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。     

云南省曲靖市啮齿动物的立克次体血清学和分子流行病学调查

目的调查云南省曲靖市啮齿动物感染立克次体状况。方法用鼠笼法捕鼠,采集鼠血清和脾脏。用间接免疫荧光试验(IFA)检测鼠血清中7种常见立克次体的IgG抗体;用巢氏PCR方法检测鼠脾中嗜单核细胞埃立克体和嗜吞噬细胞无形体16SrRNA基因片段部份序列。结果 2012年7-9月在曲靖市捕获啮齿动物3种592只,褐家鼠(Rattus norvegicus)和黄胸鼠(Rattus flavipectus)构成比分别为61.49%和35.47%。鼠血清中贝氏柯克斯体(Coxiella burentii)、莫氏立克次体(Rickettsia typhi)、恙虫病东方体(Orientia tsutsugamushi)、西伯利亚立克次体(Rickettsia sibirica)、嗜吞噬细胞无形体(Anaplasma phagocytophilum)和嗜单核细胞埃立克体(Ehrlichia chaffeensis)的抗体阳性率依次为21.45%、7.60%、7.09%、3.38%、1.18%和0.51%;未检测到猫立克次体(Rickettsia felis)抗体。从5份褐家鼠脾脏标本中检测到16SrRNA基因序列,同源性和进化分析表明,1株为嗜吞噬细胞无形体,4株为莫氏立克次体。结论曲靖市啮齿动物中存在莫氏立克次体和人粒细胞无形体流行,褐家鼠可能是主要宿主;同时还存在恙虫病东方体、贝氏柯克斯体、斑点热立克次体和埃立克体的感染。当地疾控和医疗机构应加强立克次体病的监测。     

云南省泸西县啮齿动物携带立克次体调查

目的 调查云南省泸西县啮齿动物携带恙虫病东方体、无形体和埃立克体的状况,了解该类病原体在当地自然界中的保存状况和基因特征。方法 用鼠笼和鼠夹在云南省泸西县捕鼠,将捕获的动物种类鉴定后解剖取脾脏,活鼠取血。采用巢式PCR扩增脾脏的恙虫病东方体groEL基因,无形体和埃立克体的16S rRNA基因特异片段;测定PCR扩增阳性产物的DNA序列,对获得序列进行序列比对和系统进化分析。IFA法检测鼠血清中恙虫病东方体IgG抗体。结果 在泸西县共捕获啮齿动物10种225只。其中黄胸鼠36.89%(83/225)、大绒鼠35.11%(79/225)和中华姬鼠13.78%(31/225)为优势鼠种。获得鼠血清85份。鼠脾脏中检测到5株东方体groEL基因阳性标本,带毒鼠种为黄胸鼠2.41%(2/83)和大绒鼠3.80%(3/79)。同源性比较显示,这5株东方体的相似性在99.02%~100%之间,他们分别与GenBank中已知立克次体序列的相似性在98.75%~100%。系统发生树显示,5株OT与来自日本、泰国和中国安徽的菌株位于同一分支。3份16S rRNA阳性标本,其中1份埃立克体阳性,来源于大绒鼠;1份沃尔巴克氏体和1份巴尔通体阳性均来源于黄胸鼠。无形体均为阴性。埃立克体株序列比对显示与来自美国、中国和巴西的埃立克体基因同源性为98.0%~100%,并与分离自美国野外工作者皮肤的伊文氏埃立克体在同一分支。鼠血清恙虫病IgG抗体阳性7份,阳性率8.24%(7/85)。结论 该地区存在以黄胸鼠和大绒鼠为主要宿主的恙虫病自然疫源地。埃立克体、巴尔通体和沃尔巴克氏体在啮齿动物中也存在感染,需注意防控。     

对不明原因发热者要考虑到人粒细胞无形体病的诊断

立克次体病是由各种立克次体感染导致的人兽共患自然疫源性疾病.立克次体是革兰阴性胞内寄生菌,生物学特征介于病毒和细菌之间,在动物宿主包括啮齿动物如鼠类和家畜等贮存宿主体内繁殖,传播途径主要是由节肢动物蜱、螨、蚤、虱等媒介的叮咬或暴露,以及气溶胶方式进行传播.传统的立克次体病包括斑疹伤寒、恙虫病、斑点热、战壕热、Q热,其主要致病机制是病原体侵染血管内皮细胞导致小血管炎和血管周围炎.近年来世界范围内新发立克次体病不断出现,如人粒细胞无形体病及人单核细胞埃立克体病等.     

