兰州百合病毒RT-PCR检测技术建立及应用

病毒病是引起兰州百合产量下降、品种退化的主要原因,准确、高效的病毒检测技术在百合脱毒种球生产和推广应用中十分重要。根据CMV、LSV和LMoV病毒外壳蛋白基因序列设计引物,以百合18S rRNA为内参照,建立兰州百合病毒RT-PCR、二重RT-PCR检测体系。对兰州百合主栽区病毒病的抽样调查发现,CMV、LSV带毒率分别达到98%、100%,LMoV检出率在不同时期样品中存在较大差异。

广西柑橘碎叶病和叶斑病调查及其病原的遗传多样性分析

调查了广西南宁、崇左、柳州、桂林、玉林、河池、贺州及防城港等主要柑橘种植区的柑橘碎叶病和叶斑病的发生情况,并对其病原柑橘碎叶病毒(Citrus tatter leaf virus,CTLV)、苹果茎沟病毒(Apple stem grooving virus,ASGV)和柑橘叶斑病毒(Citrus leaf blotch virus,CLBV)进行了RT-PCR检测、病毒序列测定和遗传多样性分析。结果发现,在所有疑似柑橘病毒病样品中,CTLV检出率为7.3%,CLBV检出率为5.5%,ASGV检出率为3.0%。其中在南宁、桂林和玉林3个主要柑橘种植区采集的疑似柑橘病毒病样品的3种病毒病检出率合计分别为21.2%、28.6%和7.6%,且存在多种病毒复合侵染的现象。将克隆到的上述3个病毒分离物的病毒片段,分别与已报道的相应病毒的代表性分离物的病毒片段进行系统进化分析,结果表明,ASGV和CTLV的中国分离物在进化关系上均呈寄主相关性,ASGV的日本分离物则与地理位置相关性更强,而韩国和印度的分离物未表现出明显的寄主相关性和地理位置相关性。柑橘和苹果的ASGV和CTLV分离物均表现与地理位置相关,而梨的ASGV和CTLV分离物却与地理位置和寄主均不相关;CLBV分离物则呈明显的寄主相关性。本研究首次报道了广西柑橘碎叶病和柑橘叶斑病的发生情况及其病原的遗传多样性与系统进化关系,为柑橘病毒病的诊断和防治提供参考依据。

MSM and HIV/AIDS in China

This article profiles current status of spread and control of HIV/AIDS in China. China has a significant population of MSM (men who have sex with men) and they have been becoming very much alive in many ways since 1990s due to recent social changes. Some surveys indicate that great many of MSM are engaged in high-risk behaviors. In addition, majority of MSM have also experienced sexual encounters with women sometimes in their lives, which possibly con- tribute to spread of HIV to women. Some reports documented that HIV is becoming rampant among MSM since more than 1% of them are now infected. Political, cultural and custom elements could hinder intervention activities against HIV spread among MSM. Fortunately, many cities in China have seen that MSM were in cooperation with responsible institutions carrying out certain intervention measures. The general situation is promising. The authors forecast that the fast HIV spread among MSM of China could possibly be halted within several years when the authorities become more sensible to this issue, health service institutions offer unswerving efforts toward the MSM community and those who involve in MSM undertakes necessary responsibilities.

Epstein-Barr virus-associated gastric carcinoma: Evidence of age-dependence among a Mexican population

AIM： To investigate features of Epstein-Barr virus （EBV）associated gastric carcinoma （EBVaGC） among a Mexican population. METHODS： Cases of primary gastric adenocarcinoma were retrieved from the files of the Departments of Pathology at the Instituto Nacional de Cancerologia and the Instituto Nacional de la Nutrición in Mexico City. The anatomic site of the gastric neoplasia was identified, and carcinomas were histologically classified as intestinal and diffuse types and subclassified as proposed by the Japanese Research Society for Gastric Cancer. EBV-encoded small non-polyadenylated RNA-1 （EBER-1） in situ hybridization was conducted to determine the presence of EBV in neoplastic cells. RESULTS： We studied 330 consecutive, non-selected, primary gastric carcinomas. Among these, there were 173 male and 157 female patients （male/female ratio 1.1/1）. EBER-1 was detected in 24 （7.3%） cases （male/ female ratio： 1.2/1）. The mean age for the entire group was 58.1 years （range： 20-88 years）, whereas the mean age for patients harboring EBER-1-positive gastric carcinomas was 65.3 years （range： 50-84 years）. Age and histological type showed statistically significant differences, when EBER-1-positive and -negative gastric carcinomas were compared. EBER-1 was detected in hyperplastic- and dysplastic-gastric mucosa surrounding two EBER-1-negative carcinomas, respectively. CONCLUSION： Among Latin-American countries, Mexico has the lowest frequency of EBVaGC. Indeed, the Mexican population 〉50 years of age was selectively affected. Ethnic variations are responsible for the epidemiologic behavior of EBVaGC among the worldwide population.

