The Effectiveness of Coxiella burnetii Vaccines in Occupationally Exposed Populations: A Systematic Review and Meta‐Analysis

To estimate the effect of vaccination in preventing acute Q fever in individuals occupationally exposed to Coxiella burnetii, a systematic review and meta‐analysis were undertaken in controlled trials and observational studies. Publications were obtained through a scoping study of English and non‐English articles, and those reporting a commercially licensed or licensable vaccine compared with an unvaccinated or placebo control group were included in the review. Two authors performed independent assessment of risk of systematic error and data extraction. One controlled trial and five cohort publications met the inclusion criteria. All trials used a Henzerling phase I vaccine. A random‐effects meta‐analysis estimated significant protection in abattoir workers (RR = 0.07; 95% confidence interval [CI] 0.02–0.22) compared with the control individuals. In individuals with rare or sporadic contact with the abattoir, a significant benefit of vaccination was also found (RR = 0.06; 95% CI 0–0.93). Overall, the vaccine effectively prevented acute Q fever in individuals responsible for handling animals or their products and those working in the abattoir but not directly exposed to animals (RR = 0.06; 95% CI 0.02–0.18). Caution must be taken when interpreting the effect of C. burnetii vaccination as significant heterogeneity amongst publications was observed. A meta‐regression found no significant univariate associations. This may reflect the uncertainty provided by reported data in the cohort publications. Potential systematic biases were present in the publications, and evidence included may not be sufficiently robust to extrapolate the effect of vaccination on occupationally exposed groups beyond the population of abattoir employees in Australia where all included studies occurred.     

Multiple genetic typing of Salmonella Enteritidis phage-types 4, 6, 7, 8 and 13a isolates from animals and humans in the UK

Salmonella enterica serovar Enteritidis is a common cause of salmonellosis in people in the UK. This study aimed to assess the degree of genetic diversity among animal and human isolates from UK, Wales and northern Ireland. A total of 250 isolates from humans (n=59) and animals or their environment (n=191), belonging to the most common phage-types, were fingerprinted by a combination of PFGE, PS ribotyping and plasmid profiling. The different techniques identified different degrees of polymorphism (PS ribotyping (52 types)>PFGE (22 types)>plasmid profiling (17 types)). A prevalent genomic clone, as well as a variety of less frequent clones are present for each of the phage-types. In most cases, the prevalent clones appeared within isolates from several animal species and from several geographical locations. The percentage of sporadic clones found in animal and human populations were very similar. There was not clear evidence of a higher degree of diversity for human or animal isolates. Some clones were found to be present in both human and animal.     

甘蓝型油菜BnClo1基因克隆、表达载体的构建及原核表达

【目的】克隆甘蓝型油菜(Brassica napus)油体钙蛋白(caleosin)基因BnClo1,并进行原核表达研究。【方法】在获得甘蓝型油菜BnClo1基因全长cDNA的基础上,根据BnClo1基因编码区设计1对特异引物,以甘蓝型油菜种子总RNA为模板,通过RT-PCR获得了约750bp的cDNA片段,T/A克隆后进行序列测定。随后将该蛋白成熟肽cDNA片段克隆到原核表达载体pTYB12中,构建融合表达载体pTYB12-BnClo1,转化到Escherichia coli ER2566(DE3)中进行表达。【结果】测序结果显示,RT-PCR获得的cDNA全长768bp,包含完整的开放阅读框738bp,编码245个氨基酸残基,caleosin分子量为28.1kD。原核表达产物经SDS-PAGE分析表明,以20℃、4mmol·L-1IPTG诱导该基因表达效果最好,诱导产物为一个与理论值相符的83.1kD的融合蛋白intein-caleosin。【结论】克隆了油菜BnClo1基因,并在大肠杆菌中进行了优化表达。为进一步纯化和鉴定目的蛋白,及研究其功能奠定了试验基础。     

镉对人体健康的危害效应及其机理研究进展

概述了镉对人体健康的危害效应及其机理.重点阐述了镉对肺、骨、肾、心血管、免疫系统、遗传、肝脏、生殖系统的毒害及其毒性作用机制.     

