scholarly journals Validation of an Enzyme-Linked Immunosorbent Assay That Detects Histoplasma capsulatum Antigenuria in Colombian Patients with AIDS for Diagnosis and Follow-Up during Therapy

2014 ◽  
Vol 21 (9) ◽  
pp. 1364-1368 ◽  
Author(s):  
Diego H. Caceres ◽  
Christina M. Scheel ◽  
Ángela M. Tobón ◽  
Angela Ahlquist Cleveland ◽  
Ángela Restrepo ◽  
...  
Keyword(s):  
Clinical Improvement ◽  
Immunosorbent Assay ◽  
Histoplasma Capsulatum ◽  
Response To Therapy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antigen Test ◽  
Content Type ◽  
Antigen Capture

ABSTRACTWe validated an antigen capture enzyme-linked immunosorbent assay (ELISA) in Colombian persons with AIDS and proven histoplasmosis and evaluated the correlation between antigenuria and clinical improvement during follow-up. The sensitivity of theHistoplasma capsulatumELISA was 86%, and the overall specificity was 94%. The antigen test successfully monitored the response to therapy.

scholarly journals Dynamics ofMycobacterium tuberculosisAg85B Revealed by a Sensitive Enzyme-Linked Immunosorbent Assay

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Joel D. Ernst ◽  
Amber Cornelius ◽  
Miriam Bolz
Keyword(s):  
Protein Secretion ◽  
Immunosorbent Assay ◽  
Bacterial Population ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Protein ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Bacterial Proteins

ABSTRACTSecretion of specific proteins contributes to pathogenesis and immune responses in tuberculosis and other bacterial infections, yet the kinetics of protein secretion and fate of secreted proteinsin vivoare poorly understood. We generated new monoclonal antibodies that recognize theMycobacteriumtuberculosissecreted protein Ag85B and used them to establish and characterize a sensitive enzyme-linked immunosorbent assay (ELISA) to quantitate Ag85B in samples generatedin vitroandin vivo. We found that nutritional or culture conditions had little impact on the secretion of Ag85B and that there is considerable variation in Ag85B secretion by distinct strains in theM. tuberculosiscomplex: compared with the commonly used H37Rv strain (lineage 4),Mycobacteriumafricanum(lineage 6) secretes less Ag85B, and two strains from lineage 2 secrete more Ag85B. We also used the ELISA to determine that the rate of secretion of Ag85B is 10- to 100-fold lower than that of proteins secreted by Gram-negative and Gram-positive bacteria, respectively. ELISA quantitation of Ag85B in lung homogenates ofM. tuberculosisH37Rv-infected mice revealed that although Ag85B accumulates in the lungs as the bacterial population expands, the amount of Ag85B per bacterium decreases nearly 10,000-fold at later stages of infection, coincident with the development of T cell responses and arrest of bacterial population growth. These results indicate that bacterial protein secretionin vivois dynamic and regulated, and quantitation of secreted bacterial proteins can contribute to the understanding of pathogenesis and immunity in tuberculosis and other infections.IMPORTANCEBacterial protein secretion contributes to host-pathogen interactions, yet the process and consequences of bacterial protein secretion during infection are poorly understood. We developed a sensitive ELISA to quantitate a protein (termed Ag85B) secreted byM. tuberculosisand used it to find that Ag85B secretion occurs with slower kinetics than for proteins secreted by Gram-positive and Gram-negative bacteria and that accumulation of Ag85B in the lungs is markedly regulated as a function of the bacterial population density. Our results demonstrate that quantitation of bacterial proteins during infection can reveal novel insights into host-pathogen interactions.

scholarly journals Development of a Novel Cocktail Enzyme-Linked Immunosorbent Assay and a Field-Applicable Lateral-Flow Rapid Test for Diagnosis of Contagious Bovine Pleuropneumonia

2016 ◽  
Vol 54 (6) ◽  
pp. 1557-1565 ◽  
Author(s):  
Martin Heller ◽  
Nimmo Gicheru ◽  
Georgina Tjipura-Zaire ◽  
Cecilia Muriuki ◽  
Mingyan Yu ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Rapid Test ◽  
Lateral Flow ◽  
Sub Saharan Africa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Contagious Bovine Pleuropneumonia ◽  
Serum Samples ◽  
Content Type ◽  
Mycoplasma Mycoides ◽  
Sub Saharan

