Microbiology Chapter 15 2
Terms
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- Pathogenicity is...?
- the ability to cause disease
- Virulence is...?
- the extent of pathogenicity
- The portals of entry for mucous membranes are?
- Respiratory tract, GI tract, urogenital tract.
- The portals of entry for skin are?
-
hair follicles, sweat gland ducts, conjunctiva
some worms can burrow into skin - The portals of entry for the parenteral route are?
- Puncture wounds introducing bacteria.
- What is onchocerciasis?
-
River blindness, the second leading cause of blindness worldwide.
18 million people worldwide afflicted
Parasitic worm (Onchocerca volvulus) can live in the body for up to 14 years
Larval forms are worms transmit disease
Infected blackflies also transmit disease - What is ID50?
- the infectious dose for 50% of the test population
- What is LD50?
- the lethal dose (of a toxin) for 50% of the test population
- Coagulse is...?
- coagulates blood
- Kinases are...?
- digest fibrin clots
- Hyaluronidase is...?
- hydrolyzes hyaluronic acid
- Collagenase is...?
- hydrolyzes collagen
- IgA proteases are...?
- Destroy IgA antibodies
- Siderophores are...?
- sequester iron
- Antigenic variation...?
- alter surface proteins
- Toxin is...?
- substances that contribute to pathogenicity
- Toxigenicity is...?
- ability to produce a toxin
- Toxemia is...?
- presence of a toxin in a host's blood
- Toxoid is...?
- inactivated toxin used in a vaccine
- Antitoxin is...?
- antibodies against a specific toxin
- Endotoxin is...?
-
Part of the outer portion of the cell wall of gram-negative bacteria
They are liberated when the bacteria die and the cell wall breaks apart - Exotoxin is...?
-
Produced inside mostly gram-positive bacteria
They are then secreted or released following lysis into the surrounding medium. - What is syncytium...?
- when infected cells fuse together.
- What is oncogenesis...?
- when viruses induce chromosomal changes in the host cell.
- Pathogenic properties of Fungi
-
Fungal waste products(toxins) can cause symptoms.
Chronic infections provoke allergic response.
Toxins can inhibit protein synthesis.
Proteases(modify host membranes and allow for attachment)
Capsule prevents phagocytosis. - Pathogenic properties of Protozoa
-
Waste products
Avoid defenses by:
--growing in phagocytes
--antigenic variation - Pathogenic properties of helminths
-
Use host tissue
Presence of parasite interferes with host function
Parasite's metabolic waste can cause symptoms. - What are the portals of exit?
-
Respiratory trace
--coughing, sneezing
GI tract
--feces, saliva
Genitourinary tract
--urine, secretions
Skin
Blood
--Biting arthropods, needles