scholarly journals Development of Immunoassays for Detection of Francisella tularensis Lipopolysaccharide in Tularemia Patient Samples

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 924
Author(s):  
Emily E. Hannah ◽  
Sujata G. Pandit ◽  
Derrick Hau ◽  
Haley L. DeMers ◽  
Kayleigh Robichaux ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Point Of Care ◽  
Natural Infection ◽  
Lateral Flow ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Potential Threat ◽  
Infectious Dose ◽  
Antigen Capture ◽  
Wide Range

Francisella tularensis is the causative agent of tularemia, a zoonotic bacterial infection that is often fatal if not diagnosed and treated promptly. Natural infection in humans is relatively rare, yet persistence in animal reservoirs, arthropod vectors, and water sources combined with a low level of clinical recognition make tularemia a serious potential threat to public health in endemic areas. F. tularensis has also garnered attention as a potential bioterror threat, as widespread dissemination could have devastating consequences on a population. A low infectious dose combined with a wide range of symptoms and a short incubation period makes timely diagnosis of tularemia difficult. Current diagnostic techniques include bacterial culture of patient samples, PCR and serological assays; however, these techniques are time consuming and require technical expertise that may not be available at the point of care. In the event of an outbreak or exposure a more efficient diagnostic platform is needed. The lipopolysaccharide (LPS) component of the bacterial outer leaflet has been identified previously by our group as a potential diagnostic target. For this study, a library of ten monoclonal antibodies specific to F. tularensis LPS were produced and confirmed to be reactive with LPS from type A and type B strains. Antibody pairs were tested in an antigen-capture enzyme-linked immunosorbent assay (ELISA) and lateral flow immunoassay format to select the most sensitive pairings. The antigen-capture ELISA was then used to detect and quantify LPS in serum samples from tularemia patients for the first time to determine the viability of this molecule as a diagnostic target. In parallel, prototype lateral flow immunoassays were developed, and reactivity was assessed, demonstrating the potential utility of this assay as a rapid point-of-care test for diagnosis of tularemia.

scholarly journals A Rapid Immunochromatography Test Based on Hcp1 Is a Potential Point-of-Care Test for Serological Diagnosis of Melioidosis

2018 ◽  
Vol 56 (8) ◽  
Author(s):  
Phornpun Phokrai ◽  
Wisansanee Karoonboonyanan ◽  
Nida Thanapattarapairoj ◽  
Chidchanok Promkong ◽  
Adul Dulsuk ◽  
...  
Keyword(s):  
Point Of Care ◽  
Clinical Manifestations ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Target Antigen ◽  
Northeast Thailand ◽  
Serum Samples ◽  
Serological Method ◽  
Healthy Donors ◽  
Wide Range

ABSTRACTMelioidosis is a fatal infectious disease caused by the environmental bacteriumBurkholderia pseudomallei. It is highly endemic in Asia and northern Australia but neglected in many other tropical countries. Melioidosis patients have a wide range of clinical manifestations, and definitive diagnosis requires bacterial culture, which can be time-consuming. A reliable rapid serological tool is greatly needed for disease surveillance and diagnosis. We previously demonstrated by enzyme-linked immunosorbent assay (ELISA) that a hemolysin-coregulated protein (Hcp1) is a promising target for serodiagnosis of melioidosis. In this study, we developed a rapid immunochromatography test (ICT) using Hcp1 as the target antigen (Hcp1-ICT). We evaluated this test for specific antibody detection using serum samples obtained from 4 groups of human subjects, including the following: (i) 487 culture-confirmed melioidosis patients from four hospitals in northeast Thailand; (ii) 202 healthy donors from northeast Thailand; (iii) 90 U.S. healthy donors; and (iv) 207 patients infected with other organisms. Compared to culture results as a gold standard, the sensitivity of ICT for all hospitals was 88.3%. The specificities for Thai donors and U.S. donors were 86.1% and 100%, respectively, and the specificity for other infections was 91.8%. The results of the Hcp1-ICT demonstrated 92.4% agreement with the Hcp1-ELISA results with a kappa value of 0.829, indicating that the method is much improved compared with the current serological method, the indirect hemagglutination assay (IHA) (69.5% sensitivity and 67.6% specificity for Thais). The Hcp1-ICT represents a potential point-of-care (POC) test and may be used to replace the IHA for screening of melioidosis in hospitals as well as in resource-limited areas.

