scholarly journals Microsphere-Based IgM and IgG Avidity Assays for Human Parvovirus B19, Human Cytomegalovirus, and Toxoplasma gondii

mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Yilin Wang ◽  
Lea Hedman ◽  
Visa Nurmi ◽  
Inga Ziemele ◽  
Maria F. Perdomo ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Human Cytomegalovirus ◽  
Parvovirus B19 ◽  
Clinical Samples ◽  
Human Parvovirus B19 ◽  
Serum Samples ◽  
Content Type ◽  
Reference Methods ◽  
Igg Avidity ◽  
Highly Sensitive

ABSTRACT Human parvovirus B19 (here B19), human cytomegalovirus (HCMV), and Toxoplasma gondii infections during pregnancy can lead to severe complications. While traditional diagnosis of infections is mostly confined to one pathogen at a time, a multiplex array is a feasible alternative to improve diagnostic management and cost-efficiency. In the present study, for these three pathogens, we developed microsphere-based suspension immunoassays (SIAs) in multiplex and monoplex formats for the detection of antimicrobial IgM antibodies as well as corresponding chaotrope-based IgG avidity SIAs. We determined the diagnostic performances of the SIAs versus in-house and commercial reference assays using a panel of 318 serum samples from well-characterized clinical cohorts. All the newly developed assays exhibited excellent performance compared to the corresponding high-quality reference methods. The positive and negative percent agreements of the IgM SIAs in comparison with reference methods were 95 to 100% and 98 to 100%, and those of the IgG avidity SIAs were 92 to 100% and 95 to 100%, respectively. Kappa efficiency values between the SIAs and the corresponding reference assays were 0.91 to 1. Furthermore, with another panel comprising 391 clinical samples from individuals with primary infection by B19, HCMV, or T. gondii, the IgM SIAs were highly sensitive for the detection of acute infections, and the IgG avidity SIAs were highly specific for the separation of primary infections from past immunity. Altogether, the strategy of IgM multiplex screening followed by IgG avidity reflex testing can provide high-throughput and accurate means for the detection and stage determination of B19, HCMV, and T. gondii infections. IMPORTANCE Human parvovirus B19, human cytomegalovirus, and Toxoplasma gondii are ubiquitous pathogens. Their infections are often asymptomatic or mild in the general population yet may be transmitted from mother to fetus during pregnancy. Maternal infections by these pathogens can cause severe complications to the fetus or congenital abnormalities. As a rule, the risk of maternal transmission is critically related to the infection time; hence, it is important to determine when a pregnant woman has acquired the infection. In this study, we developed new diagnostic approaches for the timing of infections by three pathogens. All the new assays appeared to be highly sensitive and specific, providing powerful tools for medical diagnosis.

scholarly journals Genotyping of human parvovirus B19 in clinical samples from Brazil and Paraguay using heteroduplex mobility assay, single-stranded conformation polymorphism and nucleotide sequencing

2011 ◽  
Vol 106 (4) ◽  
pp. 502-504 ◽  
Author(s):  
Marcos César Lima de Mendonça ◽  
Ana Maria de Amorim Ferreira ◽  
Marta Gonçalves Matos dos Santos ◽  
Elva Cristina Oviedo ◽  
Maria Sônia Dal Bello ◽  
...  
Keyword(s):  
Parvovirus B19 ◽  
Clinical Samples ◽  
Nucleotide Sequencing ◽  
Human Parvovirus B19 ◽  
Single Stranded Conformation Polymorphism ◽  
Heteroduplex Mobility Assay ◽  
Conformation Polymorphism

scholarly journals COVID-19-Associated Invasive Aspergillosis: Data from the UK National Mycology Reference Laboratory

2020 ◽  
Vol 59 (1) ◽  
pp. e02136-20 ◽  
Author(s):  
Andrew M. Borman ◽  
Michael D. Palmer ◽  
Mark Fraser ◽  
Zoe Patterson ◽  
Ciara Mann ◽  
...  
Keyword(s):  
Critically Ill ◽  
Incidence Rates ◽  
Clinical Samples ◽  
Reference Laboratory ◽  
Serum Samples ◽  
Pulmonary Aspergillosis ◽  
Content Type ◽  
Specific Pcr ◽  
The Uk ◽  
Respiratory Specimens

