scholarly journals Comparative Performance of Eight PCR Methods to Detect Cryptosporidium Species

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 647
Author(s):  
Damien Costa ◽  
Louise Soulieux ◽  
Romy Razakandrainibe ◽  
Louise Basmaciyan ◽  
Gilles Gargala ◽  
...  
Keyword(s):  
Rare Species ◽  
Limit Of Detection ◽  
Cross Reactivity ◽  
Human Infection ◽  
Cryptosporidium Species ◽  
Cross Reaction ◽  
Enteric Pathogens ◽  
Comparative Performance ◽  
Diagnostic Approaches

Diagnostic approaches based on PCR methods are increasingly used in the field of parasitology, particularly to detect Cryptosporidium. Consequently, many different PCR methods are available, both “in-house” and commercial methods. The aim of this study was to compare the performance of eight PCR methods, four “in-house” and four commercial methods, to detect Cryptosporidium species. On the same DNA extracts, performance was evaluated regarding the limit of detection for both C. parvum and C. hominis specificity and the ability to detect rare species implicated in human infection. Results showed variations in terms of performance. The best performance was observed with the FTD® Stool parasites method, which detected C. parvum and C. hominis with a limit of detection of 1 and 10 oocysts/gram of stool respectively; all rare species tested were detected (C. cuniculus, C. meleagridis, C. felis, C. chipmunk, and C. ubiquitum), and no cross-reaction was observed. In addition, no cross-reactivity was observed with other enteric pathogens. However, commercial methods were unable to differentiate Cryptosporidium species, and generally, we recommend testing each DNA extract in at least triplicate to optimize the limit of detection.

scholarly journals Are Nanobiosensors an Improved Solution for Diagnosis of Leishmania?

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 491
Author(s):  
Sona Jain ◽  
Wanessa Santana ◽  
Silvio S. Dolabella ◽  
André L. S. Santos ◽  
Eliana B. Souto ◽  
...  
Keyword(s):  
Low Income ◽  
Neglected Tropical Diseases ◽  
Diagnostic Techniques ◽  
Cross Reactivity ◽  
Low Income Countries ◽  
Future Research ◽  
Immunological Tests ◽  
Diagnostic Approaches ◽  
Signal Improvement ◽  
Adequate Management

Leishmaniasis is one of the deadliest neglected tropical diseases affecting 12–15 million people worldwide, especially in middle- and low-income countries. Rapid and accurate diagnosis of the disease is important for its adequate management and treatment. Several techniques are available for the diagnosis of leishmaniasis. Among these, parasitological and immunological tests are most widely used. However, in most cases, the utilized diagnostic techniques are not good enough, showing cross-reactivity and reduced accuracy. In recent years, many new methods have been reported with potential for improved diagnosis. This review focuses on the diagnosis of Leishmania exploring the biosensors and nanotechnology-based options for their detection. New developments including the use of nanomaterials as fluorophores, fluorescence quenchers as reducing agents and as dendrimers for signal improvement and amplification, together with the use of aptamers to replace antibodies are described. Future research opportunities to overcome the current limitations on the available diagnostic approaches are also discussed.

scholarly journals Do intestinal parasites interfere with the seroepidemiologic surveillance of Schistosoma mansoni infection?

1996 ◽  
Vol 116 (3) ◽  
pp. 323-329 ◽  
Author(s):  
B. Alarcón De Noya ◽  
C. Colmenares ◽  
S. Losada ◽  
Z. Fermin ◽  
G. Masroua ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
False Positive ◽  
Total Population ◽  
Intestinal Parasites ◽  
Field Work ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
Protein Fractions ◽  
Egg Antigen ◽  
Immunoenzymatic Assay

