一起聚集性发热伴血小板减少综合征病原S基因分子进化分析

目的 对2020年4月南京鼓楼医院送检的一起疑似聚集性发热伴血小板减少综合征(SFTS)开展病原检测,对其S基因进行测序,分析基因分型和系统发育特征。方法 采用荧光定量PCR法对6例疑似患者血清标本进行新型布尼亚病毒(SFTSV)核酸定性检测, RT-PCR扩增SFTSV S基因片段并测序。分析核苷酸同源性,构建系统进化树。结果 6例血清样本中,SFTSV核酸阳性5例。5例核苷酸高度同源,其中4例S片段基因核苷酸序列同源性100%,1例与其他4例间同源性为99.7%;最大相似株为江苏2014年分离株JS2014-06、2015年分离株JS2015-26,同源性100%。5例均聚集在C2亚型分支上。结论 聚集性疫情SFTSV基因型为C2型,与近年来国内分离株亲缘关系近。需加强监测和宣教,关注病毒的进化与变异。     

贵州省鼠伤寒沙门菌单相变异株的CRISPR基因型和遗传多样性研究北大核心CSCD

目的了解贵州省鼠伤寒沙门菌单相变异株规律的成簇间隔短回文重复序列(CRISPR)的基因型及遗传多样性,为贵州省沙门菌病的预防控制提供依据。方法对分离自2013—2018年贵州省7个市(州)的71株疑似鼠伤寒沙门菌单相变异株进行系统生化鉴定及血清分型,结合双重PCR法确定疑似菌株为鼠伤寒沙门菌单相变异株。提取鼠伤寒沙门菌单相变异株的DNA作为模板,进行CRISPR1和CRISPR2的PCR扩增,将阳性扩增产物进一步测序,获得菌株的CRISPR1和CRISPR2间隔序列,根据间隔序列的组成,确定CRISPR基因型,并使用Bionumerics软件对菌株进行遗传多样性分析。结果71株疑似鼠伤寒沙门菌单相变异菌株经系统生化鉴定、血清分型及双重PCR法鉴定为鼠伤寒沙门菌单相变异株,经CRISPR1和CRISPR2两个位点的PCR扩增和产物测序,71株菌共检测到163个间隔序列,其中CRISPR1有102个,CRISPR2有61个。联合CRISPR1和CRISPR2两个位点的间隔序列进行分析,发现71株菌被分为33个CRISPR基因型(TSTs),其中TST11和TST1为贵州省的优势基因型,分别占总菌株数的25.35%和12.68%。71株菌经Bionumerics软件聚类分析后被分为A、B、C、D 4个簇,A簇包含的菌株最多,B簇包含的基因型最多,不同来源的3株参考株独立成簇,D簇包含7个TSTs基因型。结论贵州省鼠伤寒沙门菌单相变异株具有优势的CRISPR基因型和遗传多样性的特点,可能有其他的感染来源。     

结核分枝杆菌McSpoligotyping 基因分型在宜昌地区耐多药结核病中的应用研究 凝血筛查指标变化及其对临床分型的诊断价值

[摘要]　目的　运用熔解曲线间隔区寡核苷酸分型（melting curve spacer oligonucleotide typing, McSpoligotyping）方法对宜昌地区耐多药结核分枝杆菌进行基因分型,以评价其在结核病流行病学调查中的应用价值。方法　选择2019年1月—2020年12月耐多药菌株77株作为实验组,并以异烟肼和利福平敏感菌株110株作为对照组,运用McSpoligotyping方法进行基因分型,将分型结果与SpolDB4.0数据库进行比对分析。结果　187株菌株中北京基因型116株（62.03％）,非北京基因型71株（37.97％）。对照组110株中北京基因型60株（54.55％）,其中数量最多的1组国际型别编码（spoligotype inter-national type, SIT）为1的北京基因型共44株（40.00％）;非北京基因型50株（45.45％）,以T族、Manu族常见。实验组77株中北京基因型56株（72.73％）,其中数量最多的1组为 SIT为1的北京基因型共44株（57.14％）,非北京基因型21株（27.27％）,以T族、Manu2族常见。实验组北京基因型菌株所占比例与对照组差异有统计学意义。实验组成簇率（79.22％）与对照组成簇率（79.09％）差异无统计学意义。结论　北京基因型菌株是宜昌地区结核病的主要流行菌株,在耐多药结核病患者中北京基因型菌株更为流行。耐多药结核菌株有一定的遗传多态性。McSpoligotyping方法操作简单、快速、对于结核病分子流行病学研究具有重要意义。     

