scholarly journals trans-Sialidase Neutralizing Antibody Detection in Trypanosoma cruzi-Infected Domestic Reservoirs

2011 ◽  
Vol 18 (6) ◽  
pp. 984-989 ◽  
Author(s):  
Paula A. Sartor ◽  
Martha V. Cardinal ◽  
Marcela M. Orozco ◽  
Ricardo E. Gürtler ◽  
M. Susana Leguizamón

ABSTRACTThe detection ofTrypanosoma cruziinfection in domestic dogs and cats is relevant to evaluating human transmission risks and the effectiveness of insecticide spraying campaigns. However, the serological assays routinely used are associated with cross-reactivity in sera from mammals infected withLeishmaniaspp. We used atrans-sialidase inhibition assay (TIA) forT. cruzidiagnosis in serum samples from 199 dogs and 57 cats from areas where these types of infections are endemic. TIA is based on the antibody neutralization of recombinanttrans-sialidase, an enzyme that is not detected in the coendemicLeishmaniaspecies orTrypanosoma rangeliparasites.T. cruziinfection was also evaluated by conventional serology (CS) (indirect immunofluorescence, indirect hemagglutination, enzyme-linked immunosorbent assay, and immunochromatographic dipstick test) and xenodiagnosis. Sera from 30 dogs and 15 cats from areas where these organisms are not endemic and 5 dogs with visceral leishmaniasis were found to be nonreactive by TIA and CS. Samples from dogs and cats demonstrated 91 and 95% copositivities between TIA and CS, whereas the conegativities were 98 and 97%, respectively. Sera from xenodiagnosis-positive dogs and cats also reacted by TIA (copositivities of 97 and 83%, respectively). TIA was reactive in three CS-negative samples and was able to resolve results in two cat serum samples that were CS inconclusive. Our study is the first to describe the development oftrans-sialidase neutralizing antibodies in naturally infected dogs and cats. High CS conegativity and the absence oftrans-sialidase neutralization in dog sera from areas where leishmaniasis is not endemic and from dogs with visceral leishmaniasis support TIA specificity. The TIA may be a useful tool forT. cruzidetection in the main domestic reservoirs.

2013 ◽  
Vol 21 (1) ◽  
pp. 96-106 ◽  
Author(s):  
Lourena E. Costa ◽  
Mayara I. S. Lima ◽  
Miguel A. Chávez-Fumagalli ◽  
Daniel Menezes-Souza ◽  
Vivian T. Martins ◽  
...  

ABSTRACTVisceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy andTrypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected withLeishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n= 31) compared to those from vaccinated dogs (n= 21), experimentally infected dogs with cross-reactive parasites (n= 23), and healthy controls (n= 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no cross-reactivity withT. cruzi- orEhrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes ofL. infantumantigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programs.


2009 ◽  
Vol 16 (12) ◽  
pp. 1774-1780 ◽  
Author(s):  
Eduardo A. F. Coelho ◽  
Laura Ramírez ◽  
Mariana A. F. Costa ◽  
Vinicio T. S. Coelho ◽  
Vivian T. Martins ◽  
...  

ABSTRACT In the present work, we have analyzed the antigenicity of Leishmania species ribosomal proteins (LRPs). To accomplish this, Leishmania infantum ribosomes were biochemically purified from promastigote cytosolic extracts, and their reactivities were analyzed by using the sera from dogs naturally infected with L. infantum. Since antibodies reacting against different ribosomal proteins were observed in all the serum samples obtained from dogs with symptomatic visceral leishmaniasis tested, we have analyzed the potential usefulness of the LRP extracts in the development of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of canine visceral leishmaniasis (CVL) in an area of Brazil where visceral leishmaniasis is endemic due to infection by Leishmania chagasi. A comparative ELISA with crude soluble Leishmania chagasi antigen (SLA) and L. infantum LRPs was performed. LRP- and SLA-based ELISAs gave similar sensitivities for the diagnosis of symptomatic CVL, but the LRP extract provided a very high sensitivity for the detection of oligosymptomatic and asymptomatic dogs. In addition, an LRP-based ELISA showed a higher specificity when the sera from dogs harboring other infections were included in the analysis. The LRP antigen displayed no cross-reactivity with sera from dogs that had any of the other diseases tested, notably, Chagas' disease. Our findings suggest that LRPs are a potential tool for the diagnosis of CVL and will be particularly useful for the diagnosis of asymptomatic CVL.


