scholarly journals Infection, recovery and re-infection of farmed mink with SARS-CoV-2

2021 ◽  
Vol 17 (11) ◽  
pp. e1010068
Author(s):  
Thomas Bruun Rasmussen ◽  
Jannik Fonager ◽  
Charlotte Sværke Jørgensen ◽  
Ria Lassaunière ◽  
Anne Sofie Hammer ◽  
...  
Keyword(s):  
Immune Response ◽  
Protein Gene ◽  
Virus Detection ◽  
Spike Protein ◽  
Whole Genome ◽  
Serum Samples ◽  
Initial Infection ◽  
Follow Up Studies ◽  
Additional Sequence

Mink, on a farm with about 15,000 animals, became infected with SARS-CoV-2. Over 75% of tested animals were positive for SARS-CoV-2 RNA in throat swabs and 100% of tested animals were seropositive. The virus responsible had a deletion of nucleotides encoding residues H69 and V70 within the spike protein gene as well as the A22920T mutation, resulting in the Y453F substitution within this protein, seen previously in mink. The infected mink recovered and after free-testing of 300 mink (a level giving 93% confidence of detecting a 1% prevalence), the animals remained seropositive. During further follow-up studies, after a period of more than 2 months without any virus detection, over 75% of tested animals again scored positive for SARS-CoV-2 RNA. Whole genome sequencing showed that the viruses circulating during this re-infection were most closely related to those identified in the first outbreak on this farm but additional sequence changes had occurred. Animals had much higher levels of anti-SARS-CoV-2 antibodies in serum samples after the second round of infection than at free-testing or during recovery from initial infection, consistent with a boosted immune response. Thus, it was concluded that following recovery from an initial infection, seropositive mink were readily re-infected by SARS-CoV-2.

scholarly journals Infection, recovery and re-infection of farmed mink with SARS-CoV-2

2021 ◽  
Author(s):  
Thomas Bruun Rasmussen ◽  
Jannik Fonager ◽  
Charlotte Sværke Jørgensen ◽  
Ria Lassaunière ◽  
Anne Sofie Hammer ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Protein Gene ◽  
Virus Detection ◽  
Spike Protein ◽  
Whole Genome ◽  
Initial Infection ◽  
Follow Up Studies ◽  
Additional Sequence

Mink, on a farm with about 15,000 animals, became infected with SARS-CoV-2. Over 75% of tested animals were positive for SARS-CoV-2 RNA in throat swabs and 100% of tested animals were seropositive. The virus responsible had a deletion of nucleotides encoding residues H69 and V70 within the spike protein gene. The infected mink recovered and after free-testing of the mink, the animals remained seropositive. During follow-up studies, after a period of more than 2 months without virus detection, over 75% of tested animals scored positive again for SARS-CoV-2 RNA. Whole genome sequencing showed that the virus circulating during this re-infection was most closely related to the virus identified in the first outbreak on this farm but additional sequence changes had occurred. Animals had much higher levels of anti-SARS-CoV-2 antibodies after re-infection than at free-testing. Thus, following recovery from an initial infection, seropositive mink rapidly became susceptible to re-infection by SARS-CoV-2.

scholarly journals Sensitivity of two SARS-CoV-2 variants with spike protein mutations to neutralising antibodies

Virus Genes ◽  
2021 ◽  
Author(s):  
Katharina Müller ◽  
Philipp Girl ◽  
Andreas Giebl ◽  
Stefanie Gruetzner ◽  
Markus Antwerpen ◽  
...  
Keyword(s):  
Immune Response ◽  
Humoral Immune Response ◽  
Point Of View ◽  
Spike Protein ◽  
Wild Type ◽  
Serum Samples ◽  
Antibody Treatment ◽  
Neutralising Antibodies ◽  
Humoral Immune ◽  
Protein Mutations