Hepatitis C virus genotypes: distribution and clinical significance in patients with cirrhosis type C seen at tertiary referral centres in Europe

The aim of this study was to evaluate the distribution and clinical significance of hepatitis C virus (HCV) genotypes in European patients with compensated cirrhosis due to hepatitis C (Child class A) seen at tertiary referral centres. HCV genotypes were determined by genotype-specific primer PCR in 255 stored serum samples obtained from cirrhotics followed for a median period of 7 years. Inclusion criteria were biopsy-proven cirrhosis, absence of complications of cirrhosis and exclusion of all other potential causes of chronic liver disease. The proportion of patients with types 1b, 2, 3a, 1a, 4 and 5 were 69%, 19%, 6%, 5%, 0.5% and 0.5%, respectively. Kaplan–Meier 5-year risk of hepatocellular carcinoma (HCC) was 6% and 4% for patients infected by type 1b and non-1b, respectively ( P =0.8); the corresponding figures for decompensation were 18% and 7% ( P =0.0009) and for event-free survival were 79% and 89% ( P =0.09), respectively. After adjustment for baseline clinical and serological features, HCV type 1b did not increase the risk for HCC [adjusted relative risk=1.0 (95% confidence interval=0.47–2.34)], whereas it increased the risk for decompensation by a factor of 3 (1.2–7.4) and decreased event-free survival by a factor of 1.7 (0.9–3.10). In conclusion, type 1b and, to a lesser extent, type 2, are the most common HCV genotypes in European patients with cirrhosis. HCV type 1b is not associated with a greater risk for HCC, but increases the risk for decompensation by threefold in patients with cirrhosis.     

我国部分地区蜱中莱姆病螺旋体的检测与基因分型研究

目的 对我国部分地区的多种蜱类进行莱姆病螺旋体的检测和基因分型。方法 选择我国黑龙江、吉林和浙江省部分林区为调查点，采集当地蜱类，用巢式PCR法进行检测，阳性产物进行限制性片段长度多态性（RFLP）分析和单链构象多态性（SSCP）分析，确定莱姆病螺旋体的基因型。结果 共检测蜱512只，阳性126只，阳性率24．61％。其中吉林全沟硬蜱带菌率为37．00％，黑龙江全沟硬蜱带菌率为20．87％，浙江长角血蜱带菌率为28．07％。RFLP分析表明，蜱中莱姆病螺旋体包括B．garinii和B．afzelii两种基因型。SSCP分析显示为7种亚型，其中B．garinii分为5个亚型，B．afzelii分为2个亚型。发现有3只蜱同时感染不同基因（亚）型莱姆病螺旋体。结论 证实B．garinii和B．afzelii基因型为我国莱姆病螺旋体的优势基因型，并在我国蜱中发现莱姆病螺旋体不同基因（亚）型的混合感染。     

Interleukin-10 promoter polymorphisms are associated with the mode and sequel of HBeAg seroconversion in patients with chronic hepatitis B virus infection.

BACKGROUND: The influence of interleukin-10 (IL-10) gene promoter polymorphisms on the mode and sequel of HBeAg seroconversion (a favorable event usually) in patients with chronic Hepatitis B virus (HBV) infection has not been clarified. PATIENTS AND METHODS: IL-10 genotyping and haplotype analyses of 340 HBsAg carriers and 100 volunteers with self-limiting HBV infection from southern China, a high prevalent area of HBV were performed according to the single nucleotide polymorphisms in its promoter (-1,082, -819 and -592) using a competitively differentiated PCR. RESULTS: High-producer genotype (GG at -1,082) or haplotype (GCC) was rarely found in patients from southern China (<1%). Intermediate-producer haplotype (ACC) was closely associated with chronic liver disease (P=0.004); compared with this, low-producer genotype (AA at -592) and haplotype (ATA) were closely associated with asymptomatic carriers (P=0.035 and 0.035). Intermediate-producer genotype (AC at -592) and haplotype (ACC) were closely associated with covert seroconversion of HBeAg (P=0.0086 and 0.0013) and progressive sequel after HBeAg seroconversion (P=0.013 and 0.0008), while, low-producer genotype (AA at -592) and haplotype (ATA) were closely associated with overt seroconversion of HBeAg (P=0.0023 and 0.0061) and silent sequel after HBeAg seroconversion (P=0.0009 and 0.001). CONCLUSIONS: IL-10 gene promoter polymorphisms significantly influence the mode and sequel of HBeAg seroconversion in patients with chronic HBV infection.     

