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1.
云南省鹤庆县2017年分离鼠疫菌分子溯源   总被引:5,自引:1,他引:4       下载免费PDF全文
目的 了解2017年云南省鹤庆县新分离的鼠疫菌的基因分型,为该地的鼠疫防控提供科学依据。方法 采用差异片段(DFR)、规律成簇的间隔短回文重复序列(CRISPRs)和多位点可变数目串联重复序列分析(MLVA)3种方法对10株鹤庆县新分离鼠疫菌进行分型,并将10株鼠疫菌及邻近疫源地鼠疫菌株93株纳入聚类分析。结果 鹤庆鼠疫菌株与丽江鼠疫疫源地菌株具有相同的DFR型(Genomovar 05型)及CRISPRs型(Ca7簇,22型),在MLVA聚类分析中,鹤庆鼠疫菌株与丽江野鼠鼠疫菌株位于同一个簇,两者之间仅有2个位点(N2117,M23)的差异。结论 2017年云南省鹤庆鼠疫菌株与丽江野鼠鼠疫疫源地菌株具有很高的同源性,鹤庆县疫情可能是丽江鼠疫进一步向南扩散的结果。  相似文献   

2.
目的 分析无抗生素压力下连续传代90次的4株志贺菌耐药表型及成簇规律间隔短回文重复序列(CRISPR)/CRISPR相关蛋白(Cas)基因变化。方法 对临床分离的4株耐药谱不同的志贺菌进行无抗生素压力连续传代90次,传代结束后用琼脂稀释法检测传代前、后志贺菌最小抑菌浓度;用PCR对CRISPR位点进行扩增并测序,CRISPR Finder和Clustal X 2.1分析CRISPR位点的变化。结果 经无抗生素压力传代90次后,4株志贺菌对某些抗生素的敏感性有不同程度的增加:mel-sf1998024/zz对氨苄西林、头孢氨苄、头孢噻肟、氯霉素的耐药性降低,mel-s2014026/sx对诺氟沙星、甲氧苄啶的耐药性降低,mel-sf2004004/sx对氨苄西林、头孢呋辛、头孢噻肟、氯霉素、甲氧苄啶的耐药性降低,mel-sf2013004/bj对氯霉素的耐药性降低;志贺菌mel-sf1998024/zz和mel-sf2013004/bj经无抗生素压力传代后,CRISPR3位点3''的重复-间隔序列丢失,其中间隔序列匹配基因的编码产物是Cas蛋白。结论 志贺菌在无抗生素压力下,可降低或丢失对某些抗生素的耐药性。部分志贺菌CRISPR3位点的结构发生了变化,CRISPR3位点与cas基因可能存在共进化。  相似文献   

3.
目的 探讨O26:H11及NM血清型大肠埃希菌中成簇规律间隔短回文重复序列(CRISPR)的分子分布特征及其与stx噬菌体的关系。方法 135株O26:H11及NM血清型大肠埃希菌从NCBI数据库获取,利用CRT软件及CRISPR Finder提取CRISPR信息,并用Excel软件对间隔序列进行编号及分析CRISPR亚型,并分析CRISPR与stx噬菌体之间的关系。结果 135株O26:H11及NM血清型大肠埃希菌中均存在CRISPR结构,CRISPR1包括19个亚型,CRISPR 2.1包括22个亚型,CRISPR2.2包括1个亚型,CRISPR3-4包括1个亚型。stx噬菌体在CRISPR群组C中出现,stx+ 菌株比stx-菌株拥有更多的间隔序列。结论 CRISPR位点在O26:H11或NM血清型大肠埃希菌中广泛存在,且存在着不同的亚型,stx噬菌体与CRISPR的分子分布特征有关,可能作为鉴定高毒菌株的分子靶标。  相似文献   

