Phylogenetic analysis and molecular characteristics of 17 porcine reproductive and respiratory syndrome virus isolates in Southern China from 2010 to 2011

2013 ◽  
Vol 65 ◽  
pp. 67-72 ◽  
Author(s):  
Minze Zhang ◽  
Jiexiong Xie ◽  
Long Sun ◽  
Zhenpeng Cao ◽  
Honglang Gu ◽  
...  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Gözde Erkiş-Güngör ◽  
Bayram Çevik

The presence of Citrus tristeza virus (CTV) in Turkey has been known since the 1960s and the virus was detected in all citrus growing regions of the country. Even though serological and biological characteristics of CTV have been studied since the 1980s, molecular characteristics of CTV isolates have not been studied to date in Turkey. In this study, molecular characteristics of 15 CTV isolates collected from different citrus growing regions of Turkey were determined by amplification, cloning, and sequencing of their major coat protein (CP) genes. The sequence analysis showed that the CP genes were highly conserved among Turkish isolates. However, isolates from different regions showed more genetic variation than isolates from the same region. Turkish isolates were clustered into three phylogenetic groups showing no association with geographical origins, host, or symptoms induced in indicator plants. Phylogenetic analysis of Turkish isolates with isolates from different citrus growing regions of the world including well-characterized type isolates of previously established strain specific groups revealed that some Turkish isolates were closely related to severe quick decline or stem pitting isolates. The results demonstrated that although CTV isolates from Turkey are considered biologically mild, majority of them contain severe components potentially causing quick decline or stem pitting.


2006 ◽  
Vol 36 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Shaojing Wei ◽  
Yangbin Xu ◽  
Meifang Wang ◽  
Shing Shun Tony To

2014 ◽  
Vol 24 ◽  
pp. 193-201 ◽  
Author(s):  
Xiaomin Wang ◽  
Kongwang He ◽  
Wenwen Zhang ◽  
Zhongtao Zhou ◽  
Aihua Mao ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xianlin Ye ◽  
Tong Li ◽  
Ran Li ◽  
Heng Liu ◽  
Junpeng Zhao ◽  
...  

Abstract Background Hepatitis B virus (HBV) infection is a major concern for blood safety in high-prevalence HBV countries such as China. In Shenzhen, dual hepatitis B surface antigen (HBsAg) enzyme-linked immunosorbent assays (ELISAs) have been adopted in parallel with nucleic acid testing (NAT) for donors for over a decade. A small proportion of blood donors test reactive (R) for HBsAg but negative through routine NAT, which can lead to HBV infection with an extremely low viral load. Objectives We aimed to investigate and analyze the molecular characteristics of HBV among blood donors that tested HBsAg R in a single ELISA test. Methods Blood donations were evaluated in this study if confirmed HBsAg R through one of two ELISA kits. Samples with non-reactive (NR) results by NAT were collected and tested for HBsAg by chemiluminescent microparticle immunoassay (CLIA) with a neutralization test. The level of HBsAg was further assessed by electrochemiluminescence immunoassay (ECLIA). The viral basic core promoter (BCP) and pre-core (PC) and S regions were amplified by nested PCR. Quantitative real-time PCR (qPCR) for viral load determination and individual donation (ID)-NAT were adopted simultaneously. HBsAg was confirmed with CLIA, ECLIA, nested PCR, qPCR, and ID-NAT. Results Of the 100,252 donations, 38 and 41 were identified as HBsAg R with Wantai and DiaSorin ELISA kits, respectively. Seventy-nine (0.077%, 79/100,252) blood samples with ELISA R-NR and NAT NR results were enrolled in the study. Of these, 17 (21.5%,17/79) were confirmed as HBsAg-positive. Of the 14 genotyped cases, 78.6% (11/14) were genotype B, and C and D were observed in two and one sample, respectively. Mutations were found in the S gene, including Y100C, Y103I, G145R, and L175S, which can affect the detection of HBsAg. A high-frequency mutation, T1719G (93.3%), was detected in the BCP/PC region, which reduced the viral replication. Conclusion A small number of blood samples with HBsAg ELISA R-NR and NAT NR results were confirmed as HBV infection, viral nucleic acids were found in most of the samples through routine NAT methods. It is necessary to employ more sensitive and specific assays for the detection of HBV infection among blood donors.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 728
Author(s):  
Bao-Gui Jiang ◽  
Ai-Qiong Wu ◽  
Jia-Fu Jiang ◽  
Ting-Ting Yuan ◽  
Qiang Xu ◽  
...  

A novel Borrelia species, Candidatus Borrelia javanense, was found in ectoparasite ticks, Amblyomma javanense, from Manis javanica pangolins seized in anti-smuggling operations in southern China. Overall, 12 tick samples in 227 (overall prevalence 5.3%) were positive for Candidatus B. javanense, 9 (5.1%) in 176 males, and 3 (5.9%) in 51 females. The phylogenetic analysis, based on the 16S rRNA gene and the flagellin gene sequences of the Borrelia sp., exhibited strong evidence that Candidatus B. javanense did not belong to the Lyme disease Borrelia group and the relapsing fever Borrelia group but another lineage of Borrelia. The discovery of the novel Borrelia species suggests that A. javanense may be the transmit vector, and the M. javanica pangolins should be considered a possible origin reservoir in the natural circulation of these new pathogens. To our knowledge, this is the first identification of a novel Borrelia species agent in A. javanense from pangolins. Whether the novel agent is pathogenic to humans is unknown and needs further research.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 711
Author(s):  
Sixin Zhang ◽  
Guangping Huang ◽  
Liang Li ◽  
Xianyong Liu ◽  
Xiaoli Tang ◽  
...  

Nematode infections transmitted to humans by the consumption of wild or cultured eels are increasingly being reported. In the present study, 120 Asian swamp eel, Monopterus albus (Zuiew), individuals collected from China were examined for parasite infections, and 78 larval nematodes were isolated. Morphological and molecular characteristics, including sequence and phylogenetic analysis of the internal transcribed spacer (ITS) and cytochrome c oxidase subunit I (COI) gene regions, were employed to identify these nematodes at the lowest taxonomic level possible. Asian swamp eel was infected with two zoonotic parasite taxa: Gnathostoma spinigerum advanced third-stage larvae, with 6.67% prevalence and mean intensity = 1.25, and Eustrongylides sp. fourth-stage larvae, with 26.67% prevalence and mean intensity = 2.13. These findings evidence the need to enhance public hygiene and food safety awareness toward eel consumption


2004 ◽  
Vol 73 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Silvia Utz ◽  
Jean-Luc Richard ◽  
Selja Capaul ◽  
Hans C. Matter ◽  
Meri Gorgievski Hrisoho ◽  
...  

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