serological tests
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2023 ◽  
Vol 83 ◽  
J. Yang ◽  
H. Zhao ◽  
H. Yuan ◽  
F. Zhu ◽  
W. Zhou

Abstract Coronary heart disease (CHD) has been associated with significant morbidity and mortality worldwide. Although remain controversial, several studies have demonstrated the association of M. pneumoniae infections with atherosclerosis. We evaluated the possible association of mycoplasma infections in patients diagnosed with atherosclerosis by ELISA and PCR methods. Atherosclerotic tissue samples and blood samples were collected for the detection of mycoplasma antibodies (IgA) by ELISA from the 97 patients with coronary artery disease (CAD). M. pneumoniae specific IgA, IgG and IgM were measured by using the Anti-M. pneumoniae IgA/IgG/IgM ELISA. Detection of M. pneumoniae targeting the P1 adhesion gene was performed by PCR Acute infection of M. pneumoniae was diagnosed in 43.3% (42) of patients by PCR. The M. pneumoniae specific antibodies were detected in 36.1% (35) of patients. Twenty-five (25.8%) cases had IgG antibodies, 15 (15.5%) cases had IgM antibodies, 3 (3.1%) cases had IgA antibodies, 10 (10.3%) cases had both IgM + IgG antibodies and 1 (1%) case of each had IgM + IgA and IgG + IgA antibodies. None of the cases was positive for all three antibodies. A Pearson correlation coefficient analysis revealed an excellent correlation between the PCR and the serological results (r=0.921, p<0.001). A majority (17, 40.5%) of the M. pneumoniae positive patients are within the 41-50 years of age group, followed by 10 (23.8%) patients in the age group of 61-70 years and 2 (4.8%) patients were >70 years of age. Our study reported an unusually higher prevalence of M. pneumoniae by serological tests (36.1%) and PCR (43.3%). Although the hypothesis of the association of M. pneumoniae and CAD is yet to be proven, the unusually high prevalence of M. pneumoniae in CAD patients indicates an association, if not, in the development of atherosclerosis.

S. Erdenlig Gurbilek ◽  
M.S. Karagul ◽  
A.M. Saytekin ◽  
E.A. Baklan ◽  
G. Saglam

Background: Vaccination is the most fundamental strategy in the control and eradication of brucellosis. Several vaccination programs with different vaccines have been carried out in many countries in which brucellosis continues to be a problem in livestock. One of the recommended vaccines against brucellosis in cattle is the live Brucella abortus S19 vaccine. The aim of this study is to evaluate the results of field safety and efficacy trials for the conjunctival Brucella abortus S19 vaccine prior to the mass vaccination program. Methods: In this study, 81 female cattle were vaccinated with a reduced dose of Brucella abortus S19 vaccine with the conjunctival route. The immune response after vaccination was investigated by suggested serological tests; namely, Rose Bengal Plate Test, Serum Agglutination Test and Complement Fixation Test. Result: No adverse effect was observed within the scope of safety. Isolation of vaccine strain was observed only in a milk sample of lactating animals. Excluding the diagnosis criteria of the serological tests, humoral immune response was observed in most of the animals by all the serological tests one month after vaccination. Antibody levels lasted approximately 4 months after vaccination. In conclusion, the results of this study demonstrated that besides vaccine-induced antibodies, the vaccine including changes in dose and administration way in this study did not cause any significant risks for the target animals.

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 205
Angélica Ramos ◽  
Maria João Cardoso ◽  
Luís Ribeiro ◽  
João Tiago Guimarães

The humoral response through neutralizing antibodies (NAbs) is a key component of the immune response to COVID-19. However, the plaque reduction neutralization test (PRNT), the gold standard for determining NAbs, is technically demanding, time-consuming and requires BSL-3 conditions. Correlating the NAbs and total antibodies levels, assessed by generalized and automated serological tests, is crucial. Through a commercial surrogate virus neutralization test (sVNT), we aimed to evaluate the production of SARS-CoV-2 NAbs in a set of vaccinated healthcare workers and to correlate these NAbs with the SARS-CoV-2 IgG anti-S1, anti-RBD and anti-S2 serological titers. We found that 6 months after vaccination, only 74% maintain NAbs for the Wuhan strain/UK variant (V1) and 47% maintain NAbs for the South African and Brazil variants (V2). Through Spearman’s correlation, we found the following correlations between the percentage of inhibition of NAbs and the SARS-CoV-2 IgG II Quant (Abbott Laboratories, Chicago, IL, USA) and BioPlex 2200 SARS-CoV-2 IgG Panel (Bio-Rad, Hercules, CA, USA) immunoassays: rho = 0.87 (V1) and rho = 0.73 (V2) for anti-S1 assessed by Abbott assay; rho = 0.77 (V1) and rho = 0.72 (V2) for anti-S1, rho = 0.88 (V1) and rho = 0.82 (V2) for anti-RBD, and rho = 0.68 (V1) and rho = 0.60 (V2) for anti-S2 assessed by BioPlex assay (p < 0.001 for all). In conclusion, we found a strong correlation between this fast, user-friendly, mobile and bio-safe sVNT and the serological immunoassays.

