6 results on '"Denver Greenawalt"'
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2. A Novel Real-Time PCR Assay for the Rapid Detection of Virulent Streptococcus equi Subspecies zooepidemicus—An Emerging Pathogen of Swine
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Suresh V. Kuchipudi, Meera Surendran Nair, Michele Yon, Abhinay Gontu, Ruth H. Nissly, Rhiannon Barry, Denver Greenawalt, Traci Pierre, Lingling Li, Nagaraja Thirumalapura, Deepanker Tewari, and Bhushan Jayarao
- Subjects
SzM gene ,real time PCR ,pig mortality ,virulent strains ,Streptococcus equi subspecies zooepidemicus ,Veterinary medicine ,SF600-1100 - Abstract
Streptococcus equi subspecies zooepidemicus, a zoonotic bacterial pathogen caused a series of outbreaks with high mortality affecting swine herds in multiple locations of the USA and Canada in 2019. Further genetic analysis revealed that this agent clustered with ATCC 35246, a S. zooepidemicus strain associated with high mortality outbreaks in swine herds of China originally reported in 1977. Rapid and accurate diagnosis is absolutely critical for controlling and limiting further spread of this emerging disease of swine. Currently available diagnostic methods including bacteriological examination and PCR assays do not distinguish between the virulent strains and avirulent commensal strains of S. zooepidemicus, which is critical given that this pathogen is a normal inhabitant of the swine respiratory tract. Based on comparative analyses of whole genome sequences of the virulent isolates and avirulent sequences, we identified a region in the SzM gene that is highly conserved and restricted to virulent S. zooepidemicus strains. We developed and validated a novel probe-based real-time PCR targeting the conserved region of SzM. The assay was highly sensitive and specific to the virulent swine isolates of Streptococcus equi subspecies zooepidemicus. No cross reactivity was observed with avirulent S. zooepidemicus isolates as well as other streptococcal species and a panel of porcine respiratory bacterial and viral pathogens. The PCR efficiency of the assay was 96.64 % and was able to detect as little as 20 fg of the bacterial DNA. We then validated the diagnostic sensitivity and specificity of the new PCR assay using a panel of clinical samples (n = 57) and found that the assay has 100% sensitivity and specificity as compared to bacteriological culture method. In summary, the PCR assay will be an extremely valuable tool for the rapid accurate detection of virulent swine S. zooepidemicus isolates and directly from clinical samples.
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- 2021
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3. Limited window for donation of convalescent plasma with high live-virus neutralizing antibody titers for COVID-19 immunotherapy
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Suresh V. Kuchipudi, Denver Greenawalt, David W. Bernard, Eric Salazar, James M. Musser, Picheng Zhao, Allen M. Minns, Paul A. Christensen, Catherine M. Herzog, Xin Yi, Abhinay Gontu, Ruth H. Nissly, Meera Surendran Nair, Jimmy Gollihar, Vivek Kapur, Scott E. Lindner, Ian M. Bird, Indira Poojary, Robab Katani, Brian Castillo, Todd N. Eagar, Matthew J. Ferrari, Christopher Leveque, Sreenidhi Srinivasan, Randall M. Rossi, Randall J. Olsen, and Jian Chen
- Subjects
Adult ,Male ,0301 basic medicine ,Time Factors ,QH301-705.5 ,viruses ,medicine.medical_treatment ,Medicine (miscellaneous) ,Blood Donors ,Antibodies, Viral ,Severity of Illness Index ,Article ,General Biochemistry, Genetics and Molecular Biology ,Neutralization ,Immunoglobulin G ,Young Adult ,03 medical and health sciences ,Applied immunology ,0302 clinical medicine ,medicine ,Humans ,Longitudinal Studies ,030212 general & internal medicine ,Biology (General) ,Neutralizing antibody ,Aged ,biology ,SARS-CoV-2 ,business.industry ,Age Factors ,Antibody titer ,COVID-19 ,Immunotherapy ,Middle Aged ,Antibodies, Neutralizing ,Titer ,030104 developmental biology ,Immunoglobulin M ,Immunology ,biology.protein ,Female ,Antibody ,General Agricultural and Biological Sciences ,business - Abstract
Millions of individuals who have recovered from SARS-CoV-2 infection may be eligible to participate in convalescent plasma donor programs, yet the optimal window for donating high neutralizing titer convalescent plasma for COVID-19 immunotherapy remains unknown. Here we studied the response trajectories of antibodies directed to the SARS-CoV-2 surface spike glycoprotein and in vitro SARS-CoV-2 live virus neutralizing titers (VN) in 175 convalescent donors longitudinally sampled for up to 142 days post onset of symptoms (DPO). We observed robust IgM, IgG, and viral neutralization responses to SARS-CoV-2 that persist, in the aggregate, for at least 100 DPO. However, there is a notable decline in VN titers ≥160 for convalescent plasma therapy, starting 60 DPO. The results also show that individuals 30 years of age or younger have significantly lower VN, IgG and IgM antibody titers than those in the older age groups; and individuals with greater disease severity also have significantly higher IgM and IgG antibody titers. Taken together, these findings define the optimal window for donating convalescent plasma useful for immunotherapy of COVID-19 patients and reveal important predictors of an ideal plasma donor., Gontu et al. conducted a longitudinal study in COVID patients in which they assessed the response trajectories of antibodies directed to the SARS-CoV-2 surface spike glycoprotein and in vitro SARS-CoV-2 live virus neutralizing titers. Their measurements demonstrate the presence of an optimum window for convalescent plasma donation as well as predictions of the most suitable donor type.
