scholarly journals Prolonged SARS-CoV-2 Positivity in Immunocompetent Patients: Virus Isolation, Genomic Integrity, and Transmission Risk

2021 ◽  
Author(s):  
Isabela de Carvalho Leitão ◽  
Pedro Telles Calil ◽  
Rafael Mello Galliez ◽  
Filipe Romero Rebello Moreira ◽  
Diana Mariani ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Symptom Onset ◽  
Virus Isolation ◽  
Transmission Risk ◽  
Genomic Integrity ◽  
Immunocompetent Patients

In this study, we evaluated mildly symptomatic immunocompetent patients with long-lasting positive rRT-PCR results for SARS-CoV-2. Infectious viruses were successfully isolated in cell cultures from nasopharynx samples obtained 14 days or longer after symptom onset.

Isolation of Arboviruses From Cattle and Insects at 2 Sentinel Sites in Queensland, Australia, 1979-85

1990 ◽  
Vol 38 (1) ◽  
pp. 25 ◽  
Author(s):  
DH Cybinski ◽  
MJ Muller
Keyword(s):  
Cell Cultures ◽  
Virus Isolation ◽  
Hemorrhagic Disease ◽  
Tissue Cultures ◽  
Akabane Virus ◽  
Biting Midges ◽  
Bovine Ephemeral Fever ◽  
Serotype 1 ◽  
Intrathoracic Inoculation ◽  
First Time

Blood samples were collected regularly from two sentinel herds of cattle in northern and southern Queensland between 1979 and 1985. From 2660 samples, virus isolation attempts using baby hamster kidney (BHK21) and Aedes albopictus (AA) tissue cultures and suckling mice produced 308 viruses of which 243 (79%) were in the Palyam subgroup of orbiviruses. Mosquitoes and biting midges were collected at the southern sentinel herd site in January-February 1984 and processed for virus isolation in BHK2l and AA tissue cultures and by intrathoracic inoculation of Ae. aegypti mosquitoes. Totals of 14 338 midges of four species in 156 pools, and 9030 mosquitoes of 27 species in 232 pools, were processed and yielded 59 isolations. Of the 35 viruses isolated from Culicoides brevitarsis, 17 were members of the Palyam subgroup. Bovine ephemeral fever (BEF) virus was isolated once from Anopheles bancroftii, once from C. brevitarsis and 17 times from cattle. Akabane virus was isolated for the first time from C. wadai, as well as a further 10 times from C. brevitarsis and 20 times from cattle. Other viruses isolated from cattle included bluetongue serotype 1, and serotypes 5, 6 and 7 of epizootic hemorrhagic disease of deer (EHD). A new BEF group virus, tentatively called Oak Vale, was isolated nine times from Culex edwardsi mosquitoes. Of the orbiviruses, those in the Palyam subgroup were isolated almost exclusively in BHK2l tissue cultures but those in the bluetongue and EHD subgroups were isolated almost exclusively in AA cell cultures or after passage through Ae. aegypti. Of 22 rhabdovirus isolations from blood and insects (BEF, Kimberley and Tibrogargan), 16 were made only in AA cell cultures or after passage through Ae. aegypti.

scholarly journals Isolation of Porcine Circovirus-like Viruses from Pigs with a Wasting Disease in the USA and Europe

1998 ◽  
Vol 10 (1) ◽  
pp. 3-10 ◽  
Author(s):  
G. M. Allan ◽  
F. McNeilly ◽  
S. Kennedy ◽  
B. Daft ◽  
J. A. Ellis ◽  
...  
Keyword(s):  
Cell Culture ◽  
Lymph Node ◽  
Nucleic Acid ◽  
Cell Cultures ◽  
Virus Isolation ◽  
Chicken Anemia Virus ◽  
Porcine Circovirus ◽  
Tissue Homogenate ◽  
Mesenteric Lymph ◽  
Viral Particles

