Bacteria - g. Collagenase 1). Breaks down collagen (fibrous...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Bacteria - virulent mechanisms 1. Capsules - prevent phagocytosis 2. Cell wall components - may also prevent phagocytosis or resist digestion by phagocytes 3. Pili - allow organisms to adhere to m.m. and to each other (to colonize) . Toxins - poisonous substances a. Exotoxins - toxic soluble proteins excreted b. Endotoxins 1). Cell components released when cell dies 2). Toxic to host when released from decomposing cell 3). Example - lipids in Gram neg. cell walls 5. Exoenzymes - act on host cells, tissues a. Hemolysins - lysis rbc’s b. Leukocidins - lysis wbc’s (phagocytes) c. Coagulase 1). Coagulates fibrinogen in plasma forming fibrin clot 2). Prevents phagocytosis d. Catalase 1). Breaks down H 2 O 2 produced by phagocytes into water + O 2 2). Prevents digestion of engulfed bacterium e. Kinases - breaks down blood clots f. Hyaluronidase - “spreading factor” 1). Breaks down hyaluronic acid (loose connect. tissue) 2). Allows organism to invade, spread through tissues
Background image of page 1

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

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: g. Collagenase 1). Breaks down collagen (fibrous connect. tissue) 2). Allows organism to invade tissue D. Viruses- virulent mechanisms 1. Obligate intracellular parasites 2. Effect on host cells a. Cytocidal effect - lysis of host cell b. Lysogeny - latent state 1) Recurrent infections 2) Transformation → neoplasms c. Inclusion bodies in host cells d. Multinucleated giant cells - infected cells fuse (up to 100 nuclei) e. Alter structure of host cells → autoimmune disease E. Fungi - virulent mechanisms 1. Tissue damage 2. Mycotoxins 3. Allergies – mold spores 4. Delayed hypersensitivity - tissue allergy (due to internal infections) F. Protozoans, Worms- virulent mechanisms 1. Tissue damage 2. Interfere with normal function 3. Waste products toxic to host 4. Delayed hypersensitivity - tissue allergy...
View Full Document

This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.

Page1 / 2

Bacteria - g. Collagenase 1). Breaks down collagen (fibrous...

This preview shows document pages 1 - 2. Sign up to view the full document.

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