scholarly journals DIAGNÓSTICO COMPARATIVO DE BRUCELOSIS MEDIANTE MÉTODOS SEROLÓGICOS Y MOLECULARES

e-CUCBA ◽  
2021 ◽  
Vol 8 (16) ◽  
pp. 50-55
Author(s):  
Cinthya Y. Burboa Meza ◽  
◽  
Alexandra Zazueta Avitia ◽  
David Ramírez Alvarado ◽  
Miguel A. Segura Castruita ◽  
...  
Keyword(s):  
Complement Fixation ◽  
Pcr Amplification ◽  
Molecular Technique ◽  
Serological Tests ◽  
Gene Coding ◽  
Card Test ◽  
Higher Sensitivity ◽  
False Positives And Negatives ◽  
Livestock Development ◽  
Control And Eradication

Brucellosis is an infectious disease that limits livestock development and greatly affects the livestock economy, being considered one of the most important and widely distributed zoonoses worldwide. Early diagnosis of this disease is an essential tool in its control and eradication. The methods recognized by NOM-041-ZOO-1995, such as the card test and complement fixation, present limitations in the diagnosis, compared to the PCR molecular technique. In the present work, a comparative diagnosis of Brucella spp. was performed by PCR amplification of the gene coding for a protein located in the outer membrane (Omp2a) of Brucella spp. and serological tests in blood, milk and cheese samples from goats and cattle. The results showed a higher sensitivity in the detection by PCR technique, while the card test and complement fixation showed inconsistencies due to the occurrence of false positives and negatives. Based on the results, it is suggested to include the PCR technique in the Mexican Official Standard as an objective alternative in the routine diagnosis of brucellosis.

Validity of a Serological Diagnostic Kit for SARS-CoV-2 Available in Iran

2020 ◽  
Vol 23 (9) ◽  
pp. 629-632
Author(s):  
Hamid Reza Shamsollahi ◽  
Mostafa Amini ◽  
Shaban Alizadeh ◽  
Saharnaz Nedjat ◽  
Ali Akbari-Sari ◽  
...  
Keyword(s):  
Diagnostic Techniques ◽  
Effective Control ◽  
Molecular Technique ◽  
Size Estimation ◽  
Medical Sciences ◽  
Serological Tests ◽  
Standard Case ◽  
Epidemic Size ◽  
Low Sensitivity ◽  
Negative Controls

Background: The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic broke out in December 2019 and is now characterized as a pandemic. Effective control of this infectious disease requires access to diagnostic techniques, for both case finding and epidemic size estimation. The molecular technique is routinely used worldwide. Although it is the "standard" case detection and management method, it has its own shortcomings. Thus, some easy-to-use rapid serological tests have been developed. Methods: One hundred and fourteen positive RT-PCR-diagnosed patients were tested by VivaDiag Kit, a brand of rapid serological kits available in hospitals affiliated to Tehran University of Medical Sciences (TUMS), Tehran, Iran. Frozen serum specimens taken from healthy people in summer and fall 2019 were also tested as negative controls. Results: Test sensitivity was 47.9% (95% confidence interval [CI]: 38.8-56.9) for IgM and 47.0% (95% CI: 38.0–56.0) for IgG. There was no difference between IgG and IgM seropositivity except in one case. Specificity was calculated as 99.0% (95% CI: 96.4–99.9) for IgM and of 100.0% (95% CI: 0.98.2–100.0) for IgG. Sensitivity was higher in men and older participants. Conclusion: This test can be used for epidemiological investigations, especially for the estimation of the level of infection in the community, after it is properly corrected for sensitivity and specificity. The low sensitivity could be attributed to the technical limitations of the kit or low levels of antibodies after infection. The different sensitivity in age and sex groups supports the hypothesis that different people show different immune responses to this virus.

PCR Amplification and Bioinformatics of a Novel Gene Coding Hydroxylamine Oxidoreductase*

2010 ◽  
Vol 2009 (1) ◽  
pp. 100-105
Author(s):  
Zuguo ZHAO ◽  
Qingxin KONG ◽  
Jingfeng WANG ◽  
Min JIN ◽  
Xinwei WANG ◽  
...  
Keyword(s):  
Pcr Amplification ◽  
Hydroxylamine Oxidoreductase ◽  
Novel Gene ◽  
Gene Coding

scholarly journals Serological tests for the detection of antibodies to Mycoplasma gallisepticum in chickens and turkeys

