Chikungunya virus ; genetics ; isolation & purification ; China ; Genome, Viral ; RNA, Viral ; genetics ; Sequence Analysis, RNA

OBJECTIVETo explore a convenient and effective method for norovirus nucleic acid extraction from oysters suitable for long-term viral surveillance.

METHODSTwo methods, namely method A (glycine washing and polyethylene glycol precipitation of the virus followed by silica gel centrifugal column) and method B (protease K digestion followed by application of paramagnetic silicon) were compared for their performance in norovirus nucleic acid extraction from oysters. Real-time RT-PCR was used to detect norovirus in naturally infected oysters and in oysters with induced infection.

RESULTSThe two methods yielded comparable positive detection rates for the samples, but the recovery rate of the virus was higher with method B than with method A.

CONCLUSIONMethod B is a more convenient and rapid method for norovirus nucleic acid extraction from oysters and suitable for long-term surveillance of norovirus.

Animals ; Centrifugation ; methods ; Norovirus ; genetics ; isolation & purification ; Ostreidae ; virology ; RNA, Viral ; isolation & purification

Adult ; Antibodies, Viral/isolation & purification* ; COVID-19/virology* ; Feces/chemistry* ; Female ; Humans ; Intestines/virology* ; Male ; RNA, Ribosomal, 16S/genetics* ; RNA, Viral/isolation & purification* ; SARS-CoV-2/pathogenicity*

OBJECTIVETo investigate the viral contamination of invasive medical instruments in dentistry and to provide health administrative institutions with surveillance data.

METHODSSterilized samples were randomly collected from the department of dentistry to detect HBV-DNA, HCV-RNA, HIV-RNA and HBsAg.

RESULTSOf the invasive medical instruments that were sterilized with 2% glutaraldehyde, one of the samples was positive for HBV-DNA, and another sample was positive for HBsAg.

CONCLUSIONThough massive virus contamination of invasive medical instruments in dentistry has been reduced to a low level, the occurrence of contamination still remains.

DNA, Viral ; analysis ; Dental Instruments ; virology ; Equipment Contamination ; HIV ; isolation & purification ; Hepacivirus ; isolation & purification ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B virus ; isolation & purification ; Humans ; RNA, Viral ; analysis

OBJECTIVETo compare the results of detecting HIV-1 load by using NucliSens HIV-1 QT and Amplicor HIV-1 monitor 1.5 assays.

METHODSEighty-two clinical samples were collected and HIV viral load was determined with the above-mentioned two methods.

RESULTSThe number of samples in which values obtained by NucliSens HIV-1 QT and Amplicor HIV-1 monitor 1.5 differed by <0.5 log10 RNA copies/ml and in which the viral load was undetectable accounted for 88.9 percent of the measures. The correlation coefficient between the two methods was 0.956 in 56 samples of Deltalog10 VL<0.5.

CONCLUSIONThe results of HIV-1 viral load determination with the two methods are highly comparable.

HIV Infections ; virology ; HIV-1 ; genetics ; isolation & purification ; Humans ; Nucleic Acid Amplification Techniques ; instrumentation ; methods ; RNA, Viral ; genetics ; Viral Load

OBJECTIVETo compare the molecular characteristics of 3 Crimean-Congo hemorrhagic fever viruses(CCHFV) isolated in Xinjiang province.

METHODSYL05035, YT05099 and LT05146 were isolated in 2005 from Hyalomma ticks and viral RNA was extracted from suckling mouse brains infected with these three strains respectively. The polymerase chain reaction(PCR) products of S segments from the 3 strains of CCHFV were directly sequenced.

RESULTSThe full-length'S RNA from the 3 strains of CCHFV all comprised 1673 nucleotides with ORF of them including 1449 nucleotides and encoding a protein which comprised 482 amino acids in a viral complementary sense. The sequences indicated that the three strains of CCHFV isolated from ticks in Xinjiang province were highly homologenic. Data from the phylogenetic analysis showed that the obtained sequences were identical. The homology between 3 strains of CCHFV was 99.5%. Their homologies compared with that of the other strains isolated from other region of Xinjiang were also high at nucleotide levels (92.7%-99.8%). The three strains which were clustered together with 7001 strain and 79121 strain (isolated from patient and rat in Xinjiang respectively) was only different by 2%-3%. The genetic difference from the prototype CCHFV Nigerian strain IBAR10200 was 13%. In comparison, the Nigerian CCHFV tick isolate was more divergent when compared with the reference China strains 66019 and with the three variants mentioned above.

CONCLUSIONThe CCHFV isolated from China comprised a group of genetically high conserved strains.

Animals ; Brain ; virology ; China ; Genes, Viral ; Hemorrhagic Fever Virus, Crimean-Congo ; genetics ; isolation & purification ; Mice ; RNA, Viral ; analysis

OBJECTIVETo investigate the gene variations of influenza B virus isolated in Hunan province from 2007 to 2010.