AbstractSARS-CoV-2 infections elicit a humoral immune response capable of neutralising the virus. However, multiple variants have emerged with mutations in the spike protein amongst others, the key target of neutralising antibodies. We evaluated the neutralising efficacy of 89 serum samples from patients, infected with SARS-CoV-2 in the beginning of 2020, against two virus variants isolated from acutely infected patients and harbouring spike protein mutations. One isolate was assigned to lineage B.1.351 (MUC-IMB-B.1.351) whilst the other (MUC-484) was isolated from an immunocompromised patient, sharing some but not all mutations with B.1.351 and representing a transitional variant. Both variants showed a significant reduction in neutralisation sensitivity compared to wild-type SARS-CoV-2 with MUC-IMB-B.1.351 being almost completely resistant to neutralisation. The observed reduction in neutralising activity of wild-type-specific antibodies against both variants suggests that individual mutations in the spike protein are sufficient to confer a potent escape from the humoral immune response. In addition, the effect of escape mutations seems to accumulate, so that more heavily mutated variants show a greater loss of sensitivity to neutralisation up to complete insensitivity as observed for MUC-IMB-B.1.351. From a clinical point of view, this might affect the efficacy of (monoclonal) antibody treatment of patients with prolonged infections as well as patients infected with variants other than the donor. At the same, this could also negatively influence the efficacy of current vaccines (as they are based on wild-type spike protein) emphasising the need to thoroughly surveil the emergence and distribution of variants and adapt vaccines and therapeutics accordingly.

Prevalence and persistence of Chlamydia trachomatis-specific antibodies after occasional and recurrent infections

2019 ◽  
Vol 96 (4) ◽  
pp. 277-282 ◽  
Author(s):  
Hanna Öhman ◽  
Tiina Rantsi ◽  
Päivi Joki-Korpela ◽  
Aila Tiitinen ◽  
Heljä-Marja Surcel
Keyword(s):  
Serum Antibody ◽  
Recurrent Infection ◽  
Chlamydia Infection ◽  
Recurrent Infections ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Initial Infection ◽  
Humoral Immune ◽  
Antibody Levels

ObjectivesPopulation-based Chlamydia trachomatis seroepidemiological studies help to identify trends in chlamydia infection. However, an improved understanding of the antibody response to infection is required when using serology to estimate cumulative incidence. Thus, the objectives of this longitudinal, retrospective, biobank-based study were to assess the appearance and persistence of C. trachomatis major outer membrane protein (MOMP)-specific serum IgG antibodies after infection and to evaluate the role of antibodies in providing protective immunity against recurrent infection.MethodsData of notified C. trachomatis infections in Finland were obtained from the National Infectious Diseases Register. Serum samples were acquired from the Finnish Maternity Cohort. 411 women with single chlamydia infection and 62 women with recurrent infections, and for whom suitable paired serum samples were available, were included in the study. Antibody appearance, persistence after infection and the impact of recurrent infections were evaluated. IgG antibodies specific for MOMP were measured from serum using an ELISA method.ResultsAnti-C. trachomatis MOMP-specific IgG antibodies were detected in 65.5% (269/411) of women within 3 months of notification of infection. In the absence of recurrent infection, seroprevalence declined to 34.5% (142/411) 3–10 years after the initial infection. The serum antibody levels at baseline correlated positively with seroprevalence at follow-up. Reinfection boosted the humoral immune response by increasing seroprevalence and the serum antibody levels. Seroprevalence within 3 months after first notification of infection was 65.5% (19/29) in women who were later diagnosed with recurrent infection, comparable with women with single notification of infection (65.5%, 269/411).ConclusionsApproximately one-third of women with single notification of chlamydia infection remain seropositive 3–10 years after the initial infection. The concentration of antibodies remained stable during the follow-up. Recurrent infection boosted the humoral immune response, but reinfection occurred despite the presence of pre-existing antibodies.

scholarly journals Long-lasting humoral immunity in Covid-19 infected patients at a University Hospital Clinic in Östergötland County Council during 2020-2021

2021 ◽  
Author(s):  
M Azharuddin ◽  
D Aili ◽  
R Selegård ◽  
Sajjad Naeimipour ◽  
M Sunnerhagen ◽  
...  
Keyword(s):  
County Council ◽  
University Hospital ◽  
Spike Protein ◽  
Test Results ◽  
Structural Protein ◽  
Serum Samples ◽  
Serum Igg ◽  
Nasal Swabs ◽  
Study Participants

