Systemic protection of cucumber plants against disease caused by Cladosporium cucumerinum and Colletotrichum lagenarium by prior infection with either fungus

The unusual cases of pneumonia outbreak were reported from Wuhan city in late December 2019. Serological testing provides a powerful tool for the identification of prior infection and for epidemiological studies. Pseudotype virus neutralization assays are widely used for many viruses and applications in the fields of serology. The accuracy of pseudotype neutralizing assay allows for its use in low biosafety lab and provides a safe and effective alternative to the use of wild-type viruses. In this study, we evaluated the performance of this assay compared to the standard microneutralization assay as a reference. The lentiviral pseudotype particles were generated harboring the Spike gene of SARS-CoV-2. The generated pseudotype particles assay was used to evaluate the activity of neutralizing antibodies in 300 human serum samples from a COVID-19 sero-epidemiological study. Testing of these samples resulted in 55 positive samples and 245 negative samples by pseudotype viral particles assay while microneutralization assay resulted in 64 positive and 236 negative by MN assay. Compared to the MN, the pseudotyped viral particles assay showed a sensitivity of 85.94% and a specificity of 100%. Based on the data generated from this study, the pseudotype-based neutralization assay showed a reliable performance for the detection of neutralizing antibodies against SARS-CoV-2 and can be used safely and efficiently as a diagnostic tool in a biosafety level 2 laboratory.

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Reinfection Rates Among Patients Who Previously Tested Positive for Coronavirus Disease 2019: A Retrospective Cohort Study

Clinical Infectious Diseases ◽

10.1093/cid/ciab234 ◽

2021 ◽

Author(s):

Megan M Sheehan ◽

Anita J Reddy ◽

Michael B Rothberg

Keyword(s):

Cohort Study ◽

Retrospective Cohort Study ◽

Retrospective Cohort ◽

Symptomatic Infection ◽

Symptomatic Disease ◽

Viral Shedding ◽

History Of ◽

Polymerase Chain ◽

Prior Infection ◽

Over Time

Abstract Background Protection afforded from prior disease among patients with coronavirus disease 2019 (COVID-19) infection is unknown. If infection provides substantial long-lasting immunity, it may be appropriate to reconsider vaccination distribution. Methods This retrospective cohort study of 1 health system included 150 325 patients tested for COVID-19 infection via polymerase chain reaction from 12 March 2020 to 30 August 2020. Testing performed up to 24 February 2021 in these patients was included. The main outcome was reinfection, defined as infection ≥90 days after initial testing. Secondary outcomes were symptomatic infection and protection of prior infection against reinfection. Results Of 150 325 patients, 8845 (5.9%) tested positive and 141 480 (94.1%) tested negative before 30 August. A total of 1278 (14.4%) positive patients were retested after 90 days, and 62 had possible reinfection. Of those, 31 (50%) were symptomatic. Of those with initial negative testing, 5449 (3.9%) were subsequently positive and 3191 of those (58.5%) were symptomatic. Protection offered from prior infection was 81.8% (95% confidence interval [CI], 76.6–85.8) and against symptomatic infection was 84.5% (95% CI, 77.9–89.1). This protection increased over time. Conclusions Prior infection in patients with COVID-19 was highly protective against reinfection and symptomatic disease. This protection increased over time, suggesting that viral shedding or ongoing immune response may persist beyond 90 days and may not represent true reinfection. As vaccine supply is limited, patients with known history of COVID-19 could delay early vaccination to allow for the most vulnerable to access the vaccine and slow transmission.

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Infliximab is associated with attenuated immunogenicity to BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines in patients with IBD

Gut ◽

10.1136/gutjnl-2021-324789 ◽

2021 ◽

pp. gutjnl-2021-324789

Author(s):

Nicholas A Kennedy ◽

Simeng Lin ◽

James R Goodhand ◽

Neil Chanchlani ◽

Benjamin Hamilton ◽

...

Keyword(s):

Single Dose ◽

Primary Outcome ◽

Geometric Mean ◽

Antibody Responses ◽

Antibody Assay ◽

Past Infection ◽

White Ethnicity ◽

Registration Number ◽

Inflammatory Bowel ◽

Prior Infection

ObjectiveDelayed second dose SARS-CoV-2 vaccination trades maximal effectiveness for a lower level of immunity across more of the population. We investigated whether patients with inflammatory bowel disease treated with infliximab have attenuated serological responses to a single dose of a SARS-CoV-2 vaccine.DesignAntibody responses and seroconversion rates in infliximab-treated patients (n=865) were compared with a cohort treated with vedolizumab (n=428), a gut-selective anti-integrin α4β7 monoclonal antibody. Our primary outcome was anti-SARS-CoV-2 spike (S) antibody concentrations, measured using the Elecsys anti-SARS-CoV-2 spike (S) antibody assay 3–10 weeks after vaccination, in patients without evidence of prior infection. Secondary outcomes were seroconversion rates (defined by a cut-off of 15 U/mL), and antibody responses following past infection or a second dose of the BNT162b2 vaccine.ResultsGeometric mean (SD) anti-SARS-CoV-2 antibody concentrations were lower in patients treated with infliximab than vedolizumab, following BNT162b2 (6.0 U/mL (5.9) vs 28.8 U/mL (5.4) p<0.0001) and ChAdOx1 nCoV-19 (4.7 U/mL (4.9)) vs 13.8 U/mL (5.9) p<0.0001) vaccines. In our multivariable models, antibody concentrations were lower in infliximab-treated compared with vedolizumab-treated patients who received the BNT162b2 (fold change (FC) 0.29 (95% CI 0.21 to 0.40), p<0.0001) and ChAdOx1 nCoV-19 (FC 0.39 (95% CI 0.30 to 0.51), p<0.0001) vaccines. In both models, age ≥60 years, immunomodulator use, Crohn’s disease and smoking were associated with lower, while non-white ethnicity was associated with higher, anti-SARS-CoV-2 antibody concentrations. Seroconversion rates after a single dose of either vaccine were higher in patients with prior SARS-CoV-2 infection and after two doses of BNT162b2 vaccine.ConclusionInfliximab is associated with attenuated immunogenicity to a single dose of the BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines. Vaccination after SARS-CoV-2 infection, or a second dose of vaccine, led to seroconversion in most patients. Delayed second dosing should be avoided in patients treated with infliximab.Trial registration numberISRCTN45176516.

