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;
87 Cards in this Set
- Front
- Back
|
what is the unique aspect of fungi that makes them succeptable to many antibiotics?
|
ergosterol
|
|
|
What is the normal flora found on our skin?
nose? oropharynx? colon? Vagina? |
Skin: Staphlococcus epidermidis
Nose: Staphlococcus Aureus Oropharynx: Viridans Streptococci incl. Strep. mutans and Strep. Salivarius Colon: Bacteroides (predominant organism) Escherichia Bifidobacterium Vagina: Lactobacillus |
|
|
What microorganisms make up the normal flora of the gingival crevices? (4)
|
Aneerobes: Prevotella, fusobacterium, Streptococcus, and Actinomyces
|
|
|
What are the some adherence factors of both gram positive and negative bacteria?
|
Gram (-): pili/fimbriae - adherence to cell surfaces
Gram (+): teichoic acids - adherence to cell surfaces Adhesins: colonizing factor aadhesins, pertussis toxin, and hemagglutinins. IgA proteases: cleaved Fc portion may coat bacteria and bind them to cellular Fc receptors. |
|
|
Which organisms secrete biofilms to attach to inert materials?
|
Staph. epidermidis, and strep. mutans
|
|
|
What is the numanic and organisms that have capsules?
|
Some Killers Have Pretty Nice Capsules
Streptococcus pneumoniae Klebsiella pneumoniae Haemophilus Influenzae Pseudomonas Aeruginosa Neisseria Meningitidis Cryptococcus neoformans |
|
|
What are two microorgaisms which are able to live within phagocytic cells?
How do they do this? |
M. tuberculosis (inhibits phagesome-lysosome fusion.
and Listeria (escapes the phagosome into the cytoplams before phagosome-lysosomal fusion. |
|
|
What organisms steal (chelate) and import iron?
|
siderophores
|
|
|
What is an invasin?
|
invade non-phagocytic cells, thus excaping the immune system.
|
|
|
What is the chemical in the gram negative organism that is toxic?
|
LPS, it is actually the LIPID A portion of the LPS that is toxic.
|
|
|
Usually endotoxin is not release until the gram negative organism dies. What is the one exception to this rule?
|
N. Meningitidis, which over-produces outer membrane fragments
|
|
|
What does this release of LPS cause, and what is each due to?
|
LPS activates macrophages which damages tissues.
bradykinin-induced vasodilation leads to SHOCK activation of HAGEMAN FACTOR leads to COAGULATION (DIC) |
|
|
What are exotoxins?
|
Very toxic released from living bacteria.
|
|
|
Can endotoxins or exotoxins be moeified to a toxoid?
|
Endotoxins cannot but exotoxins can be modified by chemicals or heat to produce a TOXOID that still is immunogenic, but no longer toxic and thus can be used as a vaccine.
|
|
|
How does an A-B toxin work?
|
The B part of the toxin attaches to the cell and allows the A part to enter the cell. The A part of the toxin is the toxic part (often an enzyme)
|
|
|
What are two examples of cytotoxins and
|
Cl. perfringens has the ALPHA TOXIN (enzyme) which is a lecithinase.
Staphylococcus aureus also has an ALPHA TOXIN which inserts itself to into a cells membrane to form pores in the membrane |
|
|
What does Cl. Perfringens cause?
|
gangrene
|
|
|
What is the toxin and how does it work?
Corynebacterium diphtheriae? |
Toxin is DIPHTHERIA TOXIN and it works by ADP RYBOSYL TRANSFERASE; WHICH INACTIVATES EF-2, thus stopping protein synthesis.
|
|
|
What is the toxin and how does it work?
Pseudomonas aeruginosa? |
Toxin is EXOTOSIN A and it works by ADP RYBOSYL TRANSFERASE; WHICH INACTIVATES EF-2, thus stopping protein synthesis
|
|
|
What are the primary targets for diphtheria toxin?
|
heart, nerves, and epithelium
|
|
|
What is the primary target for Exotoxin A and what organism secretes it?
|
Secreted by Pseudomonas aeruginosa, the primary target for exotoxin 2 is the LIVER.
|
|
|
What organism secretes Shiga toxin and what does it do?
|
Secreted by Shigella dysenteriae and it interferes with the 60S ribosomal subunit, thus inhibiting protein synthesis in eukaryotic cells.
|
|
|
What organism secretes Verotoxin and what is it's mechanism?
|
Secreted by Enterohemorrhagic E. Coli (EHEC). It interferes with the 60 S ribosomal subunit, thus inhibiting protein synthesis in eukaryotic cells.
|
|
|
What organism secretes Tetanus toxin and how does it work?
|
Clostribium tetani. Tetanus toxin blocks release of the inhibitory transmitters glycine and GABA, thus inhibiting neurotransmission in inhibitory synapses.
|
|
|
What organism secretes Botulinum toxin and how does it work?