AbstractLongitudinal serum samples and nasopharyngeal/nasal swab samples were collected from forty-eight individuals (median age 66yrs) with Covid-19 PCR-positive test results at Linköping University Hospital. Samples were collected from initial visit and for 6 months follow up. Presence of serum IgG and IgA against SARS-CoV-2 antigens (S1-spike, nucleocapsid and NSP3) were analyzed. Nasal swabs were tested for presence of IgA against the outer envelope S1 spike protein. Ninety-two percent of participants were seropositive against SARS-CoV-2 recombinant proteins at day 28 from study entry and all (100%) were seropositive from samples collected at 2 months or later. The most common antibody responses (both serum IgG, mainly IgG1 and IgA) were detected against the S1-spike protein and the nucleoprotein. In samples collected from nasal tissues considerably lower frequencies of IgA-positive reactivities were detected. Sixteen to 18 percent of study participants showed detectable IgA levels in nasal samples, except at day 60 when 36% of tested individuals showed presence of IgA against the S1-spike protein. The study suggests that the absolute majority of studied naturally infected Covid-19 patient in the Linkoping, Ostergotland health region develop over 6 months lasting detectable levels of serum IgG and IgA responses towards the SARS-CoV-2 S1-spike protein as well as against the nucleoprotein, but not against the non-structural protein 3.

scholarly journals IgG antibody response against Nucleocapsid and Spike protein post SARS-CoV-2 infection

2021 ◽  
Author(s):  
Hari Ram Choudhary ◽  
Debaprasad Parai ◽  
Girish Chandra Dash ◽  
Annalisha Peter ◽  
Subrat Kumar Sahoo ◽  
...  
Keyword(s):  
Spike Protein ◽  
Complete Disappearance ◽  
Serum Samples ◽  
Igg Antibody ◽  
Observational Cohort ◽  
Public Health Challenge ◽  
Qualitative Assay ◽  
Polymerase Chain ◽  
Abbott Architect

Abstract Objectives: Coronavirus disease-19 (COVID-19) pandemic became the greatest public health challenge globally. Study of dynamicity and durability of naturally developed antibodies against SARS-CoV-2 are of great importance from an epidemiological viewpoint.Methods: In this observational cohort study, we have followed up the 76 individuals who tested positive for SARS-CoV-2 infection by real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) for 16 weeks (post enrollment) to record the periodic changes in titre, concentration, clinical growth and persistence of naturally developed SARS-CoV-2 antibodies. We collected serum samples from these individuals for 16 weeks with a frequency of weekly and fortnightly during each follow-up and tested them in two CLIA-based platforms (Abbott Architect i1000SR and Roche Cobas e411) for testing SARS-CoV-2 antibodies both qualitatively and quantitatively.Results: We recorded the antibody magnitude of these individuals 10 times between September 2020 and February 2021. We found a waning of antibodies against nucleocapsid antigen protein but not a complete disappearance by the end of 16 weeks. Out of 76 cases, 30 cases (39.47%) became seronegative in qualitative assay, although all the sera samples (100%) remained positive when tested in quantitative assay.Conclusion: The lower persistence of anti-nucleocapsid SARS-CoV-2 antibody may not be the exact phenomenon as those cases were still seropositive against spike protein and help in neutralizing the virus.

What graduate follow-up studies can tell us

2000 ◽  
Vol 34 (12) ◽  
pp. 976-977 ◽  
Author(s):  
Linda H Distlehorst
Keyword(s):  
Follow Up Studies

Beurteilung der Adriamycin-Kardiotoxizität mittels der Äquilibrium-Radionuklid-Ventrikulographie

1987 ◽  
Vol 26 (05) ◽  
pp. 206-211 ◽  
Author(s):  
P. Knesewitsch ◽  
N. H. Göldel ◽  
S. Fritsch ◽  
E. Moser
Keyword(s):  
Left Ventricular ◽  
Peak Filling Rate ◽  
Base System ◽  
Filling Rate ◽  
Time To Peak ◽  
Ejection Rate ◽  
Follow Up Studies ◽  
Pathologic Findings ◽  
Peak Ejection Rate

