scholarly journals An enzyme-linked immunosorbent assay for the detection of IgG antibodies against Babesia equi in horses

2004 ◽  
Vol 34 (5) ◽  
pp. 1525-1529 ◽  
Author(s):  
Cristiane Divan Baldani ◽  
Rosangela Zacarias Machado ◽  
Paulo de Tarso Landgraf Botteon ◽  
Felipe Santoro Takakura ◽  
Carlos Luiz Massard
Keyword(s):  
Immunosorbent Assay ◽  
Serological Test ◽  
Epidemiological Studies ◽  
Sao Paulo ◽  
Enzyme Linked Immunosorbent Assay ◽  
São Paulo ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Babesia Equi ◽  
Specificity And Sensitivity

A crude antigenic preparation of Babesia equi was used to develop and establish the suitability of an enzyme-linked immunosorbent assay (ELISA) for the detection of parasite carriers. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkboard titrations. The specificity and sensitivity of the ELISA were 100 %. A total of 90 serum samples were taken from horses from the Northeast region of São Paulo State and examined for diagnosis of equine B. equi infection by ELISA. Approximately 75% (n=67) of all the horses tested were found serologically positive for B. equi. These results suggest that the ELISA described may prove to be an appropriate serological test for epidemiological studies on B. equi infections in the field and that equine piroplasmosis is a cause for serious concern in the State of São Paulo, Brazil.

scholarly journals Line Immunoassay for Confirmation and Discrimination of Human T-Cell Lymphotropic Virus Infections in Inconclusive Western Blot Serum Samples from Brazil

2019 ◽  
Vol 58 (1) ◽  
Author(s):  
Karoline R. Campos ◽  
Fred L. N. Santos ◽  
Vanessa da Silva Brito ◽  
Noilson L. S. Gonçalves ◽  
Thessika H. A. Araujo ◽  
...  
Keyword(s):  
T Cell ◽  
Western Blot ◽  
Serological Test ◽  
Sao Paulo ◽  
São Paulo ◽  
Serum Samples ◽  
Aids Patients ◽  
Human T Cell ◽  
Specificity And Sensitivity ◽  
Hiv Aids

ABSTRACT Difficulties in confirming and discriminating human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 infections by serological Western blot (WB) assays (HTLV Blot 2.4; MP Biomedicals) have been reported in Brazil, mainly in HIV/AIDS patients, with a large number of WB-indeterminate and WB-positive but HTLV-untypeable results. Nonetheless, a line immunoassay (LIA) (INNO-LIA HTLV-I/II; Fujirebio) provided enhanced specificity and sensitivity for confirming HTLV-1/2 infections. To add information concerning the improved ability of the LIA in relation to WB when applied to samples of individuals from different risk groups from Brazil, we performed the present study. Three groups were analyzed: group 1 (G1), with 62 samples from HIV/AIDS patients from São Paulo, SP (48 WB indeterminate and 14 HTLV untypeable); group 2 (G2), with 24 samples from patients with hepatitis B or hepatitis C from São Paulo (21 WB indeterminate and 3 HTLV untypeable; 17 HIV seropositive); and group 3 (G3), with 25 samples from an HTLV outpatient clinic in Salvador, Bahia (16 WB indeterminate and 9 HTLV untypeable; all HIV seronegative). Overall, the LIA confirmed HTLV-1/2 infection (HTLV-1, HTLV-2, or HTLV) in 66.1% (G1), 83.3% (G2), and 76.0% (G3) of samples. Interestingly, the majority of WB-indeterminate results were confirmed by the LIA as being HTLV-2 positive in G1 and G2 but not in G3, in which the samples were defined as being HTLV-1 or HTLV positive. These results agree with the virus types that circulate in such patients of different regions in Brazil and emphasize that the LIA is the best serological test for confirming HTLV-1 and HTLV-2 infections, independently of being applied in HTLV-monoinfected or HTLV-coinfected individuals.

Development and preliminary application of gE enzyme-linked immunosorbent assay for detection of the antibody to gE protein ofPseudorabies virusin pigs

2005 ◽  
Vol 2 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Tang Yong ◽  
Chen Huan-Chun ◽  
Qin Ya-Li ◽  
He Qi-Gai ◽  
Jin Mei-Lli ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Pseudorabies Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diagnostic Specificity ◽  
Serum Samples ◽  
Agreement Rate ◽  
Glycoprotein E ◽  
Recombinant Glycoprotein ◽  
Specificity And Sensitivity ◽  
Preliminary Application

AbstractTo differentiate pigs infected withPseudorabies virus(PrV) from pigs vaccinated with gE-PrV, a glycoprotein E enzyme-linked immunosorbent assay (gE-ELISA) based on recombinant glycoprotein E (gE) (which was expressed byEscherichia coli, purified, denatured and renatured) was developed. By testing 115 serum samples, the diagnostic specificity and sensitivity of the developed gE-ELISA were evaluated to be 94.5% and 96.7%, respectively. Five serum samples were tested with plates from five lots, and the results had a coefficient of variation of less than 10%, showing good reproducibility of gE-ELISA. This gE-ELISA was compared with a commercial blocking ELISA by testing 356 serum samples. The agreement rate of the two assays was 92.13% (328/356). These results suggested that the gE-ELISA developed in our laboratory could be used in differentiating PrV-infected and gE-PrV-vaccinated pigs.

