scholarly journals Mycoplasma hyopneumoniae Surveillance in Pig Populations: Establishing Sampling Guidelines for Detection in Growing Pigs

2021 ◽  
Vol 59 (5) ◽  
Author(s):  
Maria Jose Clavijo ◽  
Dapeng Hu ◽  
Seth Krantz ◽  
Jean Paul Cano ◽  
Thairê Pereira Maróstica ◽  
...  
Keyword(s):  
Oral Fluid ◽  
Mycoplasma Hyopneumoniae ◽  
Growing Pigs ◽  
Probability Of Detection ◽  
Sample Type ◽  
Sample Sizes ◽  
Serum Samples ◽  
Content Type ◽  
Large Sample ◽  
Oral Fluids

ABSTRACT Antemortem detection of Mycoplasma hyopneumoniae infection in swine production systems has relied on antibody testing, but the availability of tests based on DNA detection and novel diagnostic specimens, e.g., tracheal swabs and oral fluids, has the potential to improve M. hyopneumoniae surveillance. A field study was performed over a 14-week period during which 10 pigs in one pen at the center of a room with 1,250 6-week-old pigs housed in 46 pens were intratracheally inoculated with M. hyopneumoniae. Thereafter, one tracheal sample, four serum samples, and one oral fluid sample were collected from every pen at 2-week intervals. Tracheal and oral fluid samples were tested for M. hyopneumoniae DNA and serum samples for M. hyopneumoniae antibody. Test results were modeled using a hierarchical Bayesian model, based on a latent spatial piecewise exponential survival model, to estimate the probability of detection by within-pen prevalence, number of positive pens in the barn, sample allocation, sample size, and sample type over time. Analysis showed that tracheal samples provided the earliest detection, especially at large sample sizes. While serum samples are more commonly collected and are less expensive to test, high probability of detection estimates were only obtained 30 days postexposure at large sample sizes. In all scenarios, probability of detection estimates for oral fluids within 30 days were significantly lower than those for tracheal and serum samples. Ultimately, the choice of specimen type, sample number, and assay will depend on testing objectives and economics, but the estimates provided here will assist in the design of M. hyopneumoniae surveillance and monitoring programs for different situations.

scholarly journals SARS-CoV-2 RNA and antibody dynamics in a Dutch household study with dense sampling frame

2021 ◽  
Author(s):  
Wanda G.H. Han ◽  
Arno Swart ◽  
Axel Bonacic Marinovic ◽  
Dirk Eggink ◽  
Johan Reimerink ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Symptom Severity ◽  
Oral Fluid ◽  
Probability Of Detection ◽  
Serological Response ◽  
Sample Type ◽  
Sampling Frame ◽  
Rt Pcr ◽  
Specific Antibodies ◽  
Viral Loads

AbstractThis study investigated the dynamics of SARS-CoV-2 infection and diagnostics in household members of different ages and with different symptom severity after SARS-CoV-2 exposure during the early phase of the pandemic. Households with a SARS-CoV-2 confirmed positive case and at least one child in the Netherlands were followed for 6 weeks. Naso (NP)- and oropharyngeal (OP) swabs, oral fluid and feces specimens were analyzed for SARS-CoV-2 RNA and serum for SARS-CoV-2-specific antibodies. The dynamics of the presence of viral RNA and the serological response was modeled to determine the sampling time-frame and sample type with the highest sensitivity to confirm or reject a SARS-CoV-2 diagnosis. Transmission of SARS-CoV-2 between adults and children within a household was correlated with symptom severity of index cases. In children higher viral loads compared to adults were detected at symptom onset. Early in infection, higher viral loads were detected in NP and OP specimens, while RNA in especially feces were longer detectable. SARS-CoV-2-specific antibodies have a 90% probability of detection from 7 days (total Ig) and 18 days (IgG) since symptom onset. In conclusion this study has shown that on average, children carry higher loads of virus as compared to adults early after infection. For highest probability of detection in SARS-CoV-2 diagnostics early in infection, RT-PCR on NP and OP specimens are more sensitive than on oral fluid and feces. For SARS-CoV-2 diagnostics late after infection, RT-PCR on feces specimens and serology are more valuable.

