新疆维吾尔自治区2008～2017年手足口病流行病学及病原学监测分析

分析2008～2017年新疆维吾尔手足口病流行病学和病原学特征。采用描述性流行病学的方法,对2008～2017年国家疾病监测信息报告管理系统报告的手足口病例和新疆手足口病网络实验室数据的进行分析。2008～2017年新疆累计报告手足口病例68 820例,重症107例,死亡10例,年均发病率为31.33/10万;病例主要集中在乌鲁木齐市、伊犁州、昌吉州和塔城地区,占总病例数68.26%;5月～7月为发病高峰,病例以1岁～4岁儿童为主,占总病例数的74.46%,散居儿童和幼托儿童分别占51.52%和40.34%;对12 345例手足口病例标本进行核酸检测,阳性8 872例,阳性率71.87%,普通病例中肠道病毒71型(EV-A71)、柯萨奇病毒A组16型(CV-Al6)和其他肠道病毒分别占33.01%、40.33%和26.65%,重症和死亡病例的病原型别均以EV-A71为主,分别占91.03%和100%。新疆1岁～4岁的儿童为手足口病主要发病人群,不同地区发病水平不同,手足口病病原谱呈现EV-A71、CV-A16和其他EV交替流行态势。     

机械通气相关性肺炎患者病原体分布及 抗生素停药指征

目的了解机械通气相关性肺炎患者病原体分布特征,探讨降钙素原(PCT)在机械通气相关性肺炎(VAP)中对抗生素停药的指导价值。方法以在ICU行机械通气并被诊断为VAP的患者为研究对象,依据患者入组日期将患者随机分为观察组(37例)与对照组(35例)。采集患者痰液进行病原菌分离与药敏试验。观察组患者依据PCT水平决定抗生素停用时间,对照组患者依据临床医师经验决定抗生素停用时间。观察患者抗生素使用时间、PCT水平、肺部感染复发率及二重感染发生率等指标。结果 72例患者累计检出病原菌84株,其中12株为革兰阳性菌(14.33%),72株为革兰阴性菌(85.7%)。病原菌以肺炎克雷伯菌与铜绿假单胞菌最为常见,检出率分别为34.5%与31.0%,二者多重耐药率分别为44.8%与57.6%。抗生素治疗第8天时检测显示观察组与对照组患者PCT0.5ng/mL的比例分别为72.9%与71.4%,差异无统计学意义(χ2=0.021,P=0.885)。观察组患者VAP抗生素治疗平均时间为(9.8±3.2)d,显著短于对照组的(14.3±3.6)d,二者差异有统计学意义(t=5.612,P0.001)。多元线性回归分析结果显示,依据PCT水平停药是VAP抗生素治疗开始后28d内抗生素使用时间的独立影响因素(β=-8.24,95%CI:-11.37～-5.11,P0.001)。结论 VAP患者的病原菌以革兰阴性菌最为常见,铜绿假单胞菌与肺炎克雷伯菌感染高发,且二者多重耐药比例较高。PCT水平可作为VAP患者抗生素治疗停药判断标准,可有效减少抗生素使用时间。     

减蛋综合征病毒在不同品系小鼠体内的组织分布

目的通过人工感染减蛋综合征病毒(egg drop syndrome virus,EDSV),观察病毒在不同品系小鼠体内增殖情况以及动态变化规律,为EDSV构建载体提供理论依据与数据支持。方法选取免疫系统正常的BALB/c小鼠、T细胞免疫缺陷裸鼠(Nu)以及高度免疫缺陷小鼠(NSG)为研究对象,每品系32只,雌性,5～6周龄,经腹腔注射人工感染EDSV,分别于攻毒后1、3、5、7、14、21、28、35 d采集血清,应用间接ELISA方法进行抗体监测;选择攻毒后1、7、14、21、28 d小鼠,采集心脏、肺、肝、脾、肾、小肠、子宫、气管、食管、脑10种组织,应用荧光定量PCR相对定量比较Ct法(△△CT)进行各组织内病毒载量的检测。结果 BALB/c小鼠于攻毒后3 d即可在血清内检测到抗体的表达,14 d抗体水平达到最高,并一直维持至监测期内35 d;Nu小鼠也可于攻毒后3 d检测到抗体,表达水平较BALB/c小鼠有所降低,攻毒14 d后,Nu小鼠血清中抗体水平出现下降,至35 d抗体一直维持在较低的水平;NSG小鼠在整个监测过程中,抗体水平一直处于阴性状态。核酸相对定量结果显示,BALB/c小鼠感染后1 d,肝组织中的病毒表达量最高,达到5.45个数量级,其次由高到低依次是脾、食管、子宫、小肠、肺、气管、肾、心脏,脑组织中病毒含量最低,随感染时间的延长,各组织内病毒表达量较感染1 d均有所下降,至攻毒后28 d,肝、脾病毒表达量依然维持着较高的水平;Nu小鼠和NSG小鼠感染1 d表现为脾中病毒表达量最高,分别为3.95和4.05个数量级,其次为肝,攻毒28 d,两种小鼠体内各器官内仍可以检出阳性信号,肝、脾病毒表达量较高。结论 EDSV可刺激小鼠产生免疫应答,在免疫缺陷小鼠体内抗体水平表达量较低。该病毒在小鼠体内有肝、脾等组织嗜性,为EDSV开发成为载体以及在实验动物模型上的进一步研究与应用提供了参考数据。     