scholarly journals Comparative Analysis of the Euroimmun CXCL13 Enzyme-Linked Immunosorbent Assay and the ReaScan Lateral Flow Immunoassay for Diagnosis of Lyme Neuroborreliosis

2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Katharina Ziegler ◽  
Anca Rath ◽  
Christoph Schoerner ◽  
Renate Meyer ◽  
Thomas Bertsch ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Roc Curve ◽  
Point Of Care ◽  
Lateral Flow ◽  
Lyme Neuroborreliosis ◽  
Diagnostic Tools ◽  
Lateral Flow Immunoassay ◽  
Enzyme Linked Immunosorbent Assay ◽  
European Federation ◽  
Point Of Care Test

ABSTRACT Diagnosis of Lyme neuroborreliosis (LNB) is challenging, as long as Borrelia-specific intrathecal antibodies are not yet detectable. The chemokine CXCL13 is elevated in the cerebrospinal fluid (CSF) of LNB patients. Here, we compared the performances of the Euroimmun CXCL13 enzyme-linked immunosorbent assay (CXCL13 ELISA) and the ReaScan CXCL13 lateral flow immunoassay (CXCL13 LFA), a rapid point-of-care test, to support the diagnosis of LNB. In a dual-center case-control study, CSF samples from 90 patients (34 with definite LNB, 10 with possible LNB, and 46 with other central nervous system [CNS] diseases [non-LNB group]) were analyzed with the CXCL13 ELISA and the CXCL13 LFA. Classification of patients followed the European Federation of Neurological Societies (EFNS) guidelines on LNB. The CXCL13 ELISA detected elevated CXCL13 levels in all patients with definite LNB (median, 1,409 pg/ml) compared to the non-LNB controls (median, 20.7 pg/ml; P < 0.0001), with a sensitivity of 100% and a specificity of 84.8% (cutoff value, 78.6 pg/ml; area under the receiver operating characteristic [ROC] curve, 0.93). Similarly, the CXCL13 LFA yielded elevated CXCL13 levels in 31 patients with definite LNB (median arbitrary value, 223.5) compared to the non-LNB control patients (median arbitrary value, 0; P < 0.0001) and had a sensitivity and specificity of 91.2% and 93.5%, respectively (cutoff arbitrary value, 22.5; area under the ROC curve, 0.94). The correlation between the CXCL13 levels obtained by ELISA and LFA was strong (Spearman correlation coefficient r = 0.89; P < 0.0001). The CXCL13 ELISA and the CXCL13 LFA are comparable diagnostic tools for the detection of CXCL13 in the CSF of patients with definite LNB. The advantage of the CXCL13 LFA is the shorter time to result.

scholarly journals Monoclonal Antibody-Based Antigen Capture Enzyme-Linked Immunosorbent Assay Reveals High Sensitivity of the Nucleocapsid Protein in Acute-Phase Sera of Severe Acute Respiratory Syndrome Patients

2005 ◽  
Vol 12 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Biao Di ◽  
Wei Hao ◽  
Yang Gao ◽  
Ming Wang ◽  
Ya-di Wang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Acute Phase ◽  
Detection Rate ◽  
Neutralization Test ◽  
Protein Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
N Protein ◽  
Antigen Capture ◽  
Healthy Donors

ABSTRACT Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients. The results of the N protein detection analysis were directly related to the serological analysis data. From 27 SARS patients who tested positive with the neutralization test, 100% of the 24 sera collected from 1 to 10 days after the onset of symptoms were positive for the N protein. N protein was not detected beyond day 11 in this group. The positive rates of N protein for sera collected at 1 to 5, 6 to 10, 11 to 15, and 16 to 20 days after the onset of symptoms for 414 samples from 298 serologically confirmed patients were 92.9, 69.8, 36.4, and 21.1%, respectively. For 294 sera from 248 serological test-negative patients, the rates were 25.6, 16.7, 9.3, and 0%, respectively. The N protein was not detected in 66 patients with cases of what was initially suspected to be SARS but serologically proven to be negative for SARS and in 197 serum samples from healthy donors and non-SARS febrile patients. The specificity of the assay was 100%. Furthermore, of 16 sera collected from four patients during the SARS recurrence in Guangzhou, 5 sera collected from 7 to 9 days after the onset of symptoms were positive for the N protein. N protein detection exhibited a high positive rate, 96 to 100%, between day 3 and day 5 after the onset of symptoms for 27 neutralization test-positive SARS patients and 298 serologically confirmed patients. The N protein detection rate continually decreased beginning with day 10, and N protein was not detected beyond day 19 after the onset of symptoms. In conclusion, an antigen capture ELISA reveals a high N protein detection rate in acute-phase sera of patients with SARS, which makes it useful for early diagnosis of SARS.

