scholarly journals Development of Rapid Immunochromatographic Test with Recombinant NcSAG1 for Detection of Antibodies to Neospora caninum in Cattle

2005 ◽  
Vol 12 (7) ◽  
pp. 885-887 ◽  
Author(s):  
Min Liao ◽  
Shoufa Zhang ◽  
Xuenan Xuan ◽  
Guohong Zhang ◽  
Xiaohong Huang ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Rapid Detection ◽  
Reliable Method ◽  
Neospora Caninum ◽  
Antibody Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunochromatographic Test ◽  
Serum Samples ◽  
Immunofluorescent Antibody Test ◽  
Good Agreement

ABSTRACT An immunochromatographic test (ICT) with recombinant surface antigen 1 of Neospora caninum (NcSAG1) was developed for the rapid detection of antibodies to N. caninum in cattle. The ICT was used to clearly discriminate between immunofluorescent-antibody test (IFAT)-positive bovine sera and IFAT-negative bovine sera. Serum samples collected from cattle in Yanbian, China, were examined by the ICT. Of the 96 serum samples, 23 (24.0%) were positive by the ICT, and 19 (19.8%) samples were positive by a previously developed enzyme-linked immunosorbent assay (ELISA). Eighteen of 19 ELISA-positive samples were positive according to the ICT. A good agreement was found between the results of the ICT and the ELISA. The results presented here suggest that the ICT with recombinant truncated NcSAG1 fused to glutathione S-transferase is a useful and reliable method for the detection of antibodies to N. caninum in cattle.

scholarly journals Detection of Immunoglobulin G Antibodies to Neospora caninum in Humans: High Seropositivity Rates in Patients Who Are Infected by Human Immunodeficiency Virus or Have Neurological Disorders

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 ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immunoglobulin G ◽  
Neurological Disorders ◽  
Healthy Subjects ◽  
Neospora Caninum ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Immunodeficiency Virus

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.

scholarly journals Serological response to Neospora caninum infection in goats and agreement between three diagnostic techniques to detect caprine neosporosis

2019 ◽  
Vol 39 (1) ◽  
pp. 25-31
Author(s):  
Pomy C.P. Kim ◽  
Renata P.B. Melo ◽  
Jonatas C. Almeida ◽  
José G. Silva ◽  
Muller Ribeiro-Andrade ◽  
...  
Keyword(s):  
Neospora Caninum ◽  
High Sensitivity ◽  
Antibody Test ◽  
Diagnostic Techniques ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Response ◽  
Serum Samples ◽  
Caninum Infection ◽  
Reference Serum ◽  
Indirect Immunofluorescent

ABSTRACT: The present study aimed to measure the serological response of goats infected with Neospora caninum by assessing the diagnostic performance and agreement between three techniques (indirect immunofluorescent antibody test, IFAT; Neospora agglutitation test, NAT; enzyme-linked immunosorbent assay, ELISA). The panel of sera were comprised of 500 samples of goats, and 60 reference serum samples. These reference and field serum samples were tested by ELISA, NAT, and IFAT. In the field serum samples tested, the seroprevalences of anti-N. caninum antibodies were 3.2%, 4.6%, and 6.4% in the NAT, IFAT and ELISA, respectively. Using the IFAT as the gold standard, the NAT and the ELISA agreement was considered weak (k=0.28) and strong (k=0.75), respectively. When the IFAT performance was used for comparison purposes, the ELISA showed 91.3% sensitivity and 97.7%, specificity with a PPV of 65.2% and a NPV of 99.6%; The NAT presented sensitivity of 26.1% and specificity of 97.9% with a PPV of 37.5% and a NPV of 96.5%. Accordingly, the IFAT should remain the assay of choice for studies about N. caninum infection in goats in individual serum samples. A combination of serological assays with high sensitivity and specificity is recommended in serosurveys of caprine neosporosis.

scholarly journals Development of an Enzyme-Linked Immunosorbent Assay for Rapid Detection of Dengue Virus (DENV) NS1 and Differentiation of DENV Serotypes during Early Infection

2019 ◽  
Vol 57 (7) ◽  
Author(s):  
Szu-Chia Lai ◽  
Yu-Yine Huang ◽  
Pei-Yun Shu ◽  
Shu-Fen Chang ◽  
Po-Shiuan Hsieh ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Dengue Virus ◽  
Immunosorbent Assay ◽  
Rapid Detection ◽  
Denv Infection ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Dengue Disease ◽  
Denv Serotypes

ABSTRACTDengue fever, caused by infections with the dengue virus (DENV), affects nearly 400 million people globally every year. Early diagnosis and management can reduce the morbidity and mortality rates of severe forms of dengue disease as well as decrease the risk of wider outbreaks. Although the early diagnosis of dengue can be achieved using a number of commercial NS1 detection kits, none of these can differentiate among the four dengue virus serotypes. In this study, we developed an enzyme-linked immunosorbent assay (ELISA) for the detection of dengue virus (DENV) NS1 by pairing a serotype-cross-reactive monoclonal antibody (MAb) with one of four serotype-specific MAbs in order to facilitate the rapid detection of NS1 antigens and the simultaneous differentiation of DENV serotypes. A total of 146 serum samples obtained from patients suspected to be in the acute phase of DENV infection were used to evaluate the clinical application of our novel test for the detection and serotyping of DENV. The overall sensitivity rate of our test was 84.85%, and the sensitivity rates for serotyping were as follows: 88.2% (15/17) for DENV serotype 1 (DENV1), 94.7% (18/19) for DENV2, 75% (12/16) for DENV3, and 66.6% (6/9) for DENV4. Moreover, there was no cross-reactivity among serotypes, and no cross-reactivity was observed in sera from nondengue patients. Thus, our test not only enables the rapid detection of the dengue virus but also can distinguish among the specific serotypes during the early stages of infection. These results indicate that our ELISA for DENV NS1 is a convenient tool that may help elucidate the epidemiology of DENV outbreaks and facilitate the clinical management of DENV infections.