浙江磐安地区啮齿动物嗜吞噬细胞无形体感染研究

目的 调查浙江省磐安地区啮齿动物无形体属嗜吞噬细胞无形体的自然感染状况,了解其分子生物学特性。方法 在浙江省磐安地区低山田地里捕获多种啮齿动物230只(黄胸鼠、社鼠、褐家鼠、小林姬鼠、黄毛鼠、青毛鼠、大林姬鼠、白腹巨鼠、针毛鼠、黑线姬鼠和松鼠);解剖取肝脾;提取DNA,用巢式PCR扩增无形体属16S rRNA片段;PCR产物测序,并进行Blast 同源性比较,最后采用MEGA4.0软件与GenBank登录的其它无形体属种株进行系统发生分析。结果 230只啮齿动物中,1只黄胸鼠、1只褐家鼠和2只白腹巨鼠肝脾标本检出无形体属16S rRNA片段,磐安地区野鼠无形体属立克次体的自然感染率为1.7%。3份阳性标本PCR产物测序,序列比对分析表明,从褐家鼠同时检出分别与嗜吞噬细胞无形体和浙江无形体株ZJ05/2009完全一致的序列,黄胸鼠和1只白腹巨鼠的序列与浙江无形体株ZJ05/2009完全一致。结论 浙江省磐安地区野鼠检出致病性无形体属核酸,存在无形体属不同种株的复合感染感染。提示可能存在无形体病自然疫源地,需要进一步密切关注致病性无形体的人群感染情况。     

恙虫病立克次体蛋白抗原及其编码基因研究进展

恙虫病立克次体（Rickettsiatsutsugamushi）是恙虫病（Scrubtphus）的病原体,专性活细胞内寄生,革兰氏阴性,恙螨是其传播媒介。在分类地位上,恙虫病立克次体原属于立克次体科立克次体属,但由于其在许多生物学和遗传特性方面不同与其他立克次体,1995年将其另立一属一东方体属（Orientia）,称为恙虫病东方体（Orientiatsutsugamushi）[1]。近十多年来,新的技术方法尤其分子生物学方法不断引入恙虫病立克次体的研究,使病原学研究更加系统深入广泛。现对其蛋白抗原与其编码基因的研究综述如下。1恙由病立克次体的多胜组成纯化的恙虫…     

安徽三界地区啮齿动物感染恙虫病东方体调查

目的调查安徽三界地区啮齿动物自然感染恙虫病东方体分离株,并确定其基因型别。方法流行季节在野外用鼠笼捕鼠并鉴定鼠种、携螨率;巢式PCR对鼠脏器进行恙虫病东方体56kD基因片段检测;将鼠脏器接种小自鼠进行病原体分离,PCR扩增分离株0t56kD基因片段,并将目的片段进行测序,基因序列同源性及进化分析。结果捕获啮齿动物数及其携螨率,黑线姬鼠60％（15／25）;褐家鼠45．5％（5／11）;东方田鼠和购睛各2只,均阴性。40只野鼠脏器有3只恙虫病东方体PCR扩增阳性,阳性率为7．5％;从黑线姬鼠标本中分离到1株恙虫病东方体Sanjie,56kD基因片段测定该株与台湾TT071la和NT0511b分离株同源性最高（98％）,系统发生树分析也显示与Kawasaki型共处于同一分支。结论安徽三界地区存在鼠类恙虫病东方体自然感染,黑线姬鼠为其主要宿主,当地恙虫病东方体属Kawasaki基因型。     

立克次体的16SrRNA基因序列分析

目的　研究立克次体的１６ＳｒＲＮＡ基因序列的差异,为其分类和鉴定提供依据。方法　从基因数据库中选择不同的立克次体属代表种的１６ＳｒＲＮＡ基因序列,在计算机上用多序列排列程序对序列进行同源位排列和对比分析,以及依据序列的相似程度构建进化树。结果　立克次体的１６ＳｒＲＮＡ基因含有４ 个高变区,这些高变区的序列具有种或属的特异性,依据序列的相似程度构成的进化树可将立克次体目内成员分为柯克斯体、巴通体、立克次体、埃立克体等４ 个大基因群,每个大基因群含有若干个小基因群。结论　１６ＳｒＲＮＡ基因高变区的序列可用于设计立克次体种、属特异性ＰＣＲ引物和杂交探针;１６ＳｒＲＮＡ 基因序列的分析是目前立克次体分类和鉴定的最可靠依据     

