Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
73 Cards in this Set
- Front
- Back
|
What is Virulence?
|
Degree of pathogenicity
|
|
|
What is a Pathogen?
|
disease causing agent
|
|
|
What is a Host?
|
Where pathogen lives
|
|
|
Define: Infection
|
Growth of microbes on host
|
|
|
Why do microbes want in?
|
Animals (humans) provide favorable env't
-rich in organic nutrients -constant Temp and pH |
|
|
Name the 5 portals of entry
|
Respiratory Tract
GI Tract Urogential Tract Skin Parenteral route |
|
|
What does a pathogen do to a host cell?
|
If pathogen overcomes host's defenses
then it can damage host in one of four ways |
|
|
40% of all toxins cause damage to what?
|
Cell membrane of host
|
|
|
What symptoms do toxins cause?
|
Fever
shock diarrhea cardiovascular problems |
|
|
What type of bacteria do endotoxins affect?
|
Gram negative only
|
|
|
Where are endotoxins found in the cell?
|
LPS
|
|
|
How do pathogens enter the respiratory system?
|
thru inhalation
|
|
|
What is the most common portal of entry?
|
respiratory system
|
|
|
What six types of infection are acquired thru the respiratory tract?
|
cold
measles bronchitis pneumonia menengitis influenza |
|
|
How do pathogens enter the GI tract?
|
by food, water and contaminated objects
|
|
|
What three types of infection are acquired thru the GI tract?
|
Hepatitis A
typhoid fever food poisoning |
|
|
How do pathogens enter the G/U tract?
|
transmitted sexually
|
|
|
What types of infection are acquired thru the G/U tract?
|
HIV
Herpes HPV Gonorrhea |
|
|
What is the prime target for pathogens?
|
Skin
|
|
|
When can the skin be penetrated?
|
when compromised
|
|
|
What is the parenteral route?
|
microbes enter injured skin or mucous membranes
|
|
|
What are some methods of the parenteral route?
|
Insect bites
injections cuts surgery burns |
|
|
What is the preferred portal of entry?
|
pathogen has to enter the body in certain way to cause disease
|
|
|
Give an example of the preferred portal of entry
|
Clostridium tetani - must enter thru punctured skin
|
|
|
What increases the chances of a microbe causing disease?
|
Increased number of mcirobes
|
|
|
What is the lethal dose (LD 50)?
|
dose required to kill 50% of test animals
|
|
|
What is the infectious dose (ID50)?
|
dose required to produce infection in 50% of test animals
|
|
|
When can pathogens adhere to tissues?
|
Once they are inside the host
|
|
|
How is attachment accomplished?
|
by ligands or adhesin which bind to
receptors on the host's cells |
|
|
How can infection be prevented?
|
If adhesins or receptors can be altered
|
|
|
What are capsules?
|
glycocalyx around cell wall that prevents phatogytosis
|
|
|
Name a heat/acid resistant protein
|
"M" Protein
|
|
|
What does M protein prevent
|
Phagocytosis
|
|
|
What do M proteins maintain?
|
adherence
|
|
|
What is mycolic acid?
|
Waxy lipid substance in cell wall
|
|
|
What does mycolic acid prevent?
|
phagocytosis
|
|
|
What do leukocidins destroy?
|
Leukocytes
|
|
|
What do hemolysins do?
|
Lyse RBC's
|
|
|
What do Alpha hemolysins do?
|
partially break down hemoglobin
|
|
|
What do Alpha hemolysins produce?
|
green color around colonies
|
|
|
What do Beta hemolysins do?
|
completely break down hg
|
|
|
What do Beta hemolysins produce?
|
clear zone around colonies
|
|
|
What do coagulases cause?
|
Clots
|
|
|
What is the function of hyaluronidase?
|
digest hyaluronic acid
|
|
|
What is the function of hyaluronic acid?
|
Holds cell together
|
|
|
What happens if the pathogen overcomes the host's defenses?
|
the pathogen can damage the host
|
|
|
What are four ways the pathogen can damage the host?
|
-use host's nutrients
-direct damage by lysis of cell -toxins -induce hypersensitivity |
|
|
What is toxigenicity?
|
ability to produce toxins
|
|
|
What is toxemia?
|
presence of toxins in blood
|
|
|
How can toxins be transported?
|
by blood or lymph
|
|
|
What can toxins inhibit?
|
protein synthesis
|
|
|
What can toxins destroy?
|
blood cells
|
|
|
What can toxins damage?
|
blood vessels
|
|
|
What can toxins disrupt?
|
nervous system
|
|
|
What percent of toxins cause damage to cells membrane of host?
|
40%
|
|
|
Name the two types of toxins
|
Endotoxins
Exotoxins |
|
|
Where are exotoxins released?
|
into surrounding media
|
|
|
What type of microbes do exotoxins affect?
|
mainly gram positive
(some gram neg.) |
|
|
Where are exotoxins released to?
|
bloodstream
|
|
|
What are antitoxins?
|
host's defense against exotoxins
|
|
|
Name the three types of exotoxins
|
cytotoxins
Neurotoxins entertoxins |
|
|
What do cytotoxins do?
|
lyse host cell
|
|
|
What do neurotoxins do?
|
attack nerve cells
|
|
|
What do enterotoxins affect?
|
GI Tract
|
|
|
Where are endotoxins produced?
|
as part of cell wall
|
|
|
When are endotoxins released?
|
when cell wall is damaged
|
|
|
What type of bacteria do endotoxins affect?
|
Only gram negative
|
|
|
Where are endotoxins found?
|
Part of the cell wall
|
|
|
What do antibotics do to endotoxins?
|
cause endotoxin to be released
|
|
|
What happens when endotoxins are released?
|
symptoms worsen
|
|
|
What symptoms do endotoxins cause?
|
chills
fever weakness aches possibly shock |
|
|
What is pathogenicity?
|
the ability to cause disease
|
|
|
What does pathogenicity depend on?
|
ability to invade, multiply
and evade host defenses |
