scholarly journals Detection of Specific Antibodies to an Antigenic Mannoprotein for Diagnosis of Penicillium marneffeiPenicilliosis

1998 ◽  
Vol 36 (10) ◽  
pp. 3028-3031 ◽  
Author(s):  
Liang Cao ◽  
Da-Liang Chen ◽  
Cindy Lee ◽  
Che-Man Chan ◽  
King-Man Chan ◽  
...  

The disseminated and progressive fungal disease Penicillium marneffei penicilliosis is one of the most common infectious diseases in AIDS patients in Southeast Asia. To diagnose systemic penicilliosis, we developed an enzyme-linked immunosorbent assay (ELISA)-based antibody test with Mp1p, a purified recombinant antigenic mannoprotein of P. marneffei. Evaluation of the test with guinea pig sera against P. marneffei and other pathogenic fungi indicated that this assay was specific for P. marneffei. Clinical evaluation revealed that high levels of specific antibody were detected in two immunocompetent penicilliosis patients. Furthermore, approximately 80% (14 of 17) of the documented penicilliosis patients with human immunodeficiency virus tested positive for the specific antibody. No false-positive results were found for serum samples from 90 healthy blood donors, 20 patients with typhoid fever, and 55 patients with tuberculosis, indicating a high specificity of the test. Thus, this ELISA-based test for the detection of anti-Mp1p antibody can be of significant value as a diagnostic for penicilliosis.


2016 ◽  
Vol 1 (3) ◽  
pp. 612-621 ◽  
Author(s):  
Abdus Salam ◽  
Md Atiqul Haque ◽  
Md Mostafizer Rahman ◽  
Mir Rowshan Akter ◽  
Farzana Afroz

The present study was conducted on layer birds of different age groups to determine specific antibody titer level against avian reovirus (ARV) by indirect enzyme linked immunosorbent assay (iELISA) at Dinajpur district of Bangladesh. This study showed that ARV specific antibody positive cases were 84 out of 90 blood serum samples and the highest antibody titer was 26120 and lowest antibody titer was 288. The total 93.33% sera samples were showed positive result. The study showed that 100% sera sample were positive against ARV at 6 weeks of aged group and the highest, lowest and mean antibody titer were 13917, 4895 and 10269 respectively. On the other hand 88.88% sera sample were positive against ARV at 10 weeks of aged group and the highest, lowest and mean antibody titer were 9779, 288 and 5689.89 respectively. The sera sample collected from 14 weeks of aged group showed 88.88% positive and the highest, lowest and mean antibody titer were 11727, 871 and 5250 respectively. The sera sample collected from 18 weeks of aged group showed 88.88% positive against ARV and the highest, lowest and mean antibody titer were 24440, 1234 and 12648.89 respectively. The sera sample collected from 22 weeks of aged group were 100% positive against ARV and the highest, lowest and mean antibody titer were 26120, 1752 and 11373.89 respectively. The sera sample collected from 26 weeks of aged group showed 100% positive against ARV and the highest, lowest and mean antibody titer were 8566, 1630 and 4327.44 respectively. The sera sample collected from 30 weeks of aged group showed 100% positive against ARV and the highest, lowest and mean antibody titer were 13431, 1989 and 5890.56 respectively. The sera sample collected from 40 weeks of aged group showed 77.77% positive against ARV and the highest, lowest and mean antibody titer were 14618, 433 and 5103.22 respectively. The sera sample collected from 48 weeks of aged group showed 88.88% positive against ARV and the highest, lowest and mean antibody titer were 14553, 957 and 7436.5 respectively. In conclusion it is evident that avian reovirus-specific antibody was successfully detected through commercially available avian reovirus antibody test kit (ELISA kit) and the virus induced a significant antibody titer indicating the affecting virus was absolutely ARV.Asian J. Med. Biol. Res. December 2015, 1(3): 612-621



2006 ◽  
Vol 13 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Janaína Lobato ◽  
Deise A. O. Silva ◽  
Tiago W. P. Mineo ◽  
Jodi D. H. F. Amaral ◽  
Gesmar R. Silva Segundo ◽  
...  

ABSTRACT Considering that little is known about the epidemiology of Neospora caninum infection in humans, particularly in populations with high Toxoplasma gondii infection rates, the present study aimed to investigate the presence of antibodies to N. caninum in T. gondii-seropositive and -seronegative individuals. A total of 256 serum samples divided into four groups (61 samples from human immunodeficiency virus [HIV]-positive patients, 50 samples from patients with neurological disorders, 91 samples from newborns, and 54 samples from healthy subjects) were assessed for N. caninum and T. gondii serologies by indirect fluorescent-antibody test, enzyme-linked immunosorbent assay, and immunoblotting (IB). Immunoglobulin G antibodies to N. caninum were predominantly detected in HIV-infected patients (38%) and patients with neurological disorders (18%), while newborns and healthy subjects showed lower seropositivity rates (5% and 6%, respectively). Seropositivity to N. caninum was significantly associated with seropositivity to T. gondii in both HIV-infected patients and patients with neurological disorders. Seroreactivity to N. caninum was confirmed by IB, with positive sera predominantly recognizing the 29-kDa antigen of N. caninum. The results of this study indicate the presence of N. caninum infection or exposure in humans, particularly in HIV-infected patients or patients with neurological disorders, who could have opportunistic and concurrent infections with T. gondii. These findings may bring a new concern for the unstable clinical health of HIV-infected patients and the actual role of N. caninum infection in immunocompromised patients.