2022 ◽  
Vol 16 (1) ◽  
pp. e0010109
Ana Hernández-González ◽  
Belén González-Bertolín ◽  
Laura Urrea ◽  
Agnes Fleury ◽  
Elizabeth Ferrer ◽  

Background Neurocysticercosis (NCC), and cystic echinococcosis (CE) are two neglected diseases caused by cestodes, co-endemic in many areas of the world. Imaging studies and serological tests are used in the diagnosis of both parasitic diseases, but cross-reactions may confound the results of the latter. The novel multiplex bead-based assay with recombinant antigens has been reported to increases the diagnostic accuracy of serological techniques. Methodology We set-up an immunoassay based on the multiplex bead-based platform (MBA), using the rT24H (against Cysticercus cellulosae, causing cysticercosis) and r2B2t (against Echinococcus granulosus sensu lato, causing CE) recombinant antigens, for simultaneous and differential diagnosis of these infections. The antigens were tested on 356 sera from 151 patients with CE, 126 patients with NCC, and 79 individuals negative for both diseases. Specificity was calculated including sera from healthy donors, other neurological diseases and the respective NCC or CE sera counterpart. The diagnostic accuracy of this assay was compared with two commercial ELISA tests, Novalisa and Ridascreen, widely used in the routine diagnosis of cysticercosis and CE, respectively. Main findings For the diagnosis of NCC, sensitivity ranged from 57.94–63.49% for the rT24H-MBA, and 40.48–46.03% for Novalisa ELISA depending on exclusion or inclusion of sera having equivocal results on ELISA from the analysis; specificities ranged from 90.87–91.30% and 70.43–76.96%, respectively. AUC values of the ROC curve were 0.783 (rT24H) and 0.619 (Novalisa) (p-value < 0.001). For the diagnosis of CE, the sensitivity of the r2B2t-MBA ranged from 68.87–69.77% and of Ridascreen ELISA from 50.00–57.62%; specificities from 92.47–92.68% and from 74.15–80.98%, respectively. AUC values were 0.717 and 0.760, respectively. Conclusions/Significance Overall, the recombinant antigens tested with the bead-based technology showed better diagnostic accuracy than the commercial assays, particularly for the diagnosis of NCC. The possibility of testing the same serum sample simultaneously for the presence of antibodies against both antigens is an added value particularly in seroprevalence studies for cysticercosis linked to control programs in endemic areas where these two parasites coexist.

Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 114
Nico Andreas ◽  
Sebastian Weis ◽  
Steffi Kolanos ◽  
Sabine Baumgart ◽  
Thomas Kamradt ◽  

We present here a 64-year-old male participant of the CoNAN study who experienced a PCR-confirmed mild SARS-CoV-2 infection but did not develop any measurable antibody response. Additionally, after vaccination with ChAdOx1 (AstraZeneca, Cambridge, UK) 11 months later, no antibodies were detected in six serological tests three weeks after the vaccination. When we assessed T-helper (Th) cell immunity, SARS-CoV-2-specific Th cells produced detectable amounts of IFNγ and TNF six weeks after the infection. A robust T-cell immunity remained detectable at least until six months after the infection and was boosted by the vaccination thereafter. This case report points out that an assessment of a prior infection or a vaccine response based solely on antibody detection might have limitations in individual patients.