4.
目的 探讨基于CRISPR/Cas的大肠埃希菌分子标志物的监测研究。方法 通过BLAST收集GenBank数据库中135株全基因组测序大肠埃希菌、203株鸟枪法测序大肠埃希菌的CRISPR/Cas和PCR扩增、测序获得本实验室保存361株大肠埃希菌(包括38株大肠埃希菌O157:H7)的CRISPR序列,应用CRISPR Finder在线软件分析CRISPR特征、DNAMAN软件进行间隔序列的比对,使用Clustal Ⅹ进行cas多序列比对和Mega 5.1软件构建系统进化树。结果 本研究以全新的视角对大肠埃希菌的CRISPR/Cas位置进行描述;结果显示,135株全基因组测序、203株鸟枪法测序和361株本实验室测序的大肠埃希菌中分别有77.04%、100.00%和75.62%的大肠埃希菌具有CRISPR1,分别有74.81%、100.00%和92.24%的大肠埃希菌具有CRISPR2,分别有11.85%、0和1.39%的大肠埃希菌具有CRISPR3和CRISPR4;GenBank数据库下载的全基因组测序的1株和本实验室测序的2株大肠埃希菌存在4个CRISPR位点;缺少cas的CRISPR1下游有插入序列存在。在699株大肠埃希菌中,8株O55:H7、180株O157:H7、8株O157:HNM、40株O104:H4、4株O145:H28有独特的CRISPR;间隔序列的缺失可发生在CRISPR中间;依据I-E和I-F的cas构建系统发育树,均可分为两类。结论 大肠埃希菌的CRISPR/Cas可能作为鉴定强毒株大肠埃希菌或者新型菌株的分子标志物。间隔序列的缺失或获得可能与噬菌体有关。  相似文献   

5.
目的对河北省鼠疫菌株进行规律聚集间隔短回文重复序列CRISPR)基因分型。方法利用聚合酶链式反应(PCR),采用3对CRISPR引物,对河北省分离的128株鼠疫菌进行扩增,测定扩增产物核酸序列并进行分析,确定河北省菌株CRISPR基因型。结果 128株鼠疫菌在3个CRISPR位点上有8种间隔序列,包括al、a2、a3、b1、b2、c1、c2、c3,分为2个基因型。118株鼠疫菌株为Cb2型,另外10株鼠疫菌均为新基因型(命名为Cc△1型)。结论通过CRISPR分析显示河北省鼠疫菌株遗传进化比较稳定,建立了CRISPR基因库,为鼠疫菌种群遗传进化和鼠疫防控的研究提供参考。  相似文献   

6.
目的 探索志贺菌中成簇规律间隔短回文重复序列(CRISPR)的分布。方法 共选择志贺菌分离株52株, 其中河南41株, 江西6株, 北京5株。利用PCR扩增志贺菌的4个CRISPR位点(S1、S2、S3、S4), 产物送测序, 分析CRISPR的重复序列和间隔序列。结果 志贺菌的4个CRISPR位点阳性率分别为33. 69%(S1)、50.00%(S2)、82.69%(S3)和73.08%(S4);S1和S3包括2种亚型, S2有3种亚型, S4包括4种亚型。2004年前分离的河南分离株中检出S1位点, 2004年后分离的菌株中均未检出该位点;S2、S3和S4在两组的分布没有差异。结论 志贺菌各CRISPR位点含有不同亚型, 河南分离株S1的分布与细菌分离时间有关, 而S2、S3 及S4和分离时间无关。  相似文献   

7.
目的 构建云南省鼠疫菌Fse I酶切的脉冲场凝胶电泳(PFGE)图谱库并探讨其流行病学意义。方法 采用限制性内切酶Fse I对云南家、野鼠型及丽江玉龙鼠疫菌株进行酶切分析,并聚类分析电泳图谱。结果 30株被试菌株分为16种PFGE型别,其相似性系数为79.8%~100.0%;16种PFGE基因型可以分为4个簇,除EV76自成一簇,其余3个簇分别为家鼠型基因簇、野鼠型基因簇及玉龙基因簇。结论 云南省鼠疫菌PFOE基因型与生态型、生物型相吻合,具有一定的区域聚集性,而丽江玉龙鼠疫菌为一个独立基因簇。  相似文献   

