scholarly journals Viral isolation analysis of SARS-CoV-2 from clinical specimens of COVID-19 patients

2021 ◽  
Author(s):  
Emiko Igarashi ◽  
Hideki Tani ◽  
Kosuke Tamura ◽  
Masae Itamochi ◽  
Takahisa Shimada ◽  
...  
Keyword(s):  
Viral Isolation ◽  
Clinical Specimens

Comparison of WI-38, MRC-5, and IMR-90 cell strains for isolation of viruses from clinical specimens

1978 ◽  
Vol 7 (4) ◽  
pp. 368-371
Author(s):  
H M Friedman ◽  
C Koropchak
Keyword(s):  
Tissue Culture ◽  
Life Span ◽  
Fetal Lung ◽  
Cell Strain ◽  
Viral Isolation ◽  
Clinical Specimens ◽  
Cell Strains ◽  
Viral Diagnosis ◽  
Human Fetal Lung ◽  
Speed Of Onset

With the diminishing supply of the human fetal lung WI-38 cell strain, a replacement for viral isolation is needed. Two candidates are the human fetal lung strains MRC-5 and IMR-90. A comparison of WI-38, MRC-5, and IMR-90 was performed to evaluate efficiency and speed of viral isolation, clarity of cytophatic effect, and ease of growing the cells. The inocula were clinical specimens rather than tissue culture-adapted isolates. Frozen samples of 46 specimens that had previously yielded an isolate on WI-38 were thawed and inoculated onto WI-38, MRC-5, and IMR-90 cells. In addition, 95 freshly taken clinical specimens uf undetermined infectivity were inoculated onto the cell strains. Viral recovery rates were similar on all three strains, as were the appearance and speed of onset of the cytophatic effect. MRC-5 and WI-38 cells remained healthy until generation 36, whereas IMR-90 cells went into crisis by generation 20. The longer life span of the MRC-5 cells makes them more suitable than IMR-90 cells to replace the WI-38 strain for routine use in viral diagnosis.

A combined pseudoreplica-immunocytochemical technique for research and diagnostic virology

1990 ◽  
Vol 48 (3) ◽  
pp. 900-901
Author(s):  
Blayne Fritz ◽  
Stanley J. Naides ◽  
Kenneth Moore
Keyword(s):  
Phosphotungstic Acid ◽  
Immunogold Labelling ◽  
Uranyl Acetate ◽  
Distilled Water ◽  
Clinical Specimens ◽  
Tissue Sections ◽  
Specimen Retrieval ◽  
Transmission Electron ◽  
Viral Particles ◽  
Diagnostic Virology

The pseudoreplica method of staining viral particles for visualization by transmission electron microscopy is a very popular technique. The ability to concentrate clinical specimens while semi-embedding viral particles makes it especially well suited for morphologic and diagnostic virology. Immunolabelling viral particles with colloidal gold is a technique frequently employed by both research and diagnostic virologists. We have characterized a procedure which provides the advantage of both by modifying and combining pseudoreplica staining and immunogold labelling.Modification of specimen retrieval and delay of staining allows us to utilize pseudoreplica processed specimens within our standard immunogold labelling protocol. In brief, we absorbed samples onto 2% agarose, added.25% Formvar and wicked dry. We then floated the Formvar-virus film onto double distilled water, added grids and retrieved with parafilm. The Formvar-virus specimens were then treated as thin tissue sections within our standard two stage immunolabelling protocol. Following completion of immunogold labelling; each grid was negatively stained with phosphotungstic acid or uranyl acetate contrast stains.

Prevalence of Vancomycin Resistant Enterococci in Various Clinical Specimens in Tertiary Care Hospital in North Delhi

2012 ◽  
Vol 3 (3) ◽  
pp. 141-144
Author(s):  
Swati Chaudhary ◽  
◽  
Swastika Aggarwal ◽  
Pawan Kumar ◽  
SK Aggarwal SK Aggarwal ◽  
...  
Keyword(s):  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Care Hospital ◽  
Clinical Specimens ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant

Detection of Genes Encoding of Extended-Spectrum and AmpC β-Lactamases in Klebsiella pneumoniae Isolates from Clinical Specimens

2015 ◽  
Vol 18 (2) ◽  
pp. 125-132
Author(s):  
Ghusoon A. Abdulhasan ◽  
◽  
Hula Y. Fadhil ◽  
Kifah A. Jasem ◽  
◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Clinical Specimens ◽  
Extended Spectrum ◽  
Genes Encoding

scholarly journals Detection of three pandemic causing coronaviruses from non-respiratory samples: systematic review and meta-analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chandan Mishra ◽  
Suneeta Meena ◽  
Jitendra Kumar Meena ◽  
Suman Tiwari ◽  
Purva Mathur
Keyword(s):  
Systematic Review ◽  
Detection Rate ◽  
Meta Analysis ◽  
Total Sample ◽  
Urine Samples ◽  
Pathogenic Potential ◽  
Clinical Specimens ◽  
Qrt Pcr ◽  
Corona Virus ◽  
Positive Rate