Samples of lung, liver, kidney, pancreas, spleen, and lymph node from pigs with postweaning multisystemic wasting syndrome from California (USA) and samples of mesenteric lymph nodes from similarly diseased pigs from Brittany (France) were examined by light microscopy, in situ hybridization (ISH), and/or virus isolation. Whole genomic probes for porcine circovirus (PCV) and chicken anemia virus (CAV) were used for ISH. Tissue homogenate supernatants were inoculated onto PK/15 cells for virus isolation, and the presence of viral antigen and viral particles was verified by indirect immunofluorescence, ISH, and electron microscopy. Histologic examination of lung from pigs from California revealed interstitial pneumonia, alveolar epithelial hyperplasia, and basophilic nuclear and cytoplasmic inclusions in mononuclear cell infiltrates and various pulmonary epithelial cells. Granulomatous lymphadenitis with syncytial cells typified the lesions seen in the pigs from France. PCV-like nucleic acid was detected by ISH in lung, pancreas, lymph node, kidney, and liver in pigs from California. Positive signal was also obtained in lymph node sections from pigs from France. Probes for CAV were consistently negative. PK/15 cell cultures inoculated with lung preparations from diseased California pigs and mesenteric lymph node preparations from pigs from France had positive fluorescence by indirect staining for PCV using pooled polyclonal pig sera and hyperimmune rabbit serum and had variable staining with a panel of 7 monoclonal antibodies specific for cell culture contaminant PCV. PCV-like nucleic acid was also detected by ISH in cell cultures. Cytopathic effect was not observed Electron microscopic examination of inoculated cell cultures revealed 17-nm viral particles morphologically consistent with PCV No other virus particles were observed. Although genomic analysis for the definitive identification of these viral isolates remains to be done, the evidence provided strongly suggests that these tissue isolates are closely related to, although antigenically distinct from, the original PCV cell culture contaminant.

scholarly journals Capripoxviruses: Exploring the genetic relatedness between field and vaccine strains from Egypt

2019 ◽  
Vol 12 (12) ◽  
pp. 1924-1930
Author(s):  
Sherin Reda Rouby ◽  
Abdel-Hamid Bazid ◽  
Momtaz Wasfy ◽  
Magdy El-Sayed
Keyword(s):  
Cell Cultures ◽  
Vaccine Strain ◽  
Virus Isolation ◽  
Genetic Relatedness ◽  
Phylogenetic Analyses ◽  
Heart Cell ◽  
Fetal Kidney ◽  
Field Isolates ◽  
Gpcr Gene ◽  
Ovine Fetal

Background and Aim: Lumpy skin disease (LSD) and sheep pox are economically important Capripoxvirus-induced diseases of cattle and sheep, respectively. Despite the extensive vaccination program adopted by Egyptian veterinary authorities, LSD and sheep pox are still prevalent and spread throughout the whole country. The current study was designed for molecular characterization and phylogenetic analysis of LSD virus (LSDV) and Sheep pox virus (SPPV) recovered from field cases in Egypt along with vaccinal strains to assess their genetic relatedness. Materials and Methods: Skin biopsies were collected from naturally infected cases of LSD in Ismailia (n=3 farms) and Beni-Suef (n=2 farms) Governorates and sheep pox in Beni-Suef (n=1 flock). Virus isolation was carried out on primary ovine fetal kidney and heart cell cultures. DNA was extracted from infected materials (skin lesions, infected cell cultures) as well as LSDV Neethling vaccine strain and Romanian SPPV vaccine strain. Polymerase chain reaction was performed using oligonucleotide primers targeting the entire open reading frame of G protein-coupled receptors (GPCR) gene and gene sequences were analyzed. Results: Virus isolation on primary ovine fetal kidney and heart cell culture revealed a cytopathic effect at the third passage characterized by rounding of infected cells and margination of nuclear chromatin. Comparative sequence analysis of GPCR gene revealed that Egyptian LSDV isolated from Ismailia and Beni-Suef shared 99:100% nucleotide and amino acid (AA) identities with each other. In comparison to the vaccinal strains, Egyptian LSDV isolates shared 98:99 nucleotide and AA identities with LSDV Neethling vaccine strain and 93:94% with SPPV Romanian vaccine strain. No differences at the nucleotide or AAs were observed between the SPPV vaccine and virulent strains (100% identity). Phylogenetic analyses revealed that LSDV Neethling vaccine strain is more related to field Egyptian LSDV and clustered within the LSDV group while Romanian SPPV vaccine strain clustered in a separate clade with SPPV field isolates. Conclusion: Comparative sequencing and phylogenetic analyses of the GPCR gene reveal a minimal genetic variation between LSDV field isolates from different locations and a close relationship between virulent field strains and homologous vaccines.