Sensitivity of Two Enzyme-linked Immunosorbent Assay Tests in Relation to Western Blot in Detecting Human T-Cell Lymphotropic Virus Types I and II Infection among HIV-1 Infected Patients from São Paulo, Brazil

1998 ◽  
Vol 30 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Adele Caterino-de-Araujo ◽  
Elizabeth de los Santos-Fortuna ◽  
Mônica Cristina Zandoná Meleiro ◽  
Jamal Suleiman ◽  
Maria Luisa Calabrò ◽  
...  
Keyword(s):  
T Cell ◽  
Western Blot ◽  
Immunosorbent Assay ◽  
Sao Paulo ◽  
Enzyme Linked Immunosorbent Assay ◽  
São Paulo ◽  
Human T Cell ◽  
Hiv 1

scholarly journals Utility of Pandemic H1N1 2009 Influenza Virus Recombinant Hemagglutinin Protein-Based Enzyme-Linked Immunosorbent Assay for Serosurveillance

2010 ◽  
Vol 17 (9) ◽  
pp. 1481-1483 ◽  
Author(s):  
V. A. Arankalle ◽  
R. G. Virkar ◽  
B. V. Tandale ◽  
N. B. Ingle
Keyword(s):  
Immunosorbent Assay ◽  
Influenza A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Pandemic H1n1 ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Hemagglutinin Protein ◽  
Virus Recombinant ◽  
Recombinant Hemagglutinin ◽  
Pandemic H1n1 2009

ABSTRACT An enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies against the pandemic H1N1 2009 influenza A virus, employing a recombinant hemagglutinin protein of the virus, was compared to the hemagglutination inhibition (HI) test using 783 serum samples. The results showed a concordance of 98.4%, suggesting the utility of the ELISA in serosurveillance. Two hundred sixty-nine (100%) serum samples with an HI titer of ≥20 were ELISA reactive.

scholarly journals Rapid Competitive Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to Peste des Petits Ruminants Virus

2005 ◽  
Vol 12 (4) ◽  
pp. 542-547 ◽  
Author(s):  
Kang-Seuk Choi ◽  
Jin-Ju Nah ◽  
Young-Joon Ko ◽  
Shien-Young Kang ◽  
Nam-In Jo
Keyword(s):  
Immunosorbent Assay ◽  
Small Ruminants ◽  
Viral Disease ◽  
Turnaround Time ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peste Des Petits Ruminants ◽  
Rinderpest Virus ◽  
Serum Samples ◽  
Specificity And Sensitivity ◽  
Relative Specificity

ABSTRACT Peste des petits ruminants (PPR) is a contagious viral disease of small ruminants that is of economic importance in Africa, the Middle East, and Asia. We developed a rapid competitive enzyme-linked immunosorbent assay (rapid c-ELISA) for the diagnosis and surveillance of PPR. This assay detects PPR virus (PPRV) antibodies in serum samples by quantifying the amount of monoclonal antibody (MAb) P-3H12 after 30 min of incubation of a serum-MAb conjugate mixture on plates coated with a PPRV recombinant nucleocapsid protein (rPPRV-N). We tested 249 PPRV-positive serum samples and 733 PPRV-negative serum samples from field ruminants. The threshold of percent inhibition (PI) was determined to be <50 on the basis of the mean PI plus 3 standard deviations for sera from PPRV-negative ruminants. The relative specificity and sensitivity of the rapid c-ELISA were 98.5% (722 of 733 serum samples) and 93.4% (234 of 249 serum samples), respectively. The rapid c-ELISA sensitively detected PPRV antibodies in hyperimmune sera (virus neutralization test [VNT] titer, >512), even at dilutions ≥512 in normal goat serum, and as early as 6 to 13 days postinfection from 12 goats, each of which was infected with one of the four PPRV lineages. Hyperimmune sera from animals experimentally vaccinated with rinderpest virus gave positive results by the rapid c-ELISA when the rinderpest virus VNT titers were >512, although the rapid c-ELISA titers were very low (2 to 16). However, the rapid c-ELISA was negative when the rinderpest virus VNT titer was ≤128. The rapid c-ELISA developed in the present work provides a short turnaround time and could be a useful tool for the diagnosis of PPR and screening for PPRV in the field.