Molecular identification of the strains of the domestic silkworm,Bombyx mori (Lepidoptera: Bombycidae), which are endemic to Korea,based on single nucleotide polymorphisms in mitochondrial genome sequences

The domestic silkworm, Bombyx mori (Lepidoptera: Bombycidae), has been diversified into various strains over a long period. However, methods to distinguish silkworm strains remain limited partially owing to the genetic similarity caused by the long history of domestication. In this study, we developed molecular identification methods to distinguish three domestic silkworm strains, which are endemic to Korea. By comparing publicly available complete mitochondrial genome (mitogenome) sequences of five endemic strains and 34 stock silkworm strains analyzed in a previous study, we detected 15 single nucleotide polymorphisms (SNPs; SNP1–SNP15), which distinguished the following three endemic strains: Sun7ho (SN7), Sandongsammyeon (SDS), and Sammyeonhonghoeback (SMH). We used two SNPs for each strain to identify the three endemic strains. To distinguish each SN7 and SDS from the remaining four endemic and 34 stock strains, the PCR-restriction fragment length polymorphism method was employed using Acu I and Hpa I restriction enzymes, which recognize SNP1 and SNP8, respectively. Additionally, the tetra-primer amplification refractory mutation system PCR method was used to determine the regions containing SNP3, SNP11, and both SNP14 and SNP15 to distinguish SN7, SDS, and SMH, respectively, from the remaining strains. A validation test with additional individuals showed that each target strain was clearly recognized, suggesting that mitogenome SNP-based methods can be used to identify three endemic silkworm strains during culture and breeding.     

四肢深度烧伤患者创面感染的病原菌分布、危险因素分析及血清促炎因子水平变化的临床意义

摘要 目的：观察四肢深度烧伤患者创面感染的病原菌分布特点,并分析感染的危险因素及血清促炎因子水平变化的临床意义。方法：回顾性分析2018年3月~2021年1月期间海南省第三人民医院烧伤整形科收治的220例四肢深度烧伤患者的病例资料,根据是否发生创面感染分为感染组和未感染组,观察感染组创面分泌物病原菌分布特点,收集相关资料,分析创面感染的危险因素,比较感染组和未感染组血清血清促炎因子水平的差异。结果：220例四肢深度烧伤患者中,有64例出现创面感染,感染率为29.09%。64例感染患者中共检出102株病原菌,革兰阴性菌占比67.65%（69/102）,其中铜绿假单胞菌（52.94%）、鲍氏不动杆菌（7.84%）、大肠埃希菌（2.94%）排前三位;革兰阳性菌占比32.35%（33/102）,其中金黄色葡萄球菌（14.71%）、表皮葡萄球菌（7.84%）排前两位;无真菌检出。单因素分析结果显示：四肢深度烧伤患者是否发生创面感染与术后有无残余创面、是否合并糖尿病、烧伤面积、是否存在吸入性损伤、住院时长、烧伤深度有关（P<0.05）,而与年龄、性别、烧伤部位、烧伤原因无关（P>0.05）。多因素Logistic回归分析结果显示：术后有残余创面、合并糖尿病、烧伤面积≥40%、存在吸入性损伤、烧伤深度为III度是四肢深度烧伤患者发生创面感染的危险因素（P<0.05）。感染组的血清超敏C反应蛋白（hs-CRP）、白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）水平高于未感染组（P<0.05）。结论：四肢深度烧伤患者发生创面感染概率较高,且感染者的炎性反应更为剧烈,创面感染受到多种因素影响,创面感染的病原菌以铜绿假单胞菌和金黄色葡萄球菌为主,临床应及早干预并选用合适的抗菌药物。     