2019 ◽  
Vol 57 (8) ◽  
Author(s):  
Ramona Tavares Daltro ◽  
Leonardo Maia Leony ◽  
Natália Erdens Maron Freitas ◽  
Ângelo Antônio Oliveira Silva ◽  
Emily Ferreira Santos ◽  
...  

ABSTRACT Chimeric T. cruzi antigens have been proposed as a diagnostic tool for chronic Chagas disease (CD) in both settings where Chagas disease is endemic and those where it is not endemic. Antibody response varies in accordance to each T. cruzi strain, presenting challenges to the use of antigens lacking demonstrated cross-reactivity with Leishmania spp. Our group expressed four chimeric proteins (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) and previously assessed their diagnostic performance to determine cross-reactivity with Leishmania spp. Here, we validated our findings using serum samples from different Brazilian geographic areas reporting endemic Chagas disease, endemic visceral or American cutaneous leishmaniasis (ACL), or both. Overall, 829 serum samples were evaluated using commercial and IBMP enzyme-linked immunosorbent assays. Due to the absence of a reference assay to diagnosis CD, latent class analysis (LCA) was performed through the use of a statistical model. The incidence of cross-reactivity for ACL-positive samples varied from 0.35% (IBMP-8.3) to 0.70% (IBMP-8.1 and IBMP-8.2). Regarding visceral leishmaniasis (VL)-positive samples, the IBMP-8.2 and IBMP-8.3 antigens cross-reacted with six (3.49%) and with only one sample (0.58%), respectively. No cross-reactivity with either ACL or VL was observed for the IBMP-8.4 antigen. Similarly, no cross-reactions were found when VL-positive samples were assayed with IBMP-8.1. The agreement among the results obtained using IBMP antigens ranged from 97.3% for IBMP-8.2 and 99% for IBMP-8.1 and IBMP-8.3 to 100% for IBMP-8.4, demonstrating almost perfect agreement with LCA. Accordingly, in light of the negligible cross-reactivity with both ACL and VL, we suggest the use of IBMP antigens in regions where T. cruzi and Leishmania spp. are coendemic.


2014 ◽  
Vol 21 (5) ◽  
pp. 732-736 ◽  
Author(s):  
Neil W. Anderson ◽  
Diane M. Klein ◽  
Sarina M. Dornink ◽  
Deborah J. Jespersen ◽  
Joseph Kubofcik ◽  
...  

ABSTRACTDue to the limited sensitivities of stool-based microscopy and/or culture techniques forStrongyloides stercoralis, the detection of antibodies to this intestinal nematode is relied upon as a surrogate for determining exposure status or making a diagnosis ofS. stercoralisinfection. Here, we evaluated three immunoassays, including the recently released InBios Strongy Detect IgG enzyme-linked immunosorbent assay (ELISA) (InBios International, Inc., Seattle, WA), the SciMedxStrongyloidesserology microwell ELISA (SciMedx Corporation, Denville, NJ), and the luciferase immunoprecipitation system (LIPS) assay performed at the National Institutes of Health (NIH), for their detection of IgG antibodies toS. stercoralis. A total of 101 retrospective serum samples, previously submitted for routineS. stercoralisantibody detection using the SciMedx assay, were also evaluated by the InBios and LIPS assays. The qualitative results from each assay were compared using a Venn diagram analysis, to the consensus result among the three assays, and each ELISA was also evaluated using the LIPS assay as the reference standard. By Venn diagram analysis, 65% (66/101) of the samples demonstrated perfect agreement by all three assays. Also, the numbers of samples considered positive or negative by a single method were similar. Compared to the consensus result, the overall percent agreement of the InBios, SciMedx, and LIPS assays were comparable at 87.1%, 84.2%, and 89.1%, respectively. Finally, the two ELISAs performed analogously but demonstrated only moderate agreement (kappa coefficient for the two assays, 0.53) with the LIPS assay. Collectively, while the two commercially available ELISAs perform equivalently, neither should be used independently of clinical evaluation to diagnose strongyloidiasis.