8.
目的 评价并验证成簇规律间隔短回文重复序列(CRISPRs)、血清学和多位点测序分型(MLST)方法对大肠埃希菌分型的效果。方法 使用CRISPRsFinder分析大肠埃希菌全基因组序列的CRISPRs间隔序列,使用在线软件SeroTypeFinder和MLST获得血清型和序列型(ST);采用PCR扩增并分析349株大肠埃希菌CRISPRs,使用CRISPRs间隔序列预测血清型和ST,并比较血清学和MLST分型结果。结果 将I-E型CRISPR/Cas、I-F型CRISPR/Cas和CRISPR3-4分别命名CT-Ⅰ、CT-Ⅱ和CT-Ⅲ。根据CRISPRs间隔序列构成和排列进一步进行分型,203株大肠埃希菌被分为79个CT型别,76个血清型和66个ST。CRISPRs分型的区分能力最强,辛普森指数为0.936。CRISPRs和血清学的关联程度最高,调整兰德指数为0.908。CRISPRs型能进一步区分相同血清或ST产志贺毒素的大肠埃希菌[O157∶H7(ST11)、O104∶H4(ST678)和O26∶H11(ST21)]菌株。扩增实验室菌株的CRISPR1、CRISPR2、CRISPR3、CRISPR4和CRISPR3-4,检出率分别为81.1%、94.5%、1.4%、1.4%和4.6%;根据CRISPRs间隔序列预测O157∶H7(ST11)和ST131准确率分别为95.0%和100.0%。结论 基于CRISPRs的大肠埃希菌的分子分型方法呈现较好的分型效果和临床应用效果,预期可以成为大肠埃希菌分型的重要分子标志物。  相似文献   

9.
目的 对1958--2012年青海省人间鼠疫流行期间自鼠疫患者和尸体中分离的129株鼠疫菌进行病原学研究。方法 采用常规方法和分子生物学技术对鼠疫菌进行病原学研究,同时采用差异区段(DFR)基因分型技术对2004年囊谦县、2009年兴海县人间肺鼠疫暴发疫情进行溯源分析。结果 119株鼠疫菌中,205株属青藏高原型菌株,6株属祁连山型菌株,8株菌具有特殊生化特性;84.03%(100/219)的鼠疫菌具有4个毒力因子(F1+、Pst I+、VW+、Pgm+)。测试的74株菌中,72株(97.30%)为强毒菌;携带大质粒52×106、65X 106、92×106的菌株主要分布于海南、海北、海西、玉树、果洛、黄南6个州和湟源县;鼠疫菌DFR基因型以5、8型为主。其中5型占44.54%(53/119),分布于都兰、湟源、玉树、杂多、治多、称多、曲麻莱、玛多、囊谦、祁连等地区;8型占32.77%(39/119),分布于祁连山南北麓、青海湖环湖地区。2004年囊谦县肺鼠疫暴发分离株均为10型;2009年兴海县肺鼠疫暴发分离株(来自鼠疫患者、人尸和牧犬体内)的基因型均为8型。结论 本次试验菌株均具备青藏高原鼠疫病原体特性。菌株溯源分析显示,基于DFR的鼠疫菌基因分型与流行病学调查一致,可用于确定传染源。  相似文献   

10.
目的 探讨基于成簇规律间隔的短回文重复序列(CRISPR)1上游侧翼序列对大肠埃希菌和志贺菌鉴定和评价效果。方法 通过BLAST重复序列识别并获得全基因组测序大肠埃希菌和志贺菌的CRISPRs和CRISPR相关基因(CRISPR-associated,cas),并分析其种系;选取CRISPRs上、下游各500 bp侧翼序列,使用Clustal X进行序列比对;采用PCR方法扩增CRISPR1上游侧翼序列,以确定其对大肠埃希菌和志贺菌鉴定和评价效果。结果 73.4%(149/203)的大肠埃希菌存在I-E型CRISPR/Cas系统,包含了A、B1、D种系;8.4%(17/203)的大肠埃希菌存在I-F型CRISPR/Cas、17.2%(35/203)的大肠埃希菌不存在CRISPR/Cas,这2种大肠埃希菌均属于B2种系;9株志贺菌均存在I-E型CRISPR/Cas。在大肠埃希菌(B2种系外)、志贺菌CRISPR1上游和大肠埃希菌(B2种系)各存在61 bp侧翼序列,序列一致性为99%,且有种属特异性,PCR扩增此区域鉴定大肠埃希菌和志贺菌的灵敏度和特异度均>91%。结论 基于CRISPR1上游序列可用来鉴定大肠埃希菌和志贺菌,且具有很好的效果。  相似文献   

