Adaptation of an immunodot assay for multiple prey identification of squid paralarvae in field trials

2005 ◽  
Vol 85 (6) ◽  
pp. 1499-1501 ◽  
Author(s):  
H.J.T. Hoving ◽  
J.D. Venter ◽  
D.E. Worst ◽  
M.R. Lipinski
Keyword(s):  
South African ◽  
Polyclonal Antibodies ◽  
Detection Limits ◽  
Field Trials ◽  
Negative Control ◽  
Prey Detection ◽  
Cross Reactions ◽  
Prey Identification

An optimized method, using polyclonal antibodies in an immunoassay, for prey detection in the diet of paralarvae of South African Loligo reynaudii is described. The study has increased the specificity of the antisera by determining the optimum antiserum dilutions and the detection limits of the antisera. Unfed laboratory-hatched paralarvae (negative control) were exposed to antisera and showed cross-reactions with polychaete antiserum.

scholarly journals Determination of Citrinin in Barley by Indirect and Direct Enzyme Immunoassay

1996 ◽  
Vol 79 (6) ◽  
pp. 1325-1329 ◽  
Author(s):  
David Abramson ◽  
Ewald Usleber ◽  
Erwin Martlbauer
Keyword(s):  
Enzyme Immunoassay ◽  
Solid Phase ◽  
Polyclonal Antibodies ◽  
Detection Limits ◽  
Keyhole Limpet Hemocyanin ◽  
Buffer Solutions ◽  
Microtiter Plates ◽  
Coefficients Of Variation ◽  
Optimum Extraction

Abstract Polyclonal antibodies against the mycotoxin citrinin were raised in rabbits after immunization with citrinin conjugated to keyhole limpet hemocyanin. The antibodies were used in a competitive indirect enzyme immunoassay (EIA) with citrinin coupled to glucose oxidase as the solid-phase antigen for coating microtiter plates. Detection limits of this indirect EIA for citrinin ranged from 0.4 to 0.8 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 100–2000 ng/g ranged from 105 to 112%, with coefficients of variation between 4.5 and 12%. A direct competitive EIA also was established, with citrinin coupled to horseradish peroxidase as the labeled antigen. Detection limits of this direct EIA for citrinin ranged from 2 to 4 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 500–2000 ng/g ranged from 108 to 111%, with coefficients of variation between 8.4 and 26.9%. In naturally contaminated barley samples assayed with the indirect EIA, optimum extraction of citrinin was obtained in 30 min, and only one extraction was necessary to recover 72–76% of the analyte.

scholarly journals Development of an Enzyme-Linked Immunosorbent Assay for Serotyping Ureaplasma urealyticum Strains Using Monoclonal Antibodies

2001 ◽  
Vol 8 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Fedoua Echahidi ◽  
Gaëtan Muyldermans ◽  
Sabine Lauwers ◽  
Anne Naessens
Keyword(s):  
Monoclonal Antibodies ◽  
Immunosorbent Assay ◽  
Ureaplasma Urealyticum ◽  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa Method ◽  
Cross Reactions ◽  
Antigenic Preparation ◽  
Negative Controls ◽  
Reference Strains

ABSTRACT Ureaplasma urealyticum comprises 14 serotypes. The existing serotyping methods all use polyclonal antibodies. These methods are time-consuming and labor-intensive, and they cannot always be performed on primary isolates; in addition, the results are difficult to interpret. We developed a new enzyme-linked immunosorbent assay (ELISA) method using serotype-specific monoclonal antibodies (MAbs) to enable the serotyping of U. urealyticum isolates from primary broth cultures. Each of the 14 serotype reference strains was tested against 14 selected MAbs. Homologous reactions were very strong, while heterologous reactions were negligible. Three cross-reactions were observed: MAb 5 cross-reacted with serotype 2, MAb 14 cross-reacted with serotype 3, and MAb 8 cross-reacted with serotype 13. Despite the cross-reactions observed, all the serotype reference strains ofU. urealyticum could be identified and differentiated using a combination of MAbs. Reproducibility was analyzed with a fractionated antigenic preparation and with several freshly prepared antigens of the same strain. No significant interrun variation was found with the fractionated antigen, but significant variations in optical density (OD) values were found when freshly prepared antigens were tested. However, the variation in OD values did not influence the overall interpretation of the ELISA: reactions with homologous MAbs were always prominent compared to those of the negative controls. This newly developed ELISA using MAbs seems promising for serotyping of U. urealyticum clinical isolates.