scholarly journals Seroprevalence of mycoplasmosis in broiler, layer, and native chickens in Giza, Egypt

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254220
Author(s):  
Saeed El-Ashram ◽  
Mahmoud E. Hashad ◽  
G. A. Abdel-Alim ◽  
Taher Abdelhamid ◽  
Heba N. Deif
Keyword(s):  
Immunosorbent Assay ◽  
Hemagglutination Inhibition ◽  
Serological Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Passive Hemagglutination ◽  
Positive Serum ◽  
Commercial Kits ◽  
Elisa Data

We aimed to investigate Mycoplasma infections among chicken flocks (Ross, Lohmann and native) in Giza, Egypt, using serological tests, including the slide plate agglutination (SPA) test, hemagglutination inhibition (HI) test, and enzyme-linked immunosorbent assay (ELISA). The slide plate agglutination examination, a serological test, indicated the prevalence of Mg and Ms infections of 10.9% and 13.2%, respectively. On 91 SPA test positive serum samples for either Mg or Ms, a passive hemagglutination/hemagglutination inhibition (HI) test was performed. The SPA and HI test findings were found to be comparable. On 90 SPA test positive samples, an ELISA was performed using commercial kits for Mg and Ms serodiagnosis. According to the ELISA data, only 83.33% and 18.88% of SPA test positive samples were confirmed as positive for Ms and Mg infections, respectively. The prevalence increased to 84.44% and 77.77%, respectively, when suspected samples were deemed positive.

scholarly journals Anti-Toxoplasma gondii antibodies in pregnant women and their newborn infants in the region of São José do Rio Preto, São Paulo, Brazil

2011 ◽  
Vol 129 (4) ◽  
pp. 261-266 ◽  
Author(s):  
Cinara de Cássia Brandão de Mattos ◽  
Lígia Cosentino Junqueira Franco Spegiorin ◽  
Cristina da Silva Meira ◽  
Thaís da Costa Silva ◽  
Ana Iara da Costa Ferreira ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Newborn Infants ◽  
Sao Paulo ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
São Paulo ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Igg Avidity

CONTEXT AND OBJECTIVE: Toxoplasmosis transmission during pregnancy can cause severe sequelae in fetuses and newborns. Maternal antibodies may be indicators of risk or immunity. The aim here was to evaluate seropositivity for anti-Toxoplasma gondii (anti-T. gondii) immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies and IgG avidity in pregnant women and their newborn infants. DESIGN AND SETTING: Cross-sectional study in a high-risk pregnancy outpatient clinic. METHODS: Serum samples from pregnant women (n = 87) and their respective newborns (n = 87) were evaluated for anti-T. gondii antibodies using indirect immunofluorescence (IIF) (IgM and IgG), enzyme-linked immunosorbent assay (ELISA) (IgG) and an avidity test. RESULTS: Anti-T. gondii antibodies were identified in 64.4% of the serum samples from the mothers and their infants (56/87). Except for two maternal serum samples (2.3%), all others were negative for anti-T. gondii IgM antibodies, using IIF. The results showed that 92.9% of the pregnant women had high IgG avidity indexes (> 30%) and four samples had avidity indexes between 16 and 30%. Two women in the third trimester of pregnancy were positive for anti-T. gondii IgM antibodies; their babies had avidity indexes between 16 and 30%. The avidity indexes of serum from the other 83 newborns were similar to the results from their mothers. CONCLUSIONS: The results showed that 2% of the pregnant women were at risk of T. gondii transmission during the gestational period. These data seem to reflect the real situation of gestational toxoplasmosis in the northwestern region of the state of São Paulo.

scholarly journals An enzyme-linked immunosorbent assay (ELISA) for the detection of IgM antibodies against Leishmania chagasi in dogs

2009 ◽  
Vol 29 (2) ◽  
pp. 120-124 ◽  
Author(s):  
Débora Carvalho ◽  
Trícia M.F.S. Oliveira ◽  
Cristiane D. Baldani ◽  
Rosangela Z. Machado
Keyword(s):  
Visceral Leishmaniasis ◽  
Immunosorbent Assay ◽  
Fluorescent Antibody ◽  
Domestic Dog ◽  
Enzyme Linked Immunosorbent Assay ◽  
Leishmania Chagasi ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Specificity And Sensitivity ◽  
Belo Horizonte

