scholarly journals Emergomycosis, an Emerging Systemic Mycosis in Immunocompromised Patients: Current Trends and Future Prospects

2021 ◽  
Vol 8 ◽  
Author(s):  
Arghadip Samaddar ◽  
Anuradha Sharma
Keyword(s):  
Taxonomic Revision ◽  
Cross Reactivity ◽  
Antifungal Drugs ◽  
Epidemiological Surveillance ◽  
Dimorphic Fungus ◽  
Internal Transcribed Spacer Region ◽  
Serological Tests ◽  
Worldwide Distribution ◽  
Resource Limited ◽  
Disseminated Disease

Recently, the global emergence of emergomycosis, a systemic fungal infection caused by a novel dimorphic fungus Emergomyces species has been observed among immunocompromised individuals. Though initially classified under the genus Emmonsia, a taxonomic revision in 2017 based on DNA sequence analyses placed five Emmonsia-like fungi under a separate genus Emergomyces. These include Emergomyces pasteurianus, Emergomyces africanus, Emergomyces canadensis, Emergomyces orientalis, and Emergomyces europaeus. Emmonsia parva was renamed as Blastomyces parvus, while Emmonsia crescens and Emmonsia sola remained within the genus Emmonsia until a taxonomic revision in 2020 placed both the species under the genus Emergomyces. However, unlike other members of the genus, Emergomyces crescens and Emergomyces sola do not cause disseminated disease. The former causes adiaspiromycosis, a granulomatous pulmonary disease, while the latter has not been associated with human disease. So far, emergomycosis has been mapped across four continents: Asia, Europe, Africa and North America. However, considering the increasing prevalence of HIV/AIDS, it is presumed that the disease must have a worldwide distribution with many cases going undetected. Diagnosis of emergomycosis remains challenging. It should be considered in the differential diagnosis of histoplasmosis as there is considerable clinical and histopathological overlap between the two entities. Sequencing the internal transcribed spacer region of ribosomal DNA is considered as the gold standard for identification, but its application is compromised in resource limited settings. Serological tests are non-specific and demonstrate cross-reactivity with Histoplasma galactomannan antigen. Therefore, an affordable, accessible, and reliable diagnostic test is the need of the hour to enable its diagnosis in endemic regions and also for epidemiological surveillance. Currently, there are no consensus guidelines for the treatment of emergomycosis. The recommended regimen consists of amphotericin B (deoxycholate or liposomal formulation) for 1–2 weeks, followed by oral itraconazole for at least 12 months. This review elaborates the taxonomic, clinical, diagnostic, and therapeutic aspects of emergomycosis. It also enumerates several novel antifungal drugs which might hold promise in the treatment of this condition and therefore, can be potential areas of future studies.

scholarly journals Performance characteristics of the VIDAS® SARS-COV-2 IgM and IgG serological assays

2020 ◽  
Author(s):  
Nathalie Renard ◽  
Soizic Daniel ◽  
Nadège Cayet ◽  
Matthieu Pecquet ◽  
Frédérique Raymond ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Cross Reactivity ◽  
Epidemiological Surveillance ◽  
Test Results ◽  
Rt Pcr ◽  
Serological Tests ◽  
Clinical Sensitivity ◽  
Healthy Donors ◽  
Coefficients Of Variation ◽  
Respiratory Virus Infection

ABSTRACTThe COVID-19 pandemic, caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread worldwide. Serological testing for SARS-CoV-2-specific antibodies plays an important role in understanding and controlling the pandemics, notably through epidemiological surveillance. Well validated and highly specific SARS-CoV-2 serological assays are urgently needed. We describe here the analytical and clinical performance of VIDAS® SARS-CoV-2 IgM and VIDAS® SARS-CoV-2 IgG, two CE-marked, EUA-authorized, automated, qualitative assays for the detection of SARS-CoV-2-specific IgM and IgG, respectively. Both assays showed high within-run and within-laboratory precision (coefficients of variation < 11.0%) and very low cross-reactivity towards sera of patients with a past common coronavirus or respiratory virus infection. Clinical specificity determined on up to 989 pre-pandemic healthy donors was ≥ 99% with a narrow 95% confidence interval for both IgM and IgG assays. Clinical sensitivity was determined on up to 232 samples from 130 RT-PCR-confirmed SARS-CoV-2 patients. The positive percent agreement (PPA) with SARS-CoV-2 PCR reached 100% at ≥ 16 days (VIDAS® SARS-CoV-2 IgM) and ≥ 32 days (VIDAS® SARS-CoV-2 IgG) of symptom onset. Combined IgM/IgG test results improved the PPA compared to each test alone. SARS-CoV-2 IgG seroconversion followed closely that of SARS-CoV-2 IgM and remained stable over time, while SARS-CoV-2 IgM levels rapidly declined. Interestingly, SARS-CoV-2-specific IgM and IgG responses were significantly higher in COVID-19 hospitalized vs. non-hospitalized patients. Altogether, the VIDAS® SARS-CoV-2 IgM and IgG assays are highly specific and sensitive serological tests suitable for the reliable detection of past acute SARS-CoV-2 infections.