scholarly journals Comparison of a New Immunochromatographic Test to Enzyme-Linked Immunosorbent Assay for Rapid Detection of Immunoglobulin M Antibodies to Hepatitis E Virus in Human Sera

2005 ◽  
Vol 12 (5) ◽  
pp. 593-598 ◽  
Author(s):  
Hsiao Ying Chen ◽  
Yang Lu ◽  
Teresa Howard ◽  
David Anderson ◽  
Priscilla Yiquan Fong ◽  
...  
Keyword(s):  
Acute Hepatitis ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Rapid Detection ◽  
Hepatitis E Virus ◽  
Rapid Test ◽  
Hepatitis E ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunochromatographic Test ◽  
Acute Hepatitis E

ABSTRACT An immunochromatographic test for rapid detection of IgM antibodies in patients with acute hepatitis E infection was developed utilizing the well-characterized recombinant protein EP2.1 and monoclonal antibody 4B2. The new rapid test based on a novel reverse-flow technology was able to generate a positive result within 2 to 3 min. Our study showed that this test was able to detect anti-HEV IgM antibodies in 96.7% of the patient samples tested (n = 151) while maintaining an excellent specificity of 98.6% with samples from various patient or healthy control groups (total n = 208). Furthermore, this rapid test gave a good specificity of 90.9% when tested with rheumatoid factor (RF)-positive sera (RF value of ≤850 IU/ml; n = 11) although a higher concentration of RF in samples might cause cross-reactivity. The new test has a good agreement of 97.2% with a kappa value of 0.943 when compared with a reference enzyme-linked immunosorbent assay. The positive predictive value and the negative predictive value for the rapid test thus reached 98.0 and 97.6%, respectively. This is the first rapid, point-of-care test for hepatitis E and will be especially useful for the diagnosis of acute hepatitis E virus infection in field and emergency settings and in resource-poor countries.

scholarly journals COMPARISON OF A RAPID ENZYME-LINKED IMMUNOSORBANT ASSAY TEST WITH AN INDIRECT IMMUNOFLUORESCENT ANTIBODY TEST IN DIAGNOSING EHRLICHIA AND ANAPLASMA INFECTIONS IN DOGS

2019 ◽  
Vol 17 (4) ◽  
pp. 346-352
Author(s):  
Kr. Gospodinova ◽  
G. Zhelev ◽  
V. Petrov
Keyword(s):  
Serum Antibody ◽  
Rapid Test ◽  
Antibody Test ◽  
Diagnostic Value ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Immunofluorescent Antibody ◽  
Antibody Titers ◽  
Indirect Immunofluorescent ◽  
Immunofluorescent Antibody Test

PURPOSE: The objective of this study is to compare the diagnostic value of commercial enzyme-linked immunosorbent assay (ELISA) with indirect immunofluorescent antibody test (IFA) in detecting immunoglobulin-G (IgG) antibodies to Ehrlichia canis and Anaplasma phagocytophilum. METHODS: Seventy-four serum samples, obtained from dogs believed to be naturally infected with E. canis or A. phagocytophilum, were analyzed. RESULTS: By ELISA, 48 (64.9%) samples were found positive for IgG to E. canis, 10 (13.5%) to A. phagocytophilum, 12 (16.2%) to both E. canis and A. phagocytophilum, and in 4 (5.4%) samples no presence of antibodies was detected. The number of serologically positive dogs for IgG was 44 (59.5%) to E. canis, 10 (13.5%) to A. phagocytophilum, 16 (21.6%) to both E. canis and A. phagocytophilum, and 4 (5.4%) were determined negative by means of IFA. In most samples the antibody titer did not exceed 1:80 but in 5 it reached a level of 1:320, and in other 4 of even above 1:640. CONCLUSIONS: This study shows that IFA assay is more sensitive than commercial ELISA rapid test when serum antibody titers are low.

scholarly journals  Toxoplasma gondii and Neospora caninum antibodies in goats in the Czech Republic

2012 ◽  
Vol 57 (No. 3) ◽  
pp. 111-114 ◽  
Author(s):  
E. Bartova ◽  
K. Sedlak
Keyword(s):  
Czech Republic ◽  
Toxoplasma Gondii ◽  
Immunosorbent Assay ◽  
Competitive Inhibition ◽  
Neospora Caninum ◽  
Fluorescent Antibody ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Antibodies ◽  
Serum Samples ◽  
The Czech Republic

Toxoplasma gondii is zoonotic protozoan parasite that causes infections in many vertebrate species. The present study determined the seroprevalence of T. gondii and N. caninum in goats from the Czech Republic. Serum samples were collected from 251 healthy adult goats in the Czech Republic during the years 2006 to 2009. Sera samples were tested for serum antibodies to Toxoplasma gondii by an enzyme-linked immunosorbent assay with cut off equal to or higher than 50% S/P. The same samples were tested for serum antibodies to Neospora caninum by a competitive-inhibition enzyme-linked immunosorbent assay with cut off equal to or higher than 30% inhibition; positive sera were confirmed by an indirect fluorescent antibody test with cut-off titre equal to or higher than 40. Sera positive in both tests were marked as positive. In total, 166 (66%) and 15 (6%) goat sera reacted positively for T. gondii and N. caninum antibodies, respectively. All sera positive for N. caninum antibodies were simultaneously positive for T. gondii antibodies. This is the first detection of N. caninum antibodies in goats in the Czech Republic. Our findings indicate that goats in the Czech Republic are frequently exposed to T. gondii, but less frequently to N. caninum.  

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