SUMMARYIn view of the known cross-reactivity of sera from patients with intestinal parasites to some Schistosoma mansoni antigens, field work was conducted in an area of Venezuela non-endemic for schistosomiasis using the routine immunoenzymatic assay (ELISA) with soluble egg antigen (SEA). False positive reactions represented 15·3% of the total population as determined by SEA–ELISA. SEA-immunoblotting of the false positive sera indicated that protein fractions of 91 and 80 kDa appear to be responsible for cross-reactivity. Sera from hookworm infected individuals produced a higher frequency and intensity of cross-reaction than other sera. SEA-fractions of 105, 54, 46, 42, 32, 25 and 15 kDa were the most specific.

scholarly journals Trypanosoma cruzi: identification of specific epimastigote antigens by human immune sera

1989 ◽  
Vol 84 (3) ◽  
pp. 309-314 ◽  
Author(s):  
M. G. Morgado ◽  
J. Ivo-dos-Santos ◽  
R. T. Pinho ◽  
E. Argüelles ◽  
J. M. Rezende ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Trypanosoma Cruzi ◽  
Western Blot ◽  
Chagas Disease ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
The Other ◽  
Molecular Weights ◽  
Human Visceral Leishmaniasis ◽  
Human Immune

Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumentar leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzy antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-reactivity was observed when sera from human visceral leishmaniasis were used, while only a slight cross-reaction was observed with sera from tegumentar leishmaniasis. On the other hand, 10 polypeptidesspecifically reacting with sera from Chagas' disease patients were identified. Among them, the antigens with molecular weights of 46 kDa and 25 kDa reacted with all sera teste and may be good candidates for specific immunodiagnosis of Chagas' disease.

scholarly journals An effective strategy for preparation of a polyclonal antibody with an addition of carbon chain of ciprofloxacin

2018 ◽  
Vol 16 ◽  
pp. 205873921880564
Author(s):  
Dong Wei ◽  
Guozhen Fang ◽  
Shuo Wang
Keyword(s):  
Polyclonal Antibody ◽  
Limit Of Detection ◽  
High Titer ◽  
Carbon Chain ◽  
Cross Reactivity ◽  
Carrier Protein ◽  
Effective Strategy ◽  
Coating Antigen ◽  
Spacer Arm ◽  
Proper Modification

In this study, we synthesized amino propyl ciprofloxacin (CPLX-NH2) as a ciprofloxacin (CPLX) derivative. Moreover, the immune antigen CPLX-NH2-BSA and coating antigen CPLX-NH2-OVA were prepared via CPLX-NH2 coupling with bovine serum albumin (BSA) and ovalbumin (OVA), respectively. Subsequently, the Kunming mice were immunized with immune antigen to obtain the polyclonal antibody with high titer. The regression equation of CPLX-NH2 antibody was y = –17.395x + 89.331 (R2 = 0.9961); IC50 and limit of detection (LOD) were 182.39 and 20.09 ng/mL, respectively. These results were superior to that of CPLX antibody. Meanwhile, the CPLX-NH2 antibody showed cross-reactivity to fluoroquinolones (FQNs) residues. The results of the study indicated that the proper modification of the drug, namely, the addition of a suitable spacer arm between the drug and the carrier protein will improve the efficacy of the antibody, which is a favorable concept for preparation of antibody.

scholarly journals Dramatically Enhancing the Sensitivity of Immunoassay for Ochratoxin A Detection by Cascade-Amplifying Enzyme Loading

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 781
Author(s):  
Zhuolin Song ◽  
Lin Feng ◽  
Yuankui Leng ◽  
Mingzhu Huang ◽  
Hao Fang ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Cross Reaction ◽  
Molar Ratio ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Enzyme Loading ◽  
M13 Bacteriophage ◽  
Mimic Peptide

