The etiologic agent of the outbreak of pneumonia in Wuhan China was identified as severe acute respiratory syndrome associated coronavirus 2 (SARS-CoV-2) in January, 2020. The first US patient was diagnosed by the State of Washington and the US Centers for Disease Control and Prevention on January 20, 2020. We isolated virus from nasopharyngeal and oropharyngeal specimens, and characterized the viral sequence, replication properties, and cell culture tropism.We found that the virus replicates to high titer in Vero-CCL81 cells and Vero E6 cells in the absence of trypsin. We also deposited the virus into two virus repositories, making it broadly available to the public health and research communities. We hope that open access to this important reagent will expedite development of medical countermeasures. BACKGROUNDA novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified as the source of a pneumonia outbreak in Wuhan China in late 2019 (1, 2).The virus was found to be a member of the beta coronavirus family, in the same species as SARS-CoV and SARS-related bat CoVs (3, 4). Patterns of spread indicate that SARS-CoV-2 can be transmitted person-to-person, and may be more transmissible than SARS-CoV (5-7). The spike protein of coronaviruses mediates virus binding and cell entry. Initial characterization of SARS-CoV-2 spike indicate that it binds the same receptor as SARS-CoV, ACE2, which is expressed in both upper and lower human respiratory tracts (8). The unprecedented rapidity of spread of this outbreak represents a critical need for reference reagents. The public health community requires viral lysates to serve as diagnostic references, and the research community needs virus isolates to test anti-viral compounds, develop new vaccines, and perform basic : bioRxiv preprint and described its genomic sequence and replication characteristics. We have made the virus isolate available to the public health community by depositing into two virus reagent repositories. RESULTS and DISCUSSIONA patient was identified with confirmed COVID-19 in Washington State on January 22, 2020 with cycle threshold (C t s) of 18-20 (nasopharyngeal(NP)) and 21-22 (oropharyngeal (OP))(1). The positive clinical specimens were aliquoted and refrozen inoculation into cell culture on January 22, 2020. We first observed cytopathic effect (CPE) 2 days post inoculation and harvested viral lysate on day 3 post inoculation ( Figure 1B and 1C). Fifty µl of P1 viral lysates were used for nucleic acid extraction to confirm the presence of SARS-CoV-2 using the CDC molecular diagnostic assay (1). The C t s of three different nucleic acid extractions ranged from 16.0-17.1 for N1, 15.9-17.1 for N2 and 16.2-17.3 for N3, confirming isolation of SARS-CoV-2.A C t of less than 40 is considered positive. The extracts were also tested for the presence of 33 additional different respiratory pathogens with the fast track 33 assay. No other pathogens were detected. Identity was additionally supported by thin section electron ...
Local transmission of chikungunya virus (CHIKV) was first detected in the Americas in December 2013, after which it spread rapidly throughout the Caribbean islands and American mainland, causing a major chikungunya fever epidemic. Previous phylogenetic analysis of CHIKV from a limited number of countries in the Americas suggests that an Asian genotype strain was responsible, except in Brazil where both Asian and East/Central/South African (ECSA) lineage strains were detected. In this study, we sequenced thirty-three complete CHIKV genomes from viruses isolated in 2014 from fourteen Caribbean islands, the Bahamas and two mainland countries in the Americas. Phylogenetic analyses confirmed that they all belonged to the Asian genotype and clustered together with other Caribbean and mainland sequences isolated during the American outbreak, forming an ‘Asian/American’ lineage defined by two amino acid substitutions, E2 V368A and 6K L20M, and divided into two well-supported clades. This lineage is estimated to be evolving at a mean rate of 5 × 10−4 substitutions per site per year (95% higher probability density, 2.9–7.9 × 10−4) and to have arisen from an ancestor introduced to the Caribbean (most likely from Oceania) in about March 2013, 9 months prior to the first report of CHIKV in the Americas. Estimation of evolutionary rates for individual gene regions and selection analyses indicate that (in contrast to the Indian Ocean Lineage that emerged from the ECSA genotype followed by adaptive evolution and with a significantly higher substitution rate) the evolutionary dynamics of the Asian/American lineage are very similar to the rest of the Asian genotype and natural selection does not appear to have played a major role in its emergence. However, several codon sites with evidence of positive selection were identified within the non-structural regions of Asian genotype sequences outside of the Asian/American lineage.
Bacillus anthracis produces three regulators, AtxA, AcpA and AcpB, which control virulence gene transcription and belong to an emerging class of regulators termed 'PCVRs' (Phosphoenolpyruvate-dependent phosphotransferase regulation Domain-Containing Virulence Regulators). AtxA, named for its control of toxin gene expression, is the master virulence regulator and archetype PCVR. AcpA and AcpB are less well studied. Reports of PCVR activity suggest overlapping function. AcpA and AcpB independently positively control transcription of the capsule biosynthetic operon capBCADE, and culture conditions that enhance AtxA level or activity result in capBCADE transcription in strains lacking acpA and acpB. We used RNA-Seq to assess the regulons of the paralogous regulators in strains constructed to express individual PCVRs at native levels. Plasmid and chromosome-borne genes were PCVR controlled, with AtxA, AcpA and AcpB having a ≥ 4-fold effect on transcript levels of 145, 130 and 49 genes respectively. Several genes were coregulated by two or three PCVRs. We determined that AcpA and AcpB form homomultimers, as shown previously for AtxA, and we detected AtxA-AcpA heteromultimers. In co-expression experiments, AcpA activity was reduced by increased levels of AtxA. Our data show that the PCVRs have specific and overlapping activity and that PCVR stoichiometry and potential heteromultimerization can influence target gene expression.
Abstract. The genus Nairovirus of arthropod-borne bunyaviruses includes the important emerging human pathogen,
Substantial variation exists in the management of non-muscle-invasive bladder cancer (NMIBC) despite strong clinical practice guidelines. We hypothesized that socioeconomic disparities may be associated with variation in the management of NMIBC, and utilized a nationwide oncology dataset to examine this question.METHODS: We identified adult patients aged 18-89 years with Ta, T1, or Tis urothelial carcinoma of the bladder diagnosed from 2006-2016 in the NCDB. We then examined the associations of patient and socioeconomic characteristics with the guidelines-based management of high-risk NMIBC using multivariable logistic regression.RESULTS: A total of 163,949 patients were included in the study cohort, including 64% with Ta, 32% with T1, and 4% with Tis disease. Among those diagnosed with bladder cancer, male (OR 1.24, 95%CI 1.21-1.27), uninsured (OR 1.10, 95%CI 1.01-1.19 vs private), and non-White (OR 1.34, 95%CI 1.28-1.41 for Black; OR 1.10; 95%CI 1.03-1.18 for Other versus White) patients were more likely to be diagnosed with high-risk (HGT1 or Tis) disease, as well as patients from lower education level areas. Among those with high-risk NMIBC, patients who were older, non-White, Hispanic, uninsured or insured with Medicaid were less likely to receive intravesical BCG, while those residing in rural and higher education level areas were more likely to receive BCG (Table 1). When examining non-guidelines based use of radiotherapy for HGT1 disease, older age (OR 1.06; 95% CI 1.04-1.07) and VA/Military insurance (OR 2.73; 95%CI 0.93-6.36 vs private) were associated with radiotherapy use.CONCLUSIONS: There are strong disparities in the prevalence and management of high-risk NMIBC. These observations represent an important target for future efforts to identify interventions to reduce such healthcare disparities.
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