16 Spread and Replication Flashcards
What are routes for microbes spreading throughout body?
Blood lymph nerves CSF across peritoneal cavity by macrophages
Microbe breaches skin surface. What defenses does it encounter before reaching bloodstream?
Tissue fluids contain antibody/ complement
local macrophages - histiocytes
physical barrier - needs to be broken e.g hyaluronidase streptococcal
lymphatic system has host defenses waiting. Causing inflammation can block flow of lymph, which then help bacteria multiply
How to microbes enter the bloodstream?
Enter directly as very small e.g viruses
Move through lymph nodes, and drain into thoracic duct. Must survive body defense systems
Taken up by macrophages e.g brucella, listeria, and taken to blood stream
Once in bloodstream, can move to organ, invade, and replicate
What factors affect an organisms virulence?
Adhesion potential How penetrates into cells antiphagocytic activity toxin production interaction with immune system