广州市郊鼠中检出埃立克体样微生物

目的　了解曾经两次暴发犬埃立克体病流行的广州市郊某养犬基地野生啮齿动物感染埃立克体情况。方法　用 16SrRNA基因埃立克体属特异引物对抓捕的动物全血及脾脏样本进行PCR检测 ,阳性样本克隆测序 ,所得序列与Gen Bank中注册的核苷酸序列进行比较。结果　在所抓捕的 2 6只野生啮齿动物中 ,3份褐家鼠全血样本和一份脾样本检出埃立克体特异阳性带。序列测定结果显示 ,这 3只鼠所携带的埃立克体样微生物基因完全一致。该基因与核酸数据库中的埃立克体Schotti株有最大同源性 (99 0 4 % )。结论　此次发现的埃立克体与该基地流行的犬埃立克体Gzh982株和扁平埃立克体Gzh981株有很大差异。该菌在流行病学上的意义有待进一步研究。     

新疆阿尔泰山地啮齿动物及其体外寄生物调查报告

本文报告了富蕴县阿尔泰山地、阿勒泰城镇周围山地和哈纳斯湖畔林间所捕获啮齿动物及其体外寄生物。共捕获啮齿动物385只,隶属4科、12属、17种,其中有大林姬鼠(Apodemus speciosus)3只,该鼠为新疆新记录。共获蚤类810只,隶属4科、16属、25种,其中包括2个新种和2个国内新纪录。革螨21种,填补了阿尔泰山地的空白。同时概述了主要疫源动物及体外寄生蚤的分布特点及其流行病学童义。     

Molecular detection and characterization of spotted fever group rickettsiae in Taiwan

Rickettsioses are emerging infectious diseases caused by rickettsiae in association with arthropods. We report the detection of spotted fever group rickettsiae (SFGR) in Taiwan using molecular methods. Phylogenetic analyses of the 17-kd protein and citrate synthase (gltA) genes showed that SFGR TwKM01 detected in Rhipicephalus haemaphysaloides ticks was most similar to Rickettsia rhipicephali. Three TwKM01 isolates were obtained from three individual R. haemaphysaloides ticks. Small, intracellular, coccobacillary bacteria were found in infected L929 cells using immunofluorescence antibody testing and transmission electron microscopy. Two other SFGRs, TwKM02 and TwKM03, identified in Leptotrombidium chigger mites, were closely related to R. australis and R. felis URRWXCal(2), respectively. The TwKM03 strain was also detected in Ixodes granulatus ticks and widely distributed in Hualien, Kinmen, and Lienchiang counties in Taiwan. The endonucleases MaeII and HhaI selected for restriction fragment length polymorphism analysis of the gltA and 17-kd polymerase chain reaction products, respectively, were useful for genotyping Rickettsia species TwKM01, TwKM02, TwKM03, and other SFGRs. Although their infectivity and pathogenicity for vertebrates are unknown, the finding of SFGRs raises the possibility that bacteria other than Orientia tsutsugamushi, Coxiella burnetii, and R. typhi may be involved in rickettsial diseases in Taiwan.     

Antibody prevalence of Orientia tsutsugamushi,Rickettsia typhi and TT118 spotted fever group rickettsiae among Malaysian blood donors and febrile patients in the urban areas

The seroprevalence of Orientia tsutsugamushi (OT), Rickettsia typhi (RT) and TT118 spotted fever group rickettsiae (SFGR) among blood donors and febrile Malaysian patients in the urban areas was determined. Of the 240 blood donors, 5.4%, 9.2% and 1.7% had either present or previous exposure to OT, RT and SFG rickettsiae, respectively. Patients admitted to an urban hospital had high seroprevalences of OT (43.5%) and RT (22.9%), as compared to SFGR (11.6%). Antibody levels suggestive of recent infections of scrub typhus, murine typhus and tick typhus were detected in 16.8%, 12.7% and 8.2% of patients respectively. No significant difference was noted in the distribution of rickettsial antibodies among urban patients from 2 geographical locations. However, the serologic patterns of rickettsial infection in the urban areas were different form those of rural areas.     