ABSTRACTCOVID-19-associated pulmonary aspergillosis (CAPA) was recently reported as a potential infective complication affecting critically ill patients with acute respiratory distress syndrome following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, with incidence rates varying from 8 to 33% depending on the study. However, definitive diagnosis of CAPA is challenging. Standardized diagnostic algorithms and definitions are lacking, clinicians are reticent to perform aerosol-generating bronchoalveolar lavages for galactomannan testing and microscopic and cultural examination, and questions surround the diagnostic sensitivity of different serum biomarkers. Between 11 March and 14 July 2020, the UK National Mycology Reference Laboratory received 1,267 serum and respiratory samples from 719 critically ill UK patients with COVID-19 and suspected pulmonary aspergillosis. The laboratory also received 46 isolates of Aspergillus fumigatus from COVID-19 patients (including three that exhibited environmental triazole resistance). Diagnostic tests performed included 1,000 (1-3)-β-d-glucan and 516 galactomannan tests on serum samples. The results of this extensive testing are presented here. For a subset of 61 patients, respiratory specimens (bronchoalveolar lavage specimens, tracheal aspirates, and sputum samples) in addition to serum samples were submitted and subjected to galactomannan testing, Aspergillus-specific PCR, and microscopy and culture. The incidence of probable/proven and possible CAPA in this subset of patients was approximately 5% and 15%, respectively. Overall, our results highlight the challenges in biomarker-driven diagnosis of CAPA, especially when only limited clinical samples are available for testing, and the importance of a multimodal diagnostic approach involving regular and repeat testing of both serum and respiratory samples.

scholarly journals Genotype 1 of human parvovirus B19 in clinical cases

2017 ◽  
Vol 63 (3) ◽  
pp. 224-228 ◽  
Author(s):  
Maria Isabel de Oliveira ◽  
Ana Maria Sardinha Afonso ◽  
Suely Pires Curti ◽  
Patrícia Evelin Silva ◽  
Tamyris Fernanda Barbosa ◽  
...  
Keyword(s):  
Parvovirus B19 ◽  
Infectious Agent ◽  
Immunoglobulin M ◽  
Human Parvovirus B19 ◽  
Genotype 1 ◽  
Serum Samples ◽  
Chronic Anemia ◽  
Virus Surveillance ◽  
Polymerase Chain

Summary Introduction: Virus surveillance strategies and genetic characterization of human parvovirus B19 (B19V) are important tools for regional and global control of viral outbreak. In São Paulo, Brazil, we performed a study of B19V by monitoring the spread of this virus, which is an infectious agent and could be mistakenly reported as a rash and other types of infection. Method: Serum samples were subjected to enzyme immunoassay, real time polymerase chain reaction, and sequencing. Results: From the 462 patients with suspected cases of exanthematic infections, the results of the 164 serum samples were positive for B19V immunoglobulin M. Among these cases, there were 38 patients with erythema infections and B19-associated with other infections such as encephalitis, hydrops fetalis, chronic anemia, hematological malignancies. These samples were sequenced and identified as genotype 1. Conclusion: This study showed patients with infections caused by B19V and sequencing genotype 1. Continuous monitoring is necessary to detect all known genotypes, and the emergence of new genotypes of these viruses for case management in public health control activities.

scholarly journals Evaluation of the New Elecsys Toxo IgG Avidity Assay for Toxoplasmosis and New Insights into the Interpretation of Avidity Results

2012 ◽  
Vol 19 (11) ◽  
pp. 1838-1843 ◽  
Author(s):  
Jean-Benjamin Murat ◽  
Coralie L'Ollivier ◽  
Hélène Fricker Hidalgo ◽  
Jacqueline Franck ◽  
Hervé Pelloux ◽  
...  
Keyword(s):  
Severe Disease ◽  
High Avidity ◽  
Serum Samples ◽  
Recent Infection ◽  
Content Type ◽  
Additional Information ◽  
Avidity Assay ◽  
Igg Avidity ◽  
Acute Toxoplasmosis ◽  
Almost All

ABSTRACTDetection and treatment of acute toxoplasmosis during pregnancy can avoid severe disease of the fetus. In this context, assessment of anti-ToxoplasmaIgG avidity has been shown to exclude recent infection. The Elecsys Toxo IgG and IgM assays (Roche Diagnostics) have been validated for screening pregnant women and a new assay, Elecsys Toxo IgG Avidity, was recently developed. Our aims were to investigate the performance characteristics of this new avidity assay and explore whether additional information can be provided by avidity assays. The Elecsys assay was compared with the Vidas (bioMérieux) and Architect (Abbott) Avidity assays using two sets of serum samples (n= 291 andn= 255). The rate of general agreement between the Elecsys and Vidas assays was 74%, and that between the Elecsys and Architect assays was 83%. For 11% of the serum samples, avidity was high with the Vidas assay and within the gray zone with the Elecsys assay. None of the assays detected high-avidity antibodies in serum taken <4 months after infection. Avidity values of >90% were exclusively reported in sera taken >9 months after infection by the Elecsys and Architect assays. Almost all avidities of <19% with the Elecsys assay and <17% with the Architect assay corresponded to sera taken <3 and <2 months after infection, respectively. The Elecsys IgG Avidity assay can be used to exclude recent infection. New ways of interpreting the avidity result are also suggested: very high or low values could exclude infections within the last 9 months or help to confirm a recent infection, respectively. However, these potential interpretations require further investigation.