Enterovirus D-68 Molecular Virology, Epidemiology, and Treatment: an update and way forward

2020 ◽  
Vol 20 ◽  
Author(s):  
Mahmoud Ahmed Ebada ◽  
Notila Fayed ◽  
Souad Alkanj ◽  
Ahmed Wadaa Allah
Keyword(s):  
Current Knowledge ◽  
Rna Virus ◽  
Neurological Diseases ◽  
Cross Reactivity ◽  
Serological Tests ◽  
Molecular Virology ◽  
Acute Flaccid Myelitis ◽  
The Family ◽  
Pcr Products ◽  
Enterovirus D68

: Enterovirus D68 (EV-D68) is a single-stranded positive-sense RNA virus, and it is one of the family Picornaviridae. Except for EV-D68, the family Picornaviridae has been illustrated in literature. EV-D68 was first discovered and isolated in California, USA, in 1962. EV-D68 has resulted in respiratory disorders’ outbreaks among children worldwide, and it has been detected in cases of various neurological diseases such as acute flaccid myelitis (AFM). A recent study documented a higher number of EV-D68 cases associated with AFM in Europe in 2016 compared to the 2014 outbreak. EV-D68 is mainly diagnosed by quantitative PCR, and there is an affirmative strategy for EV-D68 detection by using pan-EV PCR on the untranslated region and/or the VP1 or VP2, followed by sequencing of the PCR products. Serological tests are limited due to cross-reactivity of the antigens between the different serotypes. Many antiviral drugs for EV-D68 have been evaluated, and showed promising results. In our review, we discuss the current knowledge about EV-D68 and its role in the development of AFM.

scholarly journals Recombinase-Aided Amplification Coupled with Lateral Flow Dipstick for Efficient and Accurate Detection of Porcine Parvovirus

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 762
Author(s):  
Yihong He ◽  
Wenxian Chen ◽  
Jindai Fan ◽  
Shuangqi Fan ◽  
Hongxing Ding ◽  
...  
Keyword(s):  
Detection Method ◽  
Cross Reactivity ◽  
Lateral Flow ◽  
Porcine Parvovirus ◽  
Swine Industry ◽  
Resource Limited ◽  
Efficient Detection ◽  
Lateral Flow Dipstick ◽  
Polymerase Chain ◽  
Embryonic Death

Porcine parvovirus (PPV) infection is the primary cause of SMEDI (stillbirth; mummification; embryonic death; infertility) syndrome, which is a global burden for the swine industry. Thus, it is crucial to establish a rapid and efficient detection method against PPV infection. In the present work, we developed a recombinase-aided amplification (RAA) assay, coupled with a lateral flow dipstick (LFD), to achieve an amplification of PPV DNA at 37 °C within 15 min. The detection limits of PPV RAA-LFD assay were 102 copies/μL recombinant plasmid pMD19-T-VP1, 6.38 × 10−7 ng/μL PPV DNA, and 10−1 TCID50/mL virus, respectively. This method was highly specific for PPV detection with no cross-reactivity for other swine pathogens. In contrast to polymerase chain reaction (PCR), the PPV RAA-LFD assay is more sensitive and cost-saving. Hence, the established PPV RAA-LFD assay provided an alternative for PPV detection, especially in resource-limited regions.

scholarly journals A High-Performance Multiplex Immunoassay for Serodiagnosis of Flavivirus-Associated Neurological Diseases in Horses

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Cécile Beck ◽  
Philippe Desprès ◽  
Sylvie Paulous ◽  
Jessica Vanhomwegen ◽  
Steeve Lowenski ◽  
...  
Keyword(s):  
High Performance ◽  
Neurological Diseases ◽  
Expression System ◽  
Cross Reactivity ◽  
Encephalitis Virus ◽  
Serological Tests ◽  
Multiplex Immunoassay ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus ◽  
Negative Controls