scholarly journals Detection of pseudorabies virus antibody in swine oral fluid using a serum whole-virus indirect ELISA

2020 ◽  
Vol 32 (4) ◽  
pp. 535-541
Author(s):  
Ting-Yu Cheng ◽  
Alexandra Buckley ◽  
Albert Van Geelen ◽  
Kelly Lager ◽  
Alexandra Henao-Díaz ◽  
...  
Keyword(s):  
Oral Fluid ◽  
Pseudorabies Virus ◽  
Negative Control ◽  
Wild Type Virus ◽  
Wild Type ◽  
Serum Samples ◽  
Anamnestic Response ◽  
Treatment Groups ◽  
Oral Fluids ◽  
Area Under Roc Curve

We evaluated the detection of pseudorabies virus (PRV) antibodies in swine oral fluid. Oral fluid and serum samples were obtained from 40 pigs allocated to 4 treatment groups (10 pigs/group): negative control (NC); wild-type PRV inoculation (PRV 3CR Ossabaw; hereafter PRV); PRV vaccination (Ingelvac Aujeszky MLV; Boehringer Ingelheim; hereafter MLV); and PRV vaccination followed by PRV inoculation at 21 d post-vaccination (MLV-PRV). Using a serum PRV whole-virus indirect IgG ELISA (Idexx Laboratories) adapted to the oral fluid matrix, PRV antibody was detected in oral fluid samples from treatment groups PRV, MLV, and MLV-PRV in a pattern similar to serum. Vaccination alone produced a low oral fluid antibody response (groups MLV and MLV-PRV), but a strong anamnestic response was observed following challenge with wild-type virus (group PRV). Analyses of the oral fluid PRV indirect IgG ELISA results showed good binary diagnostic performance (area under ROC curve = 93%) and excellent assay repeatability (intra-class correlation coefficient = 99.3%). The demonstrable presence of PRV antibodies in swine oral fluids suggests the possible use of oral fluids in pseudorabies surveillance.

scholarly journals Measurement error correlation within blocks of indicators in consistent partial least squares

2019 ◽  
Vol 29 (3) ◽  
pp. 448-463 ◽  
Author(s):  
Manuel E. Rademaker ◽  
Florian Schuberth ◽  
Theo K. Dijkstra
Keyword(s):  
Measurement Error ◽  
Least Squares ◽  
Partial Least Squares ◽  
Measurement Errors ◽  
Parameter Estimates ◽  
Sample Sizes ◽  
Content Type ◽  
Large Sample ◽  
Error Correlation ◽  
Consistent Partial Least Squares

Purpose The purpose of this paper is to enhance consistent partial least squares (PLSc) to yield consistent parameter estimates for population models whose indicator blocks contain a subset of correlated measurement errors. Design/methodology/approach Correction for attenuation as originally applied by PLSc is modified to include a priori assumptions on the structure of the measurement error correlations within blocks of indicators. To assess the efficacy of the modification, a Monte Carlo simulation is conducted. Findings In the presence of population measurement error correlation, estimated parameter bias is generally small for original and modified PLSc, with the latter outperforming the former for large sample sizes. In terms of the root mean squared error, the results are virtually identical for both original and modified PLSc. Only for relatively large sample sizes, high population measurement error correlation, and low population composite reliability are the increased standard errors associated with the modification outweighed by a smaller bias. These findings are regarded as initial evidence that original PLSc is comparatively robust with respect to misspecification of the structure of measurement error correlations within blocks of indicators. Originality/value Introducing and investigating a new approach to address measurement error correlation within blocks of indicators in PLSc, this paper contributes to the ongoing development and assessment of recent advancements in partial least squares path modeling.

scholarly journals Performance of Commercial Mycoplasma hyopneumoniae Serum Enzyme-Linked Immunosorbent Assays under Experimental and Field Conditions

2020 ◽  
Vol 58 (12) ◽  
Author(s):  
Ana Paula S. Poeta Silva ◽  
Ronaldo L. Magtoto ◽  
Henrique M. Souza Almeida ◽  
Aric McDaniel ◽  
Precy D. Magtoto ◽  
...  
Keyword(s):  
Serum Antibody ◽  
Mycoplasma Hyopneumoniae ◽  
Error Rates ◽  
False Positives ◽  
Field Conditions ◽  
Misclassification Error ◽  
Antibody Detection ◽  
Serum Samples ◽  
Content Type ◽  
Immunosorbent Assays