scholarly journals Cell Cultures for Virology: Usability, Advantages, and Prospects

2020 ◽  
Vol 21 (21) ◽  
pp. 7978
Author(s):  
Alexander A. Dolskiy ◽  
Irina V. Grishchenko ◽  
Dmitry V. Yudkin
Keyword(s):  
Cell Lines ◽  
Cell Cultures ◽  
Virus Isolation ◽  
Virus Detection ◽  
Clinical Samples ◽  
Laboratory Setting ◽  
Reporter Cell ◽  
Isolation And Identification ◽  
Reporter Systems ◽  
Reporter Proteins

Virus detection in natural and clinical samples is a complicated problem in research and diagnostics. There are different approaches for virus isolation and identification, including PCR, CRISPR/Cas technology, NGS, immunoassays, and cell-based assays. Following the development of genetic engineering methods, approaches that utilize cell cultures have become useful and informative. Molecular biology methods allow increases in the sensitivity and specificity of cell cultures for certain viruses and can be used to generate reporter cell lines. These cell lines express specific reporter proteins (e.g., GFP, luciferase, and CAT) in response to virus infection that can be detected in a laboratory setting. The development of genome editing and synthetic biology methods has given rise to new perspectives regarding the design of virus reporter systems in cell cultures. This review is aimed at describing both virology methods in general and examples of the development of cell-based methods that exist today.

scholarly journals SARS-CoV-2 infectious virus, viral RNA in nasopharyngeal swabs, and serostatus of symptomatic COVID-19 outpatients in the United States

2021 ◽  
Author(s):  
Katie R. Mollan ◽  
Joseph J. Eron ◽  
Taylor J. Krajewski ◽  
Wendy Painter ◽  
Elizabeth R. Duke ◽  
...  
Keyword(s):  
United States ◽  
Symptom Onset ◽  
Infectious Virus ◽  
Virus Isolation ◽  
Clinical Symptoms ◽  
Comprehensive Evaluation ◽  
Upper Airway ◽  
The United States ◽  
Viral Rna ◽  
Treatment And Prevention

Background: SARS-CoV-2 infectious virus isolation in the upper airway of COVID-19 patients is associated with higher levels of viral RNA. However, comprehensive evaluation of the relationships between host and disease factors and infectious, replication competent virus is needed. Methods: Symptomatic COVID-19 outpatients were enrolled from the United States. Clinical symptoms were recorded via patient diary. Nasopharyngeal swabs were collected to quantitate SARS-CoV-2 RNA by reverse transcriptase polymerase chain reaction and for infectious virus isolation in Vero E6-cells. SARS-CoV-2 antibodies were measured in serum using a validated ELISA assay. Findings: Among 204 participants within one week of reported symptom onset (median=5, IQR 4-5 days), median age was 40 (min-max: 18-82 years), median nasopharyngeal viral RNA was 6.5 (IQR 4.7-7.6 log10 copies/mL), and 26% had detectable SARS-CoV-2 antibodies at baseline. Infectious virus was recovered in 7% of participants with antibodies compared to 58% of participants without antibodies (probability ratio (PR)=0.12, 95% CI: 0.04, 0.36; p=0.00016). Infectious virus isolation was also associated with higher levels of viral RNA (mean RNA difference +2.6 log10, 95% CI: 2.2, 3.0; p<0.0001) and fewer days since symptom onset (PR=0.79, 95% CI: 0.71, 0.88 per day; p<0.0001). Interpretation: The presence of SARS-CoV-2 antibodies is strongly associated with clearance of infectious virus isolation. Seropositivity and viral RNA are likely more reliable markers of infectious virus suppression than subjective measure of COVID-19 symptoms. Virus-targeted treatment and prevention strategies should be administered as early as possible and ideally before seroconversion. Funding: Ridgeback Biotherapeutics, LP and NIH ClinicalTrials.gov Identifier: NCT04405570

