Module 15: Microbial Mechanisms of Pathogenicity Flashcards
What is the term for a change from a state of health?
Disease
What is the term for a disease caused by a pathogen?
Infectious disease
Name 4 things a microbe must do in order to cause disease
- Access the host
- Adhere to the host
- Penetrate/evade the host’s defenses
- Damage host tissues
What is the most important determinant of disease initiation and outcome?
Host immunity
What is the term for the ability of a microbe to cause disease in a host cell?
Pathogenicity
What is the term for the relative degree of pathogenicity?
Virulence
What is the term for the place a microbe enters a host?
Portal of entry
What 3 portals of entry are specific to females?
Mammary glands, vagina, and placenta
What is the most frequently used portal of entry?
Respiratory tract
What is the term for the membranes that line the body cavities that open to the outside?
Mucous membranes
Name 3 microbes that can cross the placenta
T. pallidum, HIV, and T. gondii
Why is unbroken skin a good barrier against infection?
Lots of layers
What is the term for the portal of entry in which there is a break in the skin?
Parenteral route
Insect bites would be transmitted via what portal of entry?
Parenteral route
What is the term for the number of microbes that are first introduced to the host?
Infecting dose
What is the term for the dose of microbes that if infected would cause disease in 50% of the population?
ID50
What is the term for the dose of microbes that if infected would cause death in 50% of the population?
LD50
What is the term for the parts of a bacterial cell wall that help it survive the normal flow inside the body?
Adhesins
The majority of adhesins are made of
Proteins
What are 4 components of bacteria that help them evade phagocytosis?
Capsules, lipopolysaccharides (LPS), mycolic acid, and slime layers
What two types of human cells help kill bacteria?
Neutrophils and macrophages
What type of bacterial cell wall contains lipopolysaccharides?
Gram-negative bacteria
What is the enzyme that causes coagulation?
Coagulase
What is the enzyme that helps break up clots?
Fibrinolysin
What is the enzyme that breaks down hylauronic acid?
Hyaluronidase
What is the enzyme that breaks down collagen?
Collagenase
What is the enzyme that breaks down IgA antibodies?
IgA protease
What is a bacterium that uses hyaluronidase and collagenase to cause gas gangrene?
C. perfringens
What is the term for a microbe changing its appearance so that the host’s immune system does not recognize it?
Antigenic variation
What type if viruses often do antigenic variation?
RNA viruses
What is the term for the movement of a membrane that allows bacteria to pass through human cells?
Membrane ruffling
What protein do bacteria cells make that helps them rearrange the host’s membrane?
Invasin
What are 2 bacteria that produce and use invasion?
Salmonella and E. coli
What is the term for something made by bacterial cells that collects free iron?
Siderophores
What is the term for a toxin that is released into the environment?
Exotoxin
What is the term for that is released from the outer membrane of a cell?
Endotoxin
What is the term for exotoxins that attack nerves?
Neurotoxins
What is the term for exotoxins that attack the intestine?
Enterotoxins
What is one example of an enterotoxin?
Staphylococcal enterotoxin
What is the term for a membrane disrupting exotoxin that attacks phagocytic white blood cells?
Leukocidin
What is the term for an exotoxin that causes hemolysis of red blood cells?
Hemolysin
What is the term for something that can cause a fever?
Pyrogens
What are 3 side effects of endotoxins?
Fever, shock, miscarriage
What condition is characterized by abnormal clotting all over the body and is cause by endotoxins?
Disseminated intravascular coagulation
What is the test performed to test for endotoxins?
LAL (limulus amoebocyte lysate assay)
What is the term for responses of your immune system that damage itself?
Hypersensitivity reactions
What is one example of a microbe that causes hypersensitivity reactions?
S. pyogenes
What are 5 portals of exit for a microbe?
- Respiratory
- Feces
- Genitourinary
- Skin
- Transplacental
What is the term for marking a microbe to be destroyed by the immune system?
Opsonization