Contagious bovine pleuropneumonia (CBPP) is a severe respiratory disease that is widespread in sub-Saharan Africa. It is caused byMycoplasma mycoidessubsp.mycoides, a bacterium belonging to theMycoplasma mycoidescluster. In the absence of an efficient CBPP vaccine, improved and easy-to-use diagnostic assays for recurrent testing combined with isolation and treatment of positive animals represent an option for CBPP control in Africa. Here we describe the comprehensive screening of 17 immunogenicMycoplasma mycoidessubsp.mycoidesproteins using well-characterized bovine sera for the development of a novel cocktail enzyme-linked immunosorbent assay (ELISA) for laboratory use. Two recombinantMycoplasmaimmunogens, MSC_0136 and MSC_0636, were used to set up a standardized cocktail ELISA protocol. According to the results from more than 100 serum samples tested, the sensitivity and specificity of the novel cocktail ELISA were 85.6% and 96.4%, respectively, with an overall diagnostic accuracy comparable to that of the Office International des Epizooties (OIE)-prescribed serological assays. In addition, we provide a proof of principle for a field-applicable, easy-to-use commercially produced prototype lateral-flow test for rapid (<30-min) diagnosis of CBPP.

scholarly journals The Trypomastigote Small Surface Antigen from Trypanosoma cruzi Improves Treatment Evaluation and Diagnosis in Pediatric Chagas Disease

2017 ◽  
Vol 55 (12) ◽  
pp. 3444-3453 ◽  
Author(s):  
Virginia Balouz ◽  
Luciano J. Melli ◽  
Romina Volcovich ◽  
Guillermo Moscatelli ◽  
Samanta Moroni ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Surface Antigen ◽  
Rapid Assessment ◽  
Drug Efficacy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
Small Surface ◽  
Content Type

ABSTRACTChagas disease is caused by the protozoan parasiteTrypanosoma cruzi. Assessment of parasitological cure upon treatment with available drugs relies on achieving consistent negative results in conventional parasitological and serological tests, which may take years to assess. Here, we evaluated the use of a recombinantT. cruziantigen termed trypomastigote small surface antigen (TSSA) as an early serological marker of drug efficacy inT. cruzi-infected children. A cohort of 78 pediatric patients born toT. cruzi-infected mothers was included in this study. Only 39 of the children were infected withT. cruzi, and they were immediately treated with trypanocidal drugs. Serological responses against TSSA were evaluated in infected and noninfected populations during the follow-up period using an in-house enzyme-linked immunosorbent assay (ELISA) and compared to conventional serological methods. Anti-TSSA antibody titers decreased significantly faster than anti-whole parasite antibodies detected by conventional serology both inT. cruzi-infected patients undergoing effective treatment and in those not infected. The differential kinetics allowed a significant reduction in the required follow-up periods to evaluate therapeutic responses or to rule out maternal-fetal transmission. Finally, we present the case of a congenitally infected patient with an atypical course in whom TSSA provided an early marker forT. cruziinfection. In conclusion, we showed that TSSA was efficacious both for rapid assessment of treatment efficiency and for early negative diagnosis in infants at risk of congenitalT. cruziinfection. Based upon these findings we propose the inclusion of TSSA for refining the posttherapeutic cure criterion and other diagnostic needs in pediatric Chagas disease.

scholarly journals Antibody Responses to CampylobacterInfections Determined by an Enzyme-Linked Immunosorbent Assay: 2-Year Follow-Up Study of 210 Patients

2001 ◽  
Vol 8 (2) ◽  
pp. 314-319 ◽  
Author(s):  
Mette Aagaard Strid ◽  
Jørgen Engberg ◽  
Lena Brandt Larsen ◽  
Kamilla Begtrup ◽  
Kåre Mølbak ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Serum Antibody ◽  
Large Degree ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Campylobacter Coli ◽  
Negative Results ◽  
Heat Stable Antigen

