encoding autotransporter proteins in order to test them as novel diagnostic targets. We evaluated antibody responses against the Sca proteins in scrub typhus patient sera and examined the genetic diversity of these genes in different strains after PCR amplification. Specific antibody responses against ScaA and ScaC were observed in patients with high indirect immunofluorescence assay titers (≥1:640), whereas specific responses against ScaB and ScaE were relatively low. Genetic analysis using genomic DNAs revealed thescagenes to be quite variable among the different strains. In contrast toscaA,scaC, andscaD, which were detected in all of the tested strains,scaBandscaEwere amplified differentially from the different strains, suggesting a differential presence of the genes in the genomes. Among the members of the gene family, the sequence ofscaCis the most highly conserved between the different strains, and the size ofscaDis the most variable due to the presence of different numbers of internal repeat sequences. These results suggest that thescagenes ofO. tsutsugamushimay be valuable targets for use in combination with classical assay methods for scrub typhus diagnosis.

scholarly journals Evaluation of an Immunoglobulin M Capture Enzyme-Linked Immunosorbent Assay for Diagnosis of Orientia tsutsugamushi Infection

2003 ◽  
Vol 10 (3) ◽  
pp. 394-398 ◽  
Author(s):  
Won-Jong Jang ◽  
Myung-Suk Huh ◽  
Kyung-Hee Park ◽  
Myung-Sik Choi ◽  
Ik-Sang Kim
Keyword(s):  
Immunosorbent Assay ◽  
Scrub Typhus ◽  
Microtiter Plate ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Orientia Tsutsugamushi ◽  
Serum Samples ◽  
Capture Elisa ◽  
Igm Antibodies ◽  
Immunodominant Antigen

ABSTRACT To differentiate scrub typhus from other acute febrile diseases, a rapid and reliable serological diagnosis is important. We developed an immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (ELISA) for diagnosis of recent Orientia tsutsugamushi infections in humans. The 56-kDa major outer membrane protein of O. tsutsugamushi is well known as the most immunodominant antigen in scrub typhus. The test is based on the use of the biotinylated recombinant 56-kDa protein of O. tsutsugamushi Boryong, Bor56, which was expressed as a fusion protein with a maltose-binding protein in Escherichia coli. In the test, the serum IgM antibodies were captured by anti-human IgM antibodies coated onto a microtiter plate. The captured IgM antibodies were revealed through sequential addition of biotinylated Bor56 antigen and peroxidase-conjugated streptavidin to the plate. The IgM capture ELISA was compared with the immunofluorescence antibody assay (IFA) by testing 176 serum samples from patients with diagnosed cases of rickettsial disease and patients with other acute febrile diseases. Of the 81 IgG IFA-positive samples, 78 tested positive (sensitivity, 96.3%) and all 31 IgM IFA-positive samples tested positive (sensitivity, 100%) by the IgM capture ELISA. The specificity of the IgM capture ELISA was 99%, and 1 of the 95 IFA-negative samples was positive in the assay. These results strongly suggest that IgM capture ELISA using the recombinant Bor56 antigen is a reliable and detailed method for the detection of early O. tsutsugamushi infection.

scholarly journals Serodiagnostic Potential of Mycobacterium avium MAV2054 and MAV5183 Proteins

2012 ◽  
Vol 20 (2) ◽  
pp. 295-301 ◽  
Author(s):  
A-Rum Shin ◽  
Kil-Soo Lee ◽  
Kang In Lee ◽  
Tae Sun Shim ◽  
Won-Jung Koh ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Characteristic Curve ◽  
Receiver Operator Characteristic Curve ◽  
Curve Analysis ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Good Discrimination ◽  
Content Type ◽  
Pulmonary Tb ◽  
Latent Tb

ABSTRACTTheMycobacterium avium-M. intracellularecomplex (MAC) causes a pulmonary disease (PD) similar to tuberculosis (TB). Diagnosis of MAC-PD is complicated and time-consuming. In this study, the serodiagnostic potential of the newly identified MAV2054 and MAV5183 proteins was evaluated in subjects with MAC-PD, pulmonary TB, or latent TB and in noninfected healthy controls (HC), together with HspX and the 38-kDa antigen, well-known serodiagnosticM. tuberculosisantigens. All four antigens evoked significantly higher IgG responses in MAC-PD and active TB than in latent TB and HC subjects. Among the antigens, MAV2054 elicited the highest antibody responses in pulmonary TB and MAC-PD patients. IgG titers against MAV2054 and MAV5183 were significantly higher in MAC-PD than in pulmonary TB subjects. In addition, the levels of IgG against all antigens in theM. intracellulareand fibrocavitary forms were higher than those in theM. aviumand nodular bronchiectatic forms, respectively. Based on sensitivity and receiver operator characteristic curve analysis, the best candidates for detection of MAC-PD and pulmonary TB were MAV2054 and the 38-kDa antigen, respectively. In total, 76.0% of MAC-PD and 65.0% of active TB patients were reactive to at least two antigens. In contrast, only 2.8% of HC subjects were reactive with two or more antigens. Our findings suggest that an enzyme-linked immunosorbent assay (ELISA) using the four antigens would be valuable for screening for mycobacterial lung disease, including MAC-PD and pulmonary TB, although it does not provide good discrimination of the disease-causing pathogens.