scholarly journals A Novel Gene, Le-Dd 10, Is Involved in Fruiting Body Formation of Lentinula Edodes

2022 ◽  
Author(s):  
Akihiro Kishikawa ◽  
Satoshi Hamada ◽  
Ichiro Kamei ◽  
Yosuke Fujimoto ◽  
Kazuhiro Miyazaki ◽  
...  
Keyword(s):  
Cdna Library ◽  
Fruiting Body ◽  
Lentinula Edodes ◽  
Polyclonal Antibodies ◽  
Single Strand Conformation Polymorphism ◽  
Positive Control ◽  
Culture Conditions ◽  
Negative Control ◽  
Polymorphism Analysis ◽  
Fruiting Body Formation

Abstract The cDNA library prepared from Lentinula edodes, Hokken 600 (H600), primordia was screened by using cDNA expressed specifically in Dictyostelium discoideum prestalk as a probe. Twenty-one clones, Le-Dd 1~21, were isolated from the L. edodes primordia cDNA library. Functional analysis of each gene was carried out by transformation into protoplast cells from L. edodes Mori 252 (M252) mycelia with the overexpression vector pLG-RasF1 of each gene because M252 protoplast cells were transformed with 11-fold higher efficiency than H600 cells. Transformants with the overexpression vector of Le-Dd10 formed a fruiting body at almost the same time as H600, a positive control, although M252, a negative control, did not form a fruiting body under culture conditions. This suggested that Le-Dd10 is involved in the formation of fruiting bodies. Single-strand conformation polymorphism analysis revealed that Le-Dd10 is located on No. 4 linkage group of L. edodes. The properties of Le-Dd10 products were investigated by Western blotting analysis using polyclonal antibodies against GST:Le-Dd10 fusion proteins. As a result, 56-kDa, 27-kDa, and 14-kDa protein bands appeared in primordial and fruiting body stages, although the expected molecular weight of the Le-Dd10 product was 50 kDa.

scholarly journals Inferring the stabilization effects of SARS-CoV-2 variants on the binding with ACE2 receptor

2021 ◽  
Author(s):  
Mattia Miotto ◽  
Lorenzo Di Rienzo ◽  
Giorgio Gosti ◽  
Leonardo Bo ◽  
Giacomo Parisi ◽  
...  
Keyword(s):  
Control Systems ◽  
South African ◽  
Negative Control ◽  
Spike Protein ◽  
Special Focus ◽  
Wild Type ◽  
Shape Complementarity ◽  
The Stability ◽  
The Moment ◽  
Dynamics Simulations

With the progression of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic, several variants of the virus are emerging with mutations distributed all over the viral sequence. While most of them are expected to have little to no effects at the phenotype level, some of these variants presenting specific mutations on the Spike protein are rapidly spreading, making urgent the need of characterizing their effects on phenotype features like contagiousness and antigenicity. With this aim, we performed extensive molecular dynamics simulations on a selected set of possible Spike variants in order to assess the stabilizing effect of particular amino acid substitutions, with a special focus on the mutations that are both characteristic of the top three most worrying variants at the moment, i.e the English, South African and Amazonian ones, and that occur at the molecular interface between SARS-CoV-2 Spike protein and its human ACE2 receptor. We characterize these variants' effect in terms of (i) residues mobility, (ii) compactness, studying the network of interactions at the interface, and (iii) variation of shape complementarity via expanding the molecular surfaces in the Zernike basis. Overall, our analyses highlighted greater stability of the three variant complexes with respect to both the wild type and two negative control systems, especially for the English and Amazonian variants. In addition, in the three variants, we investigate the effects a not-yet observed mutation in position 501 could provoke on complex stability. We found that a phenylalanine mutation behaves similarly to the English variant and may cooperate in further increasing the stability of the South African one, hinting at the need for careful surveillance for the emergence of such kind of mutations in the population. Ultimately, we show that the observables we propose describe key features for the stability of the ACE2-spike complex and can help to monitor further possible spike variants.

