SG19 - MIBO 3000 Chapter 19 Study Guide Microbial...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
MIBO 3000: Chapter 19 Study Guide Microbial Pathogenesis Surface Infections Viruses that infect cells lining the surfaces of our body usually “bud out” of host cells toward the exterior side o The measles virus, however, can bud out from both sides of a cell, allowing it access into deeper tissues of our body Invasiveness and Toxicity What is bacterial invasiveness ? What is bacterial toxigenicity ? Together, invasiveness and toxigenicity determine an organism’s virulence , or capacity of that organism to cause disease List and describe the 4 (broad) categories for routes of disease: What is the difference between LD 50 and ID 50 ? Access to Deep Tissues Wound infections are generally caused by _______________________________ pathogens Vector-borne pathogens routinely penetrate the skin o Injected directly into subcutaneous tissues o Through the wound left by an insect bite Once in the deep tissues, pathogens may: o Cause a localized infection o Invade the bloodstream, causing a systemic disease Example: Bacillus anthracis spores can actually be inhaled Once the spore is inhaled, it enters deeper lung tissue (like alveoli) and is phagocytosed by an alveolar macrophage This macrophage then enters the lymphatic system (lymph nodes) while the spore inside it finally germinates and kills the macrophage completely The new Bacillus anthracis cell can now get into the bloodstream (because lymph vessels
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
are directly attached to capillaries) Intracellular Pathogens Most pathogens that grow intracellularly enter their host cells by phagocytosis Remember, in the phagocytosis cycle, the phagosome eventually fuses with a lysosome, creating a phagolysosome Example: o Rickettsia , Shigella , and Listeria can produce enzymes that degrade the phagosome membrane, releasing them into the cytoplasm before lysosomal fusion o These pathogens can then utilize the host cell cytoskeletal system to propel
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 6

SG19 - MIBO 3000 Chapter 19 Study Guide Microbial...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online