Plant Disease ◽  
2022 ◽  
Erich Yukio Tempel Nakasu ◽  
Tatsuya Nagata ◽  
Alice Inoue-Nagata

Recently, a new blunervirus was reported in tomatoes showing fruit chlorotic lesions. This virus, named tomato fruit blotch virus (ToFBV), was found associated with the tomato fruit blotch disease in Italy and Australia, even though Koch’s postulates were not fulfilled and no viral particles were seen in leaf dips observed with an electron microscope (Ciuffo et al. 2020). In December 2019, symptoms of circular or irregular chlorotic blotches were observed in tomato fruits in an organic farm in Distrito Federal, Brazil. Five different tomato cultivars (2100 plants of cv. Sweet grape, 1700 of Giacomo, 560 of Grazianni, 160 of Tropical, and 160 of DRC 5640) were being grown in two greenhouses and all of them presented the symptoms in at least one fruit, particularly in older fruits. No virus-like symptoms were observed in young and middle leaves, but older leaves could not be examined because they were removed as a routine activity of the farm; and also due to the moderate infestation of the tomato russet mite Aculops lycopersici, associated with leaf and stem necrosis. No viral particles were observed in an electron microscope analysis of symptomatic fruit tissues, and sap inoculation and grafting of stems did not produce any symptom in indicator plants. Two young and asymptomatic plants with the first fruits still in development were removed from another greenhouse of the farm and transported to our greenhouse, but the typical blotch symptoms neither appeared in the fruits nor the necrosis symptoms in the leaves. Serological tests performed for all collected leaf and fruit samples using antibodies produced in-house against common tomato-infecting tospoviruses and potyviruses were negative, as well as a polymerase chain reaction (PCR) detection test for begomoviruses (Rojas et al. 1993). Total RNA from newly collected samples consisting of one symptomatic fruit sample and five asymptomatic leaf samples from distinct plants were individually extracted using RNeasy Plant Mini Kit (Qiagen, Hilden, Germany) and pooled for next generation sequencing (NGS). The library was constructed using TruSeq Stranded Total RNA with Ribo-Zero Plant (Illumina, San Diego, USA) and sequenced at Macrogen, Inc. (Seoul, South Korea) in an Illumina Novaseq6000 platform. The 4,621,977,958 reads obtained were trimmed using Trimommatic 0.35 (Bolger et al. 2014) and contigs were assembled using Velvet (Zerbino and Birney 2008). Following tblastx analysis on Geneious 9.1.8 (Biomatters Ltd.) and BLAST on the NCBI platform (Altschul et al. 1990), seven contigs matching tomato chlorosis virus (ToCV) and five contigs matching ToFBV were identified. Sequences for each of the four genome components of ToFBV (MK517477-MK517480) already present in databases were used as reference using the Map to Reference function in Geneious. A total of 338,402, 78,039, 555,302 and 461,474 reads mapped to virus genome components 1 to 4, respectively, with >99% coverage for each. Four final consensus sequences were used for BLAST analyses on NCBI and presented 97 to 99.7 % nucleotide identity with those used for mapping. These sequences were deposited in GenBank as isolate MAL under accession numbers MW546267 (RNA 1, 5770 nt), MW546268 (RNA 2, 3612 nt), MW546269 (RNA 3, 2826 nt) and MW546270 (RNA 4, 1950 nt). The primer pair Bluner1F (5’-ATTCCTGTTCCTTCGGATAAACTCGT-3’) and Bluner1R (5’-CACACGTGCAGGAAATGGAAAGA-3’) directed to RNA 1 was used to specifically detect the virus. Three leaf samples and two fruit samples, each from a different plant with typical symptoms, were tested positive for ToFBV and negative using ToCV-specific primers in RT-PCR (Dovas et al. 2002). This confirmed that although some plants pooled in the HTS library were infected with ToCV, the chlorotic blotch symptom was clearly associated with the presence of ToFBV. Furthermore, the ~0.5 kbp amplicon for ToFBV-specific primers from one randomly selected sample was sequenced with both primers and the resulting sequence shared 100% nt identity with the RNA 1 of ToFBV isolate Fondi2018 from Italy (MK517477). Then, the virus was detected in the tissue from the surface of another fruit, but not from its internal part, suggesting a superficial infection. The findings presented here are of high phytosanitary significance, given the strong symptoms associated with tomato fruit blotch disease and the identification of ToFBV in the tomato samples from Brazil.

2022 ◽  
Vol 35 (13) ◽  
Flávia Cunha ◽  
Isabel Lopes de Carvalho ◽  
Carolina Torres ◽  
Raquel Gonçalves

Francisella tularensis, a Gram-negative coccobacillus, is a highly virulent pathogen responsible for several zoonotic outbreaks in Europe in the last few decades. The authors report the case of a 46-year-old male who developed fever, myalgias and headache a week after having contact with animal feed contaminated by rodents. Serological tests were positive for Francisella tularensis. This first case of autochthonous tularemia in Portugal led to an intensive investigation involving several healthcare services and national governmental authorities. The authors address the possible underdiagnosis of this infection in the country.