RPA-Assisted Cas12a System for Detecting Pathogenic Xanthomonas oryzae,a Causative Agent for Bacterial Leaf Blight Disease in Rice

Xanthomonas oryzae pv. oryzae (Xoo) is a widespread pathogen causing bacterial leaf blight (BLB) disease, devastating rice productivity in many cultivated areas of Thailand. A specific and simple method for Xoo detection is required to improve surveillance of disease transmission and outbreak. This study developed a recombinase polymerase amplification (RPA) assay assisted with CRISPR-cas12a assay (RAC) for Xoo detection from bacterial cell suspension of infected rice samples without DNA extraction. The efficiency of the RAC system for Xoo detection using either Xoo80 or Xoo4009 locus was optimized to amplify and determine the sensitivity and specificity using a Xoo DNA template from bacterial cell suspension of infected rice samples without DNA extraction. The RAC system using the Xoo4009 locus gave a higher specificity than Xoo80 locus, because only Xoo species was amplified positive RPA product with fluorescence signal by cas12a digestion, which indicated no cross reactivity. Optimal RAC using the Xoo4009 locus enabled diagnosis of Xoo presence from both plant extracted samples of Xoo artificially inoculated rice leaves within 3 d post-inoculation without symptomatic BLB appearance, and Xoo naturally infected rice. Findings exhibited that RAC using the Xoo4009 locus offered sensitivity, specificity and simplicity for Xoo detection, with low intensities of Xoo-DNA (1 × 10³ copies/μL) and Xoo-cell (2.5 × 10³ cfu/mL). This developed RAC system showed significantly potential for Xoo detection at point-of-care application for early signs of BLB disease outbreak in rice fields.     

长毛兔和獭兔白细胞介素-2基因的克隆与真核表达

采用RT-PCR法从ConA诱导培养的德系安哥拉长毛兔和白色獭兔外周血淋巴细胞总RNA中扩增得到白细胞介素-2基因(IL-2),经序列测定表明,长毛兔和獭兔IL-2基因大小均为462 bp,两序列碱基组成无差异,该基因编码一个由153个氨基酸组成的多肽,包括20个氨基酸残基的信号肽和133个氨基酸残基的成熟肽。德系安哥拉长毛兔和白色獭兔IL-2基因间同源性为100%,与欧洲野兔及中国白兔的IL-2基因同源性分别为99.4%和98.9%。与GenBank中报道的猿、人、猕猴、狒狒、猫、马、大熊猫、犬、猪、水牛、山羊和鼠的IL-2核苷酸同源性分别为86.9%、86.7%、86.2%、86.1%、84.3%、84.3%、82.8%、82.6%、81.4%、76.9%、76.7%、75.0%。进化树分析发现,兔和猿的IL-2亲缘关系最近。通过脂质体法转染COS-7细胞,获得具有一定生物学活性的IL-2蛋白。     

马铃薯新品种宁薯12号选育报告

马铃薯新品种宁薯12号是宁夏回族自治区固原市农业科学研究所1998年用“中心22号”作母本,“宁88-8-306”作父本杂交选育而成。在2005-2006年宁南山区区域试验中,2 a折合平均产量26 006.25 kg/hm^2,比对照品种宁薯8号增产12.79%;在2006年宁南山区生产试验中,折合平均产量23 547.60 kg/hm^2,比对照宁薯8号增产16.77%。全生育期106 d,薯块圆形,薯皮和薯肉均为浅黄色,芽眼浅,块茎含干物质23.41%、淀粉14.90%、粗蛋白3.96%、还原糖0.3%、Vc 1.192μg/g。适宜宁南山区干旱、半干旱、阴湿区及生态条件相似的地区种植。     

