scholarly journals Development of a Flow-Free Automated Colorimetric Detection Assay Integrated with Smartphone for Zika NS1

Diagnostics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 42 ◽  
Author(s):  
Md Alamgir Kabir ◽  
Hussein Zilouchian ◽  
Mazhar Sher ◽  
Waseem Asghar

The Zika virus (ZIKV) is an emerging flavivirus transmitted to humans by Aedes mosquitoes that can potentially cause microcephaly, Guillain–Barré Syndrome, and other birth defects. Effective vaccines for Zika have not yet been developed. There is a necessity to establish an easily deployable, high-throughput, low-cost, and disposable point-of-care (POC) diagnostic platform for ZIKV infections. We report here an automated magnetic actuation platform suitable for a POC microfluidic sandwich enzyme-linked immunosorbent assay (ELISA) using antibody-coated superparamagnetic beads. The smartphone integrated immunoassay is developed for colorimetric detection of ZIKV nonstructural protein 1 (NS1) antigen using disposable chips to accommodate the reactions inside the chip in microliter volumes. An in-house-built magnetic actuator platform automatically moves the magnetic beads through different aqueous phases. The assay requires a total of 9 min to automatically control the post-capture washing, horseradish peroxidase (HRP) conjugated secondary antibody probing, washing again, and, finally, color development. By measuring the saturation intensity of the developed color from the smartphone captured video, the presented assay provides high sensitivity with a detection limit of 62.5 ng/mL in whole plasma. These results advocate a great promise that the platform would be useful for the POC diagnosis of Zika virus infection in patients and can be used in resource-limited settings.

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256220
Author(s):  
Julieta S. Roldán ◽  
Alejandro Cassola ◽  
Daniela S. Castillo

Zika virus (ZIKV) is a flavivirus that has emerged as a global health threat after the 2015 outbreak in the Americas, where devastating congenital defects were documented. There are currently no vaccines to prevent ZIKV infections nor commercially available clinical diagnostic tests demonstrated to identify ZIKV without cross-reactive interference of related flaviviruses. Early diagnosis is critical when treating symptomatic patients and in preventing ZIKV transmission. In this context, the development of sensitive and accurate diagnostic methods are urgently needed for the detection of ZIKV acute infection. The aim of this study consisted of obtaining monoclonal antibodies (mAbs) against denatured monomeric ZIKV Nonstructural protein 1 (ZNS1), a useful diagnostic marker for flavivirus early detection, in order to develop a highly specific and sensitive ZNS1 indirect competitive ELISA (icELISA). The production of hybridomas secreting ZNS1 mAbs was carried out through immunizations with denatured monomeric ZNS1. We selected 1F5 and 6E2 hybridoma clones, which recognized the heat-denatured ZNS1 hexameric form by indirect ELISA. Cross-reaction studies indicated that these mAbs specifically bind to a ZNS1 linear epitope, and that they do not cross-react with the NS1 protein from other related flaviviruses. The 1F5 mAb enabled the development of a sensitive and reproducible icELISA to detect and quantify small amounts of ZNS1 disease marker in heat-denatured human sera. Here, we establish a reliable 1F5 based-icELISA that constitutes a promising diagnostic tool for control strategies and the prevention of ZIKV propagation.


Author(s):  
Jurai Wongsawat ◽  
Patama Suttha ◽  
Sumalee Chanama ◽  
Somkid Srisopa ◽  
Nichapa Yonchoho ◽  
...  

Information is limited regarding differential serological responses after acute Zika virus (ZIKV) infections and prevalence of cross-reactivity with anti-dengue virus (DENV) assays comparing children and adults. Early convalescent sera from a cohort of suspected mild DENV cases between December 2016 and September 2018 at Bamrasnaradura Infectious Diseases Institute in Thailand were tested for nonstructural protein 1 (NS1)–based anti-ZIKV IgM and IgG ELISAs (Euroimmun), and in-house anti-DENV IgM- and IgG-capture ELISAs. ZIKV cases were identified by positive real-time reverse transcriptase-polymerase chain reaction on urine. Sera from 26 (10 children and 16 adults) ZIKV and 237 (153 children and 74 adults) non-ZIKA cases collected at the median duration of 18 days (interquartile range [IQR] 18,19) post-onset of symptoms were tested. Comparing pediatric ZIKV to adult ZIKV cases, the mean anti-ZIKV IgM ratio was higher (2.12 versus 1.27 units, respectively; P = 0.07), whereas mean anti-ZIKV IgG ratio was lower (3.13 versus 4.24 units, respectively; P = 0.03). Sensitivity of anti-ZIKV IgM and specificity of anti-ZIKV IgG in pediatric ZIKV were higher than in adult ZIKV cases (80.0% versus 43.7% and 79.1% versus 43.2%, respectively). No cross-reactivity with anti-DENV IgM- and IgG-capture ELISA were reported in pediatric ZIKV cases in our study, whereas 25% and 12.5% were found in adult ZIKV cases, respectively. Age-related ZIKV serological differences have been observed. Positive NS1-based anti-ZIKV IgM and IgG ELISA at the early convalescent phase could be useful for ZIKV diagnosis in children, even in a dengue endemic setting.