Care of HIV-infected patients in China

Compared with high infection areas of the world, the total HIV infection rate in China is relatively low. Nonetheless, because of China’s vast territory and large population, the potential infection risk must be taken seriously. In the next few years, needle sharing among injection drug users will remain the most common route of transmission for the HIV/ AIDS epidemic in China. Unprotected sex is gradually becoming a major route of transmission. China began to imple- ment HAART in 1999 according to international standards. Prior to 2003, there were only about 150 HIV/AIDS patients were treated with HAART in some clinical trials and about 100 HIV/AIDS patients were treated by private sources. Results of those treatments are the scientific basis for development of the therapeutic strategies in China. In March of 2003, the Chinese government initiated China CARES program. In November of 2003, the Chinese Ministry of Health announced a national policy of free ARV treatment to all HIV+ Chinese citizens who were in poverty and required ARV therapy. There are total of 19,456 HIV/AIDS patients received free ARV drugs to date in 159 regions and 441 towns. Current challenges are how to follow-up and evaluate those patients in the clinical settings. The longer the therapy is postponed, the more side effects and the higher probability of drug resistance are going to occur. It remains unclear, therefore, when HAART regimen should be started in the HIV/AIDS population in China.

Governmental policies on HIV infection in China

This article is a general review of the evolvement of HIV/AIDS-related public policies in China since 1980’s. It tracks the important laws, regulations and other governmental documents in regard to HIV/AIDS prevention mainly at central level.

Risk factors for primary liver carcinoma in Chinese population

AIM： To evaluate the risk factors for primary liver carcinoma （PLC） in Chinese population.METHODS： Chinese Biomedical Literature Database, China Hospital Knowledge Database and MEDLINE were searched. All the related literatures were screened, and the risk factors for PLC in Chinese population were studied. Heterogeneity was evaluated by odds ratio （OR） q test. Combined OR and its 95% confidence interval （95%CI）were calculated, the association between the investigated risk factors and PLC was determined. Validity and bias of the findings were evaluated by sensitivity analysis and funnel plot analysis respectively.RESULTS： Fifty-five of one hundred and ninety identified studies were accepted according to the inclusive criteria. Ten factors related to PLC were demonstrated by sensitive analysis and funnel plot analysis. They were cirrhosis （OR = 11.97, P= 0.000）, HBV infection （OR = 11.34, P= 0.000）,HCV infection （OR = 4.28, P = 0.000）, family history of liver cancer （OR = 3.49, P = 0.000）, unstable emotion （OR = 2.20, P = 0.000）, depressed characters （OR = 3.07,P = 0.000）, aflatoxin （OR = 1.80, P = 0.000）, alcoholic （OR = 1.88, P = 0.000）, intake of musty food （OR =1.87,P = 0.000） and drinking contaminated water from pond （OR = 1.77, P = 0.003）.CONCLUSION： The main risk factors for PLC in China are liver diseases, family history of liver carcinoma, poor psychic status, aflatoxin, and some unhealthy behaviors.

Human papillomavirus in squamous cell carcinoma of esophagus in a high-risk population

AIM: To investigate the relation of human papillomavirus (HPV) and esophageal squamous cell carcinoma (ESCC) in Iranian patients as compared to normal controls. METHODS: Using MY09/MY11 consensus primers, we compared the prevalence of a HPV L1 gene in tumor tissues from 38 ESCC cases and biopsied tissues from 38 endoscopically normal Iranian individuals. We also compared the presence of HPV16 and HPVA18 in the same samples using type-specific E6/E7 primers. RESULTS: Fourteen (36.8%) of the 38 ESCC samples but only 5 (13.2%) of the 38 control samples were positive for the HPV L1 gene (P= 0.02). Five (13.2%) of the ESCC samples but none of the control samples were positive for the HPV16 E6/E7 gene (P= 0.05). Three (7.9%) of the ESCC samples and 5 (13.2%) of the control samples were positive for the HPV18 E6/E7 gene (P= 0.71). CONCLUSION: Our data are consistent with HPV DNA studies conducted in other high-risk areas for ESCC. HPV should be considered as a potential factor contributing to the high incidence of ESCC in Iran and other high-incidence areas of the world.