ABSTRACT Mycoplasma hyopneumoniae is an economically significant pathogen of swine. M. hyopneumoniae serum antibody detection via commercial enzyme-linked immunosorbent assays (ELISAs) is widely used for routine surveillance in commercial swine production systems. Samples from two studies were used to evaluate assay performance. In study 1, 6 commercial M. hyopneumoniae ELISAs were compared using serum samples from 8-week-old cesarean-derived, colostrum-deprived (CDCD) pigs allocated to the following 5 inoculation groups of 10 pigs each: (i) negative control, (ii) Mycoplasma flocculare (strain 27399), (iii) Mycoplasma hyorhinis (strain 38983), (iv) Mycoplasma hyosynoviae (strain 34428), and (v) M. hyopneumoniae (strain 232). Weekly serum and daily oral fluid samples were collected through 56 days postinoculation (dpi). The true status of pigs was established by PCR testing on oral fluids samples over the course of the observation period. Analysis of ELISA performance at various cutoffs found that the manufacturers’ recommended cutoffs were diagnostically specific, i.e., produced no false positives, with the exceptions of 2 ELISAs. An analysis based on overall misclassification error rates found that 4 ELISAs performed similarly, although one assay produced more false positives. In study 2, the 3 best-performing ELISAs from study 1 were compared using serum samples generated under field conditions. Ten 8-week-old pigs were intratracheally inoculated with M. hyopneumoniae. Matched serum and tracheal samples (to establish the true pig M. hyopneumoniae status) were collected at 7- to 14-day intervals through 98 dpi. Analyses of sensitivity and specificity showed similar performance among these 3 ELISAs. Overall, this study provides an assessment of the performance of current M. hyopneumoniae ELISAs and an understanding of their use in surveillance.

scholarly journals Detection of antibodies to Pseudomonas aeruginosa in serum and oral fluid from patients with cystic fibrosis

2007 ◽  
Vol 56 (5) ◽  
pp. 670-674 ◽  
Author(s):  
Abbie M. Weisner ◽  
Henrik Chart ◽  
Andrew Bush ◽  
Jane C. Davies ◽  
Tyrone L. Pitt
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Oral Fluid ◽  
Specific Antigen ◽  
Serum Antibodies ◽  
Serum Samples ◽  
Core Oligosaccharide ◽  
Weak Reaction ◽  
Bacterial Surface ◽  
Oral Fluids

Cystic fibrosis (CF) patients who are chronically infected with Pseudomonas aeruginosa make serum antibodies to bacterial surface LPS as well as other pseudomonas antigens. This study investigated the feasibility of using oral fluid samples for the detection of pseudomonas antibodies in CF patients and compared these results with corresponding serum antibodies. Most strains of P. aeruginosa produce two forms of LPS molecule, termed A-band (described as a common antigen) and B-band (O-serotype-specific antigen), apparently bound to a common core oligosaccharide moiety. A-band LPS was demonstrated in 45 out of 49 clinical isolates of P. aeruginosa by SDS-PAGE and immunoblotting with a specific antibody. Oral fluids were collected from 17 adult CF patients, all of whom were sputum culture positive for P. aeruginosa (13 also provided serum samples), 11 primary ciliary dyskinesia (PCD) patients and 37 healthy volunteers. Antibodies to A-band LPS were detected by immunoblotting in all of the CF patients’ oral fluids but 10 of the volunteer samples gave weak reactions with immunoblotting. Six of the PCD patients gave a weak reaction with A-band antibodies and only one demonstrated antibodies to core LPS. In a quantitative ELISA, 15 of the 17 CF patients’ oral fluids were shown to contain antibodies to A-band LPS, whilst none of the volunteer samples contained antibodies to A-band LPS. All serum samples from the CF patients were positive by both methods. Thus this is a sensitive procedure for the detection of antibodies to A-band LPS of P. aeruginosa in oral fluid and serum from patients with CF.

