scholarly journals Optimization and Validation of Indirect ELISA Using Truncated TssB Protein for the Serodiagnosis of Glanders amongst Equines

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Harisankar Singha ◽  
Praveen Malik ◽  
Sachin K. Goyal ◽  
Sandip K. Khurana ◽  
Chiranjay Mukhopadhyay ◽  
...  

Objective. To express truncated TssB protein ofBurkholderia malleiand to evaluate its diagnostic efficacy for serological detection of glanders among equines.Materials and Methods. In an attempt to develop recombinant protein based enzyme-linked immunosorbent assay (ELISA), N-terminal 200 amino acid sequences ofB. malleiTssB protein—a type 6 secretory effector protein—were expressed in prokaryotic expression system. Diagnostic potential of recombinant TssB protein was evaluated in indirect ELISA using a panel of glanders positive (n=49), negative (n=30), and field serum samples (n=1811). Cross-reactivity of the assay was assessed with equine disease control serum and human melioidosis positive serum.Results. In comparison to CFT, diagnostic sensitivity and specificity of ELISA were 99.7% and 100%, respectively.Conclusions. The indirect ELISA method using the truncated TssB offered safer and more rapid and efficient means of serodiagnosis of glanders in equines. These data highlight the use of TssB as potential diagnostic antigen for serological diagnosis of glanders.

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 548 ◽  
Author(s):  
Muhammad Ali-ul-Husnain Naqvi ◽  
Sana Zahra Naqvi ◽  
Muhammad Ali Memon ◽  
Kalibixiati Aimulajiang ◽  
Muhammad Haseeb ◽  
...  

Haemonchus contortus is recognized as one of the important health problems in small ruminants, leading to reduced production and economic loss for farmers worldwide. Prepatent diagnosis of H. contortus infection is crucial to improve control strategies as this helminth may remove up to one-fifth of total erythrocytes and may cause anemia, edema, diarrhea, and ultimately death in young animals. In this study, one of the excretory and secretory products, rHc-HCA59, was purified and used as antigen to detect specific antibodies in H. contortus infected goats during prepatent stage of infection using indirect enzyme linked immunosorbent assay (ELISA) as screening test. All goats (n = 38) were housed indoor, experimentally infected with 8000 infective larvae (L3) of H. contortus, and serum samples were collected prior to infection and at 14th day of infection. Immunoblotting was performed to confirm the results of indirect ELISA, evaluate the cross reactivity against rHc-HCA59 in sera of most common co-infecting parasites and rectify the false negative samples. Furthermore, three different batches of rHc-HCA59 were produced to evaluate the repeatability of ELISA. No eggs were detected in feces of all goats collected at 7th and 14th day of infection but, H. contortus eggs were detected at 21 days post infection in the feces. Indirect ELISA performed in this study showed 87% sensitivity and 100% specificity. The western blot analysis confirmed immunoreactivity in serum samples which scored positive in indirect ELISA and recognized the samples as negative which had OD450 lower than negative cut-off value in indirect ELISA. Furthermore, all false negative sera (n = 5) that had OD450 value between positive and negative cut-off value in rHc-HCA59 based ELISA were clearly positive in western blot. Moreover, no cross-reactivity was detected in ELISA and western blotting against rHc-HCA59 in positive sera of Toxoplasma gondii, Fasciola hepatica, and Trichinella spiralis. The results of this study concluded that combined use of indirect ELISA and western blotting with rHc-HCA59 is a potential immunodiagnostic tool for the detection of H. contortus infection during prepatent period in goats.


2009 ◽  
Vol 16 (6) ◽  
pp. 906-915 ◽  
Author(s):  
Gabriela Hernández-Mora ◽  
Charles A. Manire ◽  
Rocío González-Barrientos ◽  
Elías Barquero-Calvo ◽  
Caterina Guzmán-Verri ◽  
...  

