scholarly journals Use of Avidity Enzyme-Linked Immunosorbent Assay and Avidity Western Blot to Discriminate between Acute and Chronic Neospora Caninum Infection in Cattle

2005 ◽  
Vol 17 (5) ◽  
pp. 442-450 ◽  
Author(s):  
A. Aguado-Martínez ◽  
G. Álvarez-García ◽  
I. Arnaiz-Seco ◽  
E. Innes ◽  
L. M. Ortega-Mora

Avidity serological tests (avidity enzyme-linked immunosorbent assay [ELISA] and avidity Western blot) were developed and used to differentiate between acute (primary infection, reinfection, and recrudescence) and chronic Neospora caninum infection in cattle. In addition, the pattern of immunoglobulin G (IgG) avidity maturation against different specific antigens of N. caninum tachyzoites was studied. Sequential serum samples were collected from cattle naturally and experimentally infected with N. caninum. Four groups of experimentally infected cattle were included in the study and were representative of primary infection, reinfection, chronic infection, and noninfection. Serum samples were also collected from naturally infected cattle classified into nonaborting and aborting cows on the basis of clinical findings and serological profiles, and a third group composed of seronegative cows that seroconverted during the course of the experiment. All samples were tested by avidity ELISA and avidity Western blot. The IgG avidity ELISA allowed the discrimination between primary and chronic infection because all experimentally primary-infection cows showed low avidity indexes at week 4 postinfection (p.i.) compared with the high avidity values found at week 20 postinfection. However, this test did not allow the discrimination of reinfection or recrudescence from chronic infection. Regarding IgG avidity Western blot results, no antigenic markers correlating with acute (primary infection, recrudescence, and reinfection) or chronic infection were recognized. However, the 17-kD immunodominant antigen was mostly responsible for high avidity values obtained by avidity ELISA because it was intensively recognized by high-avidity antibodies in all chronically infected animals after urea treatment.

2013 ◽  
Vol 20 (10) ◽  
pp. 1617-1622 ◽  
Author(s):  
Rochelle Haidee D. Ybañez ◽  
Mohamad Alaa Terkawi ◽  
Kyohko Kameyama ◽  
Xuenan Xuan ◽  
Yoshifumi Nishikawa

ABSTRACTNeospora caninumis an apicomplexan parasite that causes abortion in cattle; hence, accurate diagnosis of this pathogen is important to the cattle farming industry. Our previous proteomics and immunoscreening analyses revealed that theN. caninumsubtilisin-like serine protease 1 (NcSUB1) has potential as a serodiagnostic tool forNeospora. Consequently, we expressed two fragments containing five NcSUB1 tandem repeat copies covering amino acids (aa) 524 to 843 (NcSUB1t) and 555 to 679 (NcSUB1tr) to identify the antigenic regions. The serodiagnostic performances of NcSUB1t and NcSUB1tr were compared with that of N54, which contains a single copy of the repeats (aa 649 to 784), and with the truncated NcSAG1 (NcSAG1t), which lacks a signal peptide and C-terminal hydrophobic regions, as a positive reference. Serum samples fromN. caninumexperimentally infected cattle and mice and cattle from a farm with confirmed cases ofNeosporaabortion were tested by enzyme-linked immunosorbent assay (ELISA) with the four antigens. In theN. caninumexperimentally infected cattle, the highest IgG1 antibody titers were detected against NcSUB1t, while specific IgG1 antibodies were detectable from 16 days postinfection (dpi), with levels peaking at 36 dpi for all of the antigens. On the other hand, the levels of anti-NcSUB1 IgG2 antibodies were lower than those of anti-SAG1t IgG2 antibodies. The ELISA with NcSUB1t and NcSUB1tr had good sensitivity (94.59 to 95.95%) and specificity (80 to 100%) with bovine serum field samples compared to NcSAG1t and showed no cross-reactions with sera fromToxoplasma gondiiexperimentally infected mice. Moreover, IgG antibodies against NcSUB1t were detected during parturition in the NcSAG1t antibody-positive cattle, and NcSUB1t-specific antibody transfer was observed from a mother to her calf. Our results show that the NcSUB1 tandem repeat is potentially useful for serodiagnosis ofN. caninum.


2010 ◽  
Vol 17 (9) ◽  
pp. 1349-1355 ◽  
Author(s):  
Hossein Elyasi ◽  
Jalal Babaie ◽  
Hélène Fricker-Hidalgo ◽  
Marie-Pierre Brenier-Pinchart ◽  
Mehrak Zare ◽  
...  