1968 ◽  
Vol 66 (2) ◽  
pp. 249-267 ◽  
Author(s):  
F. T. W. Jordan ◽  
P. Kulasegaram
Keyword(s):  
Positive Reaction ◽  
Complement Fixation ◽  
Haemagglutination Inhibition ◽  
Mycoplasma Gallisepticum ◽  
Metabolic Inhibition ◽  
Agar Gel ◽  
Serological Tests ◽  
Anamnestic Response ◽  
Initial Infection ◽  
Gel Method

SUMMARYA comparison was undertaken of several serological tests in determining the response of chickens and turkeys experimentally infected with the A 514 strain of Mycoplasma gallisepticum.After a single intratracheal inoculation of chickens with a culture of the organism, the highest titres were obtained by the indirect complement fixation (ICF) test, followed by the tube agglutination (TA), haemagglutination inhibition (HI), slide agglutination (SA) and metabolic inhibition (MI) tests. By all these tests positive titres were observed within the first week and peak titres between the first and second weeks. At 5 months there was no positive reaction by the ICF test but most chickens gave positive readings by the TA, HI and SA tests for at least 14 months after infection, but turkey sera became negative by all tests after 3 months.A disadvantage of the ICF test was that sera up to a dilution of 1/8 and 1/16 for chicken and turkey respectively were anticomplementary, and in turkeys this masked the ICF titre, which presumably was low following one intratracheal inoculation. Titres in turkeys with the TA, HI and SA tests followed the pattern seen with chickens and were generally lower than those found by other workers probably because of the avirulent nature of the inoculum used.The WB test was the least sensitive of the agglutination tests but is useful as a flock test which can be undertaken on the farm.The MI test gave the lowest titres of all and antibodies could be detected for only 4 months following one intratracheal inoculation. Even with serum prepared by multiple inoculations in chickens the titre was never higher than 1/32 compared with 1/1024 for serum similarly prepared in rabbits.Precipitins were detected by the agar gel method in the sera of chickens and turkeys after two intratracheal inoculations but in only some of the chickens and none of the turkeys after one inoculation.By all tests higher titres were observed with chicken than turkey sera and antibodies persisted for a longer time.Re-infection of chickens when antibodies to the initial infection had become low, and of turkeys when antibodies were no longer detectable, gave rise to an anamnestic response with titres which were higher than before.Antiserum to M. gallisepticum prepared in chickens is comparable with that prepared in rabbits except for low titres by the MI test.

scholarly journals A quantitative comparison of the sensitivity of serological tests for bovine brucellosis to different antibody classes

1976 ◽  
Vol 76 (2) ◽  
pp. 287-298 ◽  
Author(s):  
G. S. Allan ◽  
R. J. Chappel ◽  
P. Williamson ◽  
D. J. McNaught
Keyword(s):  
Complement Fixation Test ◽  
Complement Fixation ◽  
Quantitative Comparison ◽  
Agglutination Test ◽  
Bovine Brucellosis ◽  
Serological Tests ◽  
Plate Test ◽  
Specific Antibodies ◽  
The Rose ◽  
Serum Agglutination

SUMMARYBrucella-specific antibodies of different immunoglobulin classes were quantitatively evaluated with respect to their efficiency in serological tests for bovine brucellosis.IgM reacted more efficiently than IgG1and IgG2in both the Rose Bengal plate test and serum agglutination test. The complement fixation test was found to be slightly more sensitive to IgM than to IgG1and did not react to IgG2.IgM was, however, partly inactivated when heated at 60°C. in the presence of serum.

scholarly journals Comparative evaluation of cost effective extraction free molecular technique for detection of SARS-CoV-2 with reference to standard VTM based RT-qPCR method

2021 ◽  
Author(s):  
Megh Singh Dhakad ◽  
Sanjib Gogoi ◽  
Ansu Kumari ◽  
Aashish Kumar Singh ◽  
Manoj B. Jais ◽  
...  
Keyword(s):  
Detection Method ◽  
Cost Effective ◽  
Molecular Technique ◽  
Rt Pcr ◽  
Index Method ◽  
Resource Limited ◽  
Qpcr Method ◽  
Kappa Value ◽  
The Cost ◽  
Higher Sensitivity