Complete Genome Sequence Analysis of Duck Circovirus Strains from Cherry Valley Duck

To investigate molecular epidemiology of DuCV in Cherry Valley ducks in China, the complete genomes of six DuCV strains, which were detected from Cherry Valley ducks in China between 2007 and 2008, were sequenced. Sequence and phylogenetic analysis were carried out to compare these six strains with another 27 DuCV strains from Mulard duck, Muscovy duck, Pekin ducks and Mule duck. The analysis showed that the six DuCV strains exhibited typical genetic features of the family of DuCV, such as a stem-loop structure, three major open reading frames (Rep, Cap and ORF3), four intergenic repeats and the conserved motifs for rolling circle replication and for the dNTP binding domain located in the Rep protein. Phylogenetic analysis of the nucleotide sequences of the complete genome and Cap gene of these strains together with those that have been previously published demonstrated two distinct DuCV genotypes. The DuCV strains with complete genomes containing 1988 and 1989 nucleotides clustered in genotype A, whereas the strains with complete genomes containing 1991, 1992, 1995 and 1996 nucleotides lay in genotype B. The six DuCV strains from Cherry Valley ducks were divided into the two groups. The results of the study provides some insight into the variation of DuCVs in Cherry Valley ducks.

Epidemiological Investigation and Genome Analysis of Duck Circovirus in Southern China

Duck circovirus （DuCV）, a potential immunosuppressive virus, was investigated in Southern China from March 2006 to December 2009 by using a polymerase chain reaction （PCR） based method. In this study, a total of 138 sick or dead duck samples from 18 different farms were examined with an average DuCV infection rate of-35%. It was found that ducks between the ages of 40~60 days were more susceptible to DuCV. There was no evidence showing that the DuCV virus was capable of vertical transmission. Farms with positive PCR results exhibited no regularly apparent clinical abnormalities such as feathering disorders, growth retardation or lower-than-average weight. The complete genomes of 91 strains from Fujian Province and 1 from Zhejiang Province were sequenced and analyzed. The 10 DuCV genomes, comlbared with others genomes downloaded from GenBank, ranged in size from 1988 to 1996 base pairs, with sequence identities ranging from 83.2% to 99.8%. Phylogenetic analysis based on genome sequences demonstrated that DuCVs can be divided into two distinct genetic genotypes, Group I （the Euro-USA lineage） and Group II（the Taiwan lineage）, with approximately 10.0% genetic difference between the two types. Molecular epidemiological data suggest there is no obvious difference among DuCV strains isolated from different geographic locations or different species, including Duck, Muscovy duck, Mule duck, Cheery duck, Mulard duck and Pekin duck.

Bluetongue Virus （BTV） Serological Survey and Evidence of Emergent BTV-8 Serotype in Morocco

Bluetongue （BT） is an infectious, non-contagious arthropod-borne disease that infects all ruminants, including sheep, cattle, deer, goats and camelids. Bluetongue virus （BTV） belonged to Reoviridae is ARN genome of 19 Kb. Twenty-six BTV serotypes have long been recognized, to be associated with severe disease in certain breeds of sheep, whereas cattle and goats are usually sub-clinically affected. Before 2004, BT was considered an exotic disease in Morocco, however, the first outbreak was observed in 2004 in sheep. This outbreak was caused by the isolated BTV-4. Two years later a BTV-1 emerged in Morocco. Both serotype 1 and serotype 4 circulated after 2007 across the country. The aims of the present work was to perform a serological study on sheep from different regions in Morocco in order to clarify the current BTV epidemiological situation and its evolution from 2009 to 2012, to determine the co-infection rate, and to confirm the possible circulation of other BTV Serotype mainly the BTV-8. All of 436 sera were tested by serum neutralization using reference strains. Results confirm the presence of BTV-4, BTV-1 and BTV-8. However, the present study report for the first time the emerging BTV-8 circulation in Morocco. Moreover, the founding reveal as well a higher co-infection rate in cattle compared to sheep.

