scholarly journals Incidence of Zika Virus Infection from a Dengue Epidemiological Study of Children in Ratchaburi Province, Thailand

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1802
Author(s):  
Pimolpachr Sriburin ◽  
Pichamon Sittikul ◽  
Nathamon Kosoltanapiwat ◽  
Salin Sirinam ◽  
Watcharee Arunsodsai ◽  
...  
Keyword(s):  
Zika Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Infections ◽  
Rt Pcr ◽  
Serum Samples ◽  
Infected People ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
First Case ◽  
Archived Samples

Zika virus (ZIKV) is the mosquito-transmitted virus that the WHO declared a Public Health Emergency of International Concern in 2016 due to the consequence of microcephaly from infected pregnancies. The incidence of Zika infection has been unclear in many countries because most infected people have nonspecific febrile illnesses. This study’s aim is to investigate the incidence of symptomatic Zika virus infections from the archived samples of a dengue cohort study of children in central Thailand from 2006 to 2009. We performed Zika NS1 immunoglobulin (Ig)G enzyme-linked immunosorbent assay (ELISA) screening to identify symptomatic Zika infections in paired acute/convalescent serum samples. Symptomatic Zika infections were confirmed by reverse transcription polymerase chain reactions (RT-PCR) of acute serum samples. The comparison of the Zika NS1 IgG ELISA results between acute and convalescent samples showed 290/955 (30.4%) seropositive cases. Zika RT-PCR results were positive in 28 febrile cases (15 females, 13 males). Zika RT-PCR showed that symptomatic Zika infection occurred in children aged 4–11 years in Ratchaburi province, Thailand (2007–2009, first case in April 2007), and the symptomatic Zika:dengue infection ratio was 28 Zika:394 dengue (1:14). Phylogenetic analysis showed that all Zika viruses were of Asian lineage. Zika NS1 IgG ELISA identified Zika-infected patients and showed a low Zika:dengue ratio.

scholarly journals First Report of Cucurbit aphid-borne yellows virus in Iran Causing Yellows on Four Cucurbit Crops

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 526-526 ◽  
Author(s):  
K. Bananej ◽  
C. Desbiez ◽  
C. Wipf-Scheibel ◽  
I. Vahdat ◽  
A. Kheyr-Pour ◽  
...  
Keyword(s):  
Citrullus Lanatus ◽  
Healthy Plant ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
First Report ◽  
Chain Reactions ◽  
Reference Isolate ◽  
Sigma Chemical ◽  
International Mycological Institute ◽  
Das Elisa

A survey was conducted from 2001 to 2004 in the major cucurbit-growing areas in Iran to reassess the relative incidence of cucurbit viruses. Severe yellowing symptoms were observed frequently on older leaves of cucurbit plants in various regions in outdoor crops, suggesting the presence of Cucurbit aphid-borne yellows virus (CABYV, genus Polerovirus, family Luteoviridae) (1,2). Leaf samples (n = 1019) were collected from plants of melon (Cucumis melo L.), cucumber (C. sativus L.), squash (Cucurbita sp.), and watermelon (Citrullus lanatus L.) showing various virus-like symptoms (mosaic, leaf deformation, yellowing). All samples, collected from 15 provinces, were screened for the presence of CABYV by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with IgGs and alkaline phosphatase-conjugated IgGs against a CABYV reference isolate (1). Of the 1,019 samples tested, 471 were positive for CABYV using DAS-ELISA. Some of the positive samples had typical severe yellowing symptoms while symptoms in other samples were masked by mosaic or leaf deformations caused by other viruses frequently found in mixed infections (data not shown). During the entire survey, CABYV was detected by DAS-ELISA in 201 of 503 melon samples, 72 of 129 cucumber samples, 158 of 249 squash samples, and 40 of 138 watermelon samples. These results indicate that CABYV is widely distributed on four cucurbit species in the major growing areas of Iran. In order to confirm CABYV identification, total RNA extracts (TRI-Reagent, Sigma Chemical, St Louis, MO) were obtained from 25 samples that were positive using DAS-ELISA originating from Khorasan (n = 4), Esfahan (n = 6), Teheran (n = 3), Hormozgan (n = 4), Azerbaiejan-E-Sharqi (n = 4), and Kerman (n = 4). Reverse transcription-polymerase chain reactions (RT-PCR) were carried out using forward (5′-CGCGTGGTTGTGG-TCAACCC-3′) and reverse (5′-CCYGCAACCGAGGAAGATCC-3′) primers designed in conserved regions of the coat protein gene according to the sequence of a CABYV reference isolate (3) and three other unpublished CABYV sequences. RT-PCR experiments yielded an expected 479-bp product similar to the fragment amplified with extracts from the reference isolate. No amplification of the product occurred from healthy plant extracts. To our knowledge, this is the first report of the occurrence of CABYV in Iran on various cucurbit species. The high frequency (46.2%) with which CABYV was detected in the samples assayed indicates that this virus is one of the most common virus infecting cucurbits in Iran. References: (1) H. Lecoq et al. Plant Pathol. 41:749, 1992 (2) M. A. Mayo and C. J. D'Arcy. Page 15 in: The Luteoviridae. H. G. Smith and H. Barker, eds. CAB International Mycological Institute, Wallingford, UK, 1999. (3) H. Guilley et al. Virology 202:1012, 1994.