Background and Objectives: The entire globe is undergoing an unprecedented challenge of COVID-19. Considering the need of rapid and accurate diagnostic tests for SARS-CoV-2, this study was planned to evaluate the cost effective extraction free RT-PCR technique in comparison to the standard VTM based RT-qPCR method. Materials and Methods: Paired swabs from nasopharynx and oropharynx were collected for SARS-CoV-2 testing, from 211 adult patients (≥18 years) in VTM and plain sterile tubes (dry swabs). These samples were processed and RT-qPCR was carried out as per standard protocols. Results: 54.5% of the patients were females and 45.5% were males with sex ratio 1:1.19 (M: F). 38.86% were symptomatic, of which fever (86.59%), cough (79.23%) and breathlessness (46.34%) were the most common symptoms. The positivity by VTM based method and index method was 31.27% and 13.27% respectively. Of the 27 inconclusive results from index method, 37.04% were positive, 48.15% were negative by VTM based method. However, in 40 inconclusive results by VTM based method, 90% were negative and rest remained inconclusive by index method. The sensitivity and specificity of the index method were 39.39% and 85.71% respectively. The overall agreement between VTM based method and index method was 49.59% with estimated Kappa value of 0.19. Conclusion: VTM based method showed higher sensitivity compared to the index method. The higher positivity by VTM based method, suggests that VTM based method could plausibly be a better detection method of SARS-CoV-2. Still, the index method might add value in a resource limited setups for detection of SARS-CoV-2.  

scholarly journals Model Proficiency Testing Scheme for Serological Diagnosis of Brucellosis: Interlaboratory Study

2004 ◽  
Vol 87 (4) ◽  
pp. 965-971 ◽  
Author(s):  
Donatella Nannini ◽  
Manuela Tittarelli ◽  
Lucilla Ricci ◽  
Annamaria Conte ◽  
Bernardo Di Emidio ◽  
...  
Keyword(s):  
Complement Fixation Test ◽  
Complement Fixation ◽  
Fixation Test ◽  
Reference Laboratory ◽  
Correct Result ◽  
The European Union ◽  
Serological Tests ◽  
Testing Scheme ◽  
Z Scores ◽  
Qualitative Test

Abstract A model interlaboratory testing scheme was developed by the Italian National Reference Laboratory for Brucellosis. This scheme was planned for both qualitative (Rose Bengal Plate Test; RBPT) and quantitative (Complement Fixation Test; CFT) serological tests and involved a total of 42 laboratories. In the preparation of this scheme, reference was made to general protocols and guidelines and to methods reported in the literature, which were applicable to analytical chemistry laboratories. Six field sera from naturally infected animals, one positive serum at a titer below the European Union (EU) positivity threshold, and 5 sera positive at titers between 20 and 851 International Units of Complement Fixation Test (IUCFT)/mL plus one negative serum were used to produce a panel of test sera. To evaluate laboratory performances in the quantitative test for each tested sample examined, z-scores based on robust summary statistics (the median and normalized interquartile range) were used. To evaluate overall laboratory performance, 2 types of combined z-scores were used: Rescaled Sum of Scores and Sum of Squared Scores. In the case of the qualitative test (RBPT), results were analyzed by a Bayesian approach. A Beta distribution, based on the result of each laboratory, was calculated and used to estimate the probability of each laboratory giving a correct result and its uncertainty.

Comparative studies of fungi associated with sea foods in different wetlands of Akwa Ibom State

2020 ◽  
Vol 34 (1) ◽  
pp. 41-47
Author(s):  
I.N. Bassey ◽  
N.U. Asamudo
Keyword(s):  
Phylogenetic Analysis ◽  
Food Security ◽  
Aspergillus Niger ◽  
Internal Transcribed Spacer ◽  
Natural Populations ◽  
Pcr Amplification ◽  
Potato Dextrose Agar ◽  
Molecular Technique ◽  
Fungal Isolates ◽  
Fish Samples

The study investigated fungi associated with sea foods, fish (Pellonula leonensis) and crayfish (Parapandalus pritis) from different wetlands (Ibeno, Ikot Abasi, Eket and Itu) in Akwa Ibom State. Samples were collected and cultured on Potato Dextrose Agar (PDA) and the isolated fungi were identified using molecular technique. Based on PCR amplification, sequencing of the internal transcribed spacer and phylogenetic analysis, the fungi identified were: Aspergillus niger, A. felis, A. foetidus, A. aculeatus, A. japonicus, A. flavus, A. tamari, A. terreus, Penicilium citrinum, Candida tropicalis and Trametes polyzona. The most commonly isolated fungi from fish for the four locations were A. niger (52.8) in Itu, P. citrinum (51.7) in Ibeno, A. foetidus (53.5) in Ikot Abasi and A. aculeatus (51.6) in Eket. For samples of crayfish, the most commonly isolated fungi were A. niger (25.1) in Itu and A. foetidus (20.1) in Ikot Abasi. Generally, Ibeno recorded the highest frequencies of fungal isolates while Ikot Abasi had the least. Percentage occurrence of fungi isolated from fish samples were significantly higher (p<0.05) when compared with those isolated from crayfish samples. The presence of these fungi showed that sea foods were exposed to an increasing number of virulent infectious diseases in natural populations, and fungal-like diseases can cause some of the most severe die-offs and extinctions ever witnessed in wild species thus jeopardizing food security Keywords: Fungi, Sea food, Wetland, Aspergillus, Fish.