METHODSA total of 42 strains of influenza B virus,which were isolated in the Influenza Surveillance Network Laboratories in Hunan province between year 2007 and 2010, were selected for the study. The hemagglutinin 1 (HA1) and neuraminidase (NA) genes of the selected strains were amplified by RT-PCR, and the sequence of the purified product were detected and homologically compared with the sequence of influenza vaccine strains isolated from Northern Hemisphere by WHO during the same period. In addition, the phylogenetic trees were constructed to characterize the molecular features.

RESULTSIn the Victoria branch of the HA1 gene phylogenetic tree, the strains isolated from year 2007 to 2009 were included in the V1 sub-branch, as well as the vaccine strain Malaysia/2506/2004; the strains isolated in year 2010 were involved in the V2 sub-branch, similar to the vaccine strains Brisbane/60/2008. In the Yamagata branch,the strains isolated in year 2007 were in the Y1 sub-branch,different from the strains isolated between year 2008 and 2010, which were in the Y2 sub-branch, instead. All virus in NA gene phylogenetic tree were included in the Yamagata branch, indicated their Yamagata origin. The genetic sequence analysis of the 7 strains isolated in year 2010 revealed that the viruses were classified as genotype 2 and genotype 15. The results of homological comparison between HA1 molecule and the influenza vaccine strains recommended by WHO were as below: Victoria lineage, 98.6% - 99.1% in 2007, 98.6% - 99.1% in 2008, 98.1% - 99.1% in 2009, and 97.6% - 99.1% in 2010; and Yamagata lineage, 97.9% - 98.5% in 2007, 97.9% - 98.5% in 2009 and 97.9% - 98.2% in 2010. The major mutations of the strains isolated in year 2007 were found in sites R48K, K88R, P108A, D197N and S230G. While the major mutations of the strains isolated between year 2009 and 2010 were sited in K88R, S150I, N166Y, D197N and S230G.

CONCLUSIONThe prevalent influenza B virus isolated in Hunan province from 2007 to 2010 has mutated and evolved continuously.

China ; epidemiology ; Genes, Viral ; Humans ; Influenza B virus ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; virology ; Phylogeny ; RNA, Viral ; Sequence Homology

OBJECTIVE: Tick-borne encephalitis virus (TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis (TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease. METHODS: A reverse-transcription recombinase-aided amplification (RT-RAA) assay was developed. This assay can be completed in one closed tube at 39 °C within 30 minutes. The sensitivity and specificity of RT-RAA were validated using non-infectious synthetic RNA representing a fragment of the NS5 region of the wild-type (WT) TBEV genome and the Senzhang strain. Additionally, 10 batches of tick samples were used to evaluate the performance of the RT-RAA assay. RESULTS: The analytical limit of detection of the assay was 20 copies per reaction of the TBEV synthetic transcript and 3 plaque-forming units (pfu) per reaction of TBEV titers. With the specific assay, no signal due to other arboviruses was observed. Of the 10 batches of tick samples obtained from the Changbai Mountains of China, three were TBEV-positive, which was consistent with the results of the quantitative real-time PCR assay. CONCLUSION A rapid, highly sensitive, specific, and easy-to-use method was developed for the detection of the TBEV Far-Eastern subtype.
Encephalitis Viruses, Tick-Borne ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; RNA, Viral ; analysis

Herpesvirus 4, Human ; genetics ; isolation & purification ; Humans ; Infectious Mononucleosis ; drug therapy ; pathology ; virology ; RNA, Viral ; isolation & purification ; Sensitivity and Specificity

A one step reverse transcription PCR (RT-PCR) combined nested PCR was set up to increase efficiency in the diagnosis of canine distemper virus (CDV) infection after developement of nested PCR. Two PCR primer sets were designed based on the sequence of nucleocapsid gene of CDV Onderstepoort strain. One-step RT-PCR with the outer primer pair was revealed to detect 10(2) PFU/ml. The sensitivity was increased hundredfold using the one-step RT-PCR combined with the nested PCR. Specificity of the PCR was also confirmed using other related canine virus and peripheral blood mononuclear cells (PBMC) and body secretes of healthy dogs. Of the 51 blood samples from dogs clinically suspected of CD, 45 samples were revealed as positive by one-step RT-PCR combined with nested PCR. However, only 15 samples were identified as positive with a single one step RT-PCR. Therefore approximately 60% increase in the efficiency of the diagnosis was observed by the combined method. These results suggested that one step RT-PCR combined with nested PCR could be a sensitive, specific, and practical method for diagnosis of CDV infection.
Animals ; Distemper Virus, Canine/genetics/*isolation & purification ; Dogs ; Polymerase Chain Reaction/*methods/*veterinary ; RNA, Viral/genetics/isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; Vaccines, Attenuated ; Viral Vaccines