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- 2021
4. Convalescent plasma anti–SARS-CoV-2 spike protein ectodomain and receptor-binding domain IgG correlate with virus neutralization
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Jimmy Gollihar, David Bernard, Vivek Kapur, Abhinay Gontu, Gregory C. Ippolito, Sreenidhi Srinivasan, Randall M. Rossi, Indira Poojary, Laura I. Prugar, Randall J. Olsen, Eric Salazar, Peter J. Hudson, Jose A. Cardona, James M. Musser, Ian M. Bird, Zhicheng Jin, Nicole M. Josleyn, Todd N. Eagar, Denver Greenawalt, Picheng Zhao, Kathleen E. Huie, John M. Dye, Dalton M Towers, Suresh V. Kuchipudi, Jian Chen, Andrew S. Herbert, Christopher Leveque, Xin Yi, Isabella M. Cattadori, Ruth H. Nissly, Brian Castillo, Jason J. Lavinder, S. Wesley Long, and Paul A. Christensen
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Adult ,Male ,0301 basic medicine ,Adolescent ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Antibodies, Viral ,Asymptomatic ,Article ,Immunoglobulin G ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,COVID-19 Serotherapy ,Aged ,biology ,SARS-CoV-2 ,business.industry ,Immunization, Passive ,COVID-19 ,General Medicine ,Middle Aged ,Acquired immune system ,Antibodies, Neutralizing ,In vitro ,Titer ,030104 developmental biology ,Ectodomain ,030220 oncology & carcinogenesis ,Immunology ,biology.protein ,Female ,medicine.symptom ,Antibody ,business ,Research Article - Abstract
Newly emerged pathogens such as SARS-CoV-2 highlight the urgent need for assays that detect levels of neutralizing antibodies that may be protective. We studied the relationship between anti-spike ectodomain (ECD) and anti-receptor binding domain (RBD) IgG titers, and SARS-CoV-2 virus neutralization (VN) titers generated by two different in vitro assays using convalescent plasma samples obtained from 68 COVID-19 patients, including 13 who donated plasma multiple times. Only 23% (16/68) of donors had been hospitalized. We also studied 16 samples from subjects found to have anti-spike protein IgG during surveillance screening of asymptomatic individuals. We report a strong positive correlation between both plasma anti-RBD and anti-ECD IgG titers, and in vitro VN titer. Anti-RBD plasma IgG correlated slightly better than anti-ECD IgG titer with VN titer. The probability of a VN titer ≥160 was 80% or greater with anti-RBD or anti-ECD titers of ≥1:1350. Thirty-seven percent (25/68) of convalescent plasma donors lacked VN titers ≥160, the FDA-recommended level for convalescent plasma used for COVID-19 treatment. Dyspnea, hospitalization, and disease severity were significantly associated with higher VN titer. Frequent donation of convalescent plasma did not significantly decrease either VN or IgG titers. Analysis of 2,814 asymptomatic adults found 27 individuals with anti-RBD or anti-ECD IgG titers of ≥1:1350, and evidence of VN ≥1:160. Taken together, we conclude that anti-RBD or anti-ECD IgG titers can serve as a surrogate for VN titers to identify suitable plasma donors. Plasma anti-RBD or anti-ECD titer of ≥1:1350 may provide critical information about protection against COVID-19 disease.
