Development of a sensitive immunochromatographic kit using fluorescent silica nanoparticles for rapid serodiagnosis of amebiasis

Parasitology ◽  
2018 ◽  
Vol 145 (14) ◽  
pp. 1890-1895 ◽  
Author(s):  
Hiroshi Tachibana ◽  
Azumi Kakino ◽  
Makoto Kazama ◽  
Meng Feng ◽  
Satomi Asai ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Human Monoclonal Antibody ◽  
Serum Samples ◽  
Fluorescent Intensity ◽  
Fluorescent Silica Nanoparticles ◽  
Freeze Dried ◽  
Antibody Titers ◽  
Indirect Immunofluorescent ◽  
Antibody Tests ◽  
Positive Results

AbstractWe have previously shown that the C-terminal region of the intermediate subunit ofEntamoeba histolyticagalactose- andN-acetyl-D-galactosamine-inhibitable lectin (C-Igl) is a useful antigen for serodiagnosis of amebiasis. An immunochromatographic kit was developed using fluorescent silica nanoparticles coated with C-Igl prepared inEscherichia coli. Samples for examination were added to the freeze-dried particles and then applied to the immunochromatographic device, in which a test line on the membrane was also coated with C-Igl. Fluorescent intensity was measured using a hand-held reader. In an evaluation of the kit using a human monoclonal antibody, the minimum amount of C-Igl specific antibody showing positive results was 100 pg. In the evaluation of serum samples with different antibody titers in indirect immunofluorescent antibody tests in the kit, 20µL of serum was sufficient to obtain positive results at 30 min. Serum samples from symptomatic patients with amebic colitis and amebic liver abscess and those from asymptomaticE. histolytica-cyst carriers showed positive results in the kit. Based on evaluation using sera from healthy controls and patients with other infectious diseases, the sensitivity and specificity of the kit were 100 and 97.6%, respectively. Therefore, we conclude that the newly developed kit is useful for rapid serodiagnosis of amebiasis.

scholarly journals Evaluation of Eight Serological Tests for Diagnosis of Imported Schistosomiasis

2012 ◽  
Vol 19 (6) ◽  
pp. 948-953 ◽  
Author(s):  
Hans-Friedemann Kinkel ◽  
Sabine Dittrich ◽  
Britta Bäumer ◽  
Thomas Weitzel
Keyword(s):  
Antibody Test ◽  
Parasitic Infections ◽  
Serum Samples ◽  
Serological Tests ◽  
Content Type ◽  
Commercial Kits ◽  
Few Data ◽  
Indirect Immunofluorescent ◽  
Positive Results ◽  
Immunofluorescent Antibody Test

ABSTRACTThe diagnosis of schistosomiasis in individuals from countries where the disease is not endemic is challenging, and few data are available on the accuracy of serological diagnosis in those patients. We evaluated the performance of eight serological assays, including four commercial kits, in the diagnosis of imported schistosomiasis in individuals from areas where the disease is not endemic, including six enzyme-linked immunosorbent assays using three different antigens, an indirect hemagglutination assay, and an indirect immunofluorescent-antibody test. To analyze the assays, we used a total of 141 serum samples, with 121 derived from patients with various parasitic infections (among which were 37 cases of schistosomiasis) and 20 taken from healthy volunteers. The sensitivity values for detection of schistosomiasis cases ranged from 41% to 78% and were higher forSchistosoma mansonithan forS. haematobiuminfections. Specificity values ranged from 76% to 100%; false-positive results were most frequent for samples from patients with cestode infections. By combining two or more tests, sensitivity improved markedly and specificity decreased only moderately. Serological tests are useful instruments for diagnosing imported schistosomiasis in countries where the disease is not endemic, but due to limitations in test sensitivities, we recommend the use of two or more assays in parallel.

scholarly journals Development of an Immunochromatographic Assay Kit Using Fluorescent Silica Nanoparticles for Rapid Diagnosis of Acanthamoeba Keratitis

2014 ◽  
Vol 53 (1) ◽  
pp. 273-277 ◽  
Author(s):  
Koji Toriyama ◽  
Takashi Suzuki ◽  
Tomoyuki Inoue ◽  
Hiroshi Eguchi ◽  
Saichi Hoshi ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Real Time ◽  
Real Time Pcr ◽  
High Sensitivity ◽  
Acanthamoeba Keratitis ◽  
Cross Reactivity ◽  
Immunochromatographic Assay ◽  
Content Type ◽  
Fluorescent Silica Nanoparticles ◽  
Positive Results