scholarly journals Immunoglobulin A Antibody Responses in Dengue Patients: a Useful Marker for Serodiagnosis of Dengue Virus Infection

2005 ◽  
Vol 12 (10) ◽  
pp. 1235-1237 ◽  
Author(s):  
M. Nawa ◽  
T. Takasaki ◽  
M. Ito ◽  
S. Inoue ◽  
K. Morita ◽  
...  
Keyword(s):  
Virus Infection ◽  
Dengue Virus ◽  
Immunoglobulin A ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Infections ◽  
Serum Samples ◽  
Dengue Virus Infection ◽  
Iga Antibody ◽  
Antibody Capture

ABSTRACT We determined the usefulness of an immunoglobulin A (IgA) antibody-capture enzyme-linked immunosorbent assay for serodiagnosis of dengue virus infections. The results indicate that the presence of IgA and IgM in serum samples assures recent primary dengue virus infection even with a single serum sample.

scholarly journals West Nile Virus and Related Flavivirus in European Wild Boar (Sus scrofa), Latium Region, Italy: A Retrospective Study

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 494
Author(s):  
Angela Petruccelli ◽  
Tiziana Zottola ◽  
Gianmarco Ferrara ◽  
Valentina Iovane ◽  
Cristina Di Russo ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Wild Boar ◽  
Specific Antibody ◽  
Central Italy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
West Nile ◽  
Wild Boars ◽  
European Wild Boar

Background: A retrospective sero-survey for evidence of West Nile virus (WNV) infection in European wild boar (Sus scorfa) was conducted in the Latium region, Italy, on stored serum samples of the period November 2011 to January 2012. Methods: Sera were collected from 168 European wild boars and screened for antibodies to WNV and other Flaviviruses by competitive enzyme linked immunosorbent assay (cELISA). All sera positive for Flavivirus antibodies by cELISA were further examined by virus neutralization test (VNT). To test the presence of Flavivirus RNA in samples, an RT-PCR was performed using a pan-Flavivirus primers pair. Results: Thirteen wild boars (7.73%) were seropositive for Flaviviruses. The hemolysis of serum samples limited the interpretation of the VNT for 7 samples, confirming the presence of specific antibody against WNV in a single European wild boar serum sample. The presence of ELISA positive/VNT negative samples suggests the occurrence of non-neutralizing antibodies against WNV or other antigen-related Flaviviruses. No samples resulted positive for Flavivirus by RT-PCR assay. Conclusion: Although a moderately high percentage of animals with specific antibody for WNV has been detected in wild boar in other surveillance studies in Europe, this has not been reported previously in Italy. Together, these data indicate that European wild boar are exposed to WNV and/or other related-Flavivirus in central Italy and confirm the usefulness of wild ungulates, as suitable Flavivirus sentinels.

scholarly journals Characteristic Differences in Reverse Transcription-Polymerase Chain Reaction Products of Ovine, Bovine, and Human Respiratory Syncytial Viruses