The Multifaceted Benefits of Protein Co-expression in Escherichia coli

We report here that the expression of protein complexes in vivo in Escherichia coli can be more convenient than traditional reconstitution experiments in vitro. In particular, we show that the poor solubility of Escherichia coli DNA polymerase III ε subunit (featuring 3’-5’ exonuclease activity) is highly improved when the same protein is co-expressed with the α and θ subunits (featuring DNA polymerase activity and stabilizing ε, respectively). We also show that protein co-expression in E. coli can be used to efficiently test the competence of subunits from different bacterial species to associate in a functional protein complex. We indeed show that the α subunit of Deinococcus radiodurans DNA polymerase III can be co-expressed in vivo with the ε subunit of E. coli. In addition, we report on the use of protein co-expression to modulate mutation frequency in E. coli. By expressing the wild-type ε subunit under the control of the araBAD promoter (arabinose-inducible), and co-expressing the mutagenic D12A variant of the same protein, under the control of the lac promoter (inducible by isopropyl-thio-β-D-galactopyranoside, IPTG), we were able to alter the E. coli mutation frequency using appropriate concentrations of the inducers arabinose and IPTG. Finally, we discuss recent advances and future challenges of protein co-expression in E. coli.     

Plate Colony Sample Sizes Required for Inferences about the Uniqueness of a Lactobacillus Strain within a Human Volunteer

Making inferences about the spectrum of bacterial strains on a plate as a consequence of observing only one strain in a random sample of colonies from the plate is relatively straightforward whereas making inferences about the spectrum of strains within a human volunteer as a consequence of observing only one strain in a random sample from the plate requires some care. The issue of the appropriate number of colonies to sample from a plate to make inferences about strain uniqueness within a human volunteer is examined and illustrated with an example     

FTLD‐TDP assemblies seed neoaggregates with subtype‐specific features via a prion‐like cascade

Morphologically distinct TDP‐43 aggregates occur in clinically different FTLD‐TDP subtypes, yet the mechanism of their emergence and contribution to clinical heterogeneity are poorly understood. Several lines of evidence suggest that pathological TDP‐43 follows a prion‐like cascade, but the molecular determinants of this process remain unknown. We use advanced microscopy techniques to compare the seeding properties of pathological FTLD‐TDP‐A and FTLD‐TDP‐C aggregates. Upon inoculation of patient‐derived aggregates in cells, FTLD‐TDP‐A seeds amplify in a template‐dependent fashion, triggering neoaggregation more efficiently than those extracted from FTLD‐TDP‐C patients, correlating with the respective disease progression rates. Neoaggregates are sequentially phosphorylated with N‐to‐C directionality and with subtype‐specific timelines. The resulting FTLD‐TDP‐A neoaggregates are large and contain densely packed fibrils, reminiscent of the pure compacted fibrils present within cytoplasmic inclusions in postmortem brains. In contrast, FTLD‐TDP‐C dystrophic neurites show less dense fibrils mixed with cellular components, and their respective neoaggregates are small, amorphous protein accumulations. These cellular seeding models replicate aspects of the patient pathological diversity and will be a useful tool in the quest for subtype‐specific therapeutics.     

Patterns of genomic and allochronic strain divergence in the fall armyworm,Spodoptera frugiperda (J.E. Smith)

Speciation is the process through which reproductive isolation develops between distinct populations. Because this process takes time, speciation studies often necessarily examine populations within a species that are at various stages of divergence. The fall armyworm, Spodoptera frugiperda (J.E. Smith), is comprised of two strains (R = Rice & C = Corn) that serve as a novel system to explore population divergence in sympatry. Here, we use ddRADSeq data to show that fall armyworm strains in the field are largely genetically distinct, but some interstrain hybridization occurs. Although we detected F1 hybrids of both R‐ and C‐strain maternal origin, only hybrids with R‐strain mtDNA were found to contribute to subsequent generations, possibly indicating a unidirectional barrier to gene flow. Although these strains have been previously defined as “host plant‐associated,” we recovered an equal proportion of R‐ and C‐strain moths in fields dominated by C‐strain host plants. As an alternative to host‐associated divergence, we tested the hypothesis that differences in nightly activity patterns could account for reproductive isolation by genotyping temporally collected moths. Our data indicates that strains exhibit a significant shift in the timing of their nightly activities in the field. This divergence in phenology creates a prezygotic reproductive barrier that likely maintains the genetic isolation between strains. Thus, we conclude that it may be ecologically inaccurate to refer to the C‐ and R‐ strain as “host‐associated” and they should more appropriately be considered “allochronic strains.”