上海交通大学：《医学微生物》课程教学资源（PPT课件讲稿）英文版 General introduction

RICKETTSIA ORIENTIA EHRLICHIA ANAPLASMA COXIELLA BARTONELLA

RICKETTSIA ORIENTIA EHRLICHIA ANAPLASMA COXIELLA BARTONELLA

General introduction Gram-negative, obligate intracellular coccobacilli bacteria that infect mammals and arthropods Rickettsiae are transmitted in the arthropods, which serves as both vector and reservior ■ Both dna and rna Is sensitive to antibiotic

General introduction ◼ Gram-negative, obligate intracellular coccobacilli bacteria that infect mammaols and arthropods ◼ Rickettsiae are transmitted in the arthropods,which serves as both vector and reservior ◼ Both DNA and RNA ◼ Is sensitive to antibiotic

Category of rickettsia Genus Rickettsia, Coxie/a, Orientia Ehrlichia bartonella Species Rickettsia prowazekii (epidemic typhus) Rickettsia typhi(endemic typhus), Rickettsia rickettsii(spotted fever), Rochalimaea quintana ( trench fever), Coxiella burnetii( Q fever)

Category of rickettsia ◼ Genus Rickettsia, Coxiella ,Orientia,Ehrlichia Bartonella ◼ Species Rickettsia prowazekii (epidemic typhus), Rickettsia typhi (endemic typhus), Rickettsia rickettsii (spotted fever), Rochalimaea quintana (trench fever), Coxiella burnetii (Q fever)

Bilogical features a Variable shape, coccobacilli Gram negative Microcapsule and slim 戒使 layer a Culture: in york sacs of embryonated eggs

Bilogical features ◼ Variable shape, coccobacilli ◼ Gram negative ◼ Microcapsule and slim layer ◼ Culture : in york sacs of embryonated eggs

Antigenic structure ■LPs Rickettsia tsutsugamushi Coxiella burneti(Q fever) LPS I smooth LPSI rough Weil-Felix reacrion a Surface protein(SPA)

Antigenic structure ◼ LPS Rickettsia tsutsugamushi Coxiella burnetii (Q fever) LPSⅠ smooth LPSⅡ rough Weil-Felix reacrion ◼ Surface protein(SPA)

Weil-Felix reaction Ir mmunolo gical group Type D isease 0x-19 OX-19++++ Classic European typhus 0x2+ Brils disease, OX-K Endemic murine typhus OX-K 0X-19 Tsutsugamushi disease 0x2 Scrub orrural typ hus OX-K++++ Sumatran mite fever Indeterminate 0x-19+ Spotted feversao Paulo 0x2+ typhus so uth African tick 0X-K+ fever, Kenya typ hus ndian tick typ hus north Asian tick typhus

Transmission Typhus, spotted fever and trench fever are transmitted via arthropod vectors aQ fever is acquired via inhalation or ngestion of contaminated milk or food

Transmission ◼ Typhus, spotted fever and trench fever are transmitted via arthropod vectors; ◼ Q fever is acquired via inhalation or ingestion of contaminated milk or food

Pathogenesis 沿a, Virulence factors endotoxin phospholipase A, and slime layer Sites: vascular system producing vasculitis血管炎 Characteristic triad of symptoms: fever, headache and rash(no rash with Q fever)

Pathogenesis ◼ Virulence factors: endotoxin, phospholipase A, and slime layer ◼ Sites: vascular system producing vasculitis血管炎 ◼ Characteristic triad of symptoms: fever, headache and rash (no rash with Q fever)

Rickettsia prowazeki 普氏立克次体 a epidemic typhus average incubation periods( days): 8 the louse Respiratory tract and conjunctiva a Latent period: 2 Weeks a Abrupt onset, fever, chills, headache myalgia, arthralgia

Rickettsia prowazekii 普氏立克次体 ◼ epidemic typhus ◼ average incubation periods (days):8 ◼ the louse ◼ Respiratory tract and conjunctiva ◼ Latent period: 2 weeks ◼ Abrupt onset,fever,chills,headache, myalgia,arthralgia

Replication cycle of rickettsia and Orientia Rickettsia infection of an endothelial cell Phagocytosis is induced Lysis of cell: R prowazekii 0o→(。 Bacterium escapes from phagosome Filopodium focal lysis: R. rickettsii Budding: R. tsutsugamushi

Replication cycle of Rickettsia and Orientia