1993 ◽  
Vol 5 (3) ◽  
pp. 322-328 ◽  
Author(s):  
Richard D. Oberst ◽  
Michael P. Hays ◽  
Jim F. Evermann ◽  
Clayton L. Kelling
Keyword(s):  
Reverse Transcription ◽  
Reaction Products ◽  
Rt Pcr ◽  
Specific Primers ◽  
F Protein ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Respiratory Syncytial Viruses ◽  
Polymerase Chain ◽  
Syncytial Virus

In reverse transcription-polymerase chain reactions (RT-PCR) and DNA hybridizations using primers and an oligonucleotide probe to the fusion (F) protein mRNA of bovine respiratory syncytial virus (BRSV), all the BRSV isolates and a goat isolate could be distinguished from prototype isolates of human respiratory syncytial viruses (HRSV) and ovine (sheep and bighorn sheep) respiratory syncytial viruses (RSV). However, RT-PCR amplifications with primers to sequences of the HRSV F protein mRNA resulted in amplified products of ≍ 243 bp if mRNA templates of subgroup A HRSV strains were present and slightly larger amplified products with subgroup B HRSV strains. No amplified products were observed in HRSV-primed RT-PCR with BRSV or goat or ovine RSV mRNA templates. Although the ovine RSV isolates were antigenically cross-reactive with the goat RSV, HRSV and BRSV isolates, they were not amplified with either HRSV- or BRSV-specific primers in RT-PCR. These results confirm previous immunological comparisons suggesting that some ovine RSV isolates should be considered as distinct respiratory syncytial viruses.

scholarly journals Performance Evaluation of Commercial Dengue Diagnostic Tests for Early Detection of Dengue in Clinical Samples

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Tuan Nur Akmalina Mat Jusoh ◽  
Rafidah Hanim Shueb
Keyword(s):  
Dengue Virus ◽  
Real Time ◽  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Dengue Infection ◽  
Clinical Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
Kappa Agreement

The shattering rise in dengue virus infections globally has created a need for an accurate and validated rapid diagnostic test for this virus. Rapid diagnostic test (RDT) and reverse transcription-polymerase chain reaction (RT-PCR) diagnostic detection are useful tools for diagnosis of early dengue infection. We prospectively evaluated the diagnostic performance of nonstructural 1 (NS1) RDT and real-time RT-PCR diagnostic kits in 86 patient serum samples. Thirty-six samples were positive for dengue NS1 antigen while the remaining 50 were negative when tested with enzyme-linked immunosorbent assay (ELISA). Commercially available RDTs for NS1 detection, RTK ProDetect™, and SD Bioline showed high sensitivity of 94% and 89%, respectively, compared with ELISA. GenoAmp® Trioplex Real-Time RT-PCR and RealStar® Dengue RT-PCR tests presented a comparable kappa agreement with 0.722. The result obtained from GenoAmp® Real-Time RT-PCR Dengue test showed that 14 samples harbored dengue virus type 1 (DENV-1), 8 samples harbored DENV-2, 2 samples harbored DENV-3, and 1 sample harbored DENV-4. 1 sample had a double infection with DENV-1 and DENV-2. The NS1 RDTs and real-time RT-PCR tests were found to be a useful diagnostic for early and rapid diagnosis of acute dengue and an excellent surveillance tool in our battle against dengue.

Development of Two Multiplex Polymerase Chain Reactions for the Detection of Enterotoxigenic Strains of Staphylococcus aureus Isolated from Foods

2003 ◽  
Vol 66 (6) ◽  
pp. 1055-1062 ◽  
Author(s):  
GABRIELA NÁJERA-SÁNCHEZ ◽  
ROGELIO MALDONADO-RODRÍGUEZ ◽  
PATRICIA RUÍZ OLVERA ◽  
LYDIA MOTA de la GARZA
Keyword(s):  
Staphylococcus Aureus ◽  
Simultaneous Detection ◽  
Type A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Powdered Milk ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Type D ◽  
Multiplex Reaction ◽  
Polymerase Chain