We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoebaantibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection ofAcanthamoebaand diagnosis ofAcanthamoebakeratitis (AK). The sensitivity of the FICGA kit was evaluated using samples ofAcanthamoebatrophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was also evaluated to determine its sensitivity in detectingAcanthamoebatrophozoites. To check for cross-reactivity, the FICGA was performed by using samples of other common causative pathogens of infectious keratitis, such asPseudomonas aeruginosa,Staphylococcus aureus,Staphylococcus epidermidis, andCandida albicans. Corneal scrapings from patients with suspected AK were tested with the FICGA kit to detect the presence ofAcanthamoeba, and the results were compared with those of real-time PCR. The FICGA kit detected organisms at concentrations as low as 5 trophozoites or 40 cysts per sample. There were no cross-reactivities with other pathogens. The FICGA was approximately 20 times more sensitive than the LICGA for the detection ofAcanthamoebatrophozoites. The FICGA kit yielded positive results for all 10 patients, which corresponded well with the real-time PCR results. The FICGA kit demonstrated high sensitivity for the detection ofAcanthamoebaand may be useful for the diagnosis of AK.

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 Successful return to professional men’s football (soccer) competition after the COVID-19 shutdown: a cohort study in the German Bundesliga

2020 ◽  
Vol 55 (1) ◽  
pp. 62-66 ◽  
Author(s):  
Tim Meyer ◽  
Dietrich Mack ◽  
Katrin Donde ◽  
Oliver Harzer ◽  
Werner Krutsch ◽  
...  
Keyword(s):  
Football Players ◽  
Professional Football ◽  
Antibody Testing ◽  
Serum Samples ◽  
Symptom Monitoring ◽  
The Third ◽  
Hygiene Measures ◽  
Football Training ◽  
Antibody Tests ◽  
Positive Results

ObjectivesTo evaluate the restart of the German Bundesliga (football (soccer)) during the COVID-19 pandemic from a medical perspective.MethodsParticipants were male professional football players from the two highest German leagues and the officials working closely with them. Our report covers nine match days spread over 9 weeks (May to July 2020). Daily symptom monitoring, PCR testing for SARS-CoV-2 RNA twice weekly, and antibody tests (on two occasions—early during the phase in May 2020 and in the week of the last match) were conducted. Target variables were: (1) onset of typical COVID-19 symptoms, (2) positive PCR results, and (3) IgG seroconversion against SARS-CoV-2. All detected seroconversions were controlled by neutralisation tests.FindingsSuspicious symptoms were reported for one player; an immediate additional PCR test as well as all subsequent diagnostic and antibody tests proved negative for coronavirus. Of 1702 regularly tested individuals (1079 players, 623 officials members), 8 players and 4 officials tested positive during one of the first rounds of PCR testing prior to the onset of team training, 2 players during the third round. No further positive results occurred during the remainder of the season. 694 players and 291 officials provided two serum samples for antibody testing. Nine players converted from negative/borderline to positive (without symptoms); two players who initially tested positive tested negative at the end of the season. 22 players remained seropositive throughout the season. None of the seroconversions was confirmed in the neutralisation test.ConclusionProfessional football training and matches can be carried out safely during the COVID-19 pandemic. This requires strict hygiene measures including regular PCR testing.

scholarly journals Viral, Serological, and Antioxidant Investigations of Equine Rhinitis A Virus in Serum and Nasal Swabs of Commercially Used Horses in Poland

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Barbara Bażanów ◽  
Agnieszka Frącka ◽  
Natalia Jackulak ◽  
Ewa Romuk ◽  
Tomasz Gębarowski ◽  
...  
Keyword(s):  
Nasal Swab ◽  
Virus Isolation ◽  
Serum Samples ◽  
Sod Activity ◽  
Nasal Swabs ◽  
Antioxidant Parameters ◽  
Antibody Titers ◽  
Group 2 ◽  
Positive Results ◽  
Group 1

Background. Equine rhinitis A virus (ERAV) is considered to be an important pathogen in horses, but relatively few studies are available.Aims. The purpose of this study was to verify ERAV seroprevalence in selected horses in Poland, in addition to correlation between ERAV and age and sex of analysed animals and the antioxidant status.Methods. The material collected from clinically healthy horses was tested using the VNT (353 serum samples) and virus isolation method (44 nasal swabs). 27 serum samples with antibody titers between 0 and ≥1 : 2048 were chosen for further analysis. The study was conducted in group 1 (ERAV titer ≤ 64) and group 2 (ERAV titer > 64).Results. Seroneutralisation tests showed positive results in 72% of serum samples. No significant correlation between ERAV seropositive results and selected biochemical indicators was observed. Group 2 had statistically higher concentrations of SOD and CuZnSOD than the analysed group 1.Conclusions. ERAV was not detected in the nasal swab samples. Antioxidant parameters did not significantly vary between horses of different breed, sex, or age. The ERAV virus had an impact on plasma total SOD and Cu/Zn SOD activity in horses in early stages of convalescence.