|
Botulinum toxin is secreted by Clostridium botulinum. It blocks release of acetylcholine, thus inhibiting cholinergic synapses.
|
|
|
What organism secretes TSST-1 and how does it work?
|
TSST-1 is secreted by Staphylococcus aureus and is pyrogenic, decreases liver clearance of LPS, and is a superantigen...thus it produces fever, increased susceptibility to LPS, rash, shock, and capillary leakage.
|
|
|
Other than Pseudomonas aeruginosa, what is another organism that secretes Exotoxin A and how does it work?
|
Exotoxin A secreted by Streptococcus pyogenes. it has the exact same effects as TSST-1 secreted by staph. aureus (fever, increased LPS), but is also cardiotoxic.
|
|
|
What organism secretes Heat Labile toxin (LT) and how does it work?
|
LT is secreted by Entertoxic Escherichia coli. LT stimulates an adenylate cyclase by ADP ribosylation of GTP binding protein. This promotes secretion of fluid and electrolytes from intestinal epithelium.
|
|
|
What organism secretes cholera toxin and how does it work?
|
Cholera toxin secreted by Vibrio cholerae. It acts similar to the E. coli LT and thus results in a profuse, watery diarrhea.
|
|
|
What organism secretes Anthrax toxin?
|
Bacillus anthracis
|
|
|
What are the different proteins that make up the anthrax toxin?
|
EF= edema factor
LF= lethal factor PA= protective antigen (B component for both EF and LF) |
|
|
What is the effect of the anthrax toxin?
|
Decreases phagocytosis; causes edema, kills cells.
|
|
|
What is the organism that produces Pertussis toxin and how does it work?
|
Bordatella pertussis
Pertussis toxin ADP ribosylates Gi, which is the negative regulator of adenylate cyclase. This thus INCREASES cAMP |
|
|
What are the effects of pertussis toxin?
|
Histamine sensitizing
Lymphocytosis promotion Islet activation |
|
|
What toxin is secreted by Clostridium perfringens and what does it do?
|
Alpha toxin is secreted. This Clostridium perfringens alpha toxin is a lecithinase that damages cell membranes.
|
|
|
What toxin is produced by Staphlococcus aureus and what does it do?
|
Staph. aureus secretes alpha toxin which intercalates forming pores, thus making the cell membrane leaky.
|
|
|
What type of paralysis does tetanus toxin produce?
|
Spastic paralysis due to inhibition of inhibitory synapses
|
|
|
What type of paralysis does botulinum toxin produce?
|
Flaccid paralysis due to inhibition of cholinergic synapses.
|
|
|
What is an important capsule of E. Coli and why is it important?
|
If E. Coli has the K1 capsule it is likely to cause neonatal meningitis.
|
|
|
What antibiotics work on the peptidoglycan layer?
|
penicillin and cephalosporins act on the peptidoglycan layers and split the peptidoglycan bonds, thus killing the organism.
|
|
|
What organism stain with the acid fast stain?
|
Mycobacterium and Nocardia (Nocardia is partially stained)
|
|
|
What organism is identified by it's numerous flagella.
|
Salmonella typhi
|
|
|
What is the M-protein?
|
M-protein of Strep pyogenes is a surface protein that is very important in it's virulence factor.
|
|
|
What is another name for the acid fast stain?
|
Ziehl-Neelsen Acid Fast Stain
|
|
|
What color is mycobactera in the ziehl-neelsen stain?
|
pink
|
|
|
What is the Auramine-Rhodamine Fluorescent Stain?
|
In the case of mycobacterium TB, because the acid fast stain takes some time to perform, the sputum goes thru the Rhodamine-Fluorescent Stain. If the organism is positive on the Auramine-Rhodamine stain then you will do a Acid Fast stain for confimation
|
|
|
What is the difference between bacteria and human ribosomes?
|
bacteria = 70S ribosomes
human = 80S ribosome and thus it is a major mechanism of antibiotic action |
|
|
What organisms produce endospores?
|
Baccillus genus and Clostridium genus
|
|
|
what does differential media do and what is a good example of a differential media?
|
Diff. media helps to differentiate one organism from another. A good example of this is blood agur.
|
|
|
What does blood agur help you differentiate?
|
Blood agur helps you differentiate alpha, beta, and gamma Streptcocci.
|
|
|
What is the differential medium for Corynebacterium?
|
Tellurite agar where the corynebacterium turn black.
|
|
|
What is the differential medium for Enteric bacteria and what is the significance of this medium?
|
MacConkeys agar allows gram negative organisms to grow but not gram positive. Thus it is a selective media, but at the same time it diferentiates lactose from non-lactose fermenters. Lactose fermenters show up as pik colonies.
|
|
|
What is a good example of a lactose fermenter?
|
E. Coli
|
|
|
What is a good example of a non-lactose fermenter?
|
Salmonella Typhi
|
|
|
What media is used to differentiate Vibrio cholerae?
|
TCBS (thiosulfate citrate bile salts sucrose agar)
|
|
|
What medium is selective for mycobacterium?
|
Lowenstein-Jensen medium
|
|
|
What agar is used for Neisseria?
