Ecological relationships between ticks and rickettsiae

Ticks play important roles as vectors and sometimes as reservoirs in the ecology of rickettsiae. The obligate association between ticks and rickettsiae has been elucidated in studies concerning the maintenance of rickettsiae in ticks, agent dissemination in various tick organs, rickettsial developmental cycles in the tick organism, transfer among various developmental stages in tick hosts, the effect of rickettsiae on the tick organism, the interaction between microorganisms other than rickettsiae and rickettsiae is a tick body, as well as the release of rickettsiae from ticks into the environment.Presented at the 4th European Congress of Clinical Microbiology, Nice, 177-20 April, 1989.     

新疆东部地区蜱螨区系及医学意义

通过对新疆东部地区蜱类和医螨的广泛调查，目前已发现蜱７属１２种；革螨６科１３属２７种；恙螨４属５种。革螨中的长毛美绥螨Ａｍｅｒｏｓｅｉｕｓ ｌｏｎｇｉｓｅｔｏｓｕｓ Ｙｅ ｅｔ Ｍａ，１９９３系近期发表的新种，阴阳血厉螨Ｈａｅｍｏｌａｅｌａｐｓ ａｎｄｒｏｇｙｎｕｓ Ｂｒｅｇｅｔｏｖａ，１９５２是国内新纪录，宽胸真厉螨Ｅｕｌａｅｌａｐｓ ｗｉｄｅｓｔｅｒｎａｌｉｓ Ｐｉａｏ ｅｔ Ｍａ，１９８０是     

七种媒介硬蜱基因组随机扩增多态性DNA分析

目的　研究7种硬蜱的基因组随机扩增多态性DNA(RAPD)以及种间的遗传距离。　方法　用5条不同的多聚核苷酸单链引物对草原革蜱、森林革蜱、青海血蜱、台湾血蜱、刻点血蜱、龟形花蜱、卵形硬蜱7种硬蜱基因组DNA进行随机扩增,分析DNA图谱并计算 7种硬蜱间的遗传距离。　结果　 7种硬蜱基因组随机扩增产物均有各自独特的DNA条带,种间的平均遗传距离为071。　结论　RAPD技术可以区分这7种硬蜱。     

新疆博尔塔拉和伊犁地区蜱类区系考察

本文报道了1990年4月3日至5月9日在博尔塔拉自治州的博乐、温泉和伊犁地区的察布查尔、新源、巩留、特克斯和昭苏等7县15个点,在北纬42°30′～45°15′,东经79°55′～84°35′,之间蜱类区系的考察结果。在此期间共获蜱类2700余只,结合既往的标本和资料,共记述该地区已知蜱类7属23种的采集地点、宿主及与疾病的关系。其中全沟硬蜱、边缘革蜱、森林革蜱、草原革蜱和残缘璃眼蜱的数量占优势,分布亦较广。业已证实,全沟硬蜱是森林脑炎和莱姆病的重要传播媒介,从边缘革蜱和草原革蜱体内已分离到土拉伦斯菌和蜱媒斑点热的病原体。     

吉林省长白山区斑点热立克次体自然疫源地调查

目的　了解吉林省长白山区蜱传斑点热的自然疫源地情况。方法　利用立氏立克次体[相对分子质量 (Mr) 190× 10 3 ]外膜蛋白A(R .rOmpA)基因序列设计引物 ,对 6 83只蜱类标本进行聚合酶链反应 (PCR)检测 ,并随机抽取一株森林革蜱阳性扩增产物进行克隆与序列测定。结果　从森林革蜱和嗜群血蜱标本中检测出了斑点热立克次体DNA片段 ,阳性率分别为 5 3.81%和 7.4 1% ;所测序列与前苏联的DnS 14株的同源性为 10 0 .0 0 % ,与DnS 2 8和RpA 4的同源性均为99.0 0 % ;而与国内所检测的BJ 90、HLJ 0 5 4的同源性分别为 88.0 0 %和 86 .0 0 %。结论　长白山区存在斑点热的自然疫源地 ,存在与DnS 14株型别一致的斑点热立克次体 ,在中国系首次发现。     

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.     

Growth of tick-borne encephalitis virus (European subtype) in cell lines from vector and non-vector ticks

We undertook a comparative study of the susceptibility of different tick cell lines to infection with the European subtype of tick-borne encephalitis virus (TBEV), prototype strain Neudoerfl. The growth of TBEV was investigated in lines derived from vector Ixodes ricinus L. ticks (IRE/CTVM18, 19, and 20), as well as non-vector ticks, namely Ixodes scapularis Say (IDE2), Boophilus microplus Canestrini (BME/CTVM2), Hyalomma anatolicum anatolicum Koch (HAE/CTVM9), Rhipicephalus appendiculatus Neumann (RA-257) and recently established and herein described lines from the argasid tick Ornithodoros moubata Murray (OME/CTVM21 and 22). All the tick cell lines tested were susceptible to infection by TBEV and the virus caused productive infection without any cytopathic effect. However, there was a clear difference between the TBEV growth in vector and non-vector cell lines, since I. ricinus cell lines produced 100-1000-fold higher virus yield than the non-vector cell lines. The lowest virus production was observed in O. moubata and R. appendiculatus cell lines.     

Knowledge,habits and attitudes towards TBE and other tick-borne diseases in German forestry trainees

Tick-borne encephalitis (TBE) is an occupational hazard for forestry workers. We measured knowledge levels, misbeliefs, and vaccination rates in forestry trainees in order to tailor specific measures aimed at reducing occupational TBE incidence. A paper-based survey was performed at a central training site for forestry workers in the state of Baden-Wuerttemberg. The questionnaire contained items regarding vaccination status against tick-borne encephalitis virus (TBEV), self-reported tick-borne diseases, knowledge of and attitudes towards tick-borne disease, and practices in the context of ticks and tick bites. All trainees in the period June-December 2018 were surveyed. Statistical analyses were conducted using Mann-Whitney-Rank sum test and one-way ANOVA tests. Two-hundred-twenty-five trainees participated in the survey. Almost all (>99%) were aware of living in a TBE high-risk area. Eighty-three percent of respondents were vaccinated in line with current recommendations. Seventeen percent had no effective vaccination status. Twenty-seven percent believed that ticks can transmit only TBEV and Borrelia spp. Sixty-two percent knew that TBEV infections can be fatal. Only 8% of respondents use tick repellents and only 17% wear long sleeves and pants. Trainees who graduated from a six and (eight or) nine secondary school (Realschule and Abitur respectively) had more knowledge on ticks and tick-borne disease compared to graduates from a five year school (Hauptschule) (p = 0.002 and p = 0,037 respectively). Overall, the TBE vaccination rate is not high enough in this high-risk occupational group. We identified gaps in knowledge and practices that could have an impact on TBE incidence in this group if addressed. Further epidemiological research is needed on knowledge, attitudes, and practices in different high-risk populations.