scholarly journals Archived dengue serum samples produced false-positive results in SARS-CoV-2 lateral flow-based rapid antibody tests

2021 ◽  
Vol 70 (6) ◽  
Author(s):  
Himadri Nath ◽  
Abinash Mallick ◽  
Subrata Roy ◽  
Soumi Sukla ◽  
Keya Basu ◽  
...  
Keyword(s):  
Dengue Virus ◽  
False Positive ◽  
Lateral Flow ◽  
Accurate Estimation ◽  
Serum Samples ◽  
Positive Serum ◽  
Rapid Tests ◽  
Antibody Tests ◽  
Positive Results ◽  
Rapid Antibody

Co-endemicity of SARS-CoV-2 and dengue virus (DV) infection is becoming a matter of serious concern as it has been already reported that antibodies (Ab) elicited by SARS-CoV-2 infection can produce false-positive results in dengue IgG and IgM rapid tests and vice versa. Here we communicate that five of thirteen DV antibody-positive serum samples from Kolkata, archived in 2017 (predating the COVID-19 outbreak), produced false-positive results in SARS-CoV-2 IgG/IgM lateral flow-based rapid tests. Our results emphasize the importance of implementing tests with higher specificity to conduct sero-surveillance for accurate estimation of SARS-CoV-2/DV prevalence in regions where both viruses now co-exist.

scholarly journals The Effect of Rhodamine B on The Properties of Fluorescent Nanoparticles Derived from Geothermal Silica

2020 ◽  
Vol 9 (3) ◽  
pp. 171-176
Author(s):  
Yovilianda Maulitiva Untoro ◽  
◽  
Diaz Ayu Widyasari ◽  
Edi Supriadi ◽  
Siti Nurul Aisyiyah Jenie ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Rhodamine B ◽  
Sol Gel ◽  
Specific Area ◽  
Ammonium Bromide ◽  
Fluorescent Nanoparticles ◽  
Fluorescent Intensity ◽  
Fluorescent Silica Nanoparticles ◽  
Bet Analysis ◽  
Ft Ir

Rhodamine B can be used as a fluorophore to produce fluorescent silica nanoparticles derived from geothermal sludge. The purpose of this research is to synthesize fluorescent silica nanoparticles (FSNP) modified with rhodamine B and cetyl trimethyl ammonium bromide (CTAB) using sol-gel method. Geothermal waste was used as a precursor and added with NaOH at 900C to generate sodium silicate. Rhodamine B, as the fluorescent dye were added with concentration variations ranging from 0.156 mg/g to 10 mg/g.CTAB was used as template and HCl 2N was applied as gelling catalyst with aging time of 18 hours. Characterization of FSNP was measured using spectrofluorometer to identify the fluorescent intensity, fourier transform infrared (FT-IR) to determine the functional group of FSNP, Brauner-Emmett-Teller (BET) adsorption to calculate the specific area of the particles, X-ray diffraction (XRD) to analyze the crystallographic phases, and transmission electron microscopy (TEM) to analyze the surface morphology of the FSNP. FT-IR and fluorescent intensity results showed that FSNP with 2.5 mg/g of rhodamine B had the optimum characteristics. The FSNP was in amorphous phase with uniform pore distribution. BET analysis showed that the specific surface of the FSNP was 190.22 m2/g.

scholarly journals Presence of Antibodies against Bluetongue Virus (BTV) in Sheep 5 to 7.5 Years after Vaccination with Inactivated BTV-8 Vaccines

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 533 ◽  
Author(s):  
Johanna Hilke ◽  
Heinz Strobel ◽  
Soeren Woelke ◽  
Melanie Stoeter ◽  
Katja Voigt ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Short Communication ◽  
Competition Assay ◽  
Serum Samples ◽  
Virus Serotype ◽  
Antibody Titers ◽  
Inactivated Vaccines ◽  
Female Sheep ◽  
Positive Results ◽  
Elisa Result