ABSTRACT The usefulness of a specific immunoglobulin G (IgG) avidity enzyme-linked immunosorbent assay (ELISA) based on recombinant GRA6 antigen for distinguishing between acute and chronic Toxoplasma infection was investigated. Two sets of serum samples obtained from pregnant women with acute, chronic, or no Toxoplasma infection collected in France and Iran were used. Among the French subjects, 19 of 20 (95%) women who experienced seroconversion during the past 4 months before sampling displayed low-avidity IgG antibodies against GRA6, while all 17 (100%) women with chronic infection had high-avidity antibodies. When the Euroimmun IgG avidity ELISA was used, 15 of 19 (78.9%) recently infected women had low-avidity antibodies, and 20 of 22 (90.9%) women with chronic infection displayed high-avidity antibodies. The results suggested better performance of the GRA6 avidity ELISA than the Euroimmun avidity ELISA for exclusion of a recent infection occurring less than 4 months previously. Similarly, all 35 Iranian women with acute Toxoplasma infection had low-avidity antibodies against GRA6, whereas all 34 women with chronic infection displayed IgG antibodies of high avidity, indicating the value of GRA6 avidity testing for ruling out a recent infection. Avidity tests based on lysed whole-cell Toxoplasma gondii antigen are currently used to exclude recently acquired infections; however, the use of recombinant antigen(s) might improve the diagnostic performance of avidity tests and facilitate the development of more standardized assays.


2014 ◽  
Vol 59 (No. 12) ◽  
pp. 637-640 ◽  
Author(s):  
BY Jung ◽  
SH Lee ◽  
D. Kwak

Neospora caninum is a protozoan parasite that causes abortion in ruminants, including goats. The objective of the present study was to determine the seroprevalence of N. caninum in native Korean goats (Capra hircus coreanae). A commercial enzyme-linked immunosorbent assay kit was used to analyse 464 serum samples for the presence of N. caninum antibodies. Four samples (0.9%, 95% confidence intervals – CI: 0.0–1.7) were found to be positive for N. caninum antibodies. The seroprevalence was analysed according to age (less than to one year, young; more than or equal one year, adult; and unknown), sampling season (April to September, warm; October to March, cold), and region (northern, central, and southern). However, there were no statistically significant differences in seroprevalence according to age, season, and region (P > 0.05). This is the first report on the seroprevalence of N. caninum in native Korean goats. The results of this study indicate a nationwide distribution of N. caninum among goats, with a relatively low prevalence. Therefore, the implementation of integrated control strategies as well as measures for prevention and control of N. caninum infection among goats is recommended.


Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 15 ◽  
Author(s):  
Shuai Wang ◽  
Lingjuan Li ◽  
Yi Lu ◽  
Haizhu Zhang ◽  
Qing Xie ◽  
...  

This study aimed to determine the frequency of antibodies to Neospora caninum in domestic sheep raised in Henan province, central China. Serum samples from 779 domestic sheep were collected from March 2015 to May 2016, and antibodies to N. caninum were evaluated using an enzyme-linked immunosorbent assay (ELISA). The results showed an overall IgG positive rate of 7.32% (57/779). The risk factors significantly related to seropositivity to N. caninum in sheep were the age, the presence of dogs, and the rearing system. This is the first report of N. caninum infection and associated risk factors in domestic sheep in central China.


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 ◽  
...  

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.


Author(s):  
Poonam S. Deshpande ◽  
Dupadahalli Kotresha ◽  
Rahmah Noordin ◽  
Muhammad Hafiznur Yunus ◽  
Geita Saadatnia ◽  
...  

Toxoplasmosis is an important cause of congenital infection. The present study was performed to evaluate the usefulness of recombinant (r) GRA-7 cloned from nucleotides (n) 39-711 in discriminating between acute and chronic toxoplasmosis. First, commercial IgM, IgG and IgG avidity ELISAs were used to determine the serological profile of the sera. Serum samples were from 20 symptomatic patients with acute infection (low IgG avidity, IgM positive), 10 with chronic infection (high IgG avidity, IgM negative) and 10 with indeterminate IgG avidity (IgM positive) which were tested for IgG avidity status with an in-house developed IgG avidity Western blot using the rGRA-7 recombinant antigen. All 20 sera from cases of probable acute infection showed bands which either faded out completely or reduced significantly in intensity after treatment with 8 M urea, whereas the band intensities of the 10 serum samples from chronic cases remained the same. Of the 10 sera with indeterminate IgG avidity status, after treatment with 8 M urea the band intensities with six sera remained the same, two sera had completely faded bands and another two sera had significantly reduced band intensities. Discrimination between acute and chronic toxoplasmosis was successfully performed by the in-house IgG avidity Western blot.


2007 ◽  
Vol 14 (12) ◽  
pp. 1640-1643 ◽  
Author(s):  
Penglong Huang ◽  
Min Liao ◽  
Houshuang Zhang ◽  
Eung-goo Lee ◽  
Yoshifumi Nishikawa ◽  
...  

ABSTRACT To investigate whether the production of an antigen-specific antibody is associated with Neospora caninum-induced bovine abortion, 62 serum samples were tested with an enzyme-linked immunosorbent assay using the recombinant antigens NcSAG1, NcSRS2, and NcGRA7. Our study suggested that NcGRA7 would be a new marker for the serodiagnosis of N. caninum infection resulting in abortion.


Parasitology ◽  
2012 ◽  
Vol 139 (11) ◽  
pp. 1425-1428 ◽  
Author(s):  
M. J. XU ◽  
Q. Y. LIU ◽  
J. H. FU ◽  
A. J. NISBET ◽  
D. S. SHI ◽  
...  