AbstractSARS-CoV-2 has posed an unprecedented challenge to the world. Pandemics have been caused previously by viruses of this family like Middle East Respiratory Corona Virus (MERS CoV), Severe Acute Respiratory Syndrome Corona Virus (SARS CoV). Although these viruses are primarily respiratory viruses, but they have been isolated from non-respiratory samples as well. Presently, the detection rate of SARS‐CoV‐2 RNA from different clinical specimens using Real Time Reverse Transcriptase Polymerized Chain Reaction (qRT‐PCR) after onset of symptoms is not yet well established. Therefore, the aim of this systematic review was to establish the profile of detecting SARS‐CoV‐2, MERS CoV, SARS CoV from different types of clinical specimens other than the respiratory using a standard diagnostic test (qRT‐PCR). A total of 3429 non-respiratory specimens were recorded: SARS CoV (total sample—802), MERS CoV (total sample—155), SARS CoV-2 (total sample—2347). Out of all the samples studied high positive rate was seen for saliva with 96.7% (14/14; 95% CI 87.6–100.0%) for SARS CoV and 57.5% (58/250; 95% CI − 1.2 to 116.2%) for SARS CoV-2, while low detection rate in urine samples for SARS CoV-2 with 2.2% (8/318; 95% CI 0.6–3.7%) and 9.6% (12/61; 95% CI − 0.9 to 20.1%) for SARS CoV but there was relatively higher positivity in urine samples for MERS CoV with detection rate of 32.4% (2/38; 95% CI − 37.3 to 102.1%). In Stool sample positivity was 54.9% (396/779; 95% CI 41.0–68.8%), 45.2% (180/430; 95% CI 28.1–62.3%) and 34.7% (4/38; 95% CI − 29.5 to 98.9%) for SARS CoV-2, MERS CoV, and SARS CoV, respectively. In blood sample the positivity was 33.3% (7/21; 95% CI 13.2–53.5%), 23.7% (42/277; 95% CI 10.5–36.9%) and 2.5% (2/81; 95% CI 0.00–5.8%) for MERS CoV, SARS CoV-2 and SARS CoV respectively. SARS‐CoV‐2 along with previous two pandemic causing viruses from this family, were highly detected stool and saliva. A low positive rate was recorded in blood samples. Viruses were also detected in fluids along with unusual samples like semen and vaginal secretions thus highlighting unique pathogenic potential of SARS‐CoV‐2.

scholarly journals Assessment of SARS-CoV-2 infectivity of upper respiratory specimens from COVID-19 patients by virus isolation using VeroE6/TMPRSS2 cells

2021 ◽  
Vol 8 (1) ◽  
pp. e000830
Author(s):  
Souichi Yamada ◽  
Shuetsu Fukushi ◽  
Hitomi Kinoshita ◽  
Makoto Ohnishi ◽  
Tadaki Suzuki ◽  
...  
Keyword(s):  
Virus Isolation ◽  
Laboratory Diagnostics ◽  
Viral Isolation ◽  
Viral Loads ◽  
A Cell ◽  
Blind Passage ◽  
Upper Respiratory ◽  
Novel Coronavirus ◽  
Respiratory Specimens

BackgroundAn outbreak of novel coronavirus (SARS-CoV-2)-associated respiratory infectious diseases (COVID-19) emerged in 2019 and has spread rapidly in humans around the world. The demonstration of in vitro infectiousness of respiratory specimens is an informative surrogate for SARS-CoV-2 transmission from patients with COVID-19; accordingly, viral isolation assays in cell culture are an important aspect of laboratory diagnostics for COVID-19.MethodsWe developed a simple and rapid protocol for isolating SARS-CoV-2 from respiratory specimens using VeroE6/TMPRSS2 cells, a cell line that is highly susceptible to the virus. We also investigated a correlation between isolation of SARS-CoV-2 and viral load detected by real-time RT-PCR (rRT-PCR) using N2 primer/probe set that has been developed for testing of COVID-19 in Japan.ResultsThe SARS-CoV-2 isolation protocol did not require blind passage of inoculated cells and yielded the results of viral isolation within 7 days after inoculation. Specimens with cycle threshold (Ct) values of <20.2, determined by rRT-PCR, were predicted to be isolation-positive. On the other hand, 6.9% of specimens with Ct values >35 were virus isolation-positive, indicating that low viral loads (high Ct values) in upper respiratory specimens do not always indicate no risk of containing transmissible virus.ConclusionIn combination with rRT-PCR, the SARS-CoV-2 isolation protocol provides a means for assessing the potential risk of transmissible virus in upper respiratory specimens.

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