11.
To examine trends in predictors of HIV-related mortality among cohorts of persons living with AIDS (PLWA) in New York City (NYC), nine calendar year-specific cohorts of PLWA were created from 1993 to 2001. Cohorts were defined as persons who had been alive at any time during that year and had been diagnosed with AIDS before the end of that year. Predictors of death because of HIV-related causes of death were assessed by examinnng year-specific, stratified death rates per 1,000 PLWA and adjusted relative risks (RRs) from proportional hazards models. We conducted an analysis of AIDS surveillance data PLWA in NYC between 1993 and 2001. Univariate and multivariate Cox proportional hazards models were constructed for each calendar year cohort to evaluate trends in the RR of HIV-related death over the subsequent 5 years, adjusting for sex, reace/ethnicity, age, transmission risk borough of residence, category of AIDS diagnosis [opportunistic illness (OI) or CD4 count <200 cells/μL], time since AIDS diagnosis, and CD4 count at time of AIDS diagnosis. Death rates due to all causes and HIV-related causes declined substantially during 1993–1997 and then stabilized in all subgroups of PLWA between 1998 and 2001. Beginning in 1995, differences in survival emerged in some subgroups, such that by 2001 (1) injecting drug users (IDUs) had poorer survival compared with men who have sex with men (MSM) [RR2001=2.1, 95% confidence intervals (95% CI)=1.8–2.4]; (2) black and Hispanic PLWA had a significantly higher risk of death than white PLWA (RR2001=1.4, 95% CI=1.2–1.6, RR2001=1.2, 95% CI=1.1–1.4, respectively, and (3) PLWA aged 60 and above had poorer survival compared with younger persons (RR2001=2.4, 95% CI=1.9–3.0), after adjustment for other factors. The observed disparities that began to emerge in 1995 may be attributable to differential effects of, access to, or usage of highly active antiretroviral therapy (HAART). More targeted studies are needed to determine why such disparities have emerged.  相似文献   

12.
In this article, we present preliminary findings from a qualitative study focused on the impact of the World Trade Center attacks on New York City residents who are current or former users of heroin, crack, and other forms of cocaine. In it, we present data describing their responses to and feelings about the attacks, changes in drug use after the attacks, and factors affecting changes in use. Our analysis is based on 57 open-ended interviews conducted between October 2001 and February 2002. The majority of study participants reported that the attacks had a significant emotional impact on them, causing anxiety, sadness, and anger. Several described practical impacts as well, including significant reductions in income. On September 11th and the weeks and months that followed, several participants who had been actively using did increase their use of heroin, crack, and/or other forms of cocaine. Reductions in use were, however, as common over time as were increases. There was some relapse among former users, but this was limited to those who had stopped using drugs within the 6 months immediately preceding the attacks. A diverse set of factors interacted to control use. For some participants, these factors were internal, relating to their individual motivations and drug use experiences. Other participants were essentially forced to limit use by marked reductions in income. For others, access to health and social service professionals, as well as drug treatment, proved to be key. Department of Family Medicine and Community Health at Montefiore Medical Center  相似文献   

