伯氏疏螺旋体与嗜吞噬细胞无浆体混合感染的实验研究

目的应用动物模型探讨蜱传病原体伯氏疏螺旋体和嗜吞噬细胞无浆体混合感染对组织螺旋体载量、莱姆关节炎严重性、宿主免疫功能的影响。方法建立伯氏疏螺旋体和嗜吞噬细胞无浆体混合感染和伯氏疏螺旋体单一感染小鼠模型，在不同时间点研究各组小鼠组织中的螺旋体载量、关节炎严重性和血清IgG效价，并对数据进行统计学分析。结果与单一感染组相比，在螺旋体感染后18d和30d，混合感染组小鼠组织螺旋体载量显著增高，关节炎明显严重，血清IgC效价显著偏低。结论伯氏疏螺旋体和嗜吞噬细胞无浆体混合感染显著增加小鼠组织螺旋体载量、加重关节炎症状和病理改变，且抑制体液免疫功能。     

中国嗜吞噬细胞无形体分离株多间隔序列分型分析

目的 对我国嗜吞噬细胞无形体分离株进行多间隔序列分型（MST）分型。方法 根据GenBank收录的4株无形体全基因组序列，利用Mauve 2.3.1软件行种内基因组比对，选择具有变异间隔区进行引物设计，通过引物特异性及扩增效率等预实验筛选引物，并对实验菌株进行PCR扩增，分析单核苷酸多态性（SNPs）。将每株菌间隔序列拼接后进行分型分析并构建进化树，分析不同地区、不同动物种类来源菌株遗传变异关系。结果 共筛选出22对引物，用于我国11株无形体分离株 MST 分型，SNPs 分析显示，碱基转换发生率最高（60.2%，251/417），其中 A-G 转换居首（18.9%，79/417），颠换占23.0%（96/417），插入及缺失发生率占16.7%（70/417）。11株菌22条间隔序列拼接后（约11 047 bp）均为独立变异型。进化分析发现山东省莱州地区重症患者分离株（LZ-H1、H2、H3、H4、H5）及当地长角血蜱分离株 LZ-T1 与美国 Webster 株及 HZ 株聚为一簇，而北京分离株BJ-H1 与新疆分离株 XJ-H1 和 XJ-H3 聚为一类。莱州地区另一蜱分离株 LZ-T2 与新疆另外一人源分离株聚为一类，与莱州重症患者分离株遗传关系密切。结论 我国无形体分离株间隔序列存在明显的遗传多态性，MST分型技术可用于无形体疫情暴发时的快速诊断和疫情追踪。     

Detection and identification of Anaplasma phagocytophilum, Borrelia burgdorferi, and Rickettsia helvetica in Danish Ixodes ricinus ticks

Borreliosis is an endemic infection in Denmark. Recent serosurveys have indicated that human anaplasmosis may be equally common. The aim of this study was to look for Anaplasma phagocytophilum and related pathogens in Ixodes ricinus ticks and estimate their prevalence, compared to Borrelia, using PCR. Ticks were collected from three locations in Denmark: Jutland, Funen, and Bornholm. Ticks from Jutland and Funen were analysed individually, ticks from Bornholm were analysed in pools of 20. A. phagocytophilum was found in ticks from all areas. A. phagocytophilum was found in 23.6% of ticks from Jutland and Funen, while 11% were positive for Borrelia burgdorferi. The Borrelia genotype B. afzelii was most prevalent, followed by B. valaisiana, B. burgdorferi s.s. and B. garinii.A. phagocytophilum was found in 14.5% of nymphs and 40.5% of adult ticks, while Borrelia was found in 13% of nymphs and 8% of adult ticks. The difference in prevalence between Anaplasma and Borrelia in adult ticks supports the idea that their maintenance cycles in nature may be different. Ticks were also infected with Rickettsia helvetica. Our study indicates that A. phagocytophilum prevalence in ticks in Denmark is as high as Borrelia prevalence and that human anaplasmosis may be unrecognized.     