2003 ◽  
Vol 16 (3) ◽  
pp. 261-268 ◽  
Author(s):  
I. Christova

Serum samples from Bulgarian patients with physician-diagnosed erythema migrans (EM) (n=105) were examined using Borrelia burgdorferi ELISA (Boehring, Germany) after previous absorption with Treponema phagedenis. For IgM antibody detection sera were additionally pretreated with anti-IgG serum (RF absorbent). Serum samples of 93 % of persons from healthy control group were IgM negative and all were IgG negative. Out of 105 patients with EM, 49 % were IgM positive and 14 % were borderline. IgG ELISA showed positive results for 17 % and borderline for 6 % of the patients. Positive and borderline serum samples were examined further by immunofluorescent assay (IFA) and immunoblot test with recombinant B. burgdorferi proteins from strain PKo ( B. afzelii) - p100, flagellin, OspA and OspC, and internal flagellin fragments from strains PKo and PBi ( β. garinii) [B. Wilske, V. Fingerle, P. Herzer et al. 1993. Med. Microbiol. Immunol. 182:255]. IFA detected IgM antibodies against B. burgdorferi in 47 % of the positive and in none of the borderline by IgM ELISA serum samples as well as IgG antibodies in 83 % of the positive and in 50% of the borderline by IgG ELISA samples. Presence of specific antibodies was confirmed by immunoblot in 71 % of the IgM ELISA postive and in 67 % of the IgG ELISA positive sera. In addition, anti-β. burgdorferi antibodies were detected in 60 % of the borderline by IgM ELISA serum samples. IgM serum reactivity was directed mainly against OspC antigen and flagellin and IgG antibodies were directed mainly against flagellin and p100. These findings clearly showed advantages of the ELISA test based on previous pretreatment of sera and capable to detect specific antibodies in more than half of patients with early Lyme borreliosis despite the well-known delayed immune response. IFA was less sensitive than ELISA in detection of anti- B. burgdorferi antibodies. An additional examination of ELISA borderline sera by immunoblot revealed more positive results. Serum reactivity to a single OspC antigen seems to be a sufficient criterion for positive IgM immunoblot.



Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 303
Author(s):  
Wei-Ting Hsu ◽  
Chia-Yu Chang ◽  
Chih-Hsuan Tsai ◽  
Sung-Chan Wei ◽  
Huei-Ru Lo ◽  
...  

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes serious and highly contagious enteric disease in swine worldwide. In this study, we constructed a recombinant baculovirus (S-Bac) expressing full-length spike protein of the virulent epidemic genotype 2b (G2b) PEDV strain for serological studies of infected pigs. We found that most spike-specific antibodies produced upon PEDV infection in pigs are conformation-specific and they could be detected on S-Bac-infected insect cells by immunofluorescent assay, but they were insensitive to Western blot analysis, the typical method for antiserum analysis. These results indicated that spike conformation is crucial for serum recognition. Since it is difficult to purify trimeric spike membrane protein for conventional enzyme-linked immunosorbent assay (ELISA), we used S-Bac to generate a novel cell-based ELISA for convenient PEDV detection. We analyzed 100 pig serum samples, and our cell-based ELISA exhibited a sensitivity of 100%, a specificity of 97%, and almost perfect agreement [Cohen’s kappa coefficient value (κ) = 0.98] with immunocytochemical staining results. Our cell-based ELISA rapidly presented antigen for proper detection of conformation-specific antibodies, making PEDV detection more convenient, and it will be useful for detecting many viral diseases in the future.



2018 ◽  
Vol 27 (2) ◽  
pp. 232-236 ◽  
Author(s):  
Andressa Maria Rorato Nascimento de Matos ◽  
Eloiza Teles Caldart ◽  
Fernanda Pinto Ferreira ◽  
Keila Clarine Monteiro ◽  
Marielen de Souza ◽  
...  

Abstract The aim of this study were to detect antibodies anti-Leishmania spp. and anti-Trypanosoma cruzi in two different populations of domestic cats (Felis catus domesticus) from North Paraná referred for surgical castration and to determine which characteristics of the animals studied may be associated with seropositivity. Serum samples from 679 cats were analyzed using enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence antibody test (IFAT) in series. Associations between age, sex, race, year of care and animal group were verified using the simple logistic regression. Percentage of 8.5% (58/679) of cats were positive for Leishmania spp. and 7.6% (51/673) for T. cruzi by the tests ELISA and IFAT. Animals collected by non-governmental animal protection organizations presented more seropositivity for Leishmania spp. (p<0.0001). Results shown that Leishmania spp. and T. cruzi are present in domestic cats in the northern part of the state of Paraná, as well as, owners of non-governmental animal protection organizations may be more exposed to leishmaniasis when compared to other animal owners evaluated in the present study.



