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;
99 Cards in this Set
- Front
- Back
What is the peptidoglycan layer in bacteria?
|
repeating disaccharides with 4 aas
gives rigid support and protects agains osmotic pressure |
|
What enzyme catalyzes the formation of crosslinked chains?
|
transpeptidase aka penicillin binding protein
|
|
what is the role of the murein lipoprotein?
|
extends from the peptidoglycan layer to the outer membrane of the G+s
|
|
what is teichoic acid?
|
The major surface antigen of the cell wall/cell membrane of G+s. Induces TNF and IL1
|
|
Break down LPS:
Where is it located? What are the parts of it. |
Located on the outer membrane- G-s
Oligosaccharide unit- O-antigen Center- core polysaccharide Interior- Lipid A, disaccharide- endotoxin, induces TNF and IL1; the polysaccharide is the antigen. |
|
What is the function of the plasma membrane?
|
oxidative and transport enzymes.
|
|
What is unique about bacterial ribosomes?
|
50S and 30S
Erythromycin 50 tetracycline 30 |
|
What are the G+ bugs?
|
Cocci
Streptococcus- Cat - Staphylococcus- Cat + spore producing rods: Bacillus Clostridium (Outer layer of the spore is the exospporium) plain old rods: Corynebacterium Listeria (only G+ w/ endotoxin) |
|
What is the G- diplococci?
|
Neisseria
|
|
What is the purpose of the following:
periplasm capsule pilus/fimbria Flagellum Plasmid Glycocalyx |
periplasm- fluid between cytoplasmic and outer membrane- where B-lactamases are.
capsule- protects from phagocytosis pilus- mediates adherence of bacteria to cell surface, sex pilus for conjugation Flagellum- motility- connected by basal body plasmid- has genes for resistance, enzymes, toxins Mediates adherence to surfaces, foreign |
|
What is the role of:
Catalase Peroxidase Superoxid sdismutase |
Catalase-breaks down hydrogen peroxide
peroxidase- same superoxide dismutase- breaks down the superoxide radical. w/o, not an aerobe. |
|
What bugs have superantigens?
|
S. Aureus
S. pyogenes Superantigens bind directly to MHC II and T-cell recptor, activating large numbers of T-cells to stimulate IL 1 and IL 2 S. aureus TSST-1, fever, rash, shock. (enterotoxins- food poisoning) S. pyogenes- scarlet fever-strain SPE toxin --> toxic shock |
|
What bugs have ADP Ribosylating toxins?
|
Corynebacterium diptheria
Vibrio cholerae E. coli Bordetella pertussis |
|
What is the mechanism of diptheria toxin?
|
Inactivates elongation factor-2 causing pharyngitis and "pseudomembrane"
|
|
What is the mechanism of cholera toxin?
|
ASP ribosylation of G protein stims cAMP increasing the pumping of CL- and H2O into the gut
rice-water diarrhea |
|
What is the mechanism of the E.Coli toxin?
|
Heat-labile toxin stimulates adenylate cyclase (like cholera) causing watery diarrhea. It also stimulates guanylate cyclase
|
|
What is the mechanism of Pertussis toxin?
|
Stims adenylate cyclase-> whooping cough, inhibs chemokine receptor causing lymphocytosis.
|
|
What is the mechanism of clostridium toxin?
|
alpha toxin causes gas gangrene, get double zone of hemolysis on blood agar
|
|
What is the mechanism of tatanus toxin?
|
Blocks glycine transmission-> lockjaw
|
|
What is the mechanism of botulinum toxin?
|
Blocks the release of Ach -> CNS paralysis
|
|
What is the mechanism of anthrax toxin?
|
one toxin is an adenylate cyclase
|
|
What is the mechanism of shiga toxin?
|
cleaves host cell rRNA, enhances cytokine release-> HUS
also caused by E. Coli O157:J7 |
|
What is the mechanism of S. pyogenes toxin?
|
streptolysin O is a hemolysin, Ag for ASo in rhumatic fever
|
|
What is the mechanism of endotoxin?
|
Activates macrophages:
IL-1- fever TNF- Fever, hemorrhagic tissue necrosis NO- hyoptension Activates complement (alt path) C3a- hypotension, edema C5a- neutrophil, chemtaxis Activates Hageman factor- Coag cascade-> DIC |
|
What bugs do not gram stain well?
|
These Rascals May Microscopically Lack Color
Treponema - too thin (darkfield) Rickettsia- Intracellular Mycobacteria- acid fast, high lipid content Mycoplasma- no cell wall Legionella- intracellular (silver stain) Chlamydia- intracellular |
|
What is the difference in the Nesseria species in fermentation?
|
Menigococci- ferment maltose and glucose
Gonococci- ferment glucose |
|
What bacteria produce a pigment?
|
S. aureus - yellow (gold)
P. Aeruginosa- blue-green Serratia marcescens- red (maraschino cherries |
|
What bugs use IgA proteases to colonize mucosal surfaces?
|
S. pneumoniae
Neisseria Meningitidis N. Gonorrhoeae H. Influenzae |
|
In bacterial sex, what are the differences between conjugation, transduction and transformation?
|
conjugation- DNA transferred from 1 to another bacterium, prokaryotic- chromosomal or plasmid (F plasmid)
Transduction- DNA transferred by a virus from 1 cell to another (sperm back) Transformation- purified DNA taken up by a cell |
|
What is the difference between generalized and specialized transduction?
|
generalized is any gene (virulent)- bacterial DNA is detroyed, but may be accidently packaged like viral DNA
specialized is a specific gene (temperate) DNA is accidentally repilcated when viral DNA is being replicated. |
|
What is the difference between a virulent and a temperate phage?