ABSTRACT Brucella ceti causes disease in Odontoceti. The absence of control serum collections and the diversity of cetaceans have hampered the standardization of serological tests for the diagnosis of cetacean brucellosis. Without a “gold” standard for sensitivity and specificity determination, an alternative approach was followed. We designed an indirect enzyme-linked immunosorbent assay (iELISA) that recognizes immunoglobulins G (IgGs) from 17 odontocete species as a single group. For the standardization, we used Brucella melitensis and Brucella abortus lipopolysaccharides, serum samples from seven resident odontocetes with no history of infectious disease displaying negative rose bengal test (RBT) reactions, and serum samples from seven dolphins infected with B. ceti. We compared the performance of the iELISA with those of the protein G ELISA (gELISA), the competitive ELISA (cELISA), and the immunofluorescence (IF) and dot blot (DB) tests, using 179 odontocete serum samples and RBT as the reference. The diagnostic potential based on sensitivity and specificity of the iELISA was superior to that of gELISA and cELISA. The correlation and agreement between the iELISA and the gELISA were relatively good (R i/g 2 = 0.65 and κi/g = 0.66, respectively), while the correlation and agreement of these two ELISAs with cELISA were low (R i/c 2 = 0.46, R g/c 2 = 0.37 and κi/c = 0.62, κg/c = 0.42). In spite of using the same anti-odontocete IgG antibody, the iELISA was more specific than were the IF and DB tests. An association between high antibody titers and the presence of neurological symptoms in dolphins was observed. The prediction is that iELISA based on broadly cross-reacting anti-dolphin IgG antibody would be a reliable test for the diagnosis of brucellosis in odontocetes, including families not covered in this study.


2021 ◽  
Vol 7 (12) ◽  
pp. 999
Author(s):  
Manisha Shukla ◽  
Pankaj Chandley ◽  
Harsimran Kaur ◽  
Anup K. Ghosh ◽  
Shivaprakash M. Rudramurthy ◽  
...  

Systemic candidiasis is the fourth most common bloodstream infection in ICU patients worldwide. Although C. albicans is a predominant species causing systemic candidiasis, infections caused by non-albicans Candida (NAC) species are increasingly becoming more prevalent globally along with the emergence of drug resistance. The diagnosis of systemic candidiasis is difficult due to the absence of significant clinical symptoms in patients. We investigated the diagnostic potential of recombinant secreted aspartyl proteinase 2 (rSap2) from C. parapsilosis for the detection of Candida infection. The rSap2 protein was successfully cloned, expressed and purified using Ni-NTA chromatography under denaturing conditions using an E. coli-based prokaryotic expression system, and refolded using a multi-step dialysis procedure. Structural analysis by CD and FTIR spectroscopy revealed the refolded protein to be in its near native conformation. Immunogenicity analysis demonstrated the rSap2 protein to be highly immunogenic as evident from significantly high titers of Sap2-specific antibodies in antigen immunized Balb/c mice, compared to sham-immunized controls. The diagnostic potential of rSap2 protein was evaluated using immunoblotting and ELISA assays using proven candidiasis patient serum and controls. Immunoblotting results indicate that reactivity to rSap2 was specific to candidiasis patient sera with no cross reactivity observed in healthy controls. Increased levels of anti-Sap2-specific Ig, IgG and IgM antibodies were observed in candidiasis patients compared to controls and was similar in sensitivity obtained when whole Candida was used as coating antigen. In summary, the rSap2 protein from C. parapsilosis has the potential to be used in the diagnosis of systemic candidiasis, providing a rapid, convenient, accurate and cost-effective strategy.


2002 ◽  
Vol 9 (4) ◽  
pp. 808-811 ◽  
Author(s):  
Emma Carmelo ◽  
Enrique Martínez ◽  
Ana Cristina González ◽  
José Enrique Piñero ◽  
Manuel E. Patarroyo ◽  
...  

ABSTRACT The humoral immune response against Leishmania braziliensis histone H1 by patients with cutaneous leishmaniasis is described. For this purpose, the protein was purified as a recombinant protein in a prokaryotic expression system and was assayed by enzyme-linked immunosorbent assay (ELISA) with a collection of sera from patients with cutaneous leishmaniasis and Chagas' disease. The assays showed that L. braziliensis histone H1 was recognized by 66% of the serum samples from patients with leishmaniasis and by 40% of the serum samples from patients with Chagas' disease, indicating that it acts as an immunogen during cutaneous leishmaniasis. In order to locate the linear antigenic determinants of this protein, a collection of synthetic peptides covering the L. braziliensis histone H1sequence was tested by ELISA. The experiments showed that the main antigenic determinant is located in the central region of this protein. Our results show that the recombinant L. braziliensis histone H1 is recognized by a significant percentage of serum samples from patients with cutaneous leishmaniasis, but use of this protein as a tool for the diagnosis of cutaneous leishmaniasis is hampered by the cross-reaction with sera from patients with Chagas' disease.


2020 ◽  
Author(s):  
ZHAN GAO ◽  
JUNJUN SHAO ◽  
GUANGLEI ZHANG ◽  
SUDAN GE ◽  
YANYAN CHANG ◽  
...  