scholarly journals Serological Tests

1914 ◽  
Vol 14 (3) ◽  
pp. 354-359 ◽  
Author(s):  
Lajos Gózony ◽  
Edward Hindle ◽  
Philip H. Ross
Keyword(s):  
Room Temperature ◽  
Alimentary Canal ◽  
Complement Fixation ◽  
Gut Contents ◽  
Serological Tests ◽  
Argas Persicus ◽  
Negative Results ◽  
Glass Tubes ◽  
Specific Reactions

1. Sera and antisera when kept in the dark at room temperature sealed in glass tubes occasionally give specific reactions after a period of 12 years. In most cases, however, negative results were obtained with the antisera, whilst in others the reactions were non-specific.2. Fowl blood will still give specific complement fixation and precipitin reactions after being in the alimentary canal of either Argas persicus or Ornithodorus moubata for at least 23 months. The gut contents of Pediculus vestimenti fed on man three days previously, also will give specific reactions with human antisera.

scholarly journals Microscopic and Molecular Detection of Camel Piroplasmosis in Gadarif State, Sudan

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Abdalla Mohamed Ibrahim ◽  
Ahmed A. H. Kadle ◽  
Hamisi Said Nyingilili
Keyword(s):  
Molecular Detection ◽  
Blood Film ◽  
The State ◽  
Economic Consequences ◽  
Camelus Dromedarius ◽  
Molecular Technique ◽  
Eastern Region ◽  
Prevalence Rates ◽  
First Report ◽  
Higher Sensitivity

The socioeconomic importance of camels (Camelus dromedarius) could not be neglected in the Sudan. The present study was planned to confirm the presence of piroplasmosis in camels from the Eastern region of the Sudan (Gedarif State) using microscopical (blood film) and molecular technique (PCR). A total of 55 camels of different sexes (34 females and 21 males) were sampled from four localities of the state between January 2011 and January 2012. The prevalence rates using parasitological and molecular examinations were 43.6% and 74.5%, respectively. The prevalence rates significantly vary between the localities (p=0.011) but not between the different sexes (p=0.515). PCR technique showed higher sensitivity than microscopy. The present paper was to be the first report investigating camel piroplasmosis using both parasitological and molecular methods in the Eastern region of the Sudan. Further studies in the phylogenetic sequencing are to be continued for parasite speciation. Moreover, studies on the clinical and economic consequences of camel piroplasmosis are recommended.

scholarly journals Clinical conditions associated with positive complement fixation serology forChlamydiae

1987 ◽  
Vol 98 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Mirja Puolakkainen ◽  
Merja Kousa ◽  
Pekka Saikku
Keyword(s):  
Respiratory Symptoms ◽  
Leucocyte Count ◽  
Complement Fixation ◽  
Clinical Manifestations ◽  
Serological Tests ◽  
Hospital Records ◽  
Ocular Manifestations ◽  
Normal Limits ◽  
Urinary Tract Symptoms ◽  
Clinical Conditions

SUMMARYThe hospital records of 242 patients with diagnostic chlamydial complement fixation (CF) titres (seroconversion and/or titre ≥ 64) found among 60000 patients screened for suspected viral illnesses were reviewed to study the clinical conditions associated with positive CF serology forChlamydiae. After excluding typical genitalC. trachomatisinfections, the majority of the remainder were considered to representC. psittaciinfections. Respiratory symptoms were the most common clinical manifestations of chlamydial infections detectable by CF, but the majority (58%) of the patients did not have pneumonia. Abdominal, neurological as well as urinary tract symptoms were common. Cutaneous, joint, cardiac, genital and ocular manifestations were also noted. Fever (≥ 38·5 °C) was present in 62% of the patients. The ESR was raised (≥ 20 mm/h) in the majority of the patients (83%), but the leucocyte count was usually (86%) within normal limits. Because the clinical spectrum ofC. psittaciinfections is apparently broad, serological tests for detecting antibodies toC. psittaci(e.g. CF) should be used widely in various clinical conditions and not for patients with pneumonia alone.

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