13.
Previous studies have identified a “digital divide” between African Americans and whites, with African Americans having substantially lower rates of Internet use. However, use of the Internet to access health information has not been sufficiently evaluated in this population. Therefore, we conducted a telephone survey to determine the prevalence of computer and Internet use among 457 African American adults with type 2 diabetes. Participants were 78% female, with a mean age of 57±11 years, and about one-third had a yearly income ≦$7,500. Forty percent of the participants reported having a computer at home and 46% reported knowing how to use a computer. Most participants (58%) reported that they had, at some point, used a computer, and of those, 40% reported that they used the computer to find health information. In a stratified analysis, participants with lower education levels (<high school) were less likely to have a computer; older participants, men, and individuals with lower education levels were less likely to know how to use a computer and to use it to search for health information (all P<.05). Nonetheless, of the participants who did not know how to use a computer, 66% reported that they would be willing to learn. In addition, 82% reported that they had friends or family in the neighborhood who would let them use a computer. Furthermore, 89% of participants reported that they would use a computer program to manage their diabetes if it were offered free of charge. These data show promise for the willingness of this under-served population to use computers and access health information using the Internet. New programs are needed to explore Internet-based interventions to improve self-management and diabetes care among African Americans.  相似文献   

14.
Absorption,metabolism and elimination of N,N-dimethylformamide in humans   总被引:4,自引:0,他引:4  
Summary Excretion of N,N-dimethylformamide (DMF) and DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethyl-formamide (F) and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) has been monitored in the urine of volunteers during and after their 8-h exposure to DMF vapour at a concentration of 10, 30 and 60 mg · m–3. The pulmonary ventilation in these experiments was typically about 101 · min–1 and the retention in the respiratory tract was 90%. After exposure to 30 mg DMF · m–3, the yield of compound determined in the urine represented 0.3% (DMF), 22.3% (MF), 13.2% (F) and 13.4% (AMCC) of the dose absorbed via the respiratory tract. The excretion curves of the particular compounds attained their maximum 6–8h (DMF), 6–8h (MF), 8–14h (F) and 24–34h (AMCC) after the start of the exposure. The half-times of excretion were approximately 2, 4, 7 and 23 h respectively. In contrast to slow elimination of AMCC after exposure to DMF, AMCC was eliminated rapidly after AMCC intake. This discrepancy could be explained by rate-limiting reversible protein binding of a reactive metabolic intermediate of DMF, possibly methylisocyanate.  相似文献   

15.
Summary As a consequence of contact with animals and animal products slaughterhouse workers might be at risk of infection with pathogenic microorganisms. This hypothesis has been supported by some earlier studies. In this study 217 slaughtermen and a control group of 113 greenhouse workers were investigated for the prevalence of serum antibodies to Toxoplasma gondii, Campylobacter jejuni (IgA and IgG), Yersinia enterocolitica types 3 and 9, Yersinia pseudotuberculosis types I, II, III, IV, and V, Salmonella typhi, Salmonella paratyphi, Salmonella enteritidis, Salmonella typhimurium, and Borrelia burgdorferi. No significant differences were found concerning either frequency of positive tests or magnitude of titers. The prevalence of toxoplasma antibodies was remarkably high in both groups.  相似文献   

16.
Objectives To investigate the relationship between N,N-dimethylformamide (DMF) exposure and excretion of urinary N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) and N-methylformamide (NMF) in workers at synthetic leather manufacturing factories in Korea, for the first time.Methods One-hundred forty-four male workers at nine synthetic leather manufacturing factories were surveyed. Exposure to DMF was evaluated through breathing zone air sampling followed by analysis via a gas chromatograph equipped with a flame ionization detector (GC-FID). The levels of NMF and AMCC were determined by a GC with a flame thermionic detector (GC-FTD). Urine samples were collected at the end of the workshift.Results and Conclusions Geometric mean of workplace air DMF and urinary NMF was 8.8 ppm and 47.5 mg/l, respectively, and the level of DMF and NMF was significantly correlated. The biological exposure limit for NMF (15 mg/ml) was exceeded in 89.5% of urine samples, and 37.9% of air samples exceeded the environmental DMF exposure limit (10 ppm), indicating a serious health risk to the employees of the synthetic leather industry in Korea. Exposure to 10 ppm DMF in the workplace air corresponded to a urinary NMF concentration of 53.4 mg/l. Alcohol intake the day before urine was sampled influenced NMF excretion into urine (40.5 mg/l NMF for the no-alcohol group and 94.6 mg/l for the group consuming more than 63.0 g alcohol/day). We could not find a significant relationship between air DMF and urinary AMCC concentration. Exposure to 10 ppm DMF corresponded to an AMCC concentration of 8.0 mg/l in the urine samples collected on the same day as the air was sampled.  相似文献   

