scholarly journals Epidemiologic Features and Influencing Factors of Norovirus Outbreaks in the City of Wuxi, China from 2014 to 2018

2021 ◽  
Author(s):  
Qian Geng ◽  
Yuan Shen ◽  
Ping Shi ◽  
Yu-Meng Gao ◽  
Wei-Hong Feng ◽  
...  
Keyword(s):  
Attack Rate ◽  
Primary Schools ◽  
Control Intervention ◽  
One Step ◽  
Version 2.0 ◽  
Polymerase Chain ◽  
And Control ◽  
The City ◽  
Epidemiologic Features ◽  
Step Polymerase Chain Reaction

The study investigated the genotypic changes and epidemiologic features of norovirus outbreaks and factors influencing the attack rate and outbreak duration in Wuxi from 2014 to 2018. Norovirus outbreaks, monitored through surveillance system, were investigated. The norovirus-positive specimens from outbreaks were collected and genotyped using a dual polymerase-capsid genotyping protocol based on a one-step polymerase chain reaction (PCR) amplicon. The genotypes were analyzed by Norovirus Typing Tool Version 2.0. A total of 74 norovirus outbreaks were reported in Wuxi from 2014 to 2018. Most (93.2%) norovirus outbreaks were caused by GII genotypes. The predominant norovirus genotypes in outbreaks have changed from GII.17 (20.3%) in 2014–2015 to GII.P16/GII.2 (40.5%) in 2017–2018. GII.P16/GII.2 in 2017–2018 season were more prevalent than GII.17 in 2014–2015 season (χ2 = 4.741, P = 0.029). 56.7% of the outbreaks occurred in primary schools. The re-outbreak rate was 16.2%. 66.7% of re-outbreaks were caused by norovirus variants different from previous genotypes. Outbreaks in nonprimary school settings (odds ratio [OR]: 4.007; 95% CI: 1.247–12.876) and those leading to temporary school or institution closure (OR: 20.510; 95% CI: 1.806–232.937) were reported with a higher attack rate. The outbreaks in primary schools (OR: 4.248; 95% CI: 1.211–14.903), re-outbreaks (OR: 6.433; 95% CI: 1.103–37.534) and longer report timing (OR: 8.380; 95% CI: 2.259–31.089) declared a significantly longer duration. It is of great importance that the monitoring of norovirus outbreaks for the emergence of novel strains, along with responsive prevention and control intervention should be strengthened in adults and school-age population, especially in primary students and preschool children.

Low frequency of CYP2A6 gene polymorphism as revealed by a one-step polymerase chain reaction method

1999 ◽  
Vol 9 (3) ◽  
pp. 327-332 ◽  
Author(s):  
Gen-Fu Chen ◽  
Yong-Ming Tang ◽  
Bridgett Green ◽  
Dong-Xin Lin ◽  
F. Peter Guengerich ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Gene Polymorphism ◽  
Low Frequency ◽  
Polymerase Chain Reaction Method ◽  
Chain Reaction ◽  
Reaction Method ◽  
One Step ◽  
Polymerase Chain ◽  
Cyp2a6 Gene ◽  
Step Polymerase Chain Reaction

Rapid detection of Neisseria meningitidis in cerebrospinal fluid by one-step polymerase chain reaction of the nspA gene

2005 ◽  
Vol 51 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Ivano de Filippis ◽  
Carlos R.S. do Nascimento ◽  
Maysa B.M. Clementino ◽  
Andrea B. Sereno ◽  
Cristina Rebelo ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Cerebrospinal Fluid ◽  
Neisseria Meningitidis ◽  
Rapid Detection ◽  
Chain Reaction ◽  
One Step ◽  
Polymerase Chain ◽  
Step Polymerase Chain Reaction

Molecular Detection of Plasmodiophora brassicae, Causal Agent of Clubroot of Crucifers, in Plant and Soil

Plant Disease ◽  
2007 ◽  
Vol 91 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Tiesen Cao ◽  
Jalpa Tewari ◽  
Stephen E. Strelkov
Keyword(s):  
Ribosomal Rna ◽  
Plasmodiophora Brassicae ◽  
Rrna Gene ◽  
Infested Soil ◽  
Resting Spores ◽  
One Step ◽  
Dna Fragment ◽  
Polymerase Chain ◽  
Total P ◽  
Step Polymerase Chain Reaction

Clubroot of crucifers, caused by Plasmodiophora brassicae, recently has been identified in canola (Brassica napus) fields in Alberta, Canada. An effective strategy for managing the disease is to avoid planting cruciferous crops in P. brassicae-infested soil, because the pathogen produces resting spores that can remain infectious for many years. A simple, one-step polymerase chain reaction (PCR) protocol was developed to detect the pathogen in plant and soil samples. The primers TC1F and TC1R, based on a P. brassicae partial 18S ribosomal RNA (rRNA) gene sequence from GenBank, yielded a 548-bp product in the optimized PCR. A second pair of primers, TC2F and TC2R, which amplified a fragment of the 18S and internal transcribed spacer (ITS) 1 regions of the rDNA repeat, also was tested and produced a 519-bp product. Neither set of primers amplified any DNA fragment from noninfected plant hosts, noninfested soil, or common soil fungi and bacteria tested in this study. Quantities of 100 fg or less of total P. brassicae DNA, or 1 × 103 resting spores per gram of soil, could be detected consistently using these primers and PCR protocol, corresponding to an index of disease of 11% or lower when the soil was bioassayed. The protocol also enabled detection of P. brassicae in symptomless root tissue 3 days after inoculation with the pathogen. Therefore, the PCR assay described in this study could provide a reliable diagnosis for routine detection of P. brassicae in plant and soil materials in a specific and rapid manner.

scholarly journals A Set of Plasmid-Based Modules for Easy Switching of C-Terminal Epitope Tags in Saccharomyces cerevisiae

2021 ◽  
Vol 9 (12) ◽  
pp. 2505
Author(s):  
Hiroki Hayashi ◽  
Tsutomu Kishi
Keyword(s):  
Dna Sequences ◽  
Affinity Purification ◽  
Pcr Amplification ◽  
Restriction Enzymes ◽  
Epitope Tagging ◽  
One Step ◽  
Pcr Method ◽  
Polymerase Chain ◽  
The One ◽  
Step Polymerase Chain Reaction

Epitope tagging is a powerful strategy for analyzing the functions of targeted proteins. The use of this strategy has become more convenient with the development of the epitope switch, which is another type of epitope tagging designed to convert the previously tagged epitopes on the chromosome to other epitopes of interest. Various modules for C-terminal epitope switching have been developed and amplified using the one-step polymerase chain reaction (PCR) method before transformation. However, PCR amplification occasionally generates mutations that affect the fidelity of epitope switching. Here, we constructed several plasmids to isolate modules for epitope switching through digestion by restriction enzymes. The isolated modules contained DNA sequences for homologous recombination, various epitopes (13×Myc, 6×HA, GFP, Venus, YFP, mCherry, and CFP), and a transformation marker (Candida glabrata LEU2). The restriction enzyme-digested plasmids were used to directly transform the cells for epitope switching. We demonstrate the efficient and accurate switching of the MX6 module-based C-terminal tandem affinity purification tags to each aforementioned epitope. We believe that our plasmids can serve as powerful tools for the functional analysis of yeast proteins.

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