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Relation between pigment intensity and penetrating ability in appressoria of Colletotrichum lagenarium

Canadian Journal of Microbiology ◽

10.1139/m87-152 ◽

1987 ◽

Vol 33 (10) ◽

pp. 870-873 ◽

Cited By ~ 14

Author(s):

Yasuyuki Kubo ◽

Iwao Furusawa ◽

Jiko Shishiyama

Keyword(s):

Parent Strain ◽

Colletotrichum Lagenarium ◽

Melanin Biosynthesis ◽

Glass Slides ◽

Albino Mutant

Mutant 8004 of Colletotrichum lagenarium formed slightly pigmented appressoria. The appressoria germinated laterally on glass slides, but could penetrate nitrocellulose membranes. The slightly pigmented appressoria of the albino mutant 79215 were observed to behave in a similar manner when treated with 100 μM scytalone. The appressorial pigmentation of mutant 8004 was increased by the application of scytalone, and mature appressorial pigmentation, indistinguishable from that of the parent strain 104-T, was observed when appressoria were treated with 100 μM scytalone, a lower concentration than that needed for mature pigmentation of the albino mutant. The sensitivity to tricyclazole of appressorial pigmentation of mutant 8004 was higher than that of the parent strain 104-T. These results suggest that, although melanin biosynthesis is essential for appressorial penetration, slight pigmentation is sufficient.

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Antibodies to Chlamydia trachomatis heat shock proteins in women with tubal factor infertility are associated with prior infection by C. trachomatis but not by C. pneumoniae

Human Reproduction ◽

10.1093/humrep/14.8.1969 ◽

1999 ◽

Vol 14 (8) ◽

pp. 1969-1973 ◽

Cited By ~ 17

Author(s):

K. Persson ◽

S. Osser ◽

S. Birkelund ◽

G. Christiansen ◽

H. Brade

Keyword(s):

Heat Shock ◽

Chlamydia Trachomatis ◽

Heat Shock Proteins ◽

Tubal Factor Infertility ◽

Tubal Factor ◽

Shock Proteins ◽

Prior Infection

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Molecular biological studies on the pathogenicity of Colletotrichum lagenarium

Journal of General Plant Pathology ◽

10.1007/s10327-006-0298-4 ◽

2006 ◽

Vol 72 (6) ◽

pp. 412-413

Author(s):

Gento Tsuji

Keyword(s):

Colletotrichum Lagenarium ◽

Biological Studies

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Universal PCR and antibody testing demonstrate little to no transmission of SARS-CoV-2 in a rural community

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa531 ◽

2020 ◽

Author(s):

Ayesha Appa ◽

Saki Takahashi ◽

Isabel Rodriguez-Barraquer ◽

Gabriel Chamie ◽

Aenor Sawyer ◽

...

Keyword(s):

Rural Community ◽

The United States ◽

Rural Setting ◽

Antibody Testing ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Rural Town ◽

Low Prevalence ◽

Prior Infection ◽

Estimate Precision

Abstract Background Limited systematic surveillance for SARS-CoV-2 in the early months of the United States epidemic curtailed accurate appraisal of transmission intensity. Our objective was to perform case detection of an entire rural community to quantify SARS-CoV-2 transmission using PCR and antibody testing. Methods We conducted a cross-sectional survey of SARS-CoV-2 infection in the rural town of Bolinas, California (population 1,620), four weeks following shelter-in-place orders. Participants were tested between April 20 th – 24 th, 2020. Prevalence by PCR and seroprevalence from two forms of antibody testing were performed in parallel (Abbott ARCHITECT IgG and in-house IgG ELISA). Results Of 1,891 participants, 1,312 were confirmed Bolinas residents (>80% community ascertainment). Zero participants were PCR positive. Assuming 80% sensitivity, it would have been unlikely to observe these results (p<0.05) if there were >3 active infections in the community. Based on antibody results, estimated prevalence of prior infection was 0.16% (95% CrI: 0.02%, 0.46%). The positive predictive value (PPV) of a positive result on both tests was 99.11% (95% CrI: 95.75%, 99.94%), compared to PPV 44.19%-63.32% (95% CrI range 3.25%-98.64%) if one test was utilized. Conclusions Four weeks following shelter-in-place, SARS-CoV-2 infection in a rural Northern California community was extremely rare. In this low prevalence setting, use of two antibody tests increased seroprevalence estimate precision. This was one of the first community-wide studies to successfully implement synchronous PCR and antibody testing, particularly in a rural setting. Widespread testing remains an underpinning of effective disease control in conjunction with consistent uptake of public health measures.

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