scholarly journals Prospective Evaluation of Commercial Antibody-Based Rapid Tests in Combination with a Loop-Mediated Isothermal Amplification PCR Assay for Detection of Orientia tsutsugamushi during the Acute Phase of Scrub Typhus Infection

2012 ◽  
Vol 19 (3) ◽  
pp. 391-395 ◽  
Author(s):  
Stuart D. Blacksell ◽  
Daniel H. Paris ◽  
Wirongrong Chierakul ◽  
Vanaporn Wuthiekanun ◽  
Achara Teeratakul ◽  
...  
Keyword(s):  
Antibody Titer ◽  
Scrub Typhus ◽  
Orientia Tsutsugamushi ◽  
Pcr Assay ◽  
Content Type ◽  
Igm Antibody ◽  
Rapid Tests ◽  
Increased Sensitivity ◽  
Minimal Reduction ◽  
Diagnostic Capabilities

ABSTRACTSamples from 160 prospectively recruited febrile patients with typhus-like illness in an area of Thailand (Chiang Rai, northern Thailand) where scrub typhus is endemic were used to evaluate the diagnostic capabilities of four rapid immunochromatographic tests (ICTs) for the detection ofOrientia tsutsugamushiIgM and total antibodies during acute scrub typhus infection. Of the 160 cases, 54 (34%) had been confirmed to have scrub typhus using the reference scrub typhus infection criteria (STIC), i.e., positive cell culture isolation, an admission IgM antibody titer of ≥1:12,800, a 4-fold rising IgM antibody titer, and/or positivity for ≥2 out of 3 PCR gene targets). The ICTs gave the following sensitivities and specificities: the Panbio IgM ICT, 46% (95% confidence interval [CI], 33 to 60) and 95% (95% CI, 89 to 98), respectively; the Standard Diagnostics IgM ICT, 68% (95% CI, 60 to 75) and 73% (95% CI, 68 to 78), respectively; the AccessBio IgM ICT, 56% (95% CI, 48 to 63) and 90% (95% CI, 87 to 94), respectively; and the AccessBio total antibody ABt ICT, 61% (95% CI, 53 to 68) and 68% (95% CI, 63 to 73), respectively. An isothermal loop amplification (LAMP) PCR assay for scrub typhus demonstrated a sensitivity of 52% (95% CI, 38 to 66) and a specificity of 94% (95% CI, 88 to 98). This study has revealed the diagnostic limitations of antibody-based assays in an acute care setting. However, the combination of ICTs with LAMP usually increased sensitivity with a minimal reduction in specificity. The best combination, the Panbio IgM ICT and LAMP, resulted in a sensitivity of 67% (95% CI, 53 to 79) and a specificity of 91% (95% CI, 83 to 95). The combination of antibody-based assays with DNA- or antigen-based tests shows promise for improved diagnostic sensitivity.

scholarly journals Antibodies to Borrelia burgdorferi OspA, OspC, OspF, and C6 Antigens as Markers for Early and Late Infection in Dogs

2012 ◽  
Vol 19 (4) ◽  
pp. 527-535 ◽  
Author(s):  
Bettina Wagner ◽  
Heather Freer ◽  
Alicia Rollins ◽  
David Garcia-Tapia ◽  
Hollis N. Erb ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
The United States ◽  
Sensu Stricto ◽  
Antibody Responses ◽  
Surface Proteins ◽  
Early Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Content Type ◽  
Antibody Levels

ABSTRACTLyme disease in the United States is caused byBorrelia burgdorferisensu stricto, which is transmitted to mammals by infected ticks.Borreliaspirochetes differentially express immunogenic outer surface proteins (Osp). Our aim was to evaluate antibody responses to Osp antigens to aid the diagnosis of early infection and the management of Lyme disease. We analyzed antibody responses during the first 3 months after the experimental infection of dogs using a novel multiplex assay. Results were compared to those obtained with two commercial assays detecting C6 antigen. Multiplex analysis identified antibodies to OspC and C6 as early as 3 weeks postinfection (p.i.) and those to OspF by 5 weeks p.i. Antibodies to C6 and OspF increased throughout the study, while antibodies to OspC peaked between 7 and 11 weeks p.i. and declined thereafter. A short-term antibody response to OspA was observed in 3/8 experimentally infected dogs on day 21 p.i. Quant C6 enzyme-linked immunosorbent assay (ELISA) results matched multiplex results during the first 7 weeks p.i.; however, antibody levels subsequently declined by up to 29%. Immune responses then were analyzed in sera from 125 client-owned dogs and revealed high agreement between antibodies to OspF and C6 as robust markers for infection. Results from canine patient sera supported that OspC is an early infection marker and antibodies to OspC decline over time. The onset and decline of antibody responses toB. burgdorferiOsp antigens and C6 reflect their differential expression during infection. They provide valuable tools to determine the stage of infection, treatment outcomes, and vaccination status in dogs.