scholarly journals Quantitative Approach for the Serodiagnosis of Canine Lyme Disease by the Immunoblot Procedure

2000 ◽  
Vol 38 (7) ◽  
pp. 2628-2632 ◽  
Author(s):  
Marta A. Guerra ◽  
Edward D. Walker ◽  
Uriel Kitron
Keyword(s):  
Logistic Regression ◽  
Lyme Disease ◽  
Natural Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Immunoblot Assay ◽  
Serological Status ◽  
Low Probability ◽  
Positive Results ◽  
Logistic Regression Equation

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.

Correlation of serostatus and viraemia levels among Indian dengue patients at the time of first diagnosis

2020 ◽  
Vol 114 (7) ◽  
pp. 513-520
Author(s):  
Ruta Kulkarni ◽  
Shubham Shrivastava ◽  
Harshad P Patil ◽  
Divya Tiraki ◽  
Akhilesh Chandra Mishra ◽  
...  
Keyword(s):  
Public Health Problem ◽  
Vero Cells ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Markers ◽  
Serum Samples ◽  
Infectious Dose ◽  
Therapeutic Monoclonal Antibodies ◽  
Tissue Culture Infectious Dose ◽  
First Diagnosis

Abstract Background Dengue is a public health problem worldwide. Therapeutic monoclonal antibodies (MAbs) against dengue virus (DENV) are likely to be available soon. In view of the feasibility issues pertaining to pretreatment viraemia quantitation for therapy decisions, we conducted this study for investigation of a correlation between patient serostatus (NS1/immunoglobulin M [IgM]/IgG) and viraemia levels among Indian dengue patients at the time of first diagnosis. Methods The study included 297 serum samples from dengue patients in Pune, India. The samples were tested for NS1, IgM and IgG (capture enzyme-linked immunosorbent assay [ELISA] for identifying secondary dengue) using Panbio ELISAs. Quantitation of viraemia was conducted using an NS1 ELISA-based 50% tissue culture infectious dose (TCID50) test in Vero cells. Results Viraemia was detectable only among NS1-positive patients (n = 229, range 0.5–8.3 logTCID50/ml) with a mean titre of 1.9 logTCID50/ml. Among the NS1-positive patients, DENV titres were higher in IgM-negative than IgM-positive patients (p &lt; 0.0001) and in primary (IgG &lt; 18 Panbio units) versus secondary (IgG &gt; 22 Panbio units) dengue patients (p = 0.002). Virus titres were higher during the first 3 days of illness and decreased later (p = 0.005). Conclusions The study provides a range of infectious DENV titres in relation to serologic status among dengue patients in India. The data suggest the possibility of using serological markers (NS1/IgM) as a basis for treatment decisions.

scholarly journals Surface-Enhanced Raman Scattering-Based Lateral-Flow Immunoassay

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2228
Author(s):  
Boris Khlebtsov ◽  
Nikolai Khlebtsov
Keyword(s):  
Raman Scattering ◽  
Point Of Care ◽  
Surface Enhanced Raman Scattering ◽  
Environmental Safety ◽  
Lateral Flow ◽  
Wide Range ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Low Sensitivity

Lateral flow immunoassays (LFIAs) have been developed and used in a wide range of applications, in point-of-care disease diagnoses, environmental safety, and food control. However, in its classical version, it has low sensitivity and can only perform semiquantitative detection, based on colorimetric signals. Over the past decade, surface-enhanced Raman scattering (SERS) tags have been developed in order to decrease the detection limit and enable the quantitative analysis of analytes. Of note, these tags needed new readout systems and signal processing algorithms, while the LFIA design remained unchanged. This review highlights SERS strategies of signal enhancement for LFIAs. The types of labels used, the possible gain in sensitivity from their use, methods of reading and processing the signal, and the prospects for use are discussed.