2013 ◽  
Vol 20 (8) ◽  
pp. 1197-1202 ◽  
Author(s):  
Africa Holguín ◽  
Francesca Norman ◽  
Leticia Martín ◽  
María Luisa Mateos ◽  
Jesús Chacón ◽  
...  

ABSTRACTTrypanosoma cruziserological screening is recommended for people potentially exposed to this parasite in countries whereTrypanosoma cruziis endemic and those where it is not endemic. Blood samples on filter paper may be a practical alternative to plasma/serum for antibody detection. Using the Architect Chagas assay, we detected the presence of IgG againstT. cruziin matched serum and dried blood spots (DBS) collected from 147 patients residing in Madrid, Spain, who had potential previous exposure toT. cruzi. The κ statistic for the DBS/serum proportion of agreement for the detection of antibodies againstT. cruziwas 0.803, considering an S/CO (assay result unit; chemiluminescent signal from the sample [S] divided by the mean chemiluminescent signal for the three calibrators used in the test [CO]) cutoff value of ≥1.00. The relative sensitivity of the Architect test using DBS increased from 95.2% to 98.8% when the cutoff was lowered from ≥1.00 to ≥0.88, while the relative specificity decreased from 84.1% to 71.6%. Overall, the median S/CO values for DBS were significantly lower than those for serum (2.6 versus 6.5;P< 0.001). Discrepancies that occurred with the use of DBS included 10 false positives (with low S/CO values in 9 cases [median, 2.13]) and 4 false negatives, with mean S/CO values of 0.905 (gray zone). Using DBS plus a highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) may be a simple and reliable method for detecting IgG againstT. cruziwhen blood sampling by venipuncture is not feasible. This method may also reduce the false-negative rates observed with some rapid diagnostic tests. The lower relative sensitivity compared to the reference method may be increased by lowering the optical density threshold.


2020 ◽  
Vol 94 (7) ◽  
Author(s):  
Chang Zhang ◽  
Zhongyi Wang ◽  
Jianqiu Cai ◽  
Xiaomin Yan ◽  
Fuqiang Zhang ◽  
...  

ABSTRACT Southern China is a hot spot of emerging infectious diseases, in which diverse species of bats dwell, a large group of flying mammals considered natural reservoirs for zoonotic viruses. Recently, divergent filoviruses (FiVs) have been identified in bats within this region, which pose a potential risk to public health, but the true infection situation in bats remains largely unclear. Here, 689 archived bat serum samples were analyzed by enzyme-linked immunosorbent assay (ELISA), Western blotting, and neutralization assay to investigate the seroprevalence and cross-reactivity of four divergent FiVs and two other viruses (rabies virus and Tuhoko pararubulavirus 1) of different families within the order Mononegavirales. Results showed no cross-antigenicity between FiVs and other mononegaviruses but different cross-reactivity among the FiVs themselves. The total FiV seroreactive rate was 36.3% (250/689), with infection by the indigenous Chinese FiV DH04 or an antigenically related one being the most widely and the most highly prevalent. Further viral metagenomic analysis of fruit bat tissues also identified the gene sequence of a novel FiV. These results indicate the likely prevalence of other so far unidentified FiVs within the Chinese bat population, with frugivorous Rousettus leschenaultii and Eonycteris spelaea bats and insectivorous Myotis horsfieldii and Miniopterus schreibersii bats being their major reservoirs. IMPORTANCE Bats are natural hosts of many FiVs, from which diverse FiVs were serologically or virologically detected in Africa, Europe, and East Asia. Recently, very divergent FiVs were identified in the Chinese bat population, but their antigenic relationship with other known FiVs remains unknown. Here, we conducted serological characterization and investigation of Chinese indigenous FiVs and prototypes of other viruses in bats. Results indicated that Chinese indigenous FiVs are antigenically distant to other FiVs, and infection of novel or multiple FiVs occurred in Chinese bats, with FiV DH04 or an antigenically related one being the most widely and the most highly prevalent. Additionally, besides Rousettus leschenaultii and Eonycteris spelaea bats, the insectivorous Myotis horsfieldii and M. schreibersii bats are highly preferential hosts of FiVs. Seroreactive and viral metagenomic results indicated that more as yet unknown bat-borne FiVs circulate in Southern China, and to uncover them further, investigation and timely surveillance is needed.