Visceral leishmaniasis is an emergent zoonosis with an increasing number of new cases in Brazil where the domestic dog is an important parasite reservoir in the infectious cycle of Leishmania chagasi. An enzyme-linked immunosorbent assay (ELISA), based upon the use of a total soluble antigenic preparation of L. chagasi, was adapted for the detection of IgM antibodies in the serum of infected dogs. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkboard titrations. The specificity and sensitivity of the ELISA were 100 %. A total of 110 serum samples were taken from dogs in Belo Horizonte, Minas Gerais, Brazil, and examined for anti-L. chagasi IgM antibody by ELISA and indirect fluorescent antibody test (IFAT). About 25% (n=27) of all the dogs tested were found serologically positive for L. chagasi by IFAT, while 89.09% (n=98) were seropositive by ELISA. The results obtained by ELISA and IFAT were significantly different (P<0.01). The combined use of ELISA and IFAT is recommended in order to enable veterinary services to more efficiently detect canine visceral leishmaniasis.

scholarly journals Expression and antigenic analysis of the recombinant TRP36 protein from Ehrlichia canis São Paulo strain for serologic tests

2020 ◽  
Vol 29 (3) ◽  
Author(s):  
Miguel Ângelo da Silva Medeiros ◽  
Maria Helena da Silva ◽  
Maria Adelaide do Valle Matta ◽  
Eliane de Oliveira Ferreira ◽  
Sérgio Lisboa Machado ◽  
...  
Keyword(s):  
Serological Test ◽  
Sao Paulo ◽  
Ehrlichia Canis ◽  
São Paulo ◽  
Serum Samples ◽  
Antigenic Analysis ◽  
Bacterial Dna ◽  
Canine Monocytic Ehrlichiosis ◽  
Dna Fragment ◽  
Topo Vector

Abstract Ehrlichia canis is the main etiological agent of canine monocytic ehrlichiosis (CME), a globally canine infectious disease. In Brazil, CME is considered to be endemic, and its prevalence can reach 65% in some states. The diagnosis of ehrlichiosis is important for treatment and epidemiological purposes. The E. canis TRP36 (Tandem Repeat Protein) protein elicits the earliest acute-phase antibody response observed during the course of the disease. This study aimed to generate the recombinant TRP36 protein from E. canis São Paulo strain and to evaluate its potential as a tool for the serologic diagnosis of CME. The E. canis São Paulo isolate was cultivated in DH82 lineage cells, and its genomic DNA was obtained. The bacterial DNA fragment encoding the entire ORF of TRP36 was cloned into the pBAD/Thio-TOPO vector and transformed into Escherichia coli DH10B competent cells with the trp36-bearing plasmid for protein expression. To evaluate the protein antigenicity, 16 canine serum samples were previously tested (by PCR and the commercial SNAP®4Dx® serological test). The results were in accordance with the SNAP®4Dx® test. Experiments using this recombinant protein as an antigen, targeting the development of a serologic test based on ELISA methodology, are the next step to produce a reliable, affordable and useful diagnostic tool for CME in Brazil.

scholarly journals Canine visceral leishmaniasis and Chagas disease among dogs in Araguaína, Tocantins

2013 ◽  
Vol 22 (2) ◽  
pp. 225-229 ◽  
Author(s):  
Arielle Nunes Morais ◽  
Marlos Gonçalves Sousa ◽  
Luciana Regina Meireles ◽  
Norival Kesper Jr. ◽  
Eufrosina Setsu Umezawa
Keyword(s):  
Visceral Leishmaniasis ◽  
Sao Paulo ◽  
Immunofluorescence Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Canine Visceral Leishmaniasis ◽  
São Paulo ◽  
Reference Test ◽  
Serum Samples ◽  
Canine Population ◽  
De Medicina

The present study analyzed serum samples from 111 male and female dogs of various ages from the municipality of Araguaína in the State of Tocantins, Brazil. Serological diagnosis of canine visceral leishmaniasis (CVL) was initially performed at the Central Laboratory (Laboratório Central – LACEN) of Araguaína, resulting in 61 positive samples by an indirect immunofluorescence assay (IIFA) (≥1:40) and 50 non-reactive samples. The same samples were analyzed at the São Paulo Institute of Tropical Medicine (Instituto de Medicina Tropical de São Paulo – IMTSP) by an enzyme-linked-immunosorbent assay (ELISA), resulting in 57 positive samples (51.35%) and 54 negative samples (48.64%). The Kappa coefficient of agreement between the tests was 0.74. The serum samples were also subjected to a diagnostic assay for Trypanosoma cruzi(Trypomastigote Excreted/Secreted Antigens -TESA-blot) that detected five suspect animals; three of those animals were positive for leishmaniasis by ELISA but negative by IIFA. These findings suggest that the canine population of Araguaína may be simultaneously infected withLeishmania chagasi and T. cruzi. The results obtained demonstrate the difficulty of using serology to detect CVL, thus emphasizing the necessity for a reference test to diagnose CVL, particularly in regions where the infection is endemic.

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