17.
本文报告了1986年对我国五个地区994名健康成人、373名儿童和100例肺炎病人进行三种军团菌抗体检测的结果。健康成人抗体阳性率(≥1:16)Lm为9.26%,Ld为9.05%,Lg为3.32%。儿童Lm为5.36%,Ld为2.14%,Lg为3.75%。肺炎病人抗体阳性率以Ld最高(44%),Lm次之(23%),Lg均阴性。提示我国南方和北方地区人群中均存在这三种军团菌感染的可能性,应予以注意。  相似文献   

18.
Percutaneous absorption of N,N-dimethylformamide in humans   总被引:3,自引:0,他引:3  
Summary Skin penetration fo N,N-dimethylformamide (DMF) liquid or vapour was studied in volunteers. Exposure to liquid DMF was performed in two ways: in a dipping experiment, one hand was dipped up to the wrist in DMF for 2–20 min, while in a patch experiment, 2 mmol DMF was applied to the skin and allowed to be absorbed completely. The period of exposure to DMF vapour (50 mg · m–3) was 4 h. The DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethylformamide (F), and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) were monitored in the urine. Liquid DMF was absorbed through the skin at a rate of 9.4 mg · cm–2 · h–1. Percutaneous absorption of DMF vapour depended strongly on ambient temperature and humidity and accounted for 13%–36% of totally excreted MF. The results suggest that skin absorption of liquid DMF is likely to contribute to occupational exposure substantially more than penetration of DMF vapour. The yield of metabolites after transdermal DMF absorption was only half of that seen after pulmonary absorption. Elimination of MF and F but not that of AMCC was delayed, which supports the contention that AMCC should be used instead of MF as the most suitable biomarker of DMF in cases where percutaneous intake can occur.  相似文献   

19.
56 adult ticks D. marginatus and 38 adult ticks H. punctata were sampled by the flagging method, transferred to the laboratory, dissected and tested for infection with Lyme disease spirochetes. 3 (7.9%) of the adult H. punctata and 2 (3.57%) of the adult D. marginatus were infected with B. burgdorferi (Bb). This report also presents the case of a patient, who developed Lyme disease symptoms after he had been bitten by a D. marginatus tick. The clinical diagnosis was confirmed by serological testing and by a biopsy, taken from the patient's skin lesion. The skin biopsy was examined under an electron microscope and Bb was found in the sections of the deeper strata of the dermis in two structural forms: (a) cylindrical bodies (protoplasm cylinder) with circular ends covered with a three-layered membrane; (b) granules, situated among the collagenous fibres either closely adhered to them or covered with a membrane. The result of the study demonstrates that in single cases in some ecosystems, ticks D. marginatus might be implicated in Bb transmission to humans as secondary vectors.  相似文献   

20.
Isolates of Candida albicans with varied phenotypes, including sucrose-negative variants (C. stellatoidea, serotypes A and B) and avirulent germ tube-negative forms (C. claussenii) showed significant (> 90%) DNA relatedness to classical C. albicans, but insignificant relatedness to C. tropicalis and sucrose-negative C. tropicalis. A transverse alternating-field gel electrophoresis procedure (TAFE) showed discrete karyotype patterns among the phenotypic variants of C. albicans including the sucrose-negative C. stellatoidea. The number of chromosome-sized DNA bands for C. tropicalis (7 bands) were within the range of bands observed for C. albicans (5 to 10 bands). The general DNA-migration pattern for C. albicans appeared distinct from that of C. tropicalis. An aspartyl proteinase (PrA) gene probe from C. albicans hybridized with chromosomal DNA from C. albicans, C. claussenii and C. stellatoidea but not with that from C. tropicalis.  相似文献   

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