广东连平县存在新的蜱传斑点热立克次体

目的对采自广东省连平县的3种硬蜱进行蜱传斑点热立克次体检测分析。方法斑点热立克次体的ompA基因片段扩增并测定扩增片段的DNA序列。结果20只蜱分为17组,其中15组PCR检测阳性。对4个测序成功的标本进行聚类分析,证实其中3个序列单独聚为一类,与引起Flinders岛蜱传斑点热的弗诺立克次体(R.honei)、非洲蜱咬热的非洲立克次体(R.africa)、未定名斑点热的斯洛伐克立克次体(R.slovaca)以及西伯利亚立克次体BJ-90株等亲缘关系较近,另一序列与我国长白山地区检测到的JL-02具有较高的同源性。结论本研究提示该地区除了已证实的西伯利亚斑点热外,还存在新的蜱传斑点热。     

我国部分地区蜱传斑点热分子流行病学调查研究

目的 进一步了解我国斑点热群立克次体存在的多样性,发现可能存在的斑点热群立克次体新成员、潜在媒介和动物宿主。方法 建立了扩增斑点热群立克次体190kDa rOmpA基因片段的PCR检测、鉴定方法,并用此方法检测了采用福建省和内蒙古自治区的蜱、动物和人血液标本。对扩增于越原血蜱、森林革蜱和FNH97未鉴定菌株的PCR产物采用PHYLIP软件包进行了序列分析。同时,为了寻找特异的斑点热群立克次体分类检测方法,建立了针对四种斑点热群立克次体的半巢式PCR方法,并对斑点热立克次体阳性标本进行了分类检测。结果 采用190kDa rOmpA.701/70p引物可以从7株斑点热群立克次体中的6株扩增出外膜蛋白A基因片段（小蛛立克次体除外）。并从采自福建省和内蒙古自治区的多种蜱及野生动物、人血液标本中扩增出了斑点热立克次体DNA片段,其中越原血蜱、卵形硬蜱、中华硬蜱、豪猪血蜱、森林革蜱、野鼠血块和人群血块的阳性率分别为15．69％、56．94％、8．70％、7．70％、43．56％、82．51％和0．98％。对来自越原血蜱和森林革蜱以及FNH97菌株的斑点热立克次体190kDa外膜蛋白A630bp左右核苷酸片段序列分析和推测的氨基酸序列分析结果表明：福建越原血蜱立克次体（福建立克次体）核苷酸序列与日本立克次体的该序列同源性最高（94％）。推测氨基酸序列同源性也与该立克次体最高（94％）。推测氨基酸序列同源性也与该立克次体最高（89％）;内蒙古森林革蜱立克次体（森林革蜱立克次体）核苷酸序列与扇头蜱立克次的该序列同源性最高（97％）,测氨基酸序列的同源性也最高（95％）。遗传发育分析,这两种立克次体分别与日本立克次体和扇头蜱立克次体均为同一个分支。序列中限制性核酸内切酶的位点也显示了对应的相似性。但是它们的核苷酸和推测的氨基酸序列与康氏立克次体和西伯利亚立克次体以及内蒙古立克次体（HA－91）差别较大。提示,这两种蜱携带的立克次体可能是我国尚未发现的斑点热群立克次体新成员。用初步分类引物对蜱标本、血液标本检测结果显示,以“福建立克次体”序列设计的引物检测越原血蜱阳性率为8．49％,卵形硬蜱阳性率为20．83％,中华硬蜱阳性率为4．35％,豪猪血蜱为阴性;以西伯利亚立克次体序列设计的引物检测卵形硬蜱阳性率24．39％,越原血蜱阳性率为5．56％,中华硬蜱和豪猪血蜱均为阴性。以内蒙革蜱立克次体序列设计的引物扩增森林革蜱阳性率为43．56%。结论 通过本次研究,在以下方面获得了新的认识：越原血蜱、卵形硬蜱、豪猪血蜱和中华硬蜱是福建南方蜱传斑点热立克次体的媒介或潜在媒介,其中卵形硬蜱、豪猪血蜱和中华硬蜱为我国首次证实的携带斑点热立克次体;福建的越原血蜱和内蒙古的森林革蜱分别携带一种未知斑点热群立克次体,并分别与日本立克次体和扇头蜱立克次体近缘;取自斑点热立克次体rOmpA基因的引物用于PCR,作为一种快速简便手段可直接用于斑点热立克次体初步分类和分子流行病学调查;我国可能存在斑点热群立克次体的多个成员及其自然疫源地。     