Two multiplex polymerase chain reactions were developed for the detection of enterotoxigenic strains of Staphylococcus aureus: one multiplex reaction for the simultaneous detection of enterotoxigenic strains type A (entA), type B (entB), and type E (entE) and another for the simultaneous detection of enterotoxigenic strains type C (entC) and type D (entD). Both reactions were standardized with the use of the reference enterotoxigenic strains of S. aureus: FRI 722, producer of staphylococcal enterotoxin (SE) type A (SEA); FRI 1007, producer of SEB; FRI 137, producer of SEC1; FRI 472, producer of SED; and FRI 326, producer of SEE. Optimized methods were used to determine the presence of enterotoxigenic types for 51 S. aureus strains isolated from meat (sausage, ham, and chorizo) and dairy (powdered milk and cheese) products by the Baird-Parker technique. The enterotoxigenic capacities of the strains were determined by the indirect enzyme-linked immunosorbent assay (ELISA) with the use of reference staphylococcal toxins and antitoxins. Fifty of the 51 strains isolated were enterotoxigenic and produced one to four enterotoxin types, with the most frequently produced types being SEA and SED. Levels of correlation between the presence of genes that code for the production of SE (as determined by polymerase chain reaction) and the expression of these genes (as determined by the indirect ELISA) were 100% for SEA and SEE, 86% for SEC, 89% for SED, and 47% for SEB.

scholarly journals SARS-CoV-2 show no infectivity at later stages in a prolonged COVID-19 patient despite positivity in RNA testing

2021 ◽  
Author(s):  
Xiu-Feng Wan ◽  
Cynthia Y Tang ◽  
Detlef Ritter ◽  
Yang Wang ◽  
Tao Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Disease Onset ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Virus Growth ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Asymptomatic Patients ◽  
Hospitalization Period ◽  
Polymerase Chain

Inpatient COVID-19 cases present enormous costs to patients and health systems. Many hospitalized patients may still test COVID-19 positive, even after resolution of symptoms. Thus, a pressing concern for clinicians is the safety of discharging these asymptomatic patients if they have any remaining infectivity. This case report explores the viral viability in a patient with persistent COVID-19 over the course of a two-month hospitalization. Positive nasopharyngeal swab samples, analyzed by quantitative reverse transcription polymerase chain reactions (qRT-PCR), were collected and isolated in the laboratory, and infectious doses were analyzed throughout the hospitalization period. The patient experienced waning symptoms by hospital day 40 and had no viable virus growth in the laboratory by hospital day 41, suggesting no risk of infectivity, despite positive RT-PCR results, which prolonged his hospital stay. Notably, this case showed infectivity for at least 24 days from disease onset, which is longer than the discontinuation of transmission-based precautions recommendation by CDC. Thus, our findings suggest that the timeline for discontinuing transmission-based precautions may need to be extended for patients with prolonged illness. Additional large-scale studies are needed to draw definitive conclusions on the appropriate clinical management for these patients.

scholarly journals Comparison of Four Serological Methods and Two Reverse Transcription-PCR Assays for Diagnosis and Surveillance of Zika Virus Infection

2018 ◽  
Vol 56 (3) ◽  
Author(s):  
Angel Balmaseda ◽  
José Victor Zambrana ◽  
Damaris Collado ◽  
Nadezna García ◽  
Saira Saborío ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Zika Virus ◽  
Clinical Manifestations ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Emerging Infections ◽  
Rt Pcr ◽  
Convalescent Phase ◽  
Reverse Transcription Pcr ◽  
Pcr Assays

ABSTRACTZika virus (ZIKV) is a mosquito-borne flavivirus that is responsible for recent explosive epidemics in the Americas. Notably, ZIKV infection during pregnancy has been found to cause congenital birth defects, including microcephaly, and ZIKV has been associated with Guillain-Barré syndrome in adults. Diagnosis and surveillance of Zika in the Americas have been challenging due to similar clinical manifestations and extensive antibody cross-reactivity with endemic flaviviral diseases, such as dengue. We evaluated four serological and two reverse transcription-PCR (RT-PCR) methods in acute-phase (mean day, 1.8), early-convalescent-phase (mean day, 16.7), and late-convalescent-phase (mean, ~7 months) samples from the same individuals in a long-term pediatric cohort study in Nicaragua. Well-characterized samples from 301 cases of Zika, dengue, or non-Zika, nondengue febrile illnesses were tested. Compared to a composite reference, an in-house IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the NIAID-Biodefense and Emerging Infections (BEI) MAC-ELISA measuring IgM yielded sensitivities of 94.5% and 70.1% and specificities of 85.6% and 82.8%, respectively. The NS1 blockade-of-binding ELISA measuring anti-ZIKV NS1 antibody levels yielded sensitivities of 85.0% and 96.5% and specificities of 91.4% and 92.6% at early and late convalescence, respectively. An inhibition ELISA detecting total anti-ZIKV antibodies had sensitivity and specificity values of 68.3% and 58.3% for diagnosis and 94.0% and 98.6% for measuring annual infection incidence. Finally, the ZCD and Trioplex real-time RT-PCR assays detecting Zika, chikungunya, and dengue viruses both yielded a sensitivity of 96.1% and specificity of 100%. Together, these assays resolve the urgent need for diagnostic and surveillance tools for countries affected by Zika virus infections.

