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Bellaire, B. H.

Publications and source records attributed to Bellaire, B. H..

3 recordsLinked to original sources

Validation of TRIzol-Based Inactivation Protocol with Failure Scenario Testing for Bacterial Select Agent Surrogates

Validated inactivation procedures are required for the safe handling and downstream analysis of highly pathogenic organisms, particularly those categorized as biological select agents and toxins (BSATs). TRIzol-based extraction methods are widely used for nucleic acid and protein isolation, yet their reliability for bacterial inactivation has not been comprehensively evaluated. In this study, we assessed TRIzol-based extraction methods for sample quality and inactivation reliability across a series of mock failure scenarios using five attenuated bacterial isolates: Francisella tularensis holarctica LVS, Bacillus anthracis Sterne, Yersinia enterocolitica, Mycobacterium marinum, and Burkholderia cepacia. Dilution of TRIzol to induce incomplete cell lysis for the initial extraction step, including 0% TRIzol, consistently inactivated all surrogate organisms, suggesting that downstream precipitation and sample washing reagents, including isopropanol and 70% ethanol, were sufficient to inactivate organisms in the absence of TRIzol. Several protocol failure scenarios were then evaluated to simulate human error by omitting extraction, precipitation, and washing steps individually or in combination for the most resistant organism, B. anthracis Sterne strain. Failure-scenario testing demonstrated that reliable inactivation of B. anthracis required strict adherence to the complete protocol due to the spore-forming ability of B. anthracis. Collectively, this work provides a reference with experimental evidence supporting the use of TRIzol-based extraction as a bacterial inactivation strategy for a wide range of bacterial pathogens.

microbiology↗

How Do Deer Respiratory Epithelial Cells Weather The Initial Storm of SARS-CoV-2?

The potential infectivity of SARS-CoV-2 in animals raises a public health and economic concern, particularly the high susceptibility of white-tailed deer (WTD) to SARS-CoV-2. The disparity in the disease outcome between humans and WTD is very intriguing, as the latter are often asymptomatic, subclinical carriers of SARS-CoV-2. To date, no studies have evaluated the innate immune factors responsible for the contrasting SARS-CoV-2-associated disease outcomes in these mammalian species. A comparative transcriptomic analysis in primary respiratory epithelial cells of human (HRECs) and WTD (Deer-RECs) infected with SARS-CoV-2 was assessed throughout 48 hours post inoculation (hpi). Both HRECs and Deer-RECs were susceptible to SARS-COV-2, with significantly (P < 0.001) lower virus replication in Deer-RECs. The number of differentially expressed genes (DEG) gradually increased in Deer-RECs but decreased in HRECs throughout the infection. The ingenuity pathway analysis of DEGs further identified that genes commonly altered during SARS-CoV-2 infection mainly belong to cytokine and chemokine response pathways mediated via IL-17 and NF-{kappa}B signaling pathways. Inhibition of the NF-{kappa}B signaling in the Deer-RECs pathway was predicted as early as 6 hpi. The findings from this study could explain the lack of clinical signs reported in WTD in response to SARS-CoV-2 infection as opposed to the severe clinical outcomes reported in humans. HIGHLIGHTSO_LIWhite-tailed deer primary respiratory epithelial cells are susceptible to SARS- CoV-2 without causing hyper cytokine gene expression. C_LIO_LIDownregulation of IL-17 and NF-{kappa}B signaling pathways after SARS-CoV-2 infection could be key to the regulated cytokine response in deer cells. C_LIO_LIDeer innate immune system could play a critical role in early antiviral and tissue repair response following SARS-CoV-2 infection. C_LI

genomics↗

In vitro comparison of SARS-CoV-2 variants

The Coronaviridae family hosts various coronaviruses responsible for many diseases, from the common cold, severe lung infections to pneumonia. SARS-CoV-2 was discovered to be the etiologic agent of the Coronavirus pandemic, and numerous basic and applied laboratory techniques were utilized in virus culture and examination of the disease. Understanding the replication kinetics and characterizing the virus effect on different cell lines is crucial for developing in vitro studies. With the emergence of multiple variants of SARS-CoV-2, a comparison between their infectivity and replication in common cell lines will give us a clear understanding of the characteristic differences in pathogenicity. In this study, we compared the cytopathic effect (CPE) and replication of Wild Type (WT), Omicron (B.1.1.529), and Delta (B.1.617.2) variants on 5 different cell lines; VeroE6, VeroE6 expressing high endogenous ACE2, VeroE6 highly expressing human ACE2 (VeroE6/ACE2) and TMPRSS2 (VeroE6/hACE2/ TMPRSS2), Calu3 cells highly expressing human ACE2 and A549 cells. All 3 VeroE6 cell lines were susceptible to WT strain, where CPE and replication were observed. Along with being susceptible to Wild type, VeroE6/hACE2/TMPRSS2 cells were susceptible to both omicron and delta strains, whereas VeroE6/ACE2 cells were only susceptible to omicron in a dose-dependent manner. No CPE was observed in both human lung cell lines, A549 and Calu3/hACE2, but Wild type and omicron replication was observed. As SAR-CoV-2 continues to evolve, this data will benefit researchers in experimental planning, viral pathogenicity analysis, and providing a baseline for testing future variants.

microbiology↗