Molecular background of Rh D-positive,D-negative,D(el) and weak D phenotypes in Chinese

BACKGROUND AND OBJECTIVES: The aim of this study was to elucidate the genetic background of D-negative and D(el) in the Chinese population. MATERIALS AND METHODS: We investigated nine D-positive, 76 D-negative, 26 D(el) and three weak D Chinese individuals by amplification and sequencing of the complete coding region of the RHD gene from genomic DNA. A new RHD polymerase chain reaction with sequence-specific primers (PCR-SSP) method was developed with optimized specificity for typing Chinese individuals. RESULTS: In D-positive samples the RHD sequence was in complete concordance with RHD in other populations. In 12 of 76 (15.8%) D-negative individuals we detected regions of RHD. Three new alleles were found. All 26 D(el), as well as two weak D, individuals carried an RHD 1227A allele. In the remaining weak D sample we identified a weak D type 15. CONCLUSIONS: It should now be possible to correctly predict the RhD phenotype in Chinese subjects. D(el) can also be designated as a particular weak D type.     

Relationship between measures of left ventricular systolic and diastolic dysfunction and clinical and biomarker status in patients with hypertrophic cardiomyopathy

The evaluation of left ventricular (dys)function is at the core of clinical cardiology practice in patients with hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy proceeds along paradigms that are profoundly different and follows disease-specific patterns of progression towards heart failure. By automatically applying a standard approach, much information is lost or misplaced, and severe degrees of dysfunction may be erroneously interpreted as mild by such an assumption. This is mostly evident during the assessment of systolic function, in which a superficial evaluation of standard variables, often relatively preserved (even in advanced stages), may lead to underestimation of clinical severity, with potential consequences, such as late referral for transplantation. Currently, specific biomarkers–particularly N-terminal prohormone of B-type natriuretic peptide and high-sensitivity cardiac troponin I–play a key role in the diagnosis, treatment and risk stratification of hypertrophic cardiomyopathy. Elevated biomarkers seem to depict patients with more severe disease, adding diagnostic and prognostic information to conventional assessments, such as left ventricular ejection fraction, New York Heart Association class and left ventricular outflow tract obstruction. For all these reasons, we provide a review of current knowledge on systo-diastolic function in patients with hypertrophic cardiomyopathy, in an attempt to define clinically significant degrees of dysfunction, biomarker status and specific “red alert” thresholds in clinical practice.     

Molecular surveillance of rubella viruses in Taiwan from 2005 to 2011

Rubella has been listed as a mandatory notifiable disease in Taiwan since 1988. Because of high coverage rates with an effective vaccine, rubella cases have decreased dramatically in Taiwan since 1994. However, rubella outbreaks still occur due to imported transmission. Five large clusters were detected in Taiwan from 2007 to 2011. In 2007, one cluster was caused by rubella genotype 1E viruses that were imported from Vietnam, whereas another cluster was caused by genotype 2B viruses and was untraceable. In 2008, two clusters were caused by different lineages of genotype 1E viruses that were imported from Malaysia. In 2009, a cluster that was caused by genotype 2B viruses was associated with imported cases from Vietnam. The rubella viruses from 124 confirmed cases from 2005 to 2011 were characterized, and the data revealed that these viruses were distributed in the following four genotypes: 1E (n = 56), 1h (n = 1), 1j (n = 4), and 2B (n = 63). Of these viruses, 93 (75%) were associated with imported cases, and 43 of 56 genotype 1E viruses were associated with imported cases from China, Vietnam, Malaysia, and Indonesia. One genotype 1h virus was imported from Belarus, and three of four genotype 1j viruses were imported from the Philippines. Of 63 rubella genotype 2B viruses, 46 were imported from Vietnam, Thailand, Malaysia, China, Germany, and South Africa. Molecular surveillance allows for the differentiation of circulating rubella viruses and can be used to investigate transmission pathways, which are important to identify the interruption of endemic virus transmission. J. Med. Virol. 85:745–753, 2013. © 2013 Wiley Periodicals, Inc.