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。     

Epidemiological studies on host animals of scrub typhus of the autumn-winter type in Shandong Province, China

In order to elucidate the host animals of scrub typhus in Shandong Province, epidemiological studies on host rodents of the autumn-winter type scrub typhus were carried out from 1995 to 2002 at four localities in the Shandong Province. Based upon ecological observations of the composition, seasonal fluctuation of animal hosts, isolation of Orientia tsutsugamushi, detection and identification of serotypes of antibodies to O. tsutsugamushi were conducted. Two thousand eight hundred and eighty-four rodents and insectivores were captured, including 2,055 Apodemus agrarius (71.26%), 408 Cricetulus triton (14.15%), 64 C. barabensis (2.22%), 12 Crocidura suaveolens (0.42%), 313 Rattus (R.) norvegicus (10.85%), 32 Mus (M.) musculus (1.11%). A. agrarius was predominant in the field and the seasonal fluctuation was correlated significantly to that of scrub typhus (r=0.810, p<0.005). R. norvegicus was predominant indoors. The average capture rate per year in the field was 12.76% from 1995 to 1997. Of the total 2,884 rodents and insectivores captured out- and in-doors, 527 were living rodents (including 335 A. agrarius, 119 C. triton, 6 C. barabensis, 2 C. suaveolens, 63 R. norvegicus and 2 M. musculus, and 15,467 chigger mites were collected from them. Two hundred and fifty-three of 335 A. agrarius were parasitized by chiggers, showing 75.52% (253/335) of the infestation rate and 17.53 of the chigger index; 106 C. triton were parasitized by chiggers, showing 89.08% (106/119) infestation rate and 75.93 of the chigger index. The average antibody positive rate of rodents was 14.78%. The seasonal change of the antibody positive rate was higher during December-February (the second year), and varied from 20% to 28%, but the level of antibodies remained relatively low (5.26-16.67%) during March-November. The results of serotyping with 47 antibody-positive sera were as followings: 39 sera were Gilliam types, 7 sera were Karp types, 1 serum was Kato type. Twelve strains of O. tsutsugamushi were isolated from A. agrarius (8 strains), C. triton (3 strains) and R. norvegicus (1 strain), out of the isolated 12 strains, 10 were Gilliam strains, 2 were Karp strains. A. agrarius and R. norvegicus were the main host animals in out- and indoors respectively.     

新疆克拉玛依地区蜱媒病原体的调查

目的 调查新疆克拉玛依地区蜱种类及其携带病原体。方法 于克拉玛依市不同区采集游离蜱和寄生蜱,鉴定蜱种类,利用荧光定量PCR或套氏PCR/半套氏PCR检测发热伴血小板减少综合征布尼亚病毒、斑点热群立克次体、克里米亚-刚果出血热病毒、蜱传脑炎病毒、巴贝斯虫/泰勒虫、贝氏立克次体、查菲埃立克次体、恙虫病东方体和伯氏疏螺旋体等9种病原体。结果 共采集蜱683只,分3属3种,其中亚东璃眼蜱数量(n=362)最多,其次为银盾革蜱(n=311)、图兰扇头蜱(n=10)。银盾革蜱中斑点热群立克次体的阳性率为3.2%(10/311),巴贝斯虫的阳性率为1.0%(3/311);亚东璃眼蜱中巴贝斯虫的阳性率为0.8%(3/362),泰勒虫阳性率为0.3%(1/362);其他病原体检测结果均呈阴性。PCR扩增阳性基因序列分析显示银盾革蜱携斑点热群立克次体阳性与劳氏立克次体最相关,银盾革蜱和亚东璃眼蜱携带驽巴贝斯虫。结论 新疆克拉玛依地区优势蜱为亚东璃眼蜱和银盾革蜱,银盾革蜱携带劳氏立克次体,银盾革蜱和亚东璃眼蜱携带驽巴贝斯虫,提示该地区存在斑点热、巴贝斯虫病的自然疫源地,因此有必要加强对这些蜱携疾病的防控。     

Prevalence of tick-borne zoonotic bacteria in questing adult ticks from northern Spain