Enzyme-linked immunosorbent assay (ELISA) is widely used in the routine screening of mycotoxin contamination in various agricultural and food products. Herein, a cascade-amplifying system was introduced to dramatically promote the sensitivity of an immunoassay for ochratoxin A (OTA) detection. Specifically, a biotinylated M13 bacteriophage was introduced as a biofunctional competing antigen, in which a seven-peptide OTA mimotope fused on the p3 protein of M13 was used to specifically recognize an anti-OTA monoclonal antibody, and the biotin molecules modified on capsid p8 proteins were used in loading numerous streptavidin-labeled polymeric horseradish peroxidases (HRPs). Owing to the abundance of biotinylated p8 proteins in M13 and the high molar ratio between HRP and streptavidin in streptavidin-polyHRP, the loading amount of HRP enzymes on the M13 bacteriophage were greatly boosted. Hence, the proposed method exhibited high sensitivity, with a limit of detection of 2.0 pg/mL for OTA detection, which was 250-fold lower than that of conventional ELISA. In addition, the proposed method showed a slight cross-reaction of 2.3% to OTB, a negligible cross-reaction for other common mycotoxins, and an acceptable accuracy for OTA quantitative detection in real corn samples. The practicability of the method was further confirmed with a traditional HRP-based ELISA method. In conclusion, the biotinylated bacteriophage and polyHRP structure showed potential as a cascade-amplifying enzyme loading system for ultra-trace OTA detemination, and its application can be extended to the detection of other analytes by altering specific mimic peptide sequences.

scholarly journals EVALUATION OF ELEVEN IMMUNOCHROMATOGRAPHIC ASSAYS FOR SARS-CoV-2 DETECTION: INVESTIGATING DENGUE CROSS-REACTION

2020 ◽  
Author(s):  
Beatriz Araujo Oliveira ◽  
Lea Campos de Oliveira ◽  
Franciane Mendes de Oliveira ◽  
Geovana Maria Pereira ◽  
Regina Maia de Souza ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Diagnostic Techniques ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
List Type ◽  
Rt Pcr ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Good Agreement

AbstractBackgroundCOVID-19 disease (Coronavirus disease 2019) caused by SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) is widespread worldwide, affecting more than 11 million people globally (July 6th, 2020). Diagnostic techniques have been studied in order to contain the pandemic. Immunochromatographic (IC) assays are feasible and low cost alternative for monitoring the spread of COVID-19 in the population.MethodsHere we evaluate the sensitivity and specificity of eleven different immunochromatographic tests in 98 serum samples from confirmed cases of COVID-19 through RT-PCR and 100 negative serum samples from blood donors collected in February 2019. Considering the endemic situation of Dengue in Brazil, we also evaluated the cross-reactivity with Dengue using 20 serum samples from patients with confirmed diagnosis for Dengue collected in early 2019 through four different tests.ResultsOur results demonstrated agreement between immunochromatographic assays and RT-PCR, especially after 10 days since the onset of symptoms. The evaluation of IgG and IgM antibodies combined demonstrated a strong level of agreement (0.85) of IC assays and RT-PCR. It was observed cross-reactivity between Dengue and COVID-19 using four different IC assays for COVID-19 diagnosis. The specificity of IC assays to detected COVID-19 IgM antibodies using Dengue serum samples varied from 80% to 85%; the specificity of IgG detection was 100% and total antibody was 95%.ConclusionsWe found high sensitivity, specificity and good agreement of IC assays, especially after 10 days onset of symptoms. However, we detected cross-reactivity between Dengue and COVID-19 mainly with IgM antibodies demonstrating the need for better studies about diagnostic techniques for these diseases.HighlightsImmunochromatographic assays demonstrated high sensitivity and specificity and good agreement with the gold-standard RT-PCR;Increase in sensitivity and specificity of assays using samples collected after the 10th day of symptoms;Cross-reaction with Dengue serology in evaluation of IgM.

