拉米夫定耐药株感染者HBV基因型和逆转录酶区变异分析

目的了解拉米夫定耐药株感染者HBV基因型特征并分析耐药株HBV逆转录酶（RT）区变异位点和变异类型。方法应用PCR扩增和直接测序HBV逆转录酶区并与Genebank中90株不同基因型野毒株序列进行比较,确定54例耐药株感染者HBV基因型和HBVRT核苷酸的变异特点。结果在54例拉米夫定耐药株感染者中,HBVB基因型占27．78％,C型占70．37％,B／C混合型占1．85％;51例患者出现RT保守区氨基酸变异（包括550和526位氨基酸变异）;18例患者出现除主型区外HBVRT非主型区伴随变异;3例患者未检测到与拉米夫定相关性变异。结论拉米夫定耐药株感染者HBV基因型主要为B型和C型;拉米夫定耐药株的氨基酸变异不仅见于RT区的526和550两个位点,其他位点以及RT非保守区也可发生变异。     

Rotavirus vaccine effectiveness in preventing hospitalizations due to gastroenteritis: a descriptive epidemiological study from Germany

Objectives

Rotavirus infections are common causes of infant hospitalization. The present study examined the effectiveness of anti-rotavirus vaccination in preventing rotavirus-related hospitalizations in Germany, following its state and nationwide introductions in 2008 and 2013, respectively.

Familial Mediterranean fever (FMF) in Lebanon and Jordan: a population genetics study and report of three novel mutations

Familial Mediterranean fever (FMF) is an autosomal recessive disease mostly frequent in Mediterranean populations. Over 50 mutations have been identified in the gene responsible for the disease, MEFV. The present study reports the frequencies of MEFV mutations in 558 Lebanese and 55 Jordanian FMF patients and points out the severity of the M694V frequently observed mutation among these patients. Three novel mutations, T177I, S108R and E474K were also identified in the Lebanese group. An excess of homozygotes and a deficit of heterozygotes were observed in both samples when compared to the expected number of observed genotypes under the Hardy–Weinberg hypothesis. Homozygotes for M694V and M694I were still in excess in the Lebanese group of patients, even after consanguinous homozygotes were removed, or population structure was considered. This excess is therefore neither due to consanguinity nor to subgroups in the Lebanese population, but rather to more remote consanguinity or to a selection bias favoring the census of these genotypes. The fact that FMF female patients were less censed than male patients may be due to the greater resistance of females to pain and to the possibility of confusing abdominal and gynecological pain. The phenotypic heterogeneity of the FMF could then originate both from genetic causes like allelic heterogeneity or modulating genes, and cultural background facing the physiological consequences of genotypes at risk.     

Simultaneous quantitation and genotyping of hepatitis B virus by real-time PCR and melting curve analysis

Hepatitis B virus (HBV) genotype and HBV DNA levels have been implicated in clinical evaluation and prognosis of patients with chronic HBV infection. The aim of the present study was to develop a rapid and sensitive method for simultaneous HBV DNA quantitation and differentiation between HBV genotypes B and C in a single-step reaction by real-time PCR and melting curve analysis using SYBR Green I fluorescent dye. The genotypes obtained by this method were compared with those examined by PCR-RFLP and direct sequencing on 52 serum samples of patients with chronic HBV infection. Using the results obtained by direct sequencing and phylogenetic analysis as the reference, the accuracy of HBV genotyping by PCR-RFLP and melting curve analysis was 90.38 and 92.31%, respectively. The geometric mean of HBV DNA levels was 3.42×10⁶, 2.10×10⁶, 1.19×10⁵ and 3.10×10⁴ copies/μl in asymptomatic carriers, patients with chronic hepatitis, cirrhosis and hepatocellular carcinoma, respectively. It is concluded that this method has the advantages of rapidity, reproducibility and accuracy, which would be feasible and attractive for large-scale analysis, particularly in regions where HBV genotypes B and C are prevalent.     