2022 ◽  
Vol 9 (1) ◽  
pp. 744-748
Ahmad Alzahrani ◽  
Hanady Idreis ◽  
Haifa Abdulghaffar ◽  
Layali Alakkad

Objective: Serological tests for dental workers have been suggested by different international agencies to ensure the safety of dental practitioners and, subsequently, their patients. In our organization, the percentage of dental workers who underwent serological tests was low (26%). Material and Methods: An intervention was designed using three sequential PDSA cycles to test changes proposed by team members. The percentage of dental workers who underwent these tests was used as the measure. Results: During the project period, the percentage of dental workers who underwent serological tests within nine months increased from 24% to 87%. Amongst the three interventions, the final one exhibited the most prominent change leading to major improvement.  Conclusion: Serological tests are essential investigational data used to ensure the safety of dental workers, which subsequently also enhances patient safety. Further interventions are highly recommended to maximize the number of dental workers who undergo serological investigation.

2022 ◽  
Vol 22 (1) ◽  
Jean-Robert Makulo ◽  
Madone Ndona Mandina ◽  
Placide Kingebeni Mbala ◽  
Roger Dimosi Wumba ◽  
Pierre Zalagile Akilimali ◽  

Abstract Background In symptomatic patients, the diagnostic approach of COVID-19 should be holistic. We aimed to evaluate the concordance between RT-PCR and serological tests (IgM/IgG), and identify the factors that best predict mortality (clinical stages or viral load). Methods The study included 242 patients referred to the University hospital of Kinshasa for suspected COVID-19, dyspnea or ARDS between June 1st, 2020 and August 02, 2020. Both antibody-SARS-CoV2 IgM/IgG and RT-PCR method were performed on the day of admission to hospital. The clinical stages were established according to the COVID-19 WHO classification. The viral load was expressed by the CtN2 (cycle threshold value of the nucleoproteins) and the CtE (envelope) genes of SARS- CoV-2 detected using GeneXpert. Kappa test and Cox regression were used as appropriate. Results The GeneXpert was positive in 74 patients (30.6%). Seventy two patients (29.8%) had positive IgM and 34 patients (14.0%) had positive IgG. The combination of RT-PCR and serological tests made it possible to treat 104 patients as having COVID-19, which represented an increase in cases of around 41% compared to the result based on GeneXpert alone. The comparison between the two tests has shown that 57 patients (23.5%) had discordant results. The Kappa coefficient was 0.451 (p < 0.001). We recorded 23 deaths (22.1%) among the COVID-19 patients vs 8 deaths (5.8%) among other patients. The severe-critical clinical stage increased the risk of mortality vs. mild-moderate stage (aHR: 26.8, p < 0.001). The values of CtE and CtN2 did not influence mortality significantly. Conclusion In symptomatic patients, serological tests are a support which makes it possible to refer patients to the dedicated COVID-19 units and treat a greater number of COVID-19 patients. WHO Clinical classification seems to predict mortality better than SARS-Cov2 viral load.

2022 ◽  
Monica Taminato ◽  
Ana Paula Cunha Chaves ◽  
Richarlisson Borges de Morais ◽  
Luiz Vinícius Leão Moreira ◽  
Danielle Dias Conte ◽  

Background Health Care workers (HCW) are an important group affected by this pandemic and COVID-19 has presented substantial challenges for health professionals and health systems in many countries. The Brazilian vaccination plan implemented in October, so that third dose for HCW. However, the persistence of CoronaVac vaccine-induced immunity is unknown, and immunogenicity according to age cohorts may differ among individuals. Objective Evaluate the post vaccination immune humoral response and the relationship between post-vaccination seropositivity rates and demographic data among Healthcare Workers over 6 months after CoronaVac immunization. Methods A cross section study including Healthcare professionals vaccinated with CoronaVac for 6 months or more. The study was carried with the analysis of post-vaccination serological test to assess the levels of humoral response after vaccination. Results 329 participants were included. Among them, 76% were female. Overall, 18.5% were positive quantitative titles (IQR 42.87-125.5) and the negative group was 80%, quantitative titles (IQR 5.50-13.92). Conclusion It was possible to identify a group with positive quantitative titles in serological test for IgG antibody against the SARS-CoV-2. Further investigation is required to determine the durability of post-vaccination antibodies and how serological tests can be determine the ideal timing of vaccine booster doses.

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