West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus (TBEV) are flaviviruses responsible for severe neuroinvasive infections in humans and horses. The confirmation of flavivirus infections is mostly based on rapid serological tests such as enzyme-linked immunosorbent assays (ELISAs). These tests suffer from poor specificity, mainly due to antigenic cross-reactivity among flavivirus members. Robust diagnosis therefore needs to be validated through virus neutralisation tests (VNTs) which are time-consuming and require BSL3 facilities. The flavivirus envelope (E) glycoprotein ectodomain is composed of three domains (D) named DI, DII, and DIII, with EDIII containing virus-specific epitopes. In order to improve the serological differentiation of flavivirus infections, the recombinant soluble ectodomain of WNV E (WNV.sE) and EDIIIs (rEDIIIs) of WNV, JEV, and TBEV were synthesised using theDrosophilaS2 expression system. Purified antigens were covalently bonded to fluorescent beads. The microspheres coupled to WNV.sE or rEDIIIs were assayed with about 300 equine immune sera from natural and experimental flavivirus infections and 172 nonimmune equine sera as negative controls. rEDIII-coupled microspheres captured specific antibodies against WNV, TBEV, or JEV in positive horse sera. This innovative multiplex immunoassay is a powerful alternative to ELISAs and VNTs for veterinary diagnosis of flavivirus-related diseases.

Reactivity and Specificity of Trichinella spiralis Fractions in Cutaneous and Serological Tests

1977 ◽  
Vol 6 (3) ◽  
pp. 274-279
Author(s):  
Omar O. Barriga
Keyword(s):  
Guinea Pigs ◽  
Trichinella Spiralis ◽  
Chronic Phase ◽  
Epidemiological Studies ◽  
Cross Reactivity ◽  
Serological Tests ◽  
Specific Diagnosis ◽  
Diethylaminoethyl Cellulose ◽  
Cutaneous Reactions ◽  
Healthy Persons

Six diethylaminoethyl-cellulose fractions of a larval Trichinella spiralis extract, an Ascaris suum extract, and a nonrelated protein were used for cutaneous tests in guinea pigs with 8-, 14-, and 73-day-old T. spiralis infections, in guinea pigs with 13-day-old A. suum infections, and in normal guinea pigs. A selected T. spiralis fraction was used in hemagglutination (HA) tests with sera of 8 T. spiralis -infected rabbits, 41 sera of trichinellosis patients positive by bentonite agglutination tests, and 50 sera of clinically healthy persons. Immediate-type cutaneous reactions revealed extensive cross-reactivity between both parasites, although the establishment of conventional limits for considering a reaction positive allowed the specific diagnosis of acute or chronic trichinellosis with different fractions. Delayed-type reactions were specific with all fractions except one, and different fractions reacted during either the acute or the chronic phase of trichinellosis. HA detected anti- Trichinella antibodies in all the rabbits 9 to 10 days postinfection, in all trichinellosis patients, and in none of the healthy people. Correlation between HA and bentonite agglutination titers and other considerations suggest that HA with the selected fraction detects early antibodies. HA inhibition tests with A. suum extract suggest lack of HA cross-reactivity between the A. suum - and T. spiralis -selected fractions. The use of different fractions in diverse tests for clinical or epidemiological studies is suggested.

scholarly journals Canine monocytic ehrlichiosis in Buenos Aires, Argentina: comparison of serological and molecular assays

2019 ◽  
Vol 39 (8) ◽  
pp. 649-654
Author(s):  
Paula L. Martin ◽  
María N. De Salvo ◽  
Gabriel L. Cicuttin ◽  
María S. Arauz
Keyword(s):  
Buenos Aires ◽  
Rhipicephalus Sanguineus ◽  
Control Group ◽  
Immunochromatographic Test ◽  
Serological Tests ◽  
Molecular Assays ◽  
Worldwide Distribution ◽  
Canine Monocytic Ehrlichiosis ◽  
Rhipicephalus Sanguineus Sensu Lato ◽  
Healthy Dogs

ABSTRACT: Canine monocytic ehrlichiosis (CME) is an infectious disease caused by the bacterium Ehrlichia canis and transmitted by Rhipicephalus sanguineus sensu lato, a tick with worldwide distribution. When not diagnosed and treated early, disease can be severe. Currently, the disease is confirmed by serological or molecular assays. The objective of this study was to compare a serological assay based on immunochromatography (SPEED® EHRLI immunochromatographic test; BVT, France) and a molecular assay (a screening PCR followed by a nested PCR specific for E. canis) for the diagnosis of E. canis in suspected dogs from Buenos Aires city and southern Greater Buenos Aires, Argentina. Blood samples from 20 clinically healthy dogs (Control Group) and from 80 sick dogs suspected of having CME (Groups 1 to 4) were tested in parallel. Neither the immunochromatographic test nor the PCR assay was able to detect the presence of E. canis in the Control Group. In the group which had been previously tested by serology, the agreement between the tests was low (kappa: 0.200), whereas in the group which had been previously tested by PCR, the concordance between the tests was adequate (kappa: 0.650). The concordance between the tests evaluated in the total population studied was moderate (kappa: 0.496). The results of our study suggest that the use of rapid serological tests as a first approach, together with subsequent confirmation by PCR, will improve the diagnosis of CME.