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- 2020
5. Limited window for donation of convalescent plasma with high live-virus neutralizing antibodies for COVID-19 immunotherapy
- Author
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Xin Yi, Ruth H. Nissly, Jian Chen, Catherine M. Herzog, Matthew J. Ferrari, Allen M. Minns, Christopher Leveque, Suresh V. Kuchipudi, Scott E. Lindner, Paul A. Christensen, Todd N. Eagar, Denver Greenawalt, Eric Salazar, David W. Bernard, Vivek Kapur, Robab Katani, James M. Musser, Indira Poojary, Abhinay Gontu, Meera Surendran Nair, Ian M. Bird, Jimmy Gollihar, Brian Castillo, Picheng Zhao, Sreenidhi Srinivasan, Randall M. Rossi, and Randall J. Olsen
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chemistry.chemical_classification ,biology ,business.industry ,medicine.medical_treatment ,Immunotherapy ,Neutralization ,In vitro ,Titer ,chemistry ,Ectodomain ,Immunology ,medicine ,biology.protein ,Knowledge deficit ,Antibody ,Glycoprotein ,business - Abstract
The optimal timeframe for donating convalescent plasma to be used for COVID-19 immunotherapy is unknown. To address this important knowledge deficit, we determinedin vitrolive-virus neutralizing capacity and persistence of IgM and IgG antibody responses against the receptor-binding domain and S1 ectodomain of the SARS-CoV-2 spike glycoprotein in 540 convalescent plasma samples obtained from 175 COVID-19 plasma donors for up to 142 days post-symptom onset. Robust IgM, IgG, and viral neutralization responses to SARS-CoV-2 persist, in the aggregate, for at least 100 days post-symptom onset. However, a notable acceleration in decline in virus neutralization titers ≥160, a value suitable for convalescent plasma therapy, was observed starting 60 days after first symptom onset. Together, these findings better define the optimal window for donating convalescent plasma useful for immunotherapy of COVID-19 patients and reveal important predictors of an ideal plasma donor, including age and COVID-19 disease severity score.One Sentence SummaryEvaluation of SARS-CoV-2 anti-spike protein IgM, IgG, and live-virus neutralizing titer profiles reveals that the optimal window for donating convalescent plasma for use in immunotherapy is within the first 60 days of symptom onset.
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- 2020
6. Relationship between Anti-Spike Protein Antibody Titers and SARS-CoV-2In VitroVirus Neutralization in Convalescent Plasma
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Ruth H. Nissly, Laura I. Prugar, Peter J. Hudson, Eric Salazar, Nicole Joselyn, S. Wesley Long, Abinhay Gontu, Picheng Zhao, José Rubén Parra Cardona, Vivek Kapur, Suresh V. Kuchipudi, Zhicheng Jin, Denver Greenawalt, Sreenidhi Srinivasan, David W. Bernard, Randall M. Rossi, Randall J. Olsen, Jason J. Lavinder, Indira Poojary, Ian M. Bird, Andrew S. Herbert, Xin Yi, Isabella M. Cattadori, Gregory C. Ippolito, John M. Dye, Dalton M Towers, Brian Castillo, James M. Musser, Jian Chen, Paul A. Christensen, Jimmy Gollihar, Kathleen E. Huie, Todd N. Eagar, and Christopher Leveque
- Subjects
Convalescent plasma ,biology ,business.industry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Antibody titer ,Asymptomatic ,In vitro ,Titer ,Blood plasma ,Immunology ,biology.protein ,Medicine ,Antibody ,medicine.symptom ,business - Abstract
Newly emerged pathogens such as SARS-CoV-2 highlight the urgent need for assays that detect levels of neutralizing antibodies that may be protective. We studied the relationship between anti-spike ectodomain (ECD) and anti-receptor binding domain (RBD) IgG titers, and SARS-CoV-2 virus neutralization (VN) titers generated by two differentin vitroassays using convalescent plasma samples obtained from 68 COVID-19 patients, including 13 who donated plasma multiple times. Only 23% (16/68) of donors had been hospitalized. We also studied 16 samples from subjects found to have anti-spike protein IgG during surveillance screening of asymptomatic individuals. We report a strong positive correlation between both plasma anti-RBD and anti-ECD IgG titers, andin vitroVN titer. Anti-RBD plasma IgG correlated slightly better than anti-ECD IgG titer with VN titer. The probability of a VN titer ≥160 was 80% or greater with anti-RBD or anti-ECD titers of ≥1:1350. Thirty-seven percent (25/68) of convalescent plasma donors lacked VN titers ≥160, the FDA-recommended level for convalescent plasma used for COVID-19 treatment. Dyspnea, hospitalization, and disease severity were significantly associated with higher VN titer. Frequent donation of convalescent plasma did not significantly decrease either VN or IgG titers. Analysis of 2,814 asymptomatic adults found 27 individuals with anti-RBD or anti-ECD IgG titers of ≥1:1350, and evidence of VN ≥1:160. Taken together, we conclude that anti-RBD or anti-ECD IgG titers can serve as a surrogate for VN titers to identify suitable plasma donors. Plasma anti-RBD or anti-ECD titer of ≥1:1350 may provide critical information about protection against COVID-19 disease.
- Published
- 2020
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