scholarly journals Effects of lactobacillus plantarum inoculants on maize silage quality

2017 ◽  
Vol 33 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Snezana Djordjevic ◽  
Violeta Mandic ◽  
Dragana Stanojevic ◽  
Jovanovic Ljeskovic
Keyword(s):  
Acetic Acid ◽  
Chemical Composition ◽  
Lactobacillus Plantarum ◽  
Dairy Farm ◽  
Field Trials ◽  
Positive Control ◽  
Negative Control ◽  
Maize Silage ◽  
Bacterial Inoculants ◽  
Silage Quality

In the winter time in Serbia, maize silage is the main ruminant feed. Therefore, managing maize silage is an important contributor to maintain the silage quality for livestock feed. In the study were evaluated the chemical composition, energetic and fermentation characteristics in whole-crop maize silage inoculated with different bacterial inoculants under field conditions in the commercial dairy farm, during the 2015. Three treatments were tested: negative control (untreated silage), a positive control (competitor inoculant) and Silko treatment (contains a mixture of 4 strains of Lactobacillus plantarum (LP1, LP2, LP3 and LP4). Maize is ensiled in the milk-wax grain maturity. After 90 days of ensiling, the maize silages were analyzed. The application of bacterial inoculants improved the chemical composition and energetic characteristics of silage. The inoculant Silko was more effective at improving the fermentation characteristics than competitor inoculant. Ash, cellulose, soluble N/TN, NH3-N/TN, ADF, NDF, acetic acid and pH were significantly lower in Silko treatment than positive control. There were no differences in crude fat, crude protein, ME, NEL, lactic acid and butyric acid between the treated silages. Generally, the new product bacterial inoculant Silko proved in field trials its ability to support the ensiling process in maize. The main action of the bacterial inoculant Silko is performed in two ways: the reduced degradation of protein in silage and the improvement of the aerobic stability due to the lower pH, higher content of acetic acid than negative control.

scholarly journals Identification of Novel Sources of Resistance to Sclerotinia Basal Stalk Rot in South African Sunflower Germplasm

2017 ◽  
Vol 18 (2) ◽  
pp. 87-90 ◽  
Author(s):  
Gerald J. Seiler ◽  
Christopher G. Misar ◽  
Thomas J. Gulya ◽  
William R. Underwood ◽  
Bradley C. Flett ◽  
...  
Keyword(s):  
South African ◽  
Research Council ◽  
Agricultural Research ◽  
Disease Incidence ◽  
Field Trials ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Stalk Rot ◽  
Agricultural Research Council ◽  
Moderately Resistant

Sclerotinia basal stalk rot (BSR) is a serious fungal disease that reduces yield of global sunflower (Helianthus annuus L.) production. Because limited chemical and biological controls of BSR are available and the present-day hybrids lack sufficient resistance, identification of new sources of resistance is needed to manage the disease in the future. A total of 59 cultivated oilseed sunflower accessions from the Agricultural Research Council, Grain Crops Institute, Potchefstroom, South Africa sunflower collection were evaluated for resistance to BSR in artificially inoculated field trials. Nine accessions from the South African sunflower collection were identified with a disease incidence less than or equal to the moderately resistant sunflower oilseed hybrid. These lines can be used in breeding programs to introgress the genes for resistance to Sclerotinia BSR into other adapted lines, providing a more efficient, durable, and environmentally friendly host plant resistance.

scholarly journals Two Cases of Natural Infection of Dengue-2 Virus in Bats in the Colombian Caribbean

2021 ◽  
Vol 6 (1) ◽  
pp. 35
Author(s):  
Alfonso Calderón ◽  
Camilo Guzmán ◽  
Teresa Oviedo-Socarras ◽  
Salim Mattar ◽  
Virginia Rodríguez ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Viral Infections ◽  
Polyclonal Antibodies ◽  
Natural Infection ◽  
Immunohistochemical Analysis ◽  
Positive Control ◽  
Negative Control ◽  
Sodium Pentobarbital ◽  
Rt Pcr ◽  
Cross Sectional