|
virulent- invade and replicate until the bacteria explode.
temperate- DNA is incorporated into bacterial DNA. (prophage) Bacteria with prophage are called lysogenic, they are genetic time bombs. |
|
What is Gram, catalase adn coagulase +?
|
s. aureus
|
|
What is gram and catalase + and coagulase -?
|
Novobiocin sensitive
s. epidermidis Novobiocin resistant S. saprophyticus. |
|
What is Gram +, catalase -, and alpha (green) hemolyitic?
|
S. pneumoniae- optochin sensitive, bile soluble
Viridans strep- optochin resistant, not bile soluble |
|
What is G+, cat-, and shows Beta (clear) hemolysis?
|
Group A- s. pyogenes- Bacitracin sensitive
Group B- S. agalactiae- Bacitracin resistant |
|
What is G+, cat-, and shows gamma (no) hemolysis
|
Enterococcus
peptostreptococcus |
|
What type of media do you need to culture H. influenzae?
|
Chocolate agar with factors V (NAD) and X (hematin)
|
|
What type of media do you need to culture N. Gonorrheae?
|
Thayer-Martin (VCN) media
|
|
What type of media do you need to culture B. pertussis?
|
Bordet-Gengou (potato) agar
|
|
What type of media do you need to culture C. diphtheriae?
|
Tellurite plate, Loffler's medium, blood agar
|
|
What type of media do you need to culture M. Tuberculosis?
|
Lowenstein-Jenson
|
|
What type of media do you need to culture lactos-fermeting enterics?
|
Pink colonies on MacConkey's Agar
|
|
What type of media do you need to culture Legionella?
|
Charcoal yeast extract agar buffered with increased iron and cysteine
|
|
What type of media do you need to culture Fungi?
|
Sabouraud's agar
|
|
For what organisms would you use a silver stain?
|
Fungi, PCP, Legionella
|
|
For what organisms would you use a Giemsa's stain?
|
Borrelia, Plasmodium, trypanosumes, Clamydia
|
|
For what organisms would you use a Ziehl-Neelson stain?
|
acid fast
|
|
What gram - cocci is a maltose fermentor?
|
Nesseria Meningitidis
|
|
What G- is a maltose nonfermentor?
|
Nesseria gonorrhoeae
|
|
What are the Gram - coccoid rods? (4)
|
H. influenzae
Pasteurella Brucella B. pertussis |
|
What are some fast G- lactose fermenting rods?
|
Klebsiella
E. coli Enterobacter |
|
What are some slow G- lactose fermenting rods?
|
Citrobacter
Serratia |
|
What are some non lactose fermenting Ox - G - rods?
|
Shigella
Salmonella Proteus |
|
What are some non lactose fermenting ox + G- rods?
|
Pseudomonas
|
|
What bugs are obligate aerobes?
|
Nagging Pests Must Breathe
Nocardia Pseudomonas aeruginosa M. tb Bacillus |
|
What are the obligate anaerobes?
|
Clostridium, Bacteroides, Actinomyces.
Foul smelling. hard to culture. Produce gas in tissue |
|
What class of drugs require O2 to enter the cell and kill?
|
Aminoglycosides- don't work on obligate anaerobes.
|
|
What bugs are obligate intracellulars?
|
Stay inside when its Really Cold.
Rickettsia Chlamydia |
|
What bugs are facultative intracellular?
|
Some Nasty Bugs May Live FacultativeLY
Salmonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersinia |
|
What bugs make spores?
|
Clostridium
Bacillus G+ rods |
|
What bacteria are alpha hemolytic?
|
strep pneumoniae- cat -, optochin sensitive
Viridans strep- cat - and optochin resistant |
|
What bacteria are beta hemolytic
|
Staph aureus- cat and coag +
Strep pyogenes cat - and biacitracin sensitive strep agalactiae - cat - and bacitracin resistant Listeria monocytogenes (tumbling motility, meningitis in newborns, unpasteurized milk) |
|
What is the role of the M protein?
|
Group A strep, inhibs activation of complement, protects from phagocytosis.
However, plasma cells make Ab against it. |
|
What is the role of Streptolysin O
Streptolysin S |
Group A strep enzyme.
O is oxygen labile. Inactivated by O2. Destroys red and white blood cells. allows for B-hemolytic ability. Antigenic S- also b-hemolytic, not antigenic |
|
What is the role of the pyrogenic exotoxin?
|
aka erythrogenic toxin
only found in a few strains, but can cause scarlet fever. |
|
What does Group A strep cause?
|
pyogenic- pharyngitis, cellulitis, impetigo
toxigenic- scarlet fever, toxic shock-syndrome Immunologic- rheumatic fever, acute glomerulonephritis. |
|
When would you see tea colored urine with strep?
|
acute post-strep glomerulonephritis- hematuria.
|
|
What are the Bs of Group B Strep?
|
Bacitracin resistant, B-hemolytic, cause pneumonia, meningitis, sepsis mainly in Babies.
neonates- fever, vomiting, poor feeding, and irritability. |
|
What are the 3 most common bugs of meningitis under 3 months old?
|
Strep B, E. coli, Listeria
|
|
What's up with viridans strep?
|
alpha hemolytic (viridans means green)
dental caries, S. mutans, and endocarditis, S. sanguis (blood). Optochin resistant. |
|
What does S. pneumoniae the most common cause of (4 things)?
|
Meningitis
Otitis media Pneumonia Sinusitis Encapsulated, IgA protease "rusty" sputum sepsis in sickle cell, and splenectomy |
|
if an alcoholic vomits then develops foul smelling sputum, what organisms are most likely?
|
anaerobes
|
|
Middle age male with acute monoarticular joint pain and bilateral bell's palsy?
|