scholarly journals Development of a Novel Cocktail Enzyme-Linked Immunosorbent Assay and a Field-Applicable Lateral-Flow Rapid Test for Diagnosis of Contagious Bovine Pleuropneumonia

2016 ◽  
Vol 54 (6) ◽  
pp. 1557-1565 ◽  
Author(s):  
Martin Heller ◽  
Nimmo Gicheru ◽  
Georgina Tjipura-Zaire ◽  
Cecilia Muriuki ◽  
Mingyan Yu ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Rapid Test ◽  
Lateral Flow ◽  
Sub Saharan Africa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Contagious Bovine Pleuropneumonia ◽  
Serum Samples ◽  
Content Type ◽  
Mycoplasma Mycoides ◽  
Sub Saharan

Contagious bovine pleuropneumonia (CBPP) is a severe respiratory disease that is widespread in sub-Saharan Africa. It is caused byMycoplasma mycoidessubsp.mycoides, a bacterium belonging to theMycoplasma mycoidescluster. In the absence of an efficient CBPP vaccine, improved and easy-to-use diagnostic assays for recurrent testing combined with isolation and treatment of positive animals represent an option for CBPP control in Africa. Here we describe the comprehensive screening of 17 immunogenicMycoplasma mycoidessubsp.mycoidesproteins using well-characterized bovine sera for the development of a novel cocktail enzyme-linked immunosorbent assay (ELISA) for laboratory use. Two recombinantMycoplasmaimmunogens, MSC_0136 and MSC_0636, were used to set up a standardized cocktail ELISA protocol. According to the results from more than 100 serum samples tested, the sensitivity and specificity of the novel cocktail ELISA were 85.6% and 96.4%, respectively, with an overall diagnostic accuracy comparable to that of the Office International des Epizooties (OIE)-prescribed serological assays. In addition, we provide a proof of principle for a field-applicable, easy-to-use commercially produced prototype lateral-flow test for rapid (<30-min) diagnosis of CBPP.

scholarly journals Detection of Francisella tularensis-Specific Antibodies in Patients with Tularemia by a Novel Competitive Enzyme-Linked Immunosorbent Assay

2012 ◽  
Vol 20 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Neekun Sharma ◽  
Akitoyo Hotta ◽  
Yoshie Yamamoto ◽  
Osamu Fujita ◽  
Akihiko Uda ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Francisella Tularensis ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
The Novel ◽  
Serum Samples ◽  
Content Type ◽  
Microagglutination Test ◽  
Highly Sensitive ◽  
High Degree

ABSTRACTA novel competitive enzyme-linked immunosorbent assay (cELISA) was developed and evaluated for detection of antibodies againstFrancisella tularensisin humans. The assay is based on the ability of serum antibodies to inhibit the binding of monoclonal antibodies (MAbs) directed againstF. tularensislipopolysaccharide antigens. The assay was evaluated using serum samples of tularemia patients, inactivatedF. tularensis-immunized rabbits, andF. tularensis-infected mice. Antibodies againstF. tularensiswere successfully detected in serum samples of tularemia patients as well as the immunized and infected animals. The cELISA method was compared to indirect ELISA (iELISA) and the commonly used microagglutination test (MA) using serum samples of 19 tularemia patients and 50 healthy individuals. The sensitivity and specificity of cELISA were 93.9 and 96.1%, respectively, in comparison to the iELISA. MA was less sensitive than cELISA with a sensitivity and specificity of only 81.8 and 98.0%, respectively. A high degree of correlation (R2= 0.8226) was observed between cELISA and iELISA results. The novel cELISA developed in this study appears to be highly sensitive and specific for serodiagnosis of human tularemia. The potential of the MAb-based cELISA to be used in both human and animal samples emphasizes its usefulness for serological survey of tularemia among multiple animal species.

scholarly journals P342 Correlation of the first lateral flow-based Point of Care test to quantify infliximab and anti-infliximab antibodies in a finger prick sample with the reference ELISA technique

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S366-S366
Author(s):  
M B Ruiz-Argüello ◽  
J Pascual ◽  
L Del Río ◽  
A Urigoitia ◽  
C Balo Farto ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Point Of Care ◽  
Pearson Correlation ◽  
Capillary Blood ◽  
Lateral Flow ◽  
Real Point ◽  
Infliximab Treatment ◽  
Serum Samples ◽  
Finger Prick ◽  
Elisa Technique