scholarly journals Peptide arrays incubated with three collections of human sera from patients infected with mosquito-borne viruses

F1000Research ◽  
2020 ◽  
Vol 8 ◽  
pp. 1875
Author(s):  
Maria del Pilar Martinez Viedma ◽  
Nurgun Kose ◽  
Leda Parham ◽  
Angel Balmaseda ◽  
Guillermina Kuan ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Cell Epitope ◽  
Cross Reactivity ◽  
Human Pathogens ◽  
Peptide Arrays ◽  
Serological Tests ◽  
Array Data ◽  
Prevalence Studies ◽  
Diagnostic Potential ◽  
Human Sera

Background: Global outbreaks caused by emerging or re-emerging arthropod-borne viruses (arboviruses) are becoming increasingly more common. These pathogens include the mosquito-borne viruses belonging to the Flavivirus and Alphavirus genera. These viruses often cause non-specific or asymptomatic infection, which can confound viral prevalence studies. In addition, many acute phase diagnostic tests rely on the detection of viral components such as RNA or antigen. Standard serological tests are often not reliable for diagnosis after seroconversion and convalescence due to cross-reactivity among flaviviruses. Methods: In order to contribute to development efforts for mosquito-borne serodiagnostics, we incubated 137 human sera on individual custom peptide arrays that consisted of over 866 unique peptides in quadruplicate. Our bioinformatics workflow to analyze these data incorporated machine learning, statistics, and B-cell epitope prediction. Results: Here we report the results of our peptide array data analysis, which revealed sets of peptides that have diagnostic potential for detecting past exposure to a subset of the tested human pathogens including Zika virus. These peptides were then confirmed using the well-established ELISA method. Conclusions: These array data, and the resulting peptides can be useful in diverse efforts including the development of new pan-flavivirus antibodies, more accurate epitope mapping, and vaccine development against these viral pathogens.

scholarly journals Evaluation of the Serologic Cross-Reactivity between Transmissible Gastroenteritis Coronavirus and Porcine Respiratory Coronavirus Using Commercial Blocking Enzyme-Linked Immunosorbent Assay Kits

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Ronaldo Magtoto ◽  
Korakrit Poonsuk ◽  
David Baum ◽  
Jianqiang Zhang ◽  
Qi Chen ◽  
...  
Keyword(s):  
Culture Medium ◽  
Large Deletion ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Transmissible Gastroenteritis Virus ◽  
Serum Samples ◽  
Serological Tests ◽  
Transmissible Gastroenteritis ◽  
Respiratory Coronavirus ◽  
Porcine Respiratory

ABSTRACTThis study compared the performances of three commercial transmissible gastroenteritis virus/porcine respiratory coronavirus (TGEV/PRCV) blocking enzyme-linked immunosorbent assays (ELISAs) using serum samples (n = 528) collected over a 49-day observation period from pigs inoculated with TGEV strain Purdue (n = 12), TGEV strain Miller (n = 12), PRCV (n= 12), or with virus-free culture medium (n = 12). ELISA results were evaluated both with “suspect” results interpreted as positive and then as negative. All commercial kits showed excellent diagnostic specificity (99 to 100%) when testing samples from pigs inoculated with virus-free culture medium. However, analyses revealed differences between the kits in diagnostic sensitivity (percent TGEV- or PRCV-seropositive pigs), and all kits showed significant (P < 0.05) cross-reactivity between TGEV and PRCV serum antibodies, particularly during early stages of the infections. Serologic cross-reactivity between TGEV and PRCV seemed to be TGEV strain dependent, with a higher percentage of PRCV-false-positive results for pigs inoculated with TGEV Purdue than for TGEV Miller. Moreover, the overall proportion of false positives was higher when suspect results were interpreted as positive, regardless of the ELISA kit evaluated.IMPORTANCECurrent measures to prevent TGEV from entering a naive herd include quarantine and testing for TGEV-seronegative animals. However, TGEV serology is complicated due to the cross-reactivity with PRCV, which circulates subclinically in most swine herds worldwide. Conventional serological tests cannot distinguish between TGEV and PRCV antibodies; however, blocking ELISAs using antigen containing a large deletion in the amino terminus of the PRCV S protein permit differentiation of PRCV and TGEV antibodies. Several commercial TGEV/PRCV blocking ELISAs are available, but performance comparisons have not been reported in recent research. This study demonstrates that the serologic cross-reactivity between TGEV and PRCV affects the accuracy of commercial blocking ELISAs. Individual test results must be interpreted with caution, particularly in the event of suspect results. Therefore, commercial TGEV/PRCV blocking ELISAs should only be applied on a herd basis.