The use of heterologous radioimmunoassays for the measurement of follicle-stimulating hormone and luteinizing hormone concentrations in horse and donkey serum

1983 ◽  
Vol 99 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Valerie Urwin
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Cross Reactivity ◽  
Chorionic Gonadotrophin ◽  
Cross Reaction ◽  
The Other ◽  
Corpora Lutea ◽  
Serum Concentrations ◽  
Study Support ◽  
Baseline Levels

Heterologous double-antibody radioimmunoassays were developed for the measurement of FSH and LH concentrations in the serum of both horses and donkeys. The FSH assay employed a rabbit anti-ovine FSH serum which showed a complete lack of cross-reaction with equine chorionic gonadotrophin (eCG) and negligible cross-reaction with equine LH. The LH assay utilized an antiserum raised against highly purified eCG. This similarly showed negligible cross-reaction with equine FSH but its high cross-reactivity with eCG prevented the measurement of equine LH concentrations in serum when eCG was also present. In both assays serial dilutions of horse and donkey serum were parallel to the standard. The assays were used to monitor changes in serum concentrations of FSH and LH during the first 100 days of pregnancy in pony mares and jenny donkeys. In both species during pregnancy LH levels reached a peak 1–2 days after ovulation. They then decreased rapidly to baseline levels where they remained until days 35–40 when the commencement of eCG production prevented their further measurement. Serum FSH concentrations, on the other hand, continued to fluctuate markedly throughout the first 100 days of pregnancy in both the ponies and donkeys. Pronounced surges in FSH levels occurred at regular intervals in some animals but the pattern of release was quite irregular in the others. The results of this study support the concept that it is continued pituitary FSH release, not eCG secretion, which is responsible for stimulating the secondary follicles which develop during early equine pregnancy. However, it appears likely that it is the LH-like activity of eCG which causes the subsequent ovulation and/or luteinization of these secondary follicles to produce accessory corpora lutea.

Evaluation of an alternative S100b assay for use in cardiac surgery: relationship with microemboli and neuropsychological outcome

Perfusion ◽  
2007 ◽  
Vol 22 (4) ◽  
pp. 267-272 ◽  
Author(s):  
D.C. Whitaker ◽  
A.J.E. Green ◽  
J. Stygall ◽  
M.J.G. Harrison ◽  
S.P. Newman
Keyword(s):  
Cardiac Surgery ◽  
Limit Of Detection ◽  
Artery Bypass ◽  
Sandwich Elisa ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Cell Protein ◽  
Skin Closure ◽  
Neuropsychological Outcome ◽  
The Right

Introduction. The aim of the study was to investigate the relationship between S100b release, neuropsychological outcome and cerebral microemboli. Peri-operative assay of the astroglial cell protein S100b has been used as a marker of cerebral damage after cardiac surgery but potential assay cross-reactivity has limited its specificity. The present study uses an alternative enzyme-linked immunoabsorbant assay (ELISA) for serum S100b that has documented sensitivity and specificity data in patients undergoing coronary artery bypass grafting (CABG). Methods. Fifty-five consecutive patients undergoing routine CABG surgery received serial venous S100b sampling at five time points: i) Pre-operative, ii) At the end of cardiopulmonary bypass (CPB), iii) 6 hrs, iv) 24 hrs and v) 48 hrs post skin closure. A previously described sandwich ELISA with monoclonal anti- S100b was used. This assay has a lower limit of detection of 0.04 μ g/L and < 0.006% reactivity with S100a at a concentration of 100 μg/L S100a. Cerebral microemboli during surgery were recorded by transcranial Doppler monitor over the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients' performance in a neuropsychological battery of 9 tests administered 6—8 weeks post-operatively with their pre-operative scores. Results. There was a significant increase in S100b only at the end of bypass (mean 0.30 μg/L, SD ± 0.33 and range .00 to 1.57). S100b levels at the end of bypass did not correlate with neuropsychological outcome or microemboli counts. Conclusions. The low levels of S100b detected using the present assay, despite its high sensitivity and despite the routine use of cardiotomy suction, suggest that the assay may have higher specificity for cerebral S100b than previously used assays. There was no evidence that this assay is related to neuropsychological change or cerebral microemboli in cardiac surgery. Perfusion (2007) 22, 267—272.

scholarly journals Selection and Identification of Novel Aptamers Specific for Clenbuterol Based on ssDNA Library Immobilized SELEX and Gold Nanoparticles Biosensor