Epidemiological Investigation and Genetic Characterization of Type 2 PCV2 （Type 2 Porcine Circovirus） in Mexican Commercial Herds

PCV2 （Porcine circovirus type 2） is considered as the essential infectious agent of PMWS （post weaning multisystemic wasting syndrome） in pigs. Serological studies have shown that the virus is ubiquitous. Currently, there are many reports about the epidemiology and genetic characteristics of this virus around the world, but in Mexico it has not been studied. More than 3,500 samples of serum, rectal swabs, tissues and semen of 34 Mexican porcine farms from 10 important producer regions were analyzed by PCR. Results show that 97% of the farms were positive. Both genotypes, PCV2a and PCV2b were detected. It also found that the most prevalent genotype in Mexico is PCV2b. Regarding to amino acid sequence; three major heterogenic regions were present in the positions 59-91,123-136 and 185-210.

Prevalence and clinical significance of SEN virus infection in patients with non A-E hepatitis and volunteer blood donors in Shanghai

AIM:To explore the prevalence of SEN virus (SENV) in patients with non A-E hepatitis and volunteer blood donors in Shanghai. METHODS: According to the published gene sequences, primers from the conserved region were designed. Then, the prevalence of SEN virus in 30 samples from healthy voluntary blood donors and 30 samples from patients with non A-E hepatitis were detected by nested-PCR of SENV-D/H. Some PCR products were cloned and sequenced. RESULTS: The specificity of genotype-specific PCR was confirmed by sequencing, the SENV DNA was detected in 53.3% of the patients with non A-E hepatitis and 10% of the blood donors. The prevalence of SENV-D/H viremia was significantly higher in patients with non A-E hepatitis than in blood donors (P = 0.0002). SENV-H subtype and SENV-D subtype were found in 2 and 1 samples, respectively from blood donors. SENV-H subtype, SENV D subtype, mixed SENV-D and SENV-H subtype were found in 8, 6 and 2 samples, respectively, from patients with non A-E hepatitis. CONCLUSION: The gene type of SENV in patients with non A-E hepatitis and blood donors in shanghai is D or H subtype, and transfusion is not the only transmitting form of SENV.

Epidemiological and etiological investigation of dengue fever in the Fujian province of China during 2004–2014

Dengue fever(DF) is a vector-borne disease and a tremendous socioeconomic burden on tropical and subtropical countries worldwide. To explore the characteristics of DF epidemic in the Fujian province, information of DF cases in Fujian during 2004–2014 was collected and analyzed. The complete E genes of 48 viral isolates were amplified and sequenced for phylogenetic analysis. A total of 733 cases was reported, of which 612(83.5%) occurred during the peak period from August to October. Additionally, 76%(190/250) of imported cases originated from Southeast Asia countries, by the epidemiological investigation. Phylogenetic analysis of the 48 viral isolates revealed that three genotypes(I, IV, V) of DENV1, and one genotype each of DENV2(cosmopolitan) and DENV3(I) circulated in Fujian during 2004–2014. Similar to the results of the epidemiological investigations, the source of most of the viral isolates, including imported and indigenous cases, may be Southeast Asia countries; however, importation from adjacent provinces was also observed in recent years. Overall, DF is considered an imported epidemic disease in Fujian. Increasing diversity of the viral source and geographic expansion of the area affected by DF in recent years highlights the necessity for strengthening surveillance of the DF epidemic and developing strategies for DF prevention and control in Fujian.

A novel human coronavirus:Middle East respiratory syndrome human coronavirus

In 2012,a novel coronavirus,initially named as human coronavirus EMC(HCoV-EMC) but recently renamed as Middle East respiratory syndrome human coronavirus(MERS-CoV),was identified in patients who suffered severe acute respiratory infection and subsequent renal failure that resulted in death.Ongoing epidemiological investigations together with retrospective studies have found 61 laboratory-confirmed cases of infection with this novel coronavirus,including 34 deaths to date.This novel coronavirus is culturable and two complete genome sequences are now available.Furthermore,molecular detection and indirect immunofluorescence assay have been developed.The present paper summarises the limited recent advances of this novel human coronavirus,including its discovery,genomic characterisation and detection.