190 kD R.rOmpA基因序列对斑点热群立克次体的检测

目的为探讨190 kD R.rOmpA基因序列对斑点热群立克次体的检测作用.方法从立氏立克次体190 kD外膜蛋白A(R.rOmpA)基因序列设计引物,利用PCR检测的方法,检测了683只蜱类标本和146个鼠类脏器标本,并随机抽取1株森林革蜱阳性扩增产物进行克隆与序列测定.结果从蜱类标本和鼠类脏器标本中检测出了斑点热立克次体DNA片段;所测序列的分型结果表明与前苏联的DnS 14株型别一致,与我国曾经检测出的斑点热立克次体株差异较大.结论190kD外膜蛋白A基因序列可用于斑点热立克次体检测,并可用于斑点热群立克次体基因型或亚型之间的鉴别.     

江西省赣州市蜱携带立克次体和埃立克体的调研

目的 了解江西省赣州市蜱的种类及其携带的病原体,为蜱传疾病的防控提供科学依据方法 在野外用布旗法和在动物体表采集蜱,进行种类鉴定。用PCR法扩增立克次体(Rickettsia sp.)gltA基因和埃立克体(Ehrlichia sp.)16S rRNA基因片段并测序,进行系统进化分析结果 江西省赣州市4县采集的395只蜱的种类包括2属4种,分别为血蜱属的长角血蜱(Haemaphysalislongicornis)、嗜群血蜱(H. concinna)、具角血蜱(H. cornigera)和扇头蜱属的微小扇头蜱(Rhipicephalus microplus)。395只蜱分为43批检测立克次体和埃立克体,共有18批阳性。系统进化分析显示,龙南县22批蜱中检测到16批阳性,来源于具角血蜱的LN1615株与扇头蜱立克次体(R. rhipicephali)处于同一分支,来源于微小扇头蜱的LN1620株与马赛立克次体(R. massiliae)处于同一分支,其余的12株来源于具角血蜱和2株来源于微小扇头蜱,与日本立克次体(R. japonica)处于同一分支。崇义县CY1602株来源于嗜群血蜱与R. raoultii处于同一分支。于都县YD1606株为来源于长角血蜱的埃立克体,与2010年Yonaguni206(HQ697589)、Yonaguni138(HQ697588)和2009年HLAE178(GU075695)处于同一分支。安远县微小扇头蜱检测均为阴性结论 本文对江西省赣州市采集的蜱进行了鉴定,首次在江西省赣州市的蜱中检测到日本立克次体、扇头蜱立克次体、马赛立克次体、R. raoultii和埃立克体,为江西省蜱种类的调查及其传播疾病的预防控制提供根据。     

黑龙江逊克地区森林革蜱斑点热立克次体DNA的检测

目的 调查黑龙江逊克地区蜱传斑点热自然疫源地,发现该地区蜱携带斑点热立克次体的种类。方法 采用斑点热立克次体ompA和gltA基因特异的PCR,检测该地区森林革蜱的DNA样本,并对扩得阳性产物进行测序和聚类分析。结果 从60只森林革蜱中检测有14只扩得斑点热立克次体ompA和gltA基因片段,阳性率为23.33%。随机选择2只蜱的阳性片段进行测序,二者同源性为100%,ompA基因序列与Rickettsia sp.JL-02同源性为99.30%, 与Rickettsia raoultii为99.18%。结论 黑龙江省逊克地区森林革蜱携带与Rickettsia sp.JL-02株亲缘关系相近的斑点热群立克次体。     

对黑龙江立克次体和远东蜱传斑点热调查研究的思考

斑点热立克次体病是由斑点热群立克次体(spotted fever group rickettsiae SFGR) 引起的蜱、螨传播的人兽共患病.该病广泛分布于世界各地.     