Abstract Background: African swine fever(ASF) is an acute, severe and highly fatal infectious disease of pigs. The disease spreads rapidly, causing huge economic losses to the pig industry in infected areas. The structural proteins p30 and p54 in African swine fever virus(ASFV) have been verified as diagnostic antigens.Methods: In this study, we constructed a novel multi-epitope fusion antigen gene based on P30 and P54 proteins, induced expression in a prokaryotic expression system and analyzed the reactivity of the recombinant fusion protein. The purified recombinant protein m35 was used as the coating antigen to establish an indirect enzyme-linked immunosorbent assay (ELISA) detection method for ASFV. 116 serum samples and positive sera of other swine diseases were detected by indirect ELISA.Results: Our results indicate that the m35 gene fragment with a length of 558bp was successfully constructed. SDS-PAGE and Western Blotting analysis showed that the protein had a band at 22kDa, proving its good reactogenicity. ROC analysis was performed to validate the assay, the area under the ROC curve is 0.9738 (95% confidence interval, 0.9336 to 1.014), and does not cross-react with other swine diseases.Conclusion: Our results show that its sensitivity and specificity were highly accurate. It is feasible to use this recombinant protein as a diagnostic antigen to distinguish ASFV infection.


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 507
Author(s):  
Long Pham-Thanh ◽  
Thang Nguyen-Tien ◽  
Ulf Magnusson ◽  
Vuong Bui-Nghia ◽  
Anh Bui-Ngoc ◽  
...  

Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xiao Teng Ching ◽  
Yee Ling Lau ◽  
Mun Yik Fong ◽  
Veeranoot Nissapatorn ◽  
Hemah Andiappan

Toxoplasma gondiiinfects all warm-blooded animals, including humans, causing serious public health problems and great economic loss for the food industry. Commonly used serological tests require costly and hazardous preparation of wholeToxoplasmalysate antigens from tachyzoites. Here, we have evaluated an alternative method for antigen production, which involved a prokaryotic expression system. Specifically, we expressedT. gondiidense granular protein-5 (GRA5) inEscherichia coliand isolated it by affinity purification. The serodiagnostic potential of the purified recombinant GRA5 (rGRA5) was tested through Western blot analysis against 212 human patient serum samples. We found that rGRA5 protein was 100% specific for analysis of toxoplasmosis-negative human sera. Also, rGRA5 was able to detect acute and chronicT. gondiiinfections (sensitivities of 46.8% and 61.2%, resp.).


2000 ◽  
Vol 12 (2) ◽  
pp. 142-145 ◽  
Author(s):  
James O. Mecham ◽  
Michael M. Jochim

An enzyme-linked immunosorbent assay has been developed to detect antibodies to epizootic hemorrhagic disease of deer virus (EHDV). The assay incorporates a monoclonal antibody to EHDV serotype 2 (EHDV-2) that demonstrates specificity for the viral structural protein, VP7. The assay was evaluated with sequential sera collected from cattle experimentally infected with EHDV serotype 1 (EHDV-1) and EHDV-2, as well as the four serotypes of bluetongue virus (BTV), BTV-10, BTV-11, BTV-13, and BTV-17, that currently circulate in the US. A competitive and a blocking format as well as the use of antigen produced from both EHDV-1-and EHDV-2-infected cells were evaluated. The assay was able to detect specific antibody as early as 7 days after infection and could differentiate animals experimentally infected with EHDV from those experimentally infected with BTV. The diagnostic potential of this assay was demonstrated with field-collected serum samples from cattle, deer, and buffalo.


2021 ◽  
Vol 12 ◽  
Author(s):  
Bochao Liu ◽  
Ze Wu ◽  
Chaolan Liang ◽  
Jinhui Lu ◽  
Jinfeng Li ◽  
...  

Since December 2019, a novel coronavirus (SARS-CoV-2) has resulted in a global pandemic of coronavirus disease (COVID-19). Although viral nucleic acid test (NAT) has been applied predominantly to detect SARS-CoV-2 RNA for confirmation diagnosis of COVID-19, an urgent need for alternative, rapid, and sensitive immunoassays is required for primary screening of virus. In this study, we developed a smartphone-based nanozyme-linked immunosorbent assay (SP-NLISA) for detecting the specific nucleocapsid phosphoprotein (NP) of SARS-CoV-2 in 37 serum samples from 20 COVID-19 patients who were diagnosed by NAT previously. By using SP-NLISA, 28/37 (75.7%) serum samples were detected for NP antigens and no cross-reactivity with blood donors’ control samples collected from different areas of China. In a control assay using the conventional enzyme-linked immunosorbent assay (ELISA), only 7/37 (18.91%) serum samples were detected for NP antigens and no cross-reactivity with control samples. SP-NLISA could be used for rapid detection of SARS-CoV-2 NP antigen in primary screening of SARS-CoV-2 infected individuals.


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.


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