2020 ◽  
Vol 58 (7) ◽  
Author(s):  
Higor Sette Pereira ◽  
Ludmila Tavares e Almeida ◽  
Vitória Fernandes ◽  
Renato Lima Senra ◽  
Patrícia Pereira Fontes ◽  
...  

ABSTRACT Neosporosis has become a concern since it is associated with abortion in cattle. Currently, in situ diagnosis is determined through anamnesis, evaluation of the history, and perception of the clinical signs of the herd. There is no practical and noninvasive test adapted to a large number of samples, which represents a gap for the use of new approaches that provide information about infections and the risks of herds. Here, we performed a search in the Neospora caninum genome by linear B-cell epitopes using immunoinformatic tools aiming to develop a chimeric protein with high potential to bind specifically to antibodies from infected cattle samples. An enzyme-linked immunosorbent assay with the new chimeric antigen was developed and tested with sera from natural field N. caninum-infected bovines. The cross-reactivity of the new antigen was also evaluated using sera from bovines infected by other abortive pathogens, including Trypanosoma vivax, Leptospira sp., Mycobacterium bovis, and Brucella abortus, and enzootic bovine leucosis caused by bovine leukemia virus, as well as with samples of animals infected with Toxoplasma gondii. The assay using the chimeric protein showed 96.6% ± 3.4% of sensitivity in comparison to healthy animal sera. Meanwhile, in relation to false-positive results provided by cross-reactivity with others pathogens, the specificity value was 97.0% ± 2.9%. In conclusion, immunoinformatic tools provide an efficient platform to build an accurate protein to diagnose bovine neosporosis based on serum samples.


2014 ◽  
Vol 21 (3) ◽  
pp. 354-359 ◽  
Author(s):  
Murugesan Kanagavel ◽  
Santhanam Shanmughapriya ◽  
Kumarasamy Anbarasu ◽  
Kalimuthusamy Natarajaseenivasan

ABSTRACTLeptospirosis is a reemerging infectious disease that is underdiagnosed and under-recognized due to low-sensitivity and cumbersome serological tests. Rapid reliable alternative tests are needed for early diagnosis of the disease. Considering the importance of the pathogenesis-associated leptospiral LigA protein expressedin vivo, we have evaluated its application in the diagnosis of the acute form of leptospirosis. The C-terminal coding sequence ofligA(ligA-C) was cloned into pET15b and expressed inEscherichia coli. Furthermore, the B-cell-specific epitopes were predicted and were synthesized as peptides for evaluation along with recombinant LigA-C. Epitope 1 (VVIENTPGK), with a VaxiJen score of 1.3782, and epitope 2 (TALSVGSSK), with a score of 1.2767, were utilized. A total of 140 serum samples collected from leptospirosis cases during the acute stage of the disease and 138 serum samples collected from normal healthy controls were utilized for evaluation. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the recombinant LigA-C-specific IgM enzyme-linked immunosorbent assay (ELISA) and were found to be 92.1%, 97.7%, 92.8%, and 97.5%, respectively. Epitopes 1 and 2 used in the study showed 5.1 to 5.8% increased sensitivity over recombinant LigA-C in single and combination assays for IgM antibody detection. These findings suggest that these peptides may be potential candidates for the early diagnosis of leptospirosis.