Results of 606 equilibrium radionuclide ventriculographies (ERNV) performed in 348 non-selected patients receiving Adriamycin (ADM) therapy were stored in a data base system. The aim of the study was to assess the influence of a potential cardiotoxic therapy on left ventricular pump function. Increasing ADM doses yielded a significant (p <0.05) decrease of the resting ejection fraction (R-gEF), the peak ejection rate and the peak filling rate. Enddiastolic and endsystolic volumes increased significantly. Stroke volume, heart rate and time to peak filling rate did not change significantly. 368 follow-up studies were performed in 128 patients: 65/128 patients presented a decrease of R-gEF, but only in 45 of these patients R-gEF values fell into the pathologic range. In 44 of these follow-ups, R-gEF remained unchanged. In 19 patients, a R-gEF increase was observed. At the beginning of ADM therapy 14% of the patients had subnormal R-gEF values. With increasing ADM doses pathologic findings increased to 86% in patients with ADM doses higher than 500 mg/m2.

Anticardiolipin Antibodies Are Elevated in HIV-1 Infected Haemophiliacs but Do Not Predict for Disease Progression

1989 ◽  
Vol 61 (01) ◽  
pp. 081-085 ◽  
Author(s):  
Simon Panzer ◽  
Christoph Stain ◽  
Hubert Hartl ◽  
Robert Dudczak ◽  
Klaus Lechner
Keyword(s):  
Normal Values ◽  
Anticardiolipin Antibodies ◽  
Haemophilia A ◽  
Serum Samples ◽  
Factor Viii Concentrates ◽  
Patient Groups ◽  
Anti Hiv ◽  
Hiv 1 ◽  
Cd4 Lymphocytes

SummaryLevels of anticardiolipin antibodies (ACA) were measured in 55 patients with haemophilia A in serum samples obtained in 1983 and in 1987. Twenty-one patients were negative for anti HIV-1 antibodies in 1983 and remained negative in 1987; 34 patients had anti HIV-1 antibodies in 1983; 17 of these latter patients remained asymptomatic, whereas 17 patients developed ARC or AIDS during the 4 years follow-up. Thirteen anti HIV-1 negative patients had elevated ACA levels in 1983; subsequently, a significant decrease was observed in all these subjects (p <0.001). All anti HIV-1 positive patients had elevated ACA levels in 1983; normal values were found in 9 patients in 1987. Yet, these changes were not significant (p >0.05). ACA levels were significantly higher in HIV-1 infected patients than in those without anti HIV-1 antibodies (p <0.05). There was no difference of ACA levels between the two anti HIV-1 positive patient groups, be it in 1983 or be it in 1987 (p >0.05). There was no correlation of ACA levels with serum IgG concentrations, CD4+ lymphocytes, or the consumption of factor VIII concentrates.

Synthesis and Biological Evaluation of the Antimicrobial Natural Product Lipoxazolidinone A

2018 ◽  
Author(s):  
Jonathan J. Mills ◽  
Kaylib R. Robinson ◽  
Troy E. Zehnder ◽  
Joshua G. Pierce
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Mechanism Of Action ◽  
Marine Natural Products ◽  
Biological Evaluation ◽  
Lead Compounds ◽  
Follow Up Studies ◽  
Initial Resistance ◽  
Synthesis And Biological Evaluation

The lipoxazolidinone family of marine natural products, with an unusual 4-oxazolidinone heterocycle at their core, represents a new scaffold for antimicrobial discovery; however, questions regarding their mechanism of action and high lipophilicity have likely slowed follow-up studies. Herein, we report the first synthesis of lipoxazolidinone A, 15 structural analogs to explore its active pharmacophore, and initial resistance and mechanism of action studies. These results suggest that 4-oxazolidinones are valuable scaffolds for antimicrobial development and reveal simplified lead compounds for further optimization.

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