scholarly journals Deep Sequencing Reveals Highly Complex Dynamics of Human Cytomegalovirus Genotypes in Transplant Patients over Time

2010 ◽  
Vol 84 (14) ◽  
pp. 7195-7203 ◽  
Author(s):  
Irene Görzer ◽  
Christian Guelly ◽  
Slave Trajanoski ◽  
Elisabeth Puchhammer-Stöckl
Keyword(s):  
Human Cytomegalovirus ◽  
Lung Transplant ◽  
Complex Dynamics ◽  
Clinical Samples ◽  
Mixed Genotype ◽  
Transplant Patients ◽  
Highly Sensitive ◽  
The Individual ◽  
Changes Over Time ◽  
Over Time

ABSTRACT In lung transplant patients undergoing immunosuppression, more than one human cytomegalovirus (HCMV) genotype may emerge during follow-up, and this could be critical for the outcome of HCMV infection. Up to now, many cases of infection with multiple HCMV genotypes were probably overlooked due to the limitations of the current genotyping approaches. We have now analyzed mixed-genotype infections in 17 clinical samples from 9 lung transplant patients using the highly sensitive ultradeep-pyrosequencing (UDPS) technology. UDPS genotyping was performed at three variable HCMV genes, coding for glycoprotein N (gN), glycoprotein O (gO), and UL139. Simultaneous analysis of a mean of 10,430 sequence reads per amplicon allowed the relative amounts of distinct genotypes in the samples to be determined down to 0.1% to 1% abundance. Complex mixtures of up to six different HCMV genotypes per sample were observed. In all samples, no more than two major genotypes accounted for at least 88% of the HCMV DNA load, and these were often accompanied by up to four low-abundance genotypes at frequencies of 0.1% to 8.6%. No evidence for the emergence of new genotypes or sequence changes over time was observed. However, analysis of different samples withdrawn from the same patients at different time points revealed that the relative levels of replication of the individual HCMV genotypes changed within a mixed-genotype population upon reemergence of the virus. Our data show for the first time that, similar to what has been hypothesized for the murine model, HCMV reactivation in humans seems to occur stochastically.

scholarly journals Detection of Francisella tularensis-Specific Antibodies in Patients with Tularemia by a Novel Competitive Enzyme-Linked Immunosorbent Assay

2012 ◽  
Vol 20 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Neekun Sharma ◽  
Akitoyo Hotta ◽  
Yoshie Yamamoto ◽  
Osamu Fujita ◽  
Akihiko Uda ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Francisella Tularensis ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
The Novel ◽  
Serum Samples ◽  
Content Type ◽  
Microagglutination Test ◽  
Highly Sensitive ◽  
High Degree

ABSTRACTA novel competitive enzyme-linked immunosorbent assay (cELISA) was developed and evaluated for detection of antibodies againstFrancisella tularensisin humans. The assay is based on the ability of serum antibodies to inhibit the binding of monoclonal antibodies (MAbs) directed againstF. tularensislipopolysaccharide antigens. The assay was evaluated using serum samples of tularemia patients, inactivatedF. tularensis-immunized rabbits, andF. tularensis-infected mice. Antibodies againstF. tularensiswere successfully detected in serum samples of tularemia patients as well as the immunized and infected animals. The cELISA method was compared to indirect ELISA (iELISA) and the commonly used microagglutination test (MA) using serum samples of 19 tularemia patients and 50 healthy individuals. The sensitivity and specificity of cELISA were 93.9 and 96.1%, respectively, in comparison to the iELISA. MA was less sensitive than cELISA with a sensitivity and specificity of only 81.8 and 98.0%, respectively. A high degree of correlation (R2= 0.8226) was observed between cELISA and iELISA results. The novel cELISA developed in this study appears to be highly sensitive and specific for serodiagnosis of human tularemia. The potential of the MAb-based cELISA to be used in both human and animal samples emphasizes its usefulness for serological survey of tularemia among multiple animal species.