斑点热群立克次体新种──虎林－93株的分离和鉴定

本文用鸡胚卵黄囊培养法及实验动物感染法从黑龙江省虎林县境内采集的嗜群血蜱中分离到了一株立克次体。命名为ＨＬ－９３株立克次体。经形态学及血清学试验证实为斑点热群立克次体。分别用微量免疫荧光法、十二烷基硫酸钠－聚丙烯酰胺凝胶不连续电泳法、单克隆抗体免疫酶斑点法、单克隆和多克隆抗体免疫印迹法、聚合酶链反应和限制性片段长度多态性分析法对该分离株进行鉴定并同已知国际标准株、国际及国内参考株进行比较。结果表明;ＨＬ－９３株立克次体无论在抗原性多肽上,还是在基因水平上在斑点热群立克次体中都是独特的。根据目前立克次体分类法,ＨＬ－９３株立克次体可以考虑是斑点热群立克次体的新种。     

四川石渠县牦牛源蜱感染斑点热群立克次体分子流行病学调查

目的 了解四川省石渠县牦牛体表寄生蜱的种类及其斑点热群立克次体的感染情况。方法 采集牦牛体表的蜱,经形态学初步鉴定后,提取蜱总DNA,PCR扩增蜱16S rRNA基因及斑点热群立克次体ompA、ompB基因,并对扩得阳性产物进行测序和构建进化树分析,从而确定蜱及其携带斑点热群立克次体的种类。结果 在石渠县4个乡共采集到蜱818只,其中西藏革蜱占78.97%(646/818)、青海血蜱占21.03%(172/818)。在818只蜱中有408只扩得斑点热群立克次体ompA、ompB基因,总阳性率为49.8%。经比对分析, ompA基因总共得到4条序列(uncultured Rickettsia sp.shiqu1、R.raoultii.shiqu2、R.raoultii.shiqu3和R.raoultii.shiqu4),ompB基因也得到4条序列(uncultured Rickettsia sp.shiqu1、R.raoultii.shiqu2、R.raoultii.shiqu3和R.raoultii.shiqu4)。经遗传进化分析显示ompA基因的uncultured Rickettsia sp.shiqu1与我国青海未定种的Uncultured Rickettsia sp.(MG228270)亲缘关系最近;ompB基因的uncultured Rickettsia sp.shiqu1与韩国未定种的Rickettsia sp.(KC888953)和Candidatus Rickettsia longicornii(MG906675)亲缘关系最近;ompA和ompB基因的R.raoultii.shiqu2-4与对人有致病性的劳氏立克次体(R.raoultii)的亲缘关系最近。结论 首次在牦牛体表寄生的西藏革蜱中检出劳氏立克次体。石渠县存在西藏革蜱和青海血蜱,蜱传劳氏立克次体感染率较高并且具有感染人的风险。     

应用PCR技术检测斑点热群立克次体特异性

作者对不明热患者血液,立克次体细胞培养物,疫区的微小牛蜱,野鼠脾脏等标本,应用Ｒｒ．１９９０．７０ｐ和Ｒｒ．１９０．６０２ｎ引物对,进行ＰＣＲ扩增,检测斑点热群立克次体特异性ＤＮＡ。     

新发蜱传病原体——劳氏立克次体的研究现状

劳氏立克次体是一种新发现的蜱传病原体,属于立克次体属斑点热群中的一员,其主要引起人的蜱传淋巴结炎等疾病。劳氏立克次体目前主要发现存在欧洲和亚洲。蜱是劳氏立克次体传播媒介,革蜱的携带率最高,平均携带率高达47.74%。劳氏立克次体已在我国吉林、黑龙江、西藏、新疆、甘肃等地的蜱中检出。本文从劳氏立克次体的地理分布、传播媒介、医学重要性及分子生物学等方面研究现状做一综述。     

Aponomma hydrosauri, the reptile-associated tick reservoir of Rickettsia honei on Flinders Island, Australia

Rickettsia honei is the etiologic agent of Flinders Island (Australia) spotted fever. The tick Aponomma hydrosauri is associated with reptiles and is the arthropod reservoir for this rickettsia on Flinders Island. The rickettsia appears to be maintained in the tick via vertical transmission. Of 46 ticks examined, 29 (63%) were positive for spotted fever group rickettsiae by detection of the citrate synthase gene by a polymerase chain reaction (PCR). From the positive tick samples, seven were sequenced and found to be 100% homologous with R. honei. Of 17 reptiles examined, none had evidence of rickettsiae by PCR or culture of blood.     