scholarly journals Short Communication: Evaluation of a New Rapid Diagnostic Test for Quality Assurance by Kala Azar Elimination Programme in Bangladesh

2011 ◽  
Vol 2011 ◽  
pp. 1-3 ◽  
Author(s):  
Md Gulam Musawwir Khan ◽  
Mohammad Shafiul Alam ◽  
Abu Toha Bhuiyan ◽  
Maleka Arjumand Jamil ◽  
Bijoy Saha ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Serological Test ◽  
Rapid Test ◽  
Test Strip ◽  
Cross Reactivity ◽  
Serological Tests ◽  
Kala Azar ◽  
Asymptomatic Patients ◽  
Elimination Programme ◽  
The Government

In Bangladesh, serological tests have been widely used for the primary screening of visceral leishmaniasis (VL). Several serologic tests are available for the diagnosis of VL. Selection of the best test is important to permit diagnostic differentiation between symptomatic and asymptomatic patients and to reduce cross-reactivity. We evaluated the effectiveness of a new serological test “Onsite Leishmania Ab Rapid Test” as a part of “quality assurance” activities for the kala azar elimination programme of the Government of Bangladesh. Plasma samples of 100 parasitologically confirmed cases of VL along with 101 healthy controls were tested, and “Onsite Leishmania Ab Rapid Test” strip tests were positive in 94 out of 100 confirmed VL cases, whereas four out of 51 healthy subjects from the VL endemic areas also tested positive. All the 50 healthy volunteers tested negative. Thus, the sensitivity and specificity of “Onsite Leishmania Ab Rapid Test” strip test were found to be 94% (95% CI: 87–98) and 96% (95% CI: 90–99), respectively. This study showed that the performance of the “Onsite Leishmania Ab Rapid Test” strip tests was up to the recommended level.

scholarly journals Head-to-Head Comparison of Two SARS-CoV-2 Serology Assays

2020 ◽  
Vol 5 (6) ◽  
pp. 1351-1357 ◽  
Author(s):  
Anna E Merrill ◽  
J Brooks Jackson ◽  
Alexandra Ehlers ◽  
Dena Voss ◽  
Matthew D Krasowski
Keyword(s):  
Time Frame ◽  
Cross Reactivity ◽  
Molecular Techniques ◽  
Respiratory Pathogens ◽  
Serological Tests ◽  
Antibody Assays ◽  
Clinically Significant ◽  
Low Prevalence ◽  
Roche Diagnostics ◽  
Unique Potential

Abstract Background While molecular techniques remain the gold standard for diagnosis of acute SARS-CoV-2 infection, serological tests have the unique potential to ascertain how much of the population has been exposed to the COVID-19 pathogen. There have been limited published studies to date documenting the performance of SARS-CoV-2 antibody assays. Methods We compared the DiaSorin Liaison SARS-CoV-2 S1/S2 IgG and Roche Diagnostics Elecsys Anti-SARS-CoV-2 assays using 228 samples spanning patients with positive PCR for SARS-CoV-2, patients with compatible symptoms but negative PCR, pre-COVID specimens, and potential cross-reactives. Results Both assays detected antibodies in 18/19 samples collected at least one week after a positive PCR result. Neither method consistently detected antibodies in specimens collected within one week of a positive PCR result (sensitivity &lt; 50%), but antibodies were detected by only Roche in four samples in this time frame. Using 139 pre-COVID and 35 PCR-negative samples, the Roche and DiaSorin assays demonstrated specificities of 100.0% and 98.9%, respectively. Neither assay demonstrated cross-reactivity from other coronaviruses (229E, HKU1, NL63, OC43), respiratory pathogens (adenovirus, metapneumovirus, rhinovirus/enterovirus), or antibodies to other viruses (HIV, EBV, CMV, HBV, HCV, HAV). Discussion Overall, the qualitative interpretations afforded by the Roche and DiaSorin assays agreed for 97% of samples evaluated. Minor discrepancies in sensitivity and specificity were observed between methods, with the differences in specificity more clinically significant for our low-prevalence population. For the DiaSorin assay, all disagreements with the Roche assay occurred in samples with quantitative signals near the cut-off determining positivity.

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