Detection of Mycoplasma hyopneumoniae in nasal and laryngeal swab specimens in endemically infected pig herds

2019 ◽  
Vol 186 (1) ◽  
pp. 27-27
Author(s):  
Nicolás Moiso ◽  
Maria Pieters ◽  
Facundo Degano ◽  
Claudina Vissio ◽  
Pablo Camacho ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Confidence Interval ◽  
Odds Ratio ◽  
Mycoplasma Hyopneumoniae ◽  
Growing Pigs ◽  
Pcr Detection ◽  
Sample Type ◽  
Bacterial Detection ◽  
Highly Sensitive ◽  
Nasal Swabs

BackgroundApparently, laryngeal swabs (LS) are more sensitive than nasal swabs (NS) and allow earlier detection of Mycoplasma hyopneumoniae by PCR. However, antecedents about the compared detection of M hyopneumoniae with NS and LS in growing pigs, from naturally infected herds, are lacking in the literature. Thus, this study compared the PCR detection of M hyopneumoniae from NS and LS in pigs of various ages.MethodsA longitudinal study was performed at two farms where NS and LS were collected from three consecutive groups of 20 pigs at 3, 6, 10, 16 and 22 weeks of age. All samples were analysed by nested PCR for M hyopneumoniae detection.ResultsThe probability of PCR detection of M hyopneumoniae was higher in LS for pigs of all ages (odds ratio (OR)=1.87; 95 per cent confidence interval (CI) 1.31–2.67) and in 22-week-old pigs (OR=4.87; 95 per cent CI 2.86–8.30). The agreement between both sample types was low to moderate (kappa 0.087–0.508), highlighting that M hyopneumoniae does not appear to colonise the respiratory tract in a generalised and consistent fashion.ConclusionsThe results suggest that LS could be employed at different ages to achieve greater bacterial detection. Considering that LS is a minimally invasive, highly sensitive sample compared with the traditional NS, it could be suggested to employ this sample type for M hyopneumoniae detection in naturally infected pigs.

scholarly journals SARS Antibody Testing in Children: Development of Oral Fluid Assays for IgG Measurements

2022 ◽  
Author(s):  
Katja Hoschler ◽  
Samreen Ijaz ◽  
Nick Andrews ◽  
Sammy Ho ◽  
Steve Dicks ◽  
...  
Keyword(s):  
Large Scale ◽  
Oral Fluid ◽  
Sample Type ◽  
Healthy Children ◽  
Antibody Testing ◽  
Large Scale Assessment ◽  
Oral Fluids ◽  
Scale Assessment ◽  
Children Development ◽  
Crevicular Fluid

We report on the first large-scale assessment of the suitability of oral fluids for detection of SARS-CoV-2 antibody obtained from healthy children attending school. The sample type (gingiva-crevicular fluid, which is a transudate of blood but is not saliva) can be self collected.

scholarly journals Population (Antibody) Testing for COVID-19—Technical Challenges, Application and Relevance, an English Perspective

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 550
Author(s):  
Peter A. C. Maple
Keyword(s):  
National Level ◽  
Herd Immunity ◽  
Population Based ◽  
Biological Properties ◽  
Limited Extent ◽  
Antibody Testing ◽  
Serum Samples ◽  
Oral Fluids ◽  
Antibody Assays ◽  
The Uk

In the UK, population virus or antibody testing using virus swabs, serum samples, blood spots or oral fluids has been performed to a limited extent for several diseases including measles, mumps, rubella and hepatitis and HIV. The collection of population-based infection and immunity data is key to the monitoring of disease prevalence and assessing the effectiveness of interventions such as behavioural modifications and vaccination. In particular, the biological properties of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its interaction with the human host have presented several challenges towards the development of population-based immunity testing. Measuring SARS-CoV-2 immunity requires the development of antibody assays of acceptable sensitivity and specificity which are capable of accurately detecting seroprevalence and differentiating protection from non-protective responses. Now that anti-COVID-19 vaccines are becoming available there is a pressing need to measure vaccine efficacy and the development of herd immunity. The unprecedented impact of the SARS-CoV-2 pandemic in the UK in terms of morbidity, mortality, and economic and social disruption has mobilized a national scientific effort to learn more about this virus. In this article, the challenges of testing for SARS-CoV-2 infection, particularly in relation to population-based immunity testing, will be considered and examples given of relevant national level studies.