SUMMARYToxoplasma gondii and Neospora caninum are closely related protozoan parasites which cause lowered production and increased abortion in dairy cows. The aim of the present study was to determine the seroprevalence of T. gondii and N. caninum infection in dairy cows in the Guangxi Zhuang Autonomous Region (GZAR), subtropical southern China. In total, 875 serum samples were collected from the tail veins of dairy cows in 6 main dairy cow-rearing districts of 4 administrative cities in GZAR. The samples were surveyed for T. gondii antibody using the Indirect Haemagglutination Test (IHA), and 365 of the serum samples were examined for N. caninum antibody by indirect Enzyme-Linked Immunosorbent Assay (ELISA). The overall seroprevalence of T. gondii in dairy cows was 13·71% (120/875), and the average seroprevalence of N. caninum was 15·07% (55/365). There were significant differences in the seroprevalence of N. caninum infection between different districts (P = 0·002, χ2 = 9·261). The highest prevalences of T. gondii and N. caninum were found in cows older than 8 years and those that had completed 5–6 pregnancies. Five cows (1·37%) presented antibodies against both T. gondii and N. caninum, and dairy cows with both T. gondii and N. caninum antibodies had higher abortion rates. The present results indicate widespread exposure of dairy cows to T. gondii and N. caninum in GZAR, subtropical southern China.


2021 ◽  
Author(s):  
Yohannes Equar Messele ◽  
Gebrerufael Girmay ◽  
Bezina Arega Emeru ◽  
Shelema Kelbesa Bora ◽  
Workitu Firomsa Gudeta ◽  
...  

Abstract Background Reproductive problem is one of the main constraints of livestock genetic improvement efforts in tropical countries. The aim of this study was to determine the prevalence of major infectious causes of reproductive problems of dairy cattle in selected dairy farms in central Ethiopia. Overall 86 serum samples were collected from October 2018 to February 2019 from animals with history of reproductive problems. The collected serum was tested for antibody titer against Brucella species, Neospora caninum, Bovine Viral Diarrhea (BVD), Infectious Bovine Rhinotracheitis (IBR) and Q-fever using rose-bengal and enzyme-linked immunosorbent assay (ELISA) tests. Result Among the animals with the history of reproductive disordered; abortion, still birth and repeat breeding cases were found in 61.6%, 19.8% and 18.6%, respectively. The prevalence of IBR, BVD, Neospora caninum and Coxiella brunetti was found to be 79.1%, 38.4%, 3.5% and 1.2%, respectively. The combined infection of both BVD and IBR were detected in 21% of animals. Out of the total animals examined in this study, 95.9% of Jersey breeds were found seropositive to IBR than Boran-Friesian crosses (57.7%). The incidence of BVD was significantly higher in Boran-Friesian crossbred cattle than in Jersey which was found to be 69.3% and 14.3, respectively. The prevalence of IBR and BVD was directly proportional with age of the animal and parity. Conclusion Vaccination against IBR and BVD is not practiced in Ethiopia, the rising level of those diseases in dairy sector needs regular surveillance and control program.


1999 ◽  
Vol 6 (4) ◽  
pp. 514-518 ◽  
Author(s):  
Malgorzata Paul

ABSTRACT Traditional serological techniques have some limitations in evaluating the duration of Toxoplasma gondii infection in pregnant women, patients with lymphadenopathy, and older children suspected of having congenital toxoplasmosis. In these three groups of patients, two variants of T. gondii immunoglobulin G (IgG) avidity tests were used: an EIA Kit (Labsystems) and a noncommercial enzyme-linked immunosorbent assay specially elaborated in the laboratory. The avidity of specific IgG in sera from 23 patients with a known recently acquired infection (mainly pregnant women) was low (less than 30%), whereas that in sera from 19 patients with toxoplasmic lymphadenopathy of 3 weeks to 6 months in duration (mean, 8.3 weeks) covered a large range (between 0.2 and 57.8%; mean, 25.7%); high avidity results were observed for 10 of 19 patients (52.6%). The large range of IgG avidity in patients with toxoplasmic lymphadenopathy suggests various durations of infection in these patients, with a tendency for a chronic phase of toxoplasmosis. According to the avidity marker, five patients with lymphadenopathy for less than 3 months did not have a recent Toxoplasma infection. In 6 of 19 patients with lymphadenopathy (31.6%), low IgG avidity values persisted until 5 months after the first serological examination. In all four patients with a documented chronic course of Toxoplasma infection (6 months to 8 years after the first positive serology), high IgG avidity values were observed. Among sera from 10 children and young immunocompetent adults suspected of having ocular reactivation of congenital toxoplasmosis, all had high IgG avidity values (over 40%), suggesting congenitally acquired ocular infection rather than noncongenital infection. In conclusion, the avidity of IgG is a valuable marker of recent toxoplasmosis in pregnant women, suggests the duration of invasion in patients with lymphadenopathy, and may be helpful for differentiation between reactivation of congenital infection and recently acquired ocular toxoplasmosis in immunocompetent patients. A low IgG avidity does not always identify a recent case of toxoplasmosis, but a high IgG avidity can exclude primary infections of less than 5 months’ duration.


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