Vancomycin and amikacin in cell cultures for virus isolation

Pathology ◽  
1996 ◽  
Vol 28 (4) ◽  
pp. 366-369 ◽  
Author(s):  
Janice Y. Lo ◽  
Wilina W. Lim ◽  
Betty K. Tam ◽  
Mary Y. Lai
Keyword(s):  
Cell Cultures ◽  
Virus Isolation

scholarly journals Transmission Risk of SARS-CoV-2 Before and After Symptom Onset of the Infector

2021 ◽  
Author(s):  
Mizue Kitahara ◽  
Takuya Yamagishi ◽  
Shota Tsukada ◽  
Yasuhiro Sudo ◽  
Tetsuya Yoshida ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Transmission Risk ◽  
Before And After

scholarly journals SARS-CoV-2 infectivity correlates with high viral loads and detection of viral antigen and is terminated by seroconversion

2021 ◽  
Author(s):  
Felix Buder ◽  
Markus Bauswein ◽  
Clara L Magnus ◽  
Franz Audebert ◽  
Henriette Lang ◽  
...  
Keyword(s):  
Viral Load ◽  
Symptom Onset ◽  
Viral Antigen ◽  
Virus Isolation ◽  
Point Of Care ◽  
High Viral Load ◽  
University Hospital ◽  
Public Health Perspective ◽  
Viral Loads ◽  
Restrictive Measures

Abstract Background From a public health perspective, effective containment strategies for SARS-CoV-2 should be balanced with individual liberties. Methods We collected 79 respiratory samples from 59 patients monitored in an outpatient center or in the intensive care unit of the University Hospital Regensburg. We analyzed viral load by quantitative real-time PCR, viral antigen by point-of-care assay, time since onset of symptoms and presence of SARS-CoV-2 IgG antibodies in the context of virus isolation from respiratory specimen. Results The odds ratio for virus isolation increased 1.9-fold for each log10 level of SARS-CoV-2 RNA and 7.4-fold with detection of viral antigen, while it decreased 6.3-fold beyond 10 days of symptoms and 20.0-fold with presence of SARS-CoV-2 antibodies. The latter was confirmed for B.1.1.7 strains. The positive predictive value for virus isolation was 60.0% for viral loads above 10 7 RNA copies/mL and 50.0% for the presence of viral antigen. Symptom onset before 10 days and seroconversion predicted lack of infectivity with 93.8% and 96.0%. Conclusions Our data support quarantining patients with high viral load and detection of viral antigen, and lifting restrictive measures with increasing time to symptom onset and seroconversion. Delay of antibody formation may prolong infectivity.

A survey of enteric viruses in domestic sewage

1983 ◽  
Vol 29 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Pierre Payment ◽  
Reda Ayache ◽  
Michel Trudel
Keyword(s):  
Electron Microscopy ◽  
Cell Cultures ◽  
Virus Isolation ◽  
Enteric Viruses ◽  
Domestic Sewage ◽  
Immune Electron Microscopy

In this second study (1979–1981) of the viral content of sewage we have demonstrated the presence of poliovirus types 1, 2, and 3 in Laval and Montreal. Several strains of poliovirus types 2 and 3 were nonvaccinal. This is in contrast with our first study (1977–1978) in which only type 1 poliovirus isolates were nonvaccinal. Coxsackievirus types B-3, B-4, and B-5 and echovirus types 1, 7, and 11 were also isolated from sewage. Interestingly, these isolations coincided with reports of isolation of the same strains during the same period by diagnostic laboratories. Our method based on Vero and BSC-1 cell cultures for virus isolation and immune electron microscopy for identification permitted the recovery not only of several strains of enteroviruses but also of some adenoviruses and reoviruses.

Sign in / Sign up

Export Citation Format

Share Document