亚甲基四氢叶酸还原酶基因1298A→C多态与食管癌易感性关系的病例对照研究

目的 研究亚甲基四氢叶酸还原酶(MTHFR)基因1298A→C多态及其和生活习惯相互作用与食管癌易感性的关系。方法 在食管癌高发区的淮安市楚州区开展了一项病例对照研究(食管癌患者141例,人群对照228名),调查研究对象的生活习惯,采用聚合酶链反应-限制性片段长度多态性技术检测研究对象的MTHFR 1298A→C基因型。结果 ①食管癌组中MTHFR 1298 AA、AC和CC基因型携带者的比例分别为63.8％、34.0％和2.1％,与对照组的71.9％、28.1％和0.0％相比,差异有统计学意义(X_(MH)~2=6.69,P=0.035)。②在MTHFR 1298C等位基因携带者中,伴有吸烟习惯者发生食管癌的调整OR为3.48(95％CI:1.57～7.71),伴有经常饮酒的习惯者发生食管癌的调整OR为2.91(95％CI:1.20～7.08),无饮茶习惯者发生食管癌的调整OR为3.52(95％CI:1.64～7.54)。MTHFR 1298AC和CC基因型与吸烟、饮酒和不饮茶在食管癌发生中的相互作用系数r分别为3.05、3.69和6.30。结论 MTHFR 1298AC和CC基因型对吸烟、饮酒和不饮茶增加食管癌发生风险的作用有明显的放大效应。     

Viral gastrointestinal infections and norovirus genotypes in a paediatric UK hospital, 2014–2015

BackgroundDiarrhoea in children is a common disease; understanding the incidence of causative viruses can aid infection control and vaccine development.ObjectivesDescribe the incidence and characteristics of gastroenteric viruses including norovirus genotypes in a paediatric hospital cohort.Study designNorovirus, adenovirus, sapovirus, astrovirus, rotavirus qPCR and norovirus genotyping results for all stool specimens (n = 4786; 1393 patients) at a UK paediatric tertiary referral hospital June 2014–July 2015.Results and discussion24% (329/1393) of patients were positive for a GI virus; the majority were positive for norovirus (44%, 144/329) or adenovirus (44%, 146/329). The overall incidence of rotavirus (2%) is reduced compared to pre-vaccination studies; however the incidence of other GI viruses has not increased. Norovirus infections had a significantly higher virus burden compared to other GI viruses (P ≤0.03); sapovirus infections had the lowest viral burden.The number of norovirus cases per month did not follow the typical winter seasonal trend of nationally reported outbreaks. The number of cases per month correlates with the number of hospital admissions (R = 0.703, P = 0.011); the number of admissions accounts for 50% of the variability in number of cases per month. The breadth of genotypes seen (48% non-GII.4), suggests a community source for many norovirus infections and has implications for vaccine development.All GI viruses caused chronic infections, with the majority (50–100%) in immunocompromised patients. Incidence or duration of infection in chronic norovirus infections did not differ between genotypes, suggesting host-mediated susceptibility.     

901例女性人乳头瘤病毒感染状况及基因型分布的调查

目的 探讨高低危型人乳头瘤病毒(human papilloma virus,HPV)在不同年龄段的感染情况,为防治宫颈癌、尖锐湿疣等HPV相关疾病提供理论依据.方法 收集有HPV感染临床检测指征(宫颈炎、宫颈上皮内瘤变及宫颈癌)的女性标本901例,利用导流杂交基因芯片技术对阴道分泌物进行HPV分型检测.结果 901例标本HPV阳性率为41.73％,其中单纯高、低危型HPV和高低危型HPV混合感染率分别为60.90％ (229/376)、23.67％ (89/376)和15.43％(58/376);高危型HPV感染各个年龄段的感染率为26.39％～42.19％,低危型HPV感染各个年龄段的感染率为8.96％～39.19％,各型均呈现“U”型趋势.结论 各年龄段主要感染型别为HPV16.低年龄段以高低危型HPV混合感染为主,≥55岁以单纯高危型HPV感染为主,单纯高危型HPV感染率随年龄增长而上升.     