scholarly journals Antibody Responses to Natural Rattlesnake Envenomation and a Rattlesnake Toxoid Vaccine in Horses

2013 ◽  
Vol 20 (5) ◽  
pp. 732-737 ◽  
Author(s):  
Lyndi L. Gilliam ◽  
Robert C. Carmichael ◽  
Todd C. Holbrook ◽  
Jennifer M. Taylor ◽  
Charlotte L. Ownby ◽  
...  
Keyword(s):  
Passive Transfer ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vaccine Response ◽  
Crotalus Atrox ◽  
Content Type ◽  
The Third ◽  
Significant Difference ◽  
Rattlesnake Venom ◽  
Antibody Titers

ABSTRACTAntivenom antibody titers following administration of rattlesnake venom for antivenom production in horses are well documented; however, antivenom antibody titers following natural rattlesnake envenomation in horses are not. Antibody titers produced in response to the commercially available rattlesnake venom vaccine are also not published. Our study objectives were to measure antivenom antibody titers in rattlesnake-bitten horses and compare them to titers in horses vaccinated with the rattlesnake venom vaccine. Additionally, titers were compared in pregnant versus nonpregnant horses to assess the affect of pregnancy on vaccine response and were measured pre- and postsuckle in foals of vaccinated mares to detect passive transfer of vaccine immunoglobulins. Blood samples were collected from16 rattlesnake-bitten horses. Thirty-six horses (11 pregnant mares, 12 nonpregnant mares, 13 geldings) were vaccinated using aCrotalus atroxvenom toxoid vaccine. Blood was collected before administering each vaccination and 30 days following the third vaccination. Blood was collected from foals of vaccinated mares pre- and postsuckle. All serum was assayed for anti-Crotalus atroxvenom antibodies using an enzyme-linked immunosorbent assay (ELISA). Rattlesnake-bitten horses had higher (P= 0.001) titers than vaccinated horses. There was no significant difference between titers in vaccinated pregnant versus nonpregnant horses. One mare had a positive titer at foaling, and the foals had positive postsuckle titers. Antivenom antibody titer development was variable following natural envenomation and vaccination, and vaccine-induced titers were lower than natural envenomation titers. Further studies are required to determine if natural or vaccine antivenom antibody titers reduce the effects of envenomation.

scholarly journals Orientia tsutsugamushi Nucleomodulin Ank13 Exploits the RaDAR Nuclear Import Pathway To Modulate Host Cell Transcription

mBio ◽  
2021 ◽  
Author(s):  
Haley E. Adcox ◽  
Amanda L. Hatke ◽  
Shelby E. Andersen ◽  
Sarika Gupta ◽  
Nathan B. Otto ◽  
...  
Keyword(s):  
Nuclear Import ◽  
Scrub Typhus ◽  
Bacterial Pathogen ◽  
Host Cells ◽  
Intracellular Bacteria ◽  
Orientia Tsutsugamushi ◽  
Microbial Protein ◽  
Content Type ◽  
Eukaryotic Gene Expression ◽  
Eukaryotic Gene

Nucleomodulins are recently defined effectors used by diverse intracellular bacteria to manipulate eukaryotic gene expression and convert host cells into hospitable niches. How nucleomodulins enter the nucleus, their functional domains, and the genes that they modulate are incompletely characterized. Orientia tsutsugamushi is an intracellular bacterial pathogen that causes scrub typhus, which can be fatal. O. tsutsugamushi Ank13 is the first example of a microbial protein that coopts eukaryotic RaDAR (RanGDP-ankyrin repeats) nuclear import.

scholarly journals Heterogeneous Antibody Responses in Tuberculosis

1998 ◽  
Vol 66 (8) ◽  
pp. 3936-3940 ◽  
Author(s):  
Konstantin Lyashchenko ◽  
Roberto Colangeli ◽  
Michel Houde ◽  
Hamdan Al Jahdali ◽  
Dick Menzies ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antibody Response ◽  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Antigen Recognition ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protein Antigens ◽  
Tuberculosis Patients ◽  
Specific Antibodies

ABSTRACT Antibody responses during tuberculosis were analyzed by an enzyme-linked immunosorbent assay with a panel of 10 protein antigens of Mycobacterium tuberculosis. It was shown that serum immunoglobulin G antibodies were produced against a variety of M. tuberculosis antigens and that the vast majority of sera from tuberculosis patients contained antibodies against one or more M. tuberculosis antigens. The number and the species of serologically reactive antigens varied greatly from individual to individual. In a given serum, the level of specific antibodies also varied with the antigen irrespective of the total number of antigens recognized by that particular serum. These findings indicate that person-to-person heterogeneity of antigen recognition, rather than recognition of particular antigens, is a key attribute of the antibody response in tuberculosis.

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