Dengue, a mosquito-borne zoonotic disease, is the most common vector-borne disease in tropical and subtropical areas. In this study, we aim to demonstrate biological evidence of dengue virus infection in bats. A cross-sectional study was carried out in the departments of Cordoba and Sucre, Colombia. A total of 286 bats were captured following the ethical protocols of animal experimentation. The specimens were identified and euthanized using a pharmacological treatment with atropine, acepromazine and sodium pentobarbital. Duplicate samples of brain, heart, lung, spleen, liver, and kidney were collected with one set stored in Trizol and the other stored in 10% buffered formalin for histopathological and immunohistochemical analysis using polyclonal antibodies. Brain samples from lactating mice with an intracranial inoculation of DENV-2 were used as a positive control. As a negative control, lactating mouse brains without inoculation and bats brains negative for RT-PCR were included. Tissue sections from each specimen of bat without conjugate were used as staining control. In a specimen of Carollia perspicillata captured in Ayapel (Cordoba) and Phylostomus discolor captured in San Carlos (Cordoba), dengue virus was detected, and sequences were matched to DENV serotype 2. In bats RT-PCR positive for dengue, lesions compatible with viral infections, and the presence of antigens in tissues were observed. Molecular findings, pathological lesions, and detection of antigens in tissues could demonstrate viral DENV-2 replication and may correspond to natural infection in bats. Additional studies are needed to elucidate the exact role of these species in dengue epidemics.

scholarly journals XAV-19, a Swine Glyco-Humanized Polyclonal Antibody Against SARS-CoV-2 Spike Receptor-Binding Domain, Targets Multiple Epitopes and Broadly Neutralizes Variants

2021 ◽  
Vol 12 ◽  
Author(s):  
Bernard Vanhove ◽  
Stéphane Marot ◽  
Ray T. So ◽  
Benjamin Gaborit ◽  
Gwénaëlle Evanno ◽  
...  
Keyword(s):  
South African ◽  
Receptor Binding ◽  
Polyclonal Antibodies ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Live Virus ◽  
Angiotensin Converting Enzyme 2 ◽  
The United Kingdom

Amino acid substitutions and deletions in the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants can reduce the effectiveness of monoclonal antibodies (mAbs). In contrast, heterologous polyclonal antibodies raised against S protein, through the recognition of multiple target epitopes, have the potential to maintain neutralization capacities. XAV-19 is a swine glyco-humanized polyclonal neutralizing antibody raised against the receptor binding domain (RBD) of the Wuhan-Hu-1 Spike protein of SARS-CoV-2. XAV-19 target epitopes were found distributed all over the RBD and particularly cover the receptor binding motives (RBMs), in direct contact sites with the angiotensin converting enzyme-2 (ACE-2). Therefore, in Spike/ACE-2 interaction assays, XAV-19 showed potent neutralization capacities of the original Wuhan Spike and of the United Kingdom (Alpha/B.1.1.7) and South African (Beta/B.1.351) variants. These results were confirmed by cytopathogenic assays using Vero E6 and live virus variants including the Brazil (Gamma/P.1) and the Indian (Delta/B.1.617.2) variants. In a selective pressure study on Vero E6 cells conducted over 1 month, no mutation was associated with the addition of increasing doses of XAV-19. The potential to reduce viral load in lungs was confirmed in a human ACE-2 transduced mouse model. XAV-19 is currently evaluated in patients hospitalized for COVID-19-induced moderate pneumonia in phase 2a-2b (NCT04453384) where safety was already demonstrated and in an ongoing 2/3 trial (NCT04928430) to evaluate the efficacy and safety of XAV-19 in patients with moderate-to-severe COVID-19. Owing to its polyclonal nature and its glyco-humanization, XAV-19 may provide a novel safe and effective therapeutic tool to mitigate the severity of coronavirus disease 2019 (COVID-19) including the different variants of concern identified so far.

scholarly journals Inferring the stabilization effects of SARS-CoV-2 variants on the binding with ACE2 receptor