Abstract Background The goal of this study was to validate the use of capillary blood in a real point-of-care (POC) setting for patients under infliximab treatment by using Promonitor Quick lateral flow (LF) tests. Results were compared to the Promonitor ELISA reference technique in serum samples used by centralised laboratories. Methods A prospective, observational study was designed to evaluate the performance of a rapid LF test (Promonitor Quick IFX, Progenika, Spain). 160 infliximab treated rheumatology consecutive patients (400 samples) were recruited in two hospitals in Galicia, Spain. Prior to the infusion, a finger prick sample was obtained and analysed. Anti-infliximab antibodies were also determined with Promonitor Quick ANTI-IFX1-4. Results were read with the automated portable PQreader instrument. Additionally, a serum sample was collected for subsequent comparative analysis with either LF or ELISA tests. Qualitative (positive (PPA) and negative (NPA) agreements) and quantitative (Pearson correlation and bias) performance of the LF test was compared to ELISA, as well as between different specimens following CLSI EP09-A3. Results Overall agreement between Promonitor Quick IFX finger prick and ELISA test was 91% (88% PPA; 100% NPA). The quantitative comparison showed a good correlation (Pearson correlation coefficient: 0.85 and observed bias: 25%) (Table 1). Similar results were also observed when serum was used with either the LF or the ELISA tests (98% overall agreement, 0.91 correlation coefficient; 6% bias) (Table 1). Overall agreements for visual and automated (PQreader) interpretations with Promonitor Quick ANTI-IFX were 99% and 100% for finger prick and serum specimens, respectively (Table 2). Conclusion Promonitor Quick can be used to reliably quantify infliximab in capillary blood samples and results are comparable to those obtained with the reference ELISA technique. The use of the rapid POC test with finger prick will allow clinicians to monitor their patients in a fully decentralized mode to aid in the decision making process. PQreader is a sensitive portable equipment to report drug as well as antibody levels in the patient samples. References

scholarly journals Natural Infection of Muskmelon by Eggplant Mottled Dwarf Rhabdovirus in Italy

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 78-78 ◽  
Author(s):  
M. Ciuffo ◽  
P. Roggero ◽  
V. Masenga ◽  
V. M. Stravato
Keyword(s):  
Electron Microscopy ◽  
Plant Species ◽  
Protein Pattern ◽  
Natural Infection ◽  
Central Italy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Plant ◽  
Western Blots ◽  
Type Isolate ◽  
Wide Range

Eggplant mottled dwarf rhabdovirus (EMDV) is endemic in the Mediterranean area but within the family Cucurbitaceae has been reported only in cucumber (1). In the spring of 1998 unusual symptoms of stunting, short internodes, fruit deformation, and vein yellowing were observed in about 5% of muskmelon (Cucumis melo L. var. reticulatus Naudin) cv. Hombre F1 grown under plastic in Tuscany (Central Italy). Electron microscopy of negatively stained preparations of crude sap from such melon plants revealed the presence of large numbers of particles resembling rhabdovirus. The virus, sap transmitted to several test plant species, had a host range identical to that of typical EMDV isolates, including the isolate from cucumber. Based on both electron microscopy and test plant reactions, the presence of other viruses was excluded. As with other known isolates, symptoms did not appear until about 30 days after inoculation, except for necrotic local lesions in Gomphrena globosa, which appeared in 10 days. Systemic leaf symptoms of field melon were reproduced by mechanically inoculating glasshouse melon seedlings with sap from infected White Burley tobacco. The virus was identified as EMDV by serology with an antiserum (As-0136) against the type isolate (EMDV-PV-0031), both obtained from the Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ), Germany. No differences in protein pattern in Western blots (immunoblots) were observed by coelectrophoresis of the type isolate and our melon isolate. The virus was easily detected in several experimental hosts by antigen-coated plate enzyme-linked immunosorbent assay (ELISA). The vector of EMDV is unknown, but the virus generally infects in low percentage a wide range of plant species belonging to different families. This suggests that a polyphagous insect with low vector efficiency may be involved in transmission. Reference: (1) P. Roggero et al. Plant Dis. 79:321, 1995.

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