Human pegivirus-1 infection in kidney transplant recipients: A single-center experience

Kidney transplantation is the treatment of choice for patients with end-stage renal disease. In the posttransplant period, the induced immunosuppression leads to an increased risk of developing infectious diseases, a leading cause of death after kidney transplantation. Human pegivirus-1 (HPgV-1) is considered a nonpathogenic human virus and is highly frequent in individuals parenterally exposed, however, its impact on kidney transplantation outcome is poorly understood. Given the scarcity of epidemiological data for this infection on organ recipients in Brazil, we conducted a study in a single center for kidney transplantation in Rio de Janeiro, aiming to determine HPgV-1 prevalence and genotypic distribution. Serum samples from 61 renal recipients, followed up for the first year after transplantation, were evaluated for viral RNA and genotypes were determined by sequencing of the 5′-untranslated region. HPgV-1 RNA was detected in 36.1% (22/61) of patients. Genotype 2 was the most commonly found (80.9%), followed by genotypes 3 (9.5%), 1, and 5, in 4.8% each. Statistical comparisons did not reveal any significant impact of HPgV-1 in patient outcome. Further epidemiologic studies are needed to understand if immunosuppression may interfere in HPgV-1 persistence rates and if viremia might impact graft dysfunction rates in kidney recipients.     

基于方法学评估与检测基线预测广西玉林市从业人员沙门菌带菌水平

目的基于沙门菌筛检流程的方法评价和检测基线,预测广西壮族自治区(广西)玉林市从业人员沙门菌的带菌水平。方法以沙门菌选择性增菌液(SBG)和3种选择性平板(CAS、XLD、DHL)构建沙门菌筛选和检定流程,通过测试菌株和408份从业者粪便样品实测获得统计参数,据此评估不同组合流程(SBG-CAS/XLD/DHL)筛检沙门菌的敏感性、特异性和阳性预测值;基于SBG-DHL分离沙门菌的敏感性校准和预测2014-2017年玉林市从业人员的带菌水平。结果CAS、XLD、DHL对测试菌株的敏感性和特异性分别为100.00%和96.67%、100.00%和83.33%、83.33%和50.00%;应用组合流程筛检408份从业人员粪便,共分离沙门菌22株,带菌率为5.39%;敏感性和阳性预测值分别为95.45%和89.23%(CAS)、86.36%和27.72%(XLD)、68.18%和16.15%(DHL)、100.00%和29.27%(CAS+XLD);CAS+XLD组合发现1例兼有硫化氢阴性和阳性的罗森沙门菌的无症状带菌者;校准和预测2014-2017年玉林市从业人员的平均年度带菌率为3.35%,以实测人数评估地区从业人员的带菌水平约为3350/10万。结论沙门菌检测敏感性和阳性预测值可作为检测质量和方法学的评价指标,大数据证实华南地区从业人员中沙门菌的高比例持留,公共卫生机构应加强沙门菌带菌者的防控,降低食源性病原菌的隐性扩散风险。     

Anal HPV 16 and 18 viral load: A comparison between HIV‐negative and ‐positive MSM and association with persistence

Does anal HPV viral load explain the difference in anal HPV persistence between HIV‐negative and ‐positive men who have sex with men (MSM)? MSM ≥18 years were recruited in Amsterdam, the Netherlands, in 2010‐2011. Anal self‐swabs were collected every 6 months and genotyped (SPF₁₀‐PCR‐DEIA‐LIPA₂₅‐system). HPV16 and HPV18 load was determined with a type specific quantitative (q)PCR, and compared between HIV‐negative and ‐positive men using ranksum test. Persistence was defined as ≥3 positive samples for the same HPV‐type. Determinants of persistent HPV16/18 infection and its association with HPV16/18 load were assessed with logistic regression. Of 777 recruited MSM, 54 and 22 HIV negative men were HPV16 and HPV18 positive at baseline, and 64 and 39 HIV‐positive MSM. The geometric mean titer (GMT) of HPV16 was 19.6 (95%CI 10.1‐38.0) and of HPV18 8.6 (95%CI 2.7‐27.5) DNA copies/human cell. HPV16 and HPV18 load did not differ significantly between HIV‐negative and ‐positive MSM (P = 0.7; P = 0.8, respectively). In multivariable analyses HPV16 load was an independent determinant of HPV16 persistence (OR 1.8, 95%CI 1.3‐2.4). No difference in anal HPV viral load was found between HIV‐positive and HIV‐negative MSM. HPV 16/18 viral load is an independent determinant of type‐specific persistence.     

Inspecting the Ribozyme Region of Hepatitis Delta Virus Genotype 1: Conservation and Variability

The hepatitis delta virus (HDV) genome has an autocatalytic region called the ribozyme, which is essential for viral replication. The aim of this study was to use next-generation sequencing (NGS) to analyze the ribozyme quasispecies (QS) in order to study its evolution and identify highly conserved regions potentially suitable for a gene-silencing strategy. HDV RNA was extracted from 2 longitudinal samples of chronic HDV patients and the ribozyme (nucleotide, nt 688–771) was analyzed using NGS. QS conservation, variability and genetic distance were analyzed. Mutations were identified by aligning sequences with their specific genotype consensus. The main relevant mutations were tested in vitro. The ribozyme was conserved overall, with a hyper-conserved region between nt 715–745. No difference in QS was observed over time. The most variable region was between nt 739–769. Thirteen mutations were observed, with three showing a higher frequency: T23C, T69C and C64 deletion. This last strongly reduced HDV replication by more than 1 log in vitro. HDV Ribozyme QS was generally highly conserved and was maintained during follow-up. The most conserved portion may be a valuable target for a gene-silencing strategy. The presence of the C64 deletion may strongly impair viral replication, as it is a potential mechanism of viral persistence.     