scholarly journals The prevalence of antibody to human parvovirus B19 in Rio de Janeiro, Brazil

1990 ◽  
Vol 32 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Jussara P. Nascimento ◽  
Marie M. Buckley ◽  
Kevin E. Brown ◽  
Bernard J. Cohen
Keyword(s):  
Rio De Janeiro ◽  
Parvovirus B19 ◽  
Human Parvovirus B19 ◽  
Antibody Prevalence ◽  
Serum Samples ◽  
Igg Antibody ◽  
Males And Females ◽  
Aged Eleven

During 1985 and 1986 serum samples were collected from the Rio de Janeiro population and examined for the presence of IgG antibody to human parvovirus B19. No difference in prevalence was found between males and females. Antibody prevalence rose from 35% in children less than five years old to almost 80% in children aged eleven to fifteen years. The antibody prevalence in individuals over 50 years old was over 90%.

scholarly journals Molecular Diagnosis of Invasive Aspergillosis and Detection of Azole Resistance by a Newly Commercialized PCR Kit

2017 ◽  
Vol 55 (11) ◽  
pp. 3210-3218 ◽  
Author(s):  
Eric Dannaoui ◽  
Frédéric Gabriel ◽  
Manuel Gaboyard ◽  
Gaëlle Lagardere ◽  
Lucile Audebert ◽  
...  
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Clinical Samples ◽  
Azole Resistance ◽  
Rrna Gene ◽  
28S Rrna ◽  
Serum Samples ◽  
Content Type ◽  
28S Rrna Gene

ABSTRACTAspergillus fumigatusis the main species responsible for aspergillosis in humans. The diagnosis of aspergillosis remains difficult, and the rapid emergence of azole resistance inA. fumigatusis worrisome. The aim of this study was to validate the new MycoGENIEA. fumigatusreal-time PCR kit and to evaluate its performance on clinical samples for the detection ofA. fumigatusand its azole resistance. This multiplex assay detects DNA from theA. fumigatusspecies complex by targeting the multicopy 28S rRNA gene and specific TR34and L98H mutations in the single-copy-numbercyp51Agene ofA. fumigatus. The specificity ofcyp51Amutation detection was assessed by testing DNA samples from 25 wild-type or mutated clinicalA. fumigatusisolates. Clinical validation was performed on 88 respiratory samples obtained from 62 patients and on 69 serum samples obtained from 16 patients with proven or probable aspergillosis and 13 patients without aspergillosis. The limit of detection was <1 copy for theAspergillus28S rRNA gene and 6 copies for thecyp51Agene harboring the TR34and L98H alterations. No cross-reactivity was detected with various fungi and bacteria. All isolates harboring the TR34and L98H mutations were accurately detected by quantitative PCR (qPCR) analysis. With respiratory samples, qPCR results showed a sensitivity and specificity of 92.9% and 90.1%, respectively, while with serum samples, the sensitivity and specificity were 100% and 84.6%, respectively. Our study demonstrated that this new real-time PCR kit enables sensitive and rapid detection ofA. fumigatusDNA and azole resistance due to TR34and L98H mutations in clinical samples.

scholarly journals Human parvovirus B19 infection: clinical and epidemiological study of 24 cases

1996 ◽  
Vol 38 (5) ◽  
pp. 323-328 ◽  
Author(s):  
Solange A. Oliveira ◽  
Antonio B. Brandão ◽  
Daniele G. Fernandes ◽  
Lilian R. Bettini ◽  
Anamaria B. Carvalho ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Differential Diagnosis ◽  
Infectious Diseases ◽  
Enzyme Immunoassay ◽  
Epidemiological Study ◽  
Parvovirus B19 ◽  
Human Parvovirus B19 ◽  
Serum Samples ◽  
Erythema Infectiosum ◽  
Parvovirus B19 Infection

From March 1994 to November 1995 24 cases of human parvovirus B19 infection were seen at the Infectious Diseases Department of the Hospital Universitário Antônio Pedro, Niterói - RJ. Serum samples for IgM detection (capture enzyme immunoassay) were positive from the 1st to the 27th day after the onset of the exathema. The classical features of erythema infectiosum (slapped cheecked syndrome) were observed in 8 (33.3%) cases all of them children. Eight patients (6 adults and 2 children) presented a symmetrical polyartropathy, seen more frequently in women. These results show that B19 infection diagnosis is difficult when the disease does not present the classical features and because of the frequent involvement of the joints this infection should be considered in the differential diagnosis of early rheumatoid arthritis.

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