A total of 691 questing adult ixodid ticks of the genera Ixodes, Haemaphysalis, Dermacentor, and Rhipicephalus were tested by polymerase chain reaction (PCR) and reverse line blot (RLB) for the presence of Anaplasma phagocytophilum, Coxiella burnetii, Borrelia spp., and spotted fever group (SFG) rickettsiae. Ticks were collected by blanket dragging during 2 sampling years (2003-2005) in 10 recreational areas in the Basque Country (Northern Spain). Adult ticks were collected every month of the year and eight different species were identified among which Ixodes ricinus was the most abundant and widespread. Three pathogens for humans, Borrelia burgdorferi, A. phagocytophilum, and C. burnetii, as well as rickettsiae of unknown pathogenicity were detected. The latter were identified as Rickettsia sp. RpA4/DnS14 by sequencing of the citrate synthase (gltA) gene. The infection rates varied from 0.1%-6.9%. DNA of A. phagocytophilum was detected mainly in I. ricinus, but also in Haemaphysalis punctata, H. concinna, and Rhipicephalus bursa. Coxiella burnetii was detected in only one specimen of H. punctata, and Borrelia spp. in eight ticks. Furthermore, PCR-RLB analysis specific for B. burgdorferi sensu lato detected one H. punctata with positive hybridization with the B. burgdorferi sensu stricto probe, and two I. ricinus positive for B. afzelii and B. garinii. SFG rickettsiae were the pathogens most frequently found, present in 48 of 97 D. reticulatus analyzed. Mixed infections were not found in any of the analyzed ticks. These results are compared and discussed with data obtained in previous studies carried out in the same and other regions.     

Detection of rickettsioses and Q fever in Sri Lanka

Current serological evidence suggests the presence of scrub typhus and spotted fever group (SFG) rickettsiosis in Sri Lanka. Our objective was to identify rickettsial agents/Q fever as aetiological causes for patients who were presumed having rickettsioses by the presence of an eschar or a rash. Sera from patients with unknown origin fever from Matara were tested by immunofluorescence for SFG rickettsial antigens, typhus group rickettsiae, Orientia tsutsugamushi, and Coxiella burnetii antigens. Thirteen (7.3%) of the patients presented with a rash, 11 (6.1%) had an inoculation eschar, and 16 patients recalled a tick or flea bite. We found that 25 (14%) patients had scrub typhus, 6 (3%) SFG rickettsioses, 3 (1.6%) acute Q fever, 3 (1.6%) murine typhus, and 3 (1.6%) were infected by Rickettsia felis. In addition to already described scrub and murine typhus, we found that R. felis and C. burnetii infections should be considered in Sri Lanka.     

江西省部分地区鼠形动物中巴尔通体分布及基因组序列研究

目的 了解江西省鼠形动物中巴尔通体的携带状况和基因型特征,为巴尔通体感染的疾病预防控制提供科学依据.方法 2018-2019年在南城县、广信区、横峰县、广丰区、铜鼓县5个鼠传疾病监测项目点,采集130只鼠形动物的肝、脾组织标本进行巴尔通体分离培养,挑取形态疑似巴尔通体的菌落纯培养后提取核酸,PCR检测巴尔通体属特异性基...     

我国西北部分地区Q热分子流行病学调查

目的了解西北部分地区人群及媒介蜱Q热感染情况。方法采用布旗法采集游离蜱,应用巢式PCR扩增蜱Q热贝氏柯克斯体;采用间接免疫荧光法对当地居民进行血清Q热抗体检测。结果共检测11个蜱种2 460只蜱标本,有8个蜱种239只贝氏柯克斯体DNA阳性,总阳性率为9.72%。不同蜱种间阳性率差异有统计学意义(2χ=16.69,P<0.01),其中以青海血蜱阳性率最高,为59.38%;四省区阳性率差异有统计学意义(2χ=13.28,P<0.01),以宁夏阳性率最高,为17.96%。共采集当地居民血清725份,抗体检测阳性51份,不同职业人群抗体阳性率差异有统计学意义(χ2=4.03,P<0.05),以牧民阳性率为最高。相关危险因素调查显示,饲养牛羊、饲养的牛羊有不明原因流产、给牛羊接生时未采取保护措施等因素与血清学阳性率有关,其中前两个因素为危险因素,而接生时采取保护措施为保护因素。结论我国西北地区蜱及当地居民存在Q热感染现象。