外来务工子弟小学学生血红蛋白检测结果分析

目的:了解上海市高桥社区外来务工子弟小学学生血红蛋白值的变化特征,为制定预防贫血的策略提供参考依据。方法:以2019学年上海市高桥社区外来务工子弟小学1～4年级所有在校学生为研究对象,分别于2019年6月和2020年6月对其进行血红蛋白值检测。结果:共检测学生730人,其中男生417人(57.12%)、女生313人(42.88%)。男生两次血红蛋白均值分别为(128.95±13.72) g/L和(133.07±13.32) g/L,女生分别为(126.25±12.33) g/L和(128.87±12.84) g/L,男生两次血红蛋白均值均高于女生,差异有统计学意义(t值分别为8.19和4.33,P值均<0.05)。7岁组、8岁组、9岁组和10岁组学生第二次血红蛋白均值均高于第一次,差异均有统计学意义(t值分别为5.82、3.34、5.53和3.11,P值均<0.05)。肥胖组、超重组、正常组、轻度消瘦组、中重度消瘦组学生血红蛋白均值第二次均高于第一次,差异均有统计学意义(t值分别为3.50、2.94、7.08、2.26和2.20,P值均<0.05)。研究对象贫血发病率...     

Molecular Characterization of Hereditary Persistence of Fetal Hemoglobin in the Karen People of Thailand

Hereditary persistence of fetal hemoglobin (HPFH) is the condition whereby a continuously active γ‐globin gene expression leads to elevated fetal hemoglobin (Hb F) levels in adult life [Stamatoyannopoulos G, Grosveld F. Hemoglobin switching. In: Stamatoyannopoulos G, Majerus PW, Perlmutter RM, Varmus H, eds. The Molecular Basis of Blood Diseases. Philadelphia: W.B. Saunders, 2001:135–182; Wood WG. Hereditary persistence of fetal hemoglobin and δβ thalassemia. In: Steinberg MH, Forget BG, Higgs DR, Nagel RL, eds. Disorders of Hemoglobin: Genetics, Pathophysiology, and Clinical Management. Cambridge: Cambridge University Press, 2001:356–388; and Weatherall DJ, Clegg JB. Hereditary persistence of fetal hemoglobin. In: Weatherall DJ, Clegg JB, eds. The Thalassaemia Syndromes. Oxford: Blackwell Scientific Publishers, 1981:450–507]. The condition is caused either by mutation of the β‐ and γ‐globin genes, or the γ‐gene controlled region on other chromosomes. Several families with this condition have been reported from Vietnam, Cambodia and China, and the Southeast Asian mutation (or HPFH‐6), a 27 kb deletion, was demonstrated. Here we report on a mother and her daughter of the Karen ethnic group with high levels of Hb F, living in the Suan Pueng District on the border of Thailand and Myanmar. Genotyping showed a heterozygosity for the 27 kb deletion of the β‐globin gene. Their conditions have been confirmed by gap polymerase chain reaction (PCR) with three oligonucleotide primers recently developed by Xu et al. [Xu X‐M, Li Z‐Q, Liu Z‐Y, Zhong X‐L, Zhao Y‐Z, Mo Q‐H. Molecular characterization and PCR detection of a deletional HPFH: application to rapid prenatal diagnosis for compound heterozygotes of this defect with β‐thalassemia in a Chinese family. Am J Hematol 2000; 65:183–188.], and a DNA sequencing method. Thus far there has been no official report of the HPFH‐6 anomaly from Thailand. The compound heterozygosity of β‐thalassemia (thal) and hereditary persistence of Hb F causes the phenotype of thalassemia intermedia; in contrast, homozygotes for this anomaly show only mild microcytic anemia. Hence, genetic counseling for hereditary persistence of Hb F carriers is needed for family planning.     

Norovirus seasonality and the potential impact of climate change

Seasonal variation in norovirus infection is a recognized but poorly understood phenomenon. It is likely to be based on biological, environmental and behavioural factors that regulate transmission, virulence and persistence of the virions in host populations. Understanding the seasonal dependency of norovirus infection is an important step towards understanding its epidemiology, with subsequent implementation of efficient measures of surveillance and control. Whether or not climate change could influence the seasonal patterns of norovirus infection, by impacting on its transmission, geographic distribution and prevalence, has not yet been considered. This review addresses the question.     

Phylogenetic group B2 Escherichia coli strains from the bowel microbiota of Pakistani infants carry few virulence genes and lack the capacity for long-term persistence

Escherichia coli strains of phylogenetic group B2 obtained from Western human hosts are enriched in virulence-associated genes and have a superior capacity to persist in the colonic microbiota. Here, E . coli strains from 22 infants born in Pakistan whose rectal flora was sampled regularly over the first 6 months of life were examined. B2 strains did not carry the virulence-associated genes sfaD/E , papC , neuB or hlyA more often than strains of other phylogenetic groups . B2 origin was not associated with persistence in the bowel microbiota. As compared with B2 strains from Swedish infants, Pakistani B2 strains carried significantly less often the virulence genes fimH (p 0.04), papC (p 0.02), papG class III (p 0.01), sfaD / E (p ≤0.0001), neuB (p ≤0.0001), and hlyA (p 0.005), and also the high-pathogenicity island (p ≤0.0001). A minority of Pakistani B2 strains belonged to recognized uropathogenic O-groups, which are common among 'Western' B2 strains. Thus, extra-intestinal pathogenicity may be the foremost characteristic of B2 strains colonizing Western populations.