绦虫基因组学研究进展

绦虫是一类严重危害人类身体健康的寄生虫,每年给人类造成很大的经济负担。绦虫种类众多,生物学特性各异,目前绦虫病的防控和治疗措施尚不完善,对动物和人类的危害严重。随着生物信息学和基因测序技术的发展、绦虫基因组序列的测定和解析,通过对绦虫的生物学特征和调控基因进行深度研究有助于预防和控制绦虫病,特别是人和动物的棘球蚴病和囊虫病等重要的人兽共患寄生虫病。利用绦虫基因组学和蛋白质组学等组学技术,筛选绦虫感染关键的基因和蛋白质,提供绦虫病的诊断参考依据和绦虫病治疗的潜在药物靶标。本文就绦虫基因组测序完成情况和近年来绦虫基因组学研究进展进行综述。     

湖北省部分地区2010年蚊传虫媒病毒调查

目的继续调查湖北省蚊媒和病毒种类及其分布状况。方法 2010年夏季在湖北省恩施州、神农架林区、江陵县和随州市采集蚊虫标本,用组织培养法分离病毒,用血清学和分子生物学方法对阳性病毒分离物进行鉴定,利用生物信息学软件对新分离病毒进行序列同源性和系统进化分析。结果采集到3属4种12 845只蚊虫标本,共分离到38株阳性分离物,经血清学和分子生物学鉴定,32株阳性分离物为流行性乙型脑炎病毒(JEV),5株阳性分离物为盖塔病毒,1株为JEV和盖塔病毒感染混合株。JEV E基因序列进化分析显示新分离JEV均为基因Ⅰ型JEV。盖塔病毒NS2基因序列进化分析显示新分离病毒与中国河北省和韩国毒株同源性最高,与俄罗斯分离株进化关系较远。结论首次在湖北省分离到盖塔病毒,并再次在湖北省分离到基因Ⅰ型JEV。     

DNA条形码技术在河北省坝上地区夜行鼠鉴定中的应用

目的以河北省坝上地区捕获的夜行鼠为对象,应用DNA条形码技术进行鼠类鉴定。方法在河北省坝上地区采集鼠肝脏标本,并保存整只鼠,制作标本,提取DNA,采用通用引物PCR法扩增细胞色素C氧化酶亚基Ⅰ(COⅠ)基因,并测序。将测序结果与Gen Bank中其他鼠类的DNA条码进行Blast比对,并构建分子进化树。结果 36份样本均能通过PCR扩增出特异性COⅠ基因条带,所构建的分子进化树结果与形态学鉴定结果有所不同,经头骨鉴定,进化树结果正确无误,更正形态学鉴定结果。其中2只夜行鼠未能在Gen Bank中找到同源性较高的鼠类基因,且头骨受到严重损坏,暂无法确定鼠种。结论 DNA条形码技术能够对鼠类进行有效的物种鉴定。     

我国病媒生物监测与控制现状分析及展望

我国丰富的气候条件、地理景观和生态环境孕育了多样性的病原、宿主动物和病媒生物,导致病媒传播疾病广泛分布和频繁发生,对我国人群健康造成极大危害。病媒生物监测与控制是病媒传播疾病预防和控制的根本措施。20世纪之前,鉴于人类对病媒生物认识不足,致使病媒生物防控工作相对迟缓。新中国成立后,我国病媒生物监测与控制得到重视和加强,但也走过一些弯路[1]。改革开放以来,特别是进入21世纪后,我国政府加强了病媒生物监     

鸟-胞内分枝杆菌复合群鸟和胞内分枝杆菌亚种对20种药物的敏感性特征及亚种间药物敏感性比较

目的 分析鸟-胞内分枝杆菌复合群鸟分枝杆菌亚种和胞内分枝杆菌亚种对20种药物的敏感性特征及比较2个亚种间的药物敏感性差异。方法 用微孔板Alamar blue显色法分别检测97株鸟分枝杆菌和172株胞内分枝杆菌对克拉霉素、卷曲霉素和利福布丁等20种药物的最小抑菌浓度,判断其敏感性,分析2个亚种菌株对20种药物的敏感性特征以及对利福霉素类、氨基糖苷类和大环内酯类内药物的交叉耐药性,并比较2个亚种对20种药物的敏感性差异。结果 对鸟分枝杆菌敏感率高于80%的药物依次是卷曲霉素(100%,97/97)、阿米卡星(97.9%,95/97)、利福布丁(96.9%,94/97)、利福平和卡那霉素(83.5%,81/97)及克拉霉素(82.5%,80/97);对胞内分枝杆菌敏感率高于80%的药物依次是阿米卡星(99.4%,171/172)、卡那霉素(95.9%,165/172)、利福布丁(95.4%,164/172)、克拉霉素(94.2%,162/172)、氯法齐明(87.2%,150/172)、卷曲霉素和罗红霉素(86.1%,148/172)及利福喷丁(82.6%,142/172)。97株鸟分枝杆菌分别有1株、1株和17株而172株胞内分枝杆菌中分别有0株、7株和6株同时对氨基糖苷类、利福霉素类和大环内酯类内各种药物同时耐药或中度敏感。鸟分枝杆菌对利福平和卷曲霉素的敏感率明显高于胞内分枝杆菌。胞内分枝杆菌对利福喷丁、妥布霉素、卡那霉素、乙胺丁醇、莫西沙星、克拉霉素、阿奇霉素和罗红霉素的敏感率均高于鸟分枝杆菌。结论 鸟和胞内分枝杆菌均对卷曲霉素、阿米卡星、利福布丁和克拉霉素敏感性较高,对胞内分枝杆菌敏感的药物多于鸟分枝杆菌,利福喷丁仅对胞内分枝杆菌抗菌性较好,而利福平仅对鸟分枝杆菌抗菌性较好,乙胺丁醇对两个亚种敏感性均较差;对同一种类的药物做药物敏感性试验可为临床医生治疗鸟或胞内分枝杆菌感染选择合适的替代药物做依据。     