普氏立克次体14KD蛋白基因DNA、生物素探针的制备及其应用的研究

我们用长臂光敏生物素标记了克隆的普氏立克次体Brein 1株的14KD蛋白基因DNA,并对此DNA探针的应用价值进行了研究。此DNA探针能与普氏立克次体(Rickettsia prowazekii)和莫氏立克次体(Rickettsia mooseri)的DNA杂交而不能与斑点热群立克次体(Spotted Fever Group Rickettsiae)和大肠杆菌的DNA杂交。此生物素探针能检测出1ng的普氏立克次体DNA,并能检测出人工感染豚鼠的早期血液中的普氏立克次体和莫氏立克次体。     

Short report: isolation and identification of two spotted fever group rickettsial strains from patients in Catalonia, Spain

Two rickettsial strains, 16B (previously isolated) and FB1, were isolated from blood from patients with Mediterranean spotted fever in Catalonia, Spain. These are the only 2 human rickettsial isolates of the spotted fever group obtained so far in Spain. These strains were identified by the polymerase chain reaction and sequence analysis of a fragment of the outer membrane protein A (ompA) gene. The partial ompA sequence was found to be 100% identical with that of Rickettsia conorii (Malish 7 strain) for both strains. These results confirm the presence of R. conorii in Catalonia, despite the fact that in a previous study, no R. conorii were isolated, but a new rickettsial strain of the spotted fever group (Bar29) was isolated from dog ticks (Rhipicephalus sanguineus) in Catalonia. Further studies are necessary to get a better knowledge of the epidemiology of rickettsiae in Catalonia.     

Detection of Rickettsia africae in Rhipicephalus (Boophilus) decoloratus ticks from the Republic of Botswana, South Africa

A total of 53 engorged adult ticks belonging to the species Rhipicephalus (Boophilus) decoloratus (N = 9), Rhipicephalus evertsi evertsi (N = 27), Rhipicephalus appendiculatus (N = 9), Amblyomma hebraeum (N = 5), and Hyalomma marginatum turanicum (N = 3), were removed from oryx in Botswana (South Africa). They were tested for the presence of spotted fever group (SFG) Rickettsia and Anaplasma phagocytophilum using polymerase chain reaction (PCR). Seventy-seven percent of R. decoloratus as well as twenty percent of A. hebraeum were positive for ompA, gltA and 16S rRNA SFG Rickettsia PCR assays. All nucleotide sequences were homologous to Rickettsia africae, the agent of African tick-bite fever (ATBF). None of the tested ticks was positive for 16S rRNA A. phagocytophilum PCR assays. These results suggest for the first time that R. decoloratus ticks may be reservoirs of R. africae, and support the ATBF risk in this area.     

Serologic study of the prevalence of rickettsiosis in Yucatán: evidence for a prevalent spotted fever group rickettsiosis.

Because of the discovery of a spotted fever group rickettsiosis with signs and symptoms similar to dengue fever in Yucatan, Mexico, immunofluorescence assay (IFA) serology was performed on sera from 390 persons selected from a representative geographic distribution of rural Yucatan to detect antibodies reactive with Rickettsia rickettsii, R. akari, a Thai strain (TT-118) that is most closely related to a rickettsia identified in Amblyomma cajennense ticks in southern Texas, and R. typhi. The IFA antibodies at titers > or = 1:64 against R. akari were detected in 22 (5.6%) of the samples with the expected cross-reactivity against the other antigens of the spotted fever group. Immunoblotting with antigens of R. akari identified antibodies against antigens of spotted fever group lipopolysaccharides and not against rickettsial outer membrane proteins A and B, which contain the species-specific epitopes. A rickettsiosis most likely caused by a relative of R. akari appears to be both prevalent and widely distributed geographically in Yucatan.     

Epidemiology of Rocky Mountain spotted fever in Ohio, 1981: serologic evaluation of canines and rickettsial isolation from ticks associated with human case exposure sites

A survey for the prevalence of Rocky Mountain spotted fever (RMSF) antibodies in dogs associated with confirmed human cases in Ohio was conducted during 1981. Twelve of 14 confirmed cases (85%) had a history of dog association prior to onset of RMSF. A total of 29 dogs were included in the study, with 16 dogs providing serum samples for antibody testing and the remainder providing tick samples. Serum samples tested by indirect microimmunofluorescence techniques revealed 12/16 dogs (75%) to be seropositive for Rickettsia rickettsii. A total of 310 ticks were collected from study dogs and the vegetation surrounding RMSF case exposure sites. Twenty-two (7.1%) of these ticks (all Dermacentor variabilis) were found to be infected with spotted fever group rickettsiae. Four ticks (1.3%) were infected with R. rickettsii, 13 (4.2%) with Rickettsia montana, and four (1.3%) with Rickettsia bellii. R. montana, a nonpathogen, was the only rickettsia found in dogs (antibodies) and ticks (isolation) associated with human cases in Southern Ohio.