scholarly journals Zika virus isolation, propagation, and quantification using multiple methods

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255314
Author(s):  
Worawat Dangsagul ◽  
Kriengsak Ruchusatsawat ◽  
Apiwat Tawatsin ◽  
Don Changsom ◽  
Pirom Noisumdaeng ◽  
...  
Keyword(s):  
Real Time ◽  
Zika Virus ◽  
Immunofluorescence Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
Cell Monolayers ◽  
Viral Genomes ◽  
Mosquito Cells ◽  
Autopsy Specimens ◽  
Intrathoracic Inoculation

Zika virus (ZIKV) was isolated from the archival urine, serum, and autopsy specimens by intrathoracic inoculation of Toxorhynchitis splendens and followed by three blind sub-passaging in C6/36 mosquito cells. The virus isolates were identified using an immunofluorescence assay and real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). This study analyzed 11 ZIKV isolates. One isolate (0.6%) was obtained from 171 urine samples, eight (8.7%) from 92 serum samples and two from tissues of an abortive fetus. After propagation in C6/36 cells, ZIKV was titrated by plaque and focus forming unit (FFU) assays in Vero cell monolayers, and viral genomes were determined via real-time and digital RT-PCR. Plaque and FFU assay quantitations were comparable, with the amount of infectious viruses averaging 106−107 PFU or FFU/ml. Real-time RT-PCR semi-quantified the viral genome numbers, with Ct values varying from 12 to 14. Digital RT-PCR, which precisely determines the numbers of the viral genomes, consistently averaged 10–100 times higher than the number of infectious units. There was good correlation between the results of these titration methods. Therefore, the selection of a method should be based on the objectives of each research studies.

scholarly journals Prognostic value of Serum miR-217 Level in Osteosarcoma Patients

2020 ◽  
Author(s):  
Jia Ye ◽  
Zhi-Hui Jin ◽  
Ren Chen ◽  
Sen Chen ◽  
Yi-Jun Ren ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Poor Prognosis ◽  
Prognostic Significance ◽  
Serum Levels ◽  
High Serum ◽  
Rt Pcr ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Polymerase Chain ◽  
Low Serum

Abstract Background MicroRNA (miR)-217 is a tumor suppressor significantly associated with osteosarcoma. We try to evaluate serum levels miR-217 in osteosarcoma patients and evaluate its prognostic significance. Methods A total of 163 consecutive osteosarcoma patients and 96 healthy participates were enrolled. Serum miR-217 levels were evaluated by using real-time quantitative reverse transcription polymerase chain reactions(RT-PCR). The association between serum miR-217 level and survival outcomes was evaluated by univariate and multivariate analysis. Results Serum miR-217 levels in osteosarcoma patients was significantly lower than healthy volunteers (P<0.05). Low serum miR-217 was significantly related to advanced cancer and metastasis (both P<0.05). Moreover, patients with a low serum miR-217 had a poorer overall survival than those with a high serum miR-217 levels (P<0.05). Serum miR-217 level also been showed as independent risk factor for osteosarcoma in multivariate analysis (HR, 0.42; 95%CI: 0.12–0.98; p<0.01). Conclusions Serum miR-217 levels was significantly downregulated in osteosarcoma patients and remarkably associated with poor prognosis, indicating that serum miR-217 might serve as a useful diagnostic and prognostic indictor for osteosarcoma.

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