Laboratory diagnosis of human toxocariasis

Toxocariasis is a helminth zoonosis caused by infection with the larvae of Toxocara spp. ascarid worms. Only two species, Toxocara canis and Toxocara cati, are recognised as causative agents of human disease. The best choice for serodiagnosis of the generalised forms of toxocariasis, visceral larva migrans (VLM) or covert toxocariasis, relies upon the initial use of TES-ELISA, after which any positive result should subsequently be tested by Western blotting (WB). Covert toxocariasis is mostly a benign infection, so a large majority of infected subjects are asymptomatic or have very few symptoms and therefore go undiagnosed. In this form, this helminthosis is often self-limiting, leaving residual specific antibodies. A positive serodiagnosis caused by residual antibodies that do not have any diagnostic significance can be associated with any infectious or non-infectious disease. If separated from the ongoing clinical and laboratory context, such a positive result has no diagnostic value and should be only taken into account after the possible etiologies of any observed syndromes have been ruled out. Unlike the methods used for the immunodiagnosis of bacterial, viral or protozoal (toxoplasmosis) infections, it is not possible with toxocariasis to assess the age of the presence of specific IgG using the levels of specific IgM because IgM antibodies can be found throughout the course of helminthiasis. The detection of other classes of immunoglobulins, namely IgE and IgA, the subclasses, namely IgG4 or circulating Ag was proven to be unable to discriminate between active and self-cured generalised toxocaral infections. Currently, the diagnosis of an active covert toxocariasis relies upon indirect arguments, e.g., the presence of otherwise unexplained symptoms along with blood eosinophilia and/or elevated levels of eosinophil cationic protein (ECP). This situation is far from ideal and more research should be carried out to solve this difficult problem.     

表达传染性法氏囊病病毒VP2蛋白的重组复制缺陷型HAdV-5的构建及鉴定

【目的】采用AdEasy系统构建能表达传染性法氏囊病病毒（Infectious bursal disease virus,IBDV） VP2蛋白的重组复制缺陷型人5型腺病毒（Human adenovirus serotype-5,HAdV-5）,以期为IBDV活载体疫苗的研发提供新的思路。【方法】通过同源重组将VP2基因克隆至穿梭质粒pAdTrack-GOI构建重组穿梭质粒pAdTrack-VP2;PmeⅠ酶线性化pAdTrack-VP2后热击转化大肠杆菌BJ5183-AD-1感受态细胞,利用菌内同源重组构建重组腺病毒质粒pAd-VP2;将pAd-VP2经PacⅠ酶线性化和纯化后转染HEK293A细胞,包装表达VP2蛋白的重组复制缺陷型HAdV-5（rAd5-VP2）,将鉴定正确的重组病毒感染非复制型细胞（Vero、CEF和DF1细胞）并分析目的蛋白的表达情况。【结果】将rAd5-VP2通过HEK293A细胞扩大培养,测得第10代病毒的滴度为7.9×10⁹ IFU/mL;RT-PCR结果显示,VP2基因在重组腺病毒中能稳定翻译;Western blotting和间接免疫荧光试验均检测到VP2蛋白的表达,蛋白分子质量为41 ku;将rAd5-VP2感染Vero、CEF和DF1细胞也检测到VP2蛋白的表达,表明HAdV-5有作为IBDV活载体疫苗研发的可能性。【结论】本研究构建了重组复制缺陷型HAdV-5,该毒株能感染部分哺乳动物细胞和家禽细胞并能检测到目的蛋白的表达。     

轮枝镰孢菌FvST12基因敲除载体的构建及功能分析

[目的]鉴定并分析轮枝镰孢菌中 STE12 类转录因子的基因功能.[方法]以尖孢镰孢菌转录因子Fost12蛋白为靶序列,在轮枝镰孢菌基因组数据库中进行BlastP搜索,发现一个与Fost12蛋白同源性高达98%的基因,命名为FvST12.基于Double-Joint PCR技术,构建该基因的敲除载体,通过真菌原生质体转化及筛选获得基因敲除突变体,并对突变体的表型及致病性进行系统分析,以明确该基因的功能.[结果l突变体在生长速率、菌落形态,产孢量以及高渗和氧化等逆境胁迫反应上与野生型无显著差异;致病性分析表明,突变体致病力明显下降.[结论]轮枝镰孢菌FvST12对致病性起重要调控作用,但不参与营养生长、产孢和高渗和氧化胁迫等逆境反应.