Which is usually used |
Chocolate agar and Thayer-Martin medium.
The Thayer-Martin medium is usually used because it is selective for Neisseria. It is basically a chololate agar with antibiotics to inhibit the growth of normal flora. |
|
|
What is an important test for the identification of neisseria gonnorrhea?
|
oxidate test
|
|
|
What are three good examples of obligate aerobes?
|
mycobacterium TB
pseudomonas bacillus |
|
|
What are the three major obligate anaerobes?
|
actinomyces
bacteriodes clostridium |
|
|
What is the differential medium for Corynebacterium?
|
Tellurite agar where the corynebacterium turn black.
|
|
|
What is the differential medium for Enteric bacteria and what is the significance of this medium?
|
MacConkeys agar allows gram negative organisms to grow but not gram positive. Thus it is a selective media, but at the same time it diferentiates lactose from non-lactose fermenters. Lactose fermenters show up as pik colonies.
|
|
|
What is a good example of a lactose fermenter?
|
E. Coli
|
|
|
What is a good example of a non-lactose fermenter?
|
Salmonella Typhi
|
|
|
What media is used to differentiate Vibrio cholerae?
|
TCBS (thiosulfate citrate bile salts sucrose agar)
|
|
|
What medium is selective for mycobacterium?
|
Lowenstein-Jensen medium
|
|
|
What agar is used for Neisseria?
Which is usually used |
Chocolate agar and Thayer-Martin medium.
The Thayer-Martin medium is usually used because it is selective for Neisseria. It is basically a chololate agar with antibiotics to inhibit the growth of normal flora. |
|
|
What is an important test for the identification of neisseria gonnorrhea?
|
oxidate test
|
|
|
What are three good examples of obligate aerobes?
|
mycobacterium TB
pseudomonas bacillus |
|
|
What are the three major obligate anaerobes?
|
actinomyces
bacteriodes clostridium |
|
|
Aerobically or anaerobically, how are most bacteria classified?
|
Facultative anaerobes
|
|
|
What is the mneumonic for the organisms that require cysteine to grow?
|
The four sister Ells and the Cysteine chapel.
Flancisella, Brucella, Legionella, and Pasteurella |
|
|
What is hte mneumonic for remembering the three obligate anaerobes?
|
ABCs of anaerobiosis = Actinomyces, Bacteroides, and Clostridium
|
|
|
What are the microareophilic organisms and what does each cause?
|
Campylobacter and helicobacter
Camplobacter causes gastroenteritis Helicobacter causes gastric and duodenal ulcers |
|
|
What is included in the DTP vaccine?
|
Diphtheria: diphtheria toxoid
Tetanus: tetanus toxoid Pertussis: killed Bordetella pertussisis cells |
|
|
When is the DTP vaccine given?
|
2 months, 4 months, 6 months, 18 months, and 5 years old
|
|
|
What is the vaccine with the new pertussis called and what is the difference?
|
The new vacccine is DTaP. The a stands for a cellular b/c it is no longer the dead organism in the vaccine...it is some cellular components. it contains the capsule, toxoid, and hemagluttinin fimbrie
|
|
|
What is the HIB vaccine and what does it contain?
|
Haemophilus influenzae type b
It is an H. influenzae capsular polysaccharide conjugated to protein |
|
|
When is the HIB vaccine given and what disease has it helped significantly?
|
It is given at 2, 4, 6, 18 months and 5 years old and it has helped neonates fight meningitis.
|
|
|
Who should get the spreptococcus pneumoniae vacine and what is it composed of?
|
elderly people should get the spreptococcus pneumoniae vaccine and it is composed of capsular polysaccharides of 23 different Pneumoncoccus strains.
|
|
|
Why shouold the spreptococcus pneumoniae vaccine be given to people who lack a spleen?
|
The spleen is the major organ that clears capsular proteins.
|
|
|
What does the neisseria meningitidis vaccine contain.
|
Four capsular polysaccharides: Y, W-135, C, and A.
These are the four different types of capsules |
|
|
Who should the salmonella typhi vaccine be given to and what does it contain?
|
it should be given to travelers to endemic typhoid areas and it is composed of attenuated bacterium
|
|
|
What is the new salmonella typhi vaccine called?
|
ty21
|
|
|
What is the vaccine for TB?
|
BCG = Bacille Calmette Guerin (BCG)
|
|
|
What is the BCG vaccine composed of?
|
Attenuated (living) strain of Mycobacterium bovis
|
|
|
What is the bacillus anthracis vaccine composed of and who is it used on?
|
composed of a supernatant of partially purified proteins and it is used for military and people around cows and wool a lot.
|