嗜吞噬细胞无形体研究进展

本文重点阐述了嗜吞噬细胞无形体Anaplasmaphagocytophilum的病原学、生态学方面的研究进展：简要介绍了人群中嗜吞噬细胞无形体感染流行的特征、主要临床特点和治疗要点；概括了嗜吞噬细胞无形体感染的预防控制手段；分析了嗜吞噬细胞无形体相关研究存在的一些不足及其今后的研究方向。     

Detection of Anaplasma phagocytophilum in animals by real-time polymerase chain reaction

The aim of this study was to detect Anaplasma phagocytophilum in wild and domesticated animals and to identify the phylogenetic relationships of different strains of this bacterium. We adapted six published conventional methods targeting 16S fragments for real-time polymerase chain reaction. Initial screening of samples from 419 animals found 37 Anaplasma positives, later confirmed with several different primers and a TaqMan probe. We also performed DNA quantification and melting curve analysis. The nucleic acid of Anaplasma sp. was detected in a higher percentage of cases in members of the deer family, hares, bank voles and mice (12.5 approximately 15%) than in foxes, boars, cows, and horses (around 4 approximately 6%). We also performed blood analysis of cows, horses, mice, and ticks removed from animals, evaluating the presence of antibodies against granulocytic Anaplasma sp. Finally, we subjected 11 randomly selected PCR amplified products to direct sequencing and we constructed the corresponding phylogenetic tree with respect to the Ehrlichia equi sequence, homologous to the human granulocytic ehrlichiosis agent. Mutual identity of the sequencing ranged from 99% to 100%.     

Reservoir Competence of Vertebrate Hosts for Anaplasma phagocytophilum

Fourteen vertebrate species (10 mammals and 4 birds) were assessed for their ability to transmit Anaplasma phagocytophilum, the bacterium that causes human granulocytic anaplasmosis, to uninfected feeding ixodid ticks. Small mammals were most likely to infect ticks but all species assessed were capable of transmitting the bacterium, in contrast to previous findings.     

疑似人粒细胞无形体病医院感染的调查分析

目的 了解人粒细胞无形体病(HGA)的特点及流行病学特征.方法 搜集相关临床病例和实验室诊断资料,分析感染的危险因素和流行病学特征.结果 次发病例与首发病例有密切接触史,均具有高热、不明原因白细胞及血小板进行性降低、转氨酶升高,HGA PCR诊断为阴性,外周血有疑似桑葚样包涵体等特征.结论 人粒细胞无形体病可通过体液传播,医务工作者在诊疗中应注意防护隔离.     

黑龙江省口岸地区蜱类感染嗜吞噬细胞无形体Anaplasma phagocytophila的初步调查

为调查黑龙江省口岸蜱类携带嗜吞噬细胞无形体Anaplasma phagocytophila感染情况,运用聚合酶链式反应方法扩增嗜吞噬细胞无形体柠檬酸合成酶（gltA）基因片段,对黑龙江省各口岸地区采集的蜱标本进行检测,并对阳性结果进行序列分析.共检测蜱1 609只,29只阳性,阳性率为1.80%,结果表明,黑龙江省口岸蜱类除日本血蜱外均有自然感染嗜吞噬细胞无形体的现象.所感染的嗜吞噬细胞无形体gltA 基因与GenBank 中登录的嗜吞噬无形体gltA基因片段,相似性为82%～98%.因此,我国黑龙江省口岸地区存在蜱粒细胞无形体感染.     

Seroepidemiological Investigation of Lyme Disease and Human Granulocytic Anaplasmosis among People Living in Forest Areas of Eight Provinces in China

Objective Lyme disease and Human granulocytic anaplasmosis are tick‐borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum respectively. We have investigated infection and co-infection of the two diseases in the population of forest areas of eight provinces in China by measuring seroprevalence of antibodies against B. burgdorferi and A. phagocytophilum. Methods Forest areas in 8 provinces were chosen for investigation using whole sampling and questionnaire survey methods. 3 669 serum samples from people in the forest areas were tested for the presence of antibodies by indirect immunofluorescent assay (IFA). Results Seroprevalence against B. burgdorferi was 3% to 15% and against A. phagocytophilum was 2% to 18% in the study sites in the 8 provinces in China. We also found co-infection of B. burgdorferi and A. phagocytophilum in 7 of the 8 provinces (the exception being the Miyun area in Beijing). The seroprevalence for both B. burgdorferi and A. phagocytophilum was significantly higher among people exposed to ticks than among people who were not exposed to ticks. Conclusion We conclude that both pathogens are endemic in the forest areas in the eight provinces, but the prevalence of B. burgdorferi and A. phagocytophilum differs between the provinces.