Author(s):  
Eide Dias Camargo ◽  
Paulo Mutuko Nakamura ◽  
Adelaide José Vaz ◽  
Marcos Vinícius da Silva ◽  
Pedro Paulo Chieffi ◽  
...  

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.



1999 ◽  
Vol 179 (6) ◽  
pp. 1591-1592 ◽  
Author(s):  
Adele Caterino‐de‐Araujo ◽  
Maria Luisa Calabrò ◽  
Elizabeth de los Santos‐Fortuna ◽  
Jamal Suleiman ◽  
Luigi Chieco‐Bianchi


2000 ◽  
Vol 38 (7) ◽  
pp. 2628-2632 ◽  
Author(s):  
Marta A. Guerra ◽  
Edward D. Walker ◽  
Uriel Kitron

Serum samples obtained from healthy, asymptomatic dogs in areas of Wisconsin and northern Illinois where Lyme disease is endemic or nonendemic were assayed for antibodies to Borrelia burgdorferi by enzyme-linked immunosorbent assay (ELISA), and positive results were confirmed by immunoblot assay. We found that 56.9% (562 of 1,077) of the samples were positive by ELISA and 82.0% (461 of 562) were positive by immunoblotting. A logistic regression model was developed to distinguish between nonvaccinated dogs naturally infected with B. burgdorferi from areas where the disease is endemic and dogs from areas where the disease is nonendemic that were vaccinated against Lyme disease. Of the 18 protein bands analyzed, 8 were found to be significantly different (P < 0.05) between the two groups. p93, p34, p31, and p28 occurred with increased frequency in vaccinated dogs, while p58, p37, p35, and p30 occurred more frequently in naturally infected dogs. The logistic regression equation obtained was used to determine the probability of natural infection among vaccinated dogs residing in areas where the disease is endemic. Of 125 samples, 87.2% had a very low probability of natural infection and only 2.4% were highly likely to be infected. Logistic regression is a useful method for distinguishing between vaccinated and naturally infected dogs and predicting the serological status of vaccinated dogs from areas where Lyme disease is endemic.



2021 ◽  
Vol 8 (12) ◽  
pp. 310
Author(s):  
Ísis Assis Braga ◽  
Isis Indaiara Gonçalves Granjeiro Taques ◽  
Estefânia Crivelatti Grontoski ◽  
Ingrid Savino de Oliveira Dias ◽  
Nathalia Assis Pereira ◽  
...  

Cats naturally exposed to Ehrlichia canis have been described in different regions of the world, but little is known about the genotypes associated with infection in these animals. To detect E. canis-specific antibodies and investigate the E. canis TRP genotypes in cats, serum samples from 76 domestic cats reactive to crude E. canis antigens by the indirect fluorescence antibody test (IFAT) were analyzed by ELISA, using E. canis-specific peptides (i.e., TRP19 and TRP36 /BR/US/CR). Of these, 25 (32.9%) cats reacted to at least one TRP peptide, confirming their specific exposure to E. canis. Eighteen (23.7%) cats reacted to TRP19, 15 (19.8%) to BRTRP36, and 11 (14.5%) to USTRP36, but none of them reacted to CRTRP36. Eight (10.5%) cats reacted to TRP19 but not to any TRP36 genotype, demonstrating the possible existence of a new E. canis genotype infecting felines. Nevertheless, this study provides the first report of anti-E. canis-specific antibodies in domestic cats.



Parasitology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Fernanda F. Ramos ◽  
Grasiele S. V. Tavares ◽  
Fernanda Ludolf ◽  
Amanda S. Machado ◽  
Thaís T. O. Santos ◽  
...  

Abstract The diagnosis of visceral leishmaniasis (VL) has improved with the search of novel antigens; however, their performance is limited when samples from VL/human immunodeficiency virus (HIV)-coinfected patients are tested. In this context, studies conducted to identify more suitable antigens to detect both VL and VL/HIC coinfection cases should be performed. In the current study, phage display was performed using serum samples from healthy subjects and VL, HIV-infected and VL/HIV-coinfected patients; aiming to identify novel phage-exposed epitopes to be evaluated with this diagnostic purpose. Nine non-repetitive and valid sequences were identified, synthetized and tested as peptides in enzyme-linked immunosorbent assay experiments. Results showed that three (Pep2, Pep3 and Pep4) peptides showed excellent performance to diagnose VL and VL/HIV coinfection, with 100% sensitivity and specificity values. The other peptides showed sensitivity varying from 50.9 to 80.0%, as well as specificity ranging from 60.0 to 95.6%. Pep2, Pep3 and Pep4 also showed a potential prognostic effect, since specific serological reactivity was significantly decreased after patient treatment. Bioinformatics assays indicated that Leishmania trypanothione reductase protein was predicted to contain these three conformational epitopes. In conclusion, data suggest that Pep2, Pep3 and Pep4 could be tested for the diagnosis of VL and VL/HIV coinfection.



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