慢性乙型肝炎病毒感染者转化生长因子-β1基因单核苷酸多态性分析

目的 探讨转化生长因子(TGF)-β1单核苷酸多态性(SNP)与慢性HBV感染的关系.方法 采用PCR方法,对74例慢性乙型肝炎患者、41例乙型肝炎肝硬化患者和41例健康人外周血细胞基因组DNA的TGF-β1基因中三个SNP位点(rs2241715、rs2241716、rs4803455)进行基因分型.数据分析采用χ2或Fisher精确概率法检验.结果 健康人的 rs2241715基因型及等位基因频率与慢性乙型肝炎和肝硬化患者相比,差异有统计学意义(χ2=11.419,P＜0.01或χ2=6.218χ2=5.961;P＜0.05),rs2241715 T/T基因型的个体患慢性乙型肝炎和乙型肝炎肝硬化的相对危险度分别为其他型的2.974倍(95%CI=1.209～7.314,P=0.018)和3.228倍(95%CI=1.201～8.675,P=0.020),rs2241716和rs4803455位点则无上述相关性.结论 TGF-131基因的rs2241715 SNP位点T/T基因型可能与慢性HBV感染密切相关.     

Current status of measles in Japan: molecular and seroepidemiological studies

On account of the measles vaccination campaign, with vaccinations carried out on the first birthdays of children, the number of reported cases of measles was reduced to 545 in 2005, which is the lowest so far in Japan. We conducted a molecular epidemiological study of measles virus to determine the circulating measles virus genotypes in Japan since 1984. Different genotypes, C1, D3, D5, and H1, were the major strains isolated in outbreaks in 1984, 1987–1988, 1991–1993, and 2000, respectively. When measles was in the control phase, a sporadic outbreak was reported, but the causative virus was found to be of imported measles virus lineage. We also conducted a seroepidemiological study to investigate the persistence of vaccine-acquired immunity in Himeji City, Japan. Before 1990, vaccine coverage was 84.5% and it increased gradually, to 88.5% in 1991–1995, 92.7% in 1996–2000, and 94.6% after 2000. Measles outbreaks were observed annually before 1978 and in 1980, 1981, 1984, 1990, and 1996; there were no measles cases after 1997 in Himeji City. In 1994–1998, a serological study of 795 sera showed that measles neutralization test (NT) antibodies were sufficiently preserved, even 12 years after the first-dose immunization. In 1999–2003, 26 (3.7%) of 695 sera were negative for NT. The positive rate for measles NT decreased to approximately 90% as the elapsed time after the first-dose immunization increased to 6 or 7 years. The immunity obtained after receiving measles vaccine decays by 6–7 years after the first dose when the measles was controlled. A two-dose schedule of measles vaccine was implemented in Japan in 2006; we should continue molecular and serological surveillance.     

基因芯片在乙肝病毒检测中的应用

[目的]评价基因芯片技术在同时进行乙肝病毒基因分型及耐药突变基因检测中的准确性、敏感性和临床应用价值.[方法]50例血清标本都用荧光定量PCR和基因芯片两种方法进行检测,然后对两种方法的结果进行比较,同时对基因芯片技术检测结果中乙肝病毒基因分型和耐药突变基因的情况进行分析.[结果]荧光定量PCR的阳性检出率为46%.基因芯片的阳性检出率为38%,其中10例为B型,9例为C型,结合荧光定量的结果,在整个基因芯片的检测结果中检测到的最低拷贝数为1.387e3 copies/ml.19例阳性都存在拉米夫定敏感位点,共检测到3例对拉米夫定耐药的患者(2例为rt204I突变,1例为rt108M、rt204V突变).[结论]基因芯片技术在同时进行乙肝病毒基因分型和耐药突变基因的检测中,结果准确、灵敏度高、通量性好,适合各大临床单位开展应用.