Rickettsia

1. Rickettsia 徐桂香 王莹 赵云鹏 张爱娟 张璐娴 朱玉

2. 斑疹伤寒群生物群 斑点热群生物群 Howard Ricketts 立克次体属 (Rickettsia) 柯克斯体属 立克次体目 东方体属 埃立克体属 巴通体属 Reckettsiales

3. Common characters • Obligated intracellular parasites; • Related to arthropod vector.; • Zoonosis.

4. Morphology & stains • Arranged irregularly; polymorphism • Small G- bacilli; • Giemsa stain: violet or blue;

5. Cultural properties • Binary fission • Have both DNA and RNA • Culture :susceptible animal (guinea pig), yolksac of chick embryo, cell culture.

6. Resistance • weak, sensitive to antibiotic • Survive in low temperature and dry condition • Sulfanilamide can stimulate reckettsia’s proliferation

7. Antigenic sturcture • Group specific antigen • Endotoxin: similarly to endotoxin of bacteria • Specy specific antigen membrane protein: Weil-Felix reaction(外斐反应）: Detect anti-rickettsial antibodies in a patients serum by agglutination of the proteus organisms. ( rickettsia posses Ag that cross-react with Ab of the O antigen of certain proteus)

8. Pathogenic mechanism Endotoxin 、 Phospholipase A Pathogenic material Bite or feces of arthropod vector Local（ small blood vesselsinlymphoid tissue ） Pathogenic mechanism (First bacteremia) vascular endothelial cells (Second bacteremia) Fever, headache, rash Pathogenic sites vessels

9. Pathogenicity Pathogenic materials Endotoxin: similarly to endotoxin of bacteria Phospholipase A: lysis the cell membrane and lysosome membrane of the host cell, causing hemolysis Pathogenic mechanism: invade the epithelial cells of small blood vessule

10. Pathogenic mechanism Endotoxin 、 Phospholipase A Pathogenic material Bite or feces of arthropod vector Local（ small blood vesselsinlymphoid tissue ） Pathogenic mechanism (First bacteremia) vascular endothelial cells (Second bacteremia) Fever, headache, rash Pathogenic sites vessels

11. Infective route • Source:Rickettsiae normally enter the body (mammalian reservoir) through the bite or feces of an infected arthropod vector.-----arthropod vector: mite, tifck, louse, flea • Pathogenic mechanism: invade the epithelial cells of small blood vessule

12. Pathogenic mechanism Endotoxin 、 Phospholipase A Pathogenic material Bite or feces of arthropod vector Local（ small blood vesselsinlymphoid tissue ） Pathogenic mechanism (First bacteremia) vascular endothelial cells (Second bacteremia) Fever, headache, rash Pathogenic sites vessels

14. 主要病原性立克次体 种类 传染源 媒介昆虫 主要临床表现 免疫力 普氏立克次体 人 人体虱发热、头痛、皮疹持久 （流行性斑疹伤寒） 神经系统、心血管系统损伤 斑疹伤寒立克次体 鼠 鼠蚤发热、头痛、皮疹持久 （地方性斑疹伤寒） 鼠虱 恙虫病东方体鼠 恙螨局部黑色焦痂持久 （恙虫热）发热、头痛、皮疹 内脏损害 贝纳柯克斯体家畜 蜱发热、头痛 一定程度 （动物间） 心内膜炎

15. Epidemic typhus (R.prowazekii)普氏立克次体 Louse-borne; substandard living condition, poor sanitaion; overwhelming bacterimia Human Human louse Human louse Human

16. Epidemic typhus (R.prowazekii)普氏立克次体 Fever (temperature rises to 40ºC; Treatment: sanitation, eradication of human lice; vaccine, tetracycline

17. 主要病原性立克次体 种类 传染源 媒介昆虫 主要临床表现 免疫力 普氏立克次体 人 人体虱发热、头痛、皮疹持久 （流行性斑疹伤寒） 神经系统、心血管系统损伤 斑疹伤寒立克次体 鼠 鼠蚤发热、头痛、皮疹持久 （地方性斑疹伤寒） 鼠虱 恙虫病东方体鼠 恙螨局部黑色焦痂持久 （恙虫热）发热、头痛、皮疹 内脏损害 贝纳柯克斯体家畜 蜱发热、头痛 一定程度 （动物间） 心内膜炎

18. Endemic typhus (R. mooseri)斑疹伤寒立克次体 Transmitted way: human louse rat rat flea rat louse human human rat flea human louse rat fever;headack:maculopapular rash

19. 主要病原性立克次体 种类 传染源 媒介昆虫 主要临床表现 免疫力 普氏立克次体 人 人体虱发热、头痛、皮疹持久 （流行性斑疹伤寒） 神经系统、心血管系统损伤 斑疹伤寒立克次体 鼠 鼠蚤发热、头痛、皮疹持久 （地方性斑疹伤寒） 鼠虱 恙虫病东方体鼠 恙螨局部黑色焦痂持久 （恙虫热）发热、头痛、皮疹 内脏损害 贝纳柯克斯体家畜 蜱发热、头痛 一定程度 （动物间） 心内膜炎

20. Immunity Mainly depends on CMI Strong immunity after recovery

21. Microbiological examination Specimen : blood Isolation and culture: guinea pig Serological test: Weil-Felix reaction

22. Principle of prevention and treatment Control and eradicate its intermediate host and reservoir host Specificity：Rat lung vaccine（全细胞灭活疫苗） Prevention Treatment Chloramphenicol(氯霉素) Tetracycline(四环素) Ban-Sulfa drugs(禁用磺胺类药)

23. Thank you!