2019 ◽  
Vol 57 (5) ◽  
Author(s):  
Marcílio Jorge Fumagalli ◽  
William Marciel de Souza ◽  
Marília Farignoli Romeiro ◽  
Michell Charles de Souza Costa ◽  
Renata Dezengrini Slhessarenko ◽  
...  

ABSTRACT Mayaro virus (MAYV) is a neglected arthropod-borne virus (arbovirus) antigenically clustered into the Semliki Forest complex group of Alphavirus genus (Togaviridae family), maintained in an unclear zoonotic cycle involving mosquitoes from Haemagogus genus as the main vector. The genome is composed of a positive single-stranded RNA of 11.5 kb in length, which contains two genes that encode four nonstructural (nsP1 to nsP4) and five structural (C, E3, E2, 6K, and E1) proteins. In the present study, we have developed an enzyme-linked immunosorbent assay (ELISA) using as antigen the recombinant envelope protein 2 of MAYV produced in an Escherichia coli system (rE2-MAYV ELISAs). A panel of 68 human serum samples from suspected arboviral cases was analyzed and titrated for anti-MAYV IgM and IgG antibody detection. The rE2-MAYV ELISA detected 33.8% (23/68) IgG-positive samples, demonstrating 100% sensitivity and 78.95% specificity compared to the MAYV-specific 50% plaque reduction neutralization assay. In addition, the positive MAYV-neutralizing samples showed high titers of detection by rE2-MAYV ELISA, suggesting a highly sensitive test. The rE2-MAYV ELISA also detected 42.5% (29/68) IgM-positive samples, of which 13.8% (4/29) presented high-avidity interactions with rE2-MAYV. Cross-reactivity was observed with Chikungunya virus (CHIKV)-specific murine antibody sample but not with CHIKV-specific human and other Alphavirus murine antibodies. In short, we have developed a rapid, simple, specific, and sensitive MAYV rE2-ELISA, and our preliminary results show its potential applicability to diagnosis of MAYV infections.


2011 ◽  
Vol 18 (10) ◽  
pp. 1650-1655 ◽  
Author(s):  
Sriveny Dangoudoubiyam ◽  
Ramesh Vemulapalli ◽  
Momar Ndao ◽  
Kevin R. Kazacos

ABSTRACTBaylisascarislarva migrans is an important zoonotic disease caused byBaylisascaris procyonis, the raccoon roundworm, and is being increasingly considered in the differential diagnosis of eosinophilic meningoencephalitis in children and young adults. Although aB. procyonisexcretory-secretory (BPES) antigen-based enzyme-linked immunosorbent assay (ELISA) and a Western blot assay are useful in the immunodiagnosis of this infection, cross-reactivity remains a major problem. Recently, a recombinantB. procyonisantigen, BpRAG1, was reported for use in the development of improved serological assays for the diagnosis ofBaylisascarislarva migrans. In this study, we tested a total of 384 human patient serum samples in a BpRAG1 ELISA, including samples from 20 patients with clinicalBaylisascarislarva migrans, 137 patients with other parasitic infections (8 helminth and 4 protozoan), and 227 individuals with unknown/suspected parasitic infections. A sensitivity of 85% and a specificity of 86.9% were observed with the BpRAG1 ELISA, compared to only 39.4% specificity with the BPES ELISA. In addition, the BpRAG1 ELISA had a low degree of cross-reactivity with antibodies toToxocarainfection (25%), while the BPES antigen showed 90.6% cross-reactivity. Based on these results, the BpRAG1 antigen has a high degree of sensitivity and specificity and should be very useful and reliable in the diagnosis and seroepidemiology ofBaylisascarislarva migrans by ELISA.


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