The emergence of HIV-1 primary drug resistance genotypes among treatment-naïve men who have sex with men in high-prevalence areas in China

The prevalence of HIV-1 infection in men who have sex with men (MSM) in China has drastically increased, and circulating strains may have acquired transmitted drug resistance (TDR). We determined TDR genotypes among antiretroviral therapy (ART)-naïve MSM in 19 provinces/cities where HIV-1 prevalence among MSM is high, and found an overall 4.9 % TDR rate. Although protease inhibitors (PI) were not in the first-line antiretroviral drug list provided through the National ART Program, 70.4 % of the detected TDR belongs to this category. Our findings confirm the urgent need for TDR surveillance in order to optimize treatment effects of the National ART Program.     

Comparative proteomics reveals essential mechanisms for osmotolerance in Gluconacetobacter diazotrophicus

Plant growth-promoting bacteria are a promising alternative to improve agricultural sustainability. Gluconacetobacter diazotrophicus is an osmotolerant bacterium able to colonize several plant species, including sugarcane, coffee, and rice. Despite its biotechnological potential, the mechanisms controlling such osmotolerance remain unclear. The present study investigated the key mechanisms of resistance to osmotic stress in G. diazotrophicus. The molecular pathways regulated by the stress were investigated by comparative proteomics, and proteins essential for resistance were identified by knock-out mutagenesis. Proteomics analysis led to identify regulatory pathways for osmotic adjustment, de novo saturated fatty acids biosynthesis, and uptake of nutrients. The mutagenesis analysis showed that the lack of AccC protein, an essential component of de novo fatty acid biosynthesis, severely affected G. diazotrophicus resistance to osmotic stress. Additionally, knock-out mutants for nutrients uptake (Δtbdr and ΔoprB) and compatible solutes synthesis (ΔmtlK and ΔotsA) became more sensitive to osmotic stress. Together, our results identified specific genes and mechanisms regulated by osmotic stress in an osmotolerant bacterium, shedding light on the essential role of cell envelope and extracytoplasmic proteins for osmotolerance.     

耐多药结核分枝杆菌中embB基因突变与乙胺丁醇耐药的相关性研究

目的 研究耐多药结核分枝菌中embB基因突变与乙胺丁醇耐药的相关性. 方法 比例法检测84株耐多药结核分枝杆菌的乙胺丁醇(EMB)耐药性,基因测序检测embB基因的突变,2检验分析二者之间的相关性. 结果 84株耐多药结核分枝杆菌中有43株(51.2%)对EMB耐药,41株(48.8%)对EMB敏感,57株耐多药菌株(67.9%)的embB基因发生突变.在43株EMB耐药菌株中,embB基因突变的菌株为40株(93.0%),而41株EMB敏感菌株中,embB基因突变的菌株为17株(41.5%),embB基因在耐药菌株中的突变频率远高于敏感菌株(2=25.58,P=0.00).embB306是最常见的突变位点,其在耐药菌株的突变率也高于敏感菌株(2=12.37,P=0.00),embB基因和embB306位点检测EMB耐药的敏感度、特异度和准确性分别为93.0%和65.1%,58.5%和73.2%,76.2%和69.0%. 结论 EMB耐药的产生与embB基因和embB306突变有关,二者用于检测EMB耐药有一定的参考意义.     

Genetic Diversity,Antimicrobial Resistance,and Virulence Genes of Aeromonas Isolates from Clinical Patients,Tap Water Systems,and Food

Objective This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of Aeromonas isolates from clinical patients, tap water systems, and food.Methods Ninety Aeromonas isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing(MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated gyr B-cpn60 sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing.Results The 90 Aeromonas isolates were divided into 84 sequence types, 80 of which were novel,indicating high genetic diversity. The Aeromonas isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes act, aer A, alt,and ast found in 47(52.2%), 13(14.4%), 22(24.4%), and 12(13.3%) of the isolates, respectively. The majority of the isolates(≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol,gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new mcr-3 variant.Conclusions Sequence type, virulence properties, and antibiotic resistance vary in Aeromonas isolates from clinical patients, tap water systems, and food.