Microbiology and Immunology 2500A/B Lecture Notes - Lecture 17: Sensu, Lyme Disease, Endothelium
Document Summary
Major cause of lyme disease in na. Found widely throughout temperate zones in northern hemisphere. Contains variable plasmids (circular & linear) from strain-strain. Antigen testing controversial b/c bac can modify genetic material. Limited metabolic capability (ie. require host to thrive) In north america: primarily i. scapularis (black-legged) & i. pacifica (deer) Life cycle: larva nymph adult. Must acquire bac through blood meal individually. Primary transmitters: nymphs due to small size. Sit on grasses/shrubs & wait for host to pass (don"t fly/jump) Tick inserts feeding tube w/ barbs secretes local anesthetic. Suck slowly for several days engorge & appear grey. Infection: causes disseminated & persistent infection to propagate through life cycle. Spread in skin invade endothelial cells hematogenous dissemination. Invades tissue & spreads infections in multiple tissues. Compounds in tick saliva thought to inhibit dc function. Axial filaments: periplasmic flagella that wrap around cells corkscrew shape. Rotation allows bac to move in corkscrew-like manner.