ABSTRACT An enzyme-linked immunosorbent assay (ELISA) was adapted to measure immunoglobulin G (IgG), IgM, and IgA classes of human serum antibody toCampylobacter jejuni and Campylobacter coli. Heat-stable antigen, a combination of C. jejuni serotype O:1,44 and O:53 in the ratio 1:1, was used as a coating antigen in the ELISA test. A total of 631 sera from 210 patients with verifiedCampylobacter enteritis were examined at various intervals after infection, and a control group of 164 sera were tested to determine the cut-off for negative results. With a 90th percentile of specificity, IgG, IgM, and IgA showed a sensitivity of 71, 60, and 80%, respectively. By combining all three antibody classes, the sensitivity was 92% within 35 days after infection, whereas within 90 days after infection, a combined sensitivity of 90% was found (IgG 68%, IgM 52%, and IgA 76%). At follow-up of the patients, IgG antibodies were elevated 4.5 months after infection but exhibited a large degree of variation in antibody decay profiles. IgA and IgM antibodies were elevated during the acute phase of infection (up to 2 months from onset of infection). The antibody response did not depend on Campylobacter species or C. jejuniserotype, with the important exception of response to C. jejuni O:19, the serotype most frequently associated with Guillain-Barré syndrome. All of the patients infected with this serotype had higher levels of both IgM (P = 0.006) and IgA (P = 0.06) compared with other C. jejuni and C. coli serotypes.

scholarly journals Comparison of Western Immunobloting to an Enzyme-Linked Immunosorbent Assay for the Determination of Anti-Bordetella pertussis Antibodies

2011 ◽  
Vol 18 (4) ◽  
pp. 615-620 ◽  
Author(s):  
Stephen D. Merrigan ◽  
Ryan J. Welch ◽  
Christine M. Litwin
Keyword(s):  
Immunosorbent Assay ◽  
Bordetella Pertussis ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Recent Infection ◽  
Content Type ◽  
Igm Elisa ◽  
Iga Antibodies ◽  
Health Organization

ABSTRACTDuringBordetella pertussisinfection, it has been established that an increase of anti-pertussis toxin (PT) and anti-filamentous hemagglutinin (FHA) antibodies occurs. Immunoblots from two manufacturers using FHA and PT antigens were compared with an enzyme-linked immunosorbent assay (ELISA) that used both FHA and PT. One manufacturer used two concentrations of PT bands for the IgG immunoblot, calibrated to the World Health Organization standard for PT in international units (IU/ml), 100 IU/ml (PT-100) and 8 IU/ml (PT). The second immunoblot kit measured antibodies to a single calibrated PT band. Both kits measured IgA antibodies, and one additionally measured IgM antibodies. Two of 41 (5%) ELISA IgM positives were confirmed positive by IgM immunoblotting, suggesting poor specificity of the IgM ELISA. The agreements of the IgG and IgA immunoblots with the ELISA ranged from 72.5% to 85.3%, with only 38 to 51% of IgA positives confirmed by immunoblotting and only 61 to 68% of IgG positives confirmed by immunoblotting. The two immunoblots correlated well with each other, with 91.7% and 94.3% agreement for IgG and IgA, respectively. When the FHA band was used with the PT band as the criterion for positivity, significant differences existed in specificity compared to the ELISA (IgG, 84.1% versus 33.3%; IgA, 82.4% versus 71.0%). When the positive IgA immunoblots (evidence of natural recent infection) were compared to the positive PT-100 IgG immunoblots (evidence of recent infection or vaccination), the PT-100 blot showed a 71% sensitivity in detecting natural recent infection.B. pertussisimmunoblots, alone or in combination with ELISAs, can aid in the diagnosis ofB. pertussisinfection.

scholarly journals Detection of Antibodies to the Biofilm Exopolysaccharide of Histophilus somni following Infection in Cattle by Enzyme-Linked Immunosorbent Assay

2014 ◽  
Vol 21 (10) ◽  
pp. 1463-1467 ◽  
Author(s):  
Yu Pan ◽  
Taylor Fisher ◽  
Christina Olk ◽  
Thomas J. Inzana
Keyword(s):  
Immunosorbent Assay ◽  
Biofilm Formation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Content Type ◽  
Histophilus Somni ◽  
Index Value

ABSTRACTAn enzyme-linked immunosorbent assay (ELISA) was developed to detect bovine antibodies toHistophilus somniexopolysaccharide (EPS), which is created during biofilm formation. When an index value of 0.268 was used, the sensitivity of the assay for infected calves was 90.5% at 3 weeks postinfection, but the number of positive animals increased by week 4. The specificity of the assay for healthy calves was 92.5%. The EPS ELISA may aid in identifying calves withH. somnidiseases.

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