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2337 ◽  
Author(s):  
Xixia Liu ◽  
Qi Lu ◽  
Sirui Chen ◽  
Fang Wang ◽  
Jianjun Hou ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Limit Of Detection ◽  
Retention Rate ◽  
Pcr Amplification ◽  
Cross Reactivity ◽  
Enriched Library ◽  
Amplification Curve ◽  
Specificity And Sensitivity

We describe a multiple combined strategy to discover novel aptamers specific for clenbuterol (CBL). An immobilized ssDNA library was used for the selection of specific aptamers using the systematic evolution of ligands by exponential enrichment (SELEX). Progress was monitored using real-time quantitative PCR (Q-PCR), and the enriched library was sequenced by high-throughput sequencing. Candidate aptamers were picked and preliminarily identified using a gold nanoparticles (AuNPs) biosensor. Bioactive aptamers were characterized for affinity, circular dichroism (CD), specificity and sensitivity. The Q-PCR amplification curve increased and the retention rate was about 1% at the eighth round. Use of the AuNPs biosensor and CD analyses determined that six aptamers had binding activity. Affinity analysis showed that aptamer 47 had the highest affinity (Kd = 42.17 ± 8.98 nM) with no cross reactivity to CBL analogs. Indirect competitive enzyme linked aptamer assay (IC-ELAA) based on a 5′-biotin aptamer 47 indicated the limit of detection (LOD) was 0.18 ± 0.02 ng/L (n = 3), and it was used to detect pork samples with a mean recovery of 83.33–97.03%. This is the first report of a universal strategy including library fixation, Q-PCR monitoring, high-throughput sequencing, and AuNPs biosensor identification to select aptamers specific for small molecules.

Cross-Reactivity between IgE-Binding Proteins from Anisakis Simplex and Dermatophagoides Pteronyssinus

2005 ◽  
Vol 18 (4) ◽  
pp. 671-675 ◽  
Author(s):  
R. Bernardini ◽  
G. Mistrello ◽  
E. Novembre ◽  
D. Roncarolo ◽  
S. Zanotta ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Binding Proteins ◽  
Specific Ige ◽  
Dermatophagoides Pteronyssinus ◽  
Cross Reactivity ◽  
Anisakis Simplex ◽  
Cross Reaction ◽  
Ige Binding ◽  
Sds Page ◽  
The Cross

An association was found between Anisakis simplex (As) and Dermatophagoides pteronyssinus (Dp) sensitization. One recent study shows a cross-reactivity between As and Dp and tropomyosin (tr) is suspected as being one of the proteins responsible of this cross-reaction. The aim of our study was: 1) to confirm the cross-reactivity between Dp and As; 2) to determine the importance of tr in this cross reaction. SDS-PAGE analysis of Dp and As (metabolic and somatic) extracts was carried out. Then an IgE immunoblotting test using serum from a patient who had specific IgE only to Dp and As and immunoblotting inhibition experiments using Dp extract and tr as inhibitors were performed. We found that patient's serum reacted: 1) against larval As antigens with a molecular weight (mw) of 25 kilodalton (kD) and a mw > 100 kD, 2) against various metabolic As antigens with a mw > 100 kD, a mw ranging approximately from 35 to 50 kD, and a mw around 20 kD, and 3) against Dp proteins with mw between 35 and 55 kD. Preincubation of patient's serum with Dp extract caused the disappearance of reactivity against antigens with a mw > 100 kD in both larval and metabolic As extracts and against proteins with mw ranging approximately from 35 to 50 kD in the metabolic As extract. Preincubation of patient's serum with As extract caused the disappearance of reactivity against antigens with mw between 35 and 55 kD in the Dp extract. Pre-incubation of patient's serum with tr did not induce any change in the immunoblotting profile. The results show that 1) cross-reactive components between Dp and As are some proteins with a mw ranging approximately from 35 to 50 kD and with a mw > 100 kD, and 2) tr is not involved in cross-reactivity between As and Dp.

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