Thirty-six female sheep, previously vaccinated against Bluetongue virus serotype 8 (BTV-8) using inactivated vaccines, were included in this field study. In Germany, vaccination was compulsory in 2008 and 2009, voluntary in 2010 and early 2011, and later, was prohibited in 2011. Due to their age, eighteen sheep had been vaccinated for two or more consecutive years, while a further eighteen animals had only been vaccinated once or not at all. The sheep were blood sampled five (n = 31) to 7.5 years (n = 5) after their last vaccination. All serum samples (n = 36) were tested for BTV group-specific antibodies by an ELISA (IDScreen® Bluetongue Competition assay, ID Vet). In five of the animals, the BTV-8 serotype-specific antibody titers were measured by serum neutralization (SN). The majority of sheep that were vaccinated annually for two or more years showed a positive ELISA (14/18 sheep) and a SN (two of two sheep) result 5 years after their last vaccination. Most of the sheep vaccinated fewer than twice showed a negative ELISA result 5 to 7.5 years after their last vaccination (13/18 animals). The three animals in this group tested by SN showed one negative and two positive results. This short communication is the first to describe the presence of BTV antibodies in sheep 5 to 7.5 years after vaccination with inactivated BTV-8 vaccines.

scholarly journals Serum Neutralizing Activity against B.1.1.7, B.1.351, and P.1 SARS-CoV-2 Variants of Concern in Hospitalized COVID-19 Patients

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1347
Author(s):  
Claudia Maria Trombetta ◽  
Serena Marchi ◽  
Simonetta Viviani ◽  
Alessandro Manenti ◽  
Linda Benincasa ◽  
...  
Keyword(s):  
Natural Infection ◽  
Neutralizing Antibody ◽  
Original Strain ◽  
Immune Protection ◽  
Serum Samples ◽  
Symptomatic Infection ◽  
Neutralizing Activity ◽  
The United Kingdom ◽  
Antibody Titers ◽  
Pandemic Wave

The recent spreading of new SARS-CoV-2 variants, carrying several mutations in the spike protein, could impact immune protection elicited by natural infection or conferred by vaccination. In this study, we evaluated the neutralizing activity against the viral variants that emerged in the United Kingdom (B.1.1.7), Brazil (P.1), and South Africa (B.1.351) in human serum samples from hospitalized patients infected by SARS-CoV-2 during the first pandemic wave in Italy in 2020. Of the patients studied, 59.5% showed a decrease (≥2 fold) in neutralizing antibody titer against B.1.1.7, 83.3% against P.1, and 90.5% against B.1.351 with respect to the original strain. The reduction in antibody titers against all analyzed variants, and in particular P.1 and B.1.351, suggests that previous symptomatic infection might be not fully protective against exposure to SARS-CoV-2 variants carrying a set of relevant spike mutations.

scholarly journals Performance evaluation of ImmunoCAP® ISAC 112: a multi-site study

2017 ◽  
Vol 55 (4) ◽  
Author(s):  
Marianne van Hage ◽  
Peter Schmid-Grendelmeier ◽  
Chrysanthi Skevaki ◽  
Mario Plebani ◽  
Walter Canonica ◽  
...  
Keyword(s):  
South African ◽  
Low Frequency ◽  
Specific Ige ◽  
High Concentration ◽  
Serum Samples ◽  
Site Analysis ◽  
Calibration Sample ◽  
Clustering And Classification ◽  
Study Sites ◽  
Positive Results

Abstract Background: After the re-introduction of ImmunoCAP Methods: The study was carried out at 22 European and one South African site. Microarrays from different batches, eight specific IgE (sIgE) positive, three sIgE negative serum samples and a calibration sample were sent to participating laboratories where assays were performed according to the manufacturer’s instructions. Results: For both the negative and positive samples results were consistent between sites, with a very low frequency of false positive results (0.014%). A similar pattern of results for each of the samples was observed across the 23 sites. Homogeneity analysis of all measurements for each sample were well clustered, indicating good reproducibility; unsupervised hierarchical clustering and classification via random forests, showed clustering of identical samples independent of the assay site. Analysis of raw continuous data confirmed the good accuracy across the study sites; averaged standardized, site-specific ISU-E values fell close to the center of the distribution of measurements from all sites. After outlier filtering, variability across the whole study was estimated at 25.5%, with values of 22%, 27.1% and 22.4% for the ‘Low’, ‘Moderate to High’ and ‘Very High’ concentration categories, respectively. Conclusions: The study shows a robust performance of the ImmunoCAP

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