2021 ◽  
Vol 32 ◽  
pp. 102334
Author(s):  
Marianna Teixeira Pinho Favaro ◽  
Monica Josiane Rodrigues-Jesus ◽  
Alexia Adrianne Venceslau-Carvalho ◽  
Rúbens Prince Dos Santos Alves ◽  
Lennon Ramos Pereira ◽  
...  

2016 ◽  
Vol 54 (8) ◽  
pp. 2090-2095 ◽  
Author(s):  
Elizabeth A. Hunsperger ◽  
Tyler M. Sharp ◽  
Paul Lalita ◽  
Kini Tikomaidraubuta ◽  
Yolanda Rebello Cardoso ◽  
...  

Dengue is major public health problem, globally. Timely verification of suspected dengue outbreaks allows for public health response, leading to the initiation of appropriate clinical care. Because the clinical presentation of dengue is nonspecific, dengue diagnosis would benefit from a sensitive rapid diagnostic test (RDT). We evaluated the diagnostic performance of an RDT that detects dengue virus (DENV) nonstructural protein 1 (NS1) and anti-DENV IgM during suspected acute febrile illness (AFI) outbreaks in four countries. Real-time reverse transcription-PCR and anti-DENV IgM enzyme-linked immunosorbent assay were used to verify RDT results. Anti-DENV IgM RDT sensitivity and specificity ranged from 55.3 to 91.7% and 85.3 to 98.5%, respectively, and NS1 sensitivity and specificity ranged from 49.7 to 92.9% and 22.2 to 89.0%, respectively. Sensitivity varied by timing of specimen collection and DENV serotype. Combined test results moderately improved the sensitivity. The use of RDTs identified dengue as the cause of AFI outbreaks where reference diagnostic testing was limited or unavailable.


Author(s):  
Binita Joseph Aring ◽  
Dipali Magan Bhai Gavali ◽  
Pushpa Ramjibhai Kateshiya ◽  
Hiral Modbhai Gadhvi ◽  
Summaiya Mullan ◽  
...  

Introduction: Dengue has rapidly emerged as a vector - borne viral disease in recent years and also endemic in all continents. The agent of dengue, i.e., dengue viruses, are categorised under the genus Flavivirus, with the four dengue virus serotypes: designated as DENV-1, DENV-2, DENV-3 and DENV-4. These all four serotypes are in circulation either singly, or more than one at the same time. Aim: To study the epidemiological update of dengue with circulating serotype and co-infection in Saurashtra region, Gujarat, India. Materials and Methods: A cross-sectional study was conducted during January 2019 to December 2020 and total samples received were 12,563 which were clinically suspected dengue samples case. After receiving blood samples, serum was separated and proceeded for Dengue NS1Ag (nonstructural protein 1 antigen), and Dengue IgM Ab (Immunoglobulin M antibody). After serological confirmation, 151 samples from different geographical area were selected for Dengue specific Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR) for serotyping. results: Total 4069 (32%) had confirmed dengue positive by Enzyme Linked Immunosorbent Assay (ELISA). The ratio of male cases was higher than female, and in age group 21-35 year (47%). Seasonal trend showed a gradual increase in positivity from June with high peak in October. Circulation of all the four serotypes in area, higher monotypic infection by DENV-1 serotype (41%), followed by DENV-4, DENV-2 and DENV-3. Co-infection of different serotypes were also found. conclusion: The present study concluded that all four serotypes circulate with predominant being DENV-1 type and co-infection of different serotypes in the saurashtra region. Dengue mainly affected adult male population, and seasonal peak during monsoon and post-monsoon period.


Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 93 ◽  
Author(s):  
Li ◽  
Collins ◽  
Widen ◽  
Davis ◽  
Kaiser ◽  
...  

Zika virus (ZIKV) is a mosquito-borne Flavivirus. Previous studies have shown that mosquito-transmitted flaviviruses, including yellow fever, Japanese encephalitis, and West Nile viruses, could be attenuated by serial passaging in human HeLa cells.  Therefore, it was hypothesized that wild-type ZIKV would also be attenuated after HeLa cell passaging. A human isolate from the recent ZIKV epidemic was subjected to serial HeLa cell passaging, resulting in attenuated in vitro replication in both Vero and A549 cells. Additionally, infection of AG129 mice with 10 plaque forming units (pfu) of wild-type ZIKV led to viremia and mortality at 12 days, whereas infection with 103 pfu of HeLa-passage 6 (P6) ZIKV led to lower viremia, significant delay in mortality (median survival: 23 days), and increased cytokine and chemokine responses.  Genomic sequencing of HeLa-passaged virus identified two amino acid substitutions as early as HeLa-P3: pre-membrane E87K and nonstructural protein 1 R103K. Furthermore, both substitutions were present in virus harvested from HeLa-P6-infected animal tissue. Together, these data show that, similarly to other mosquito-borne flaviviruses, ZIKV is attenuated following passaging in HeLa cells. This strategy can be used to improve understanding of substitutions that contribute to attenuation of ZIKV and be applied to vaccine development across multiple platforms.


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