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Mattia Miotto ◽  
Lorenzo Di Rienzo ◽  
Giorgio Gosti ◽  
Leonardo Bo’ ◽  
Giacomo Parisi ◽  
...  
Keyword(s):  
Control Systems ◽  
South African ◽  
Selective Advantage ◽  
Negative Control ◽  
Spike Protein ◽  
Wild Type ◽  
Shape Complementarity ◽  
The Stability ◽  
The Moment ◽  
Dynamics Simulations

AbstractAs the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic continues to spread, several variants of the virus, with mutations distributed all over the viral genome, are emerging. While most of the variants present mutations having little to no effects at the phenotypic level, some of these variants are spreading at a rate that suggests they may present a selective advantage. In particular, these rapidly spreading variants present specific mutations on the spike protein. These observations call for an urgent need to characterize the effects of these variants’ mutations on phenotype features like contagiousness and antigenicity. With this aim, we performed molecular dynamics simulations on a selected set of possible spike variants in order to assess the stabilizing effect of particular amino acid substitutions on the molecular complex. We specifically focused on the mutations that are both characteristic of the top three most worrying variants at the moment, i.e the English, South African, and Amazonian ones, and that occur at the molecular interface between SARS-CoV-2 spike protein and its human ACE2 receptor. We characterize these variants’ effect in terms of (i) residue mobility, (ii) compactness, studying the network of interactions at the interface, and (iii) variation of shape complementarity via expanding the molecular surfaces in the Zernike basis. Overall, our analyses highlighted greater stability of the three variant complexes with respect to both the wild type and two negative control systems, especially for the English and Amazonian variants. In addition, in the three variants, we investigate the effects a not-yet observed mutation in position 501 could provoke on complex stability. We found that a phenylalanine mutation behaves similarly to the English variant and may cooperate in further increasing the stability of the South African one, hinting at the need for careful surveillance for the emergence of these mutations in the population. Ultimately, we show that the proposed observables describe key features for the stability of the ACE2-spike complex and can help to monitor further possible spike variants.

scholarly journals Efficacy of Ivermectin, Liquid Paraffin, and Carbaryl against Mange of Farmed Rabbits in Central Kenya

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Kennedy O. Ogolla ◽  
Joyce Chebet ◽  
Robert M. Waruiru ◽  
Peter K. Gathumbi ◽  
Paul O. Okumu ◽  
...  
Keyword(s):  
Liquid Paraffin ◽  
Strong Association ◽  
Negative Control Group ◽  
Field Trials ◽  
Positive Control ◽  
Negative Control ◽  
Control Group ◽  
Common Disease ◽  
Laboratory Trial ◽  
Group 5

Mange is a common disease of rabbits globally, and knowledge of efficacy of drugs used in its treatment is critical for effective disease control. The current study evaluated the efficacy of three commonly used therapeutic agents in Kenya against mange. In a controlled laboratory trial, 20 adult rabbits were recruited for the study (16 of which were infested with mange, while 4 were mange-free). The 16 mange-infested rabbits were randomly allocated into 4 treatment groups each consisting of 4 rabbits, while 4 mange-free rabbits formed the negative control group. Treatments were administered as follows: group 1 (G1) received two ivermectin injections at an interval of 14 days, group 2 (G2) was treated with a combination of carbaryl and liquid paraffin applied every other day up to the end of the experiment, group 3 (G3) was treated with liquid paraffin droplets applied daily until the lesion cleared, while group 4 (G4, infected-untreated) received distilled water applied topically on their ears and group 5 (G5, uninfected-untreated negative control) was not treated with any preparation. The lesions were scored and sampled daily to check the viability of the mites. A field efficacy trial of the test compounds was performed using 105 mange-infested rabbits. The results revealed that all the test agents: ivermectin, liquid paraffin, carbaryl-water, and carbaryl-liquid paraffin combination were effective against mange, recording the lesion score of zero for psoroptic mange by day 21 in the laboratory and field trials. Lesion scores in the treated groups were significantly reduced (p<0.05) at the termination of study compared with those of the positive control group in the laboratory trial. A point-biserial correlation revealed a strong association (rpb = 0.79, p<0.05) between the presence of viable mites and degree of psoroptic lesions in the field trial.

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