scholarly journals High heterogeneity undermines generalization of differential expression results in RNA-Seq analysis

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Weitong Cui ◽  
Huaru Xue ◽  
Lei Wei ◽  
Jinghua Jin ◽  
Xuewen Tian ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Expression ◽  
Small Sample ◽  
Differentially Expressed ◽  
Cancer Type ◽  
Rna Seq ◽  
Sample Sizes ◽  
Large Sample ◽  
Expression Levels ◽  
Gene Expression Levels

Abstract Background RNA sequencing (RNA-Seq) has been widely applied in oncology for monitoring transcriptome changes. However, the emerging problem that high variation of gene expression levels caused by tumor heterogeneity may affect the reproducibility of differential expression (DE) results has rarely been studied. Here, we investigated the reproducibility of DE results for any given number of biological replicates between 3 and 24 and explored why a great many differentially expressed genes (DEGs) were not reproducible. Results Our findings demonstrate that poor reproducibility of DE results exists not only for small sample sizes, but also for relatively large sample sizes. Quite a few of the DEGs detected are specific to the samples in use, rather than genuinely differentially expressed under different conditions. Poor reproducibility of DE results is mainly caused by high variation of gene expression levels for the same gene in different samples. Even though biological variation may account for much of the high variation of gene expression levels, the effect of outlier count data also needs to be treated seriously, as outlier data severely interfere with DE analysis. Conclusions High heterogeneity exists not only in tumor tissue samples of each cancer type studied, but also in normal samples. High heterogeneity leads to poor reproducibility of DEGs, undermining generalization of differential expression results. Therefore, it is necessary to use large sample sizes (at least 10 if possible) in RNA-Seq experimental designs to reduce the impact of biological variability and DE results should be interpreted cautiously unless soundly validated.

Is Islamic bank profitability driven by same forces as conventional banks?

2016 ◽  
Vol 9 (1) ◽  
pp. 46-66 ◽  
Author(s):  
Hajer Zarrouk ◽  
Khoutem Ben Jedidia ◽  
Mouna Moualhi
Keyword(s):  
Dynamic Panel Data ◽  
Islamic Banking ◽  
Subprime Crisis ◽  
Islamic Banks ◽  
Mena Region ◽  
Bank Profitability ◽  
Content Type ◽  
Large Sample ◽  
Islamic Bank ◽  
Conventional Banks

Purpose The purpose of this paper is to ascertain whether Islamic bank profitability is driven by same forces as those driving conventional banking in the Middle East and North Africa (MENA) region. Distinguished by its principles in conformity with sharia, Islamic banking is different from conventional banking, which is likely to affect profitability. Design/methodology/approach The paper builds on a dynamic panel data model to identify the banks’ specific determinants and the macroeconomic factors influencing the profitability of a large sample of 51 Islamic banks operating in the MENA region from 1994 to 2012. The system-generalized method of moment estimators are applied. Findings The findings reveal that profitability is positively affected by banks’ cost-effectiveness, asset quality and level of capitalization. The results also indicate that non-financing activities allow Islamic banks to earn higher profits. Islamic banks perform better in environments where the gross domestic product and investment are high. There is evidence of several elements of similarities between determinants of the profitability for Islamic and conventional banks. The inflation rate, however, is negatively associated with Islamic bank profitability. Practical Implications The authors conclude that profitability determinants did not differ significantly between Islamic and conventional banks. Many factors are deemed the same in explaining the profitability of conventional as well as Islamic banks. The findings reported in the current paper might be of interest for policy makers. It is recommended to better implement non-financing activities to improve Islamic bank profitability. Originality/value Unlike the previous empirical research, this empirical investigation assesses the issue whether Islamic banks profitability is influenced by same factors as conventional model. It enriches the literature in this regard by considering the specificities of Islamic banking to identify the determinants of profitability. Moreover, this study considers a large sample (51 Islamic banks) through a different selection of countries/banks than previous studies. In addition, the period of study considers the subprime crisis insofar it ranges from 1994 to 2012. Hence, this broader study allows the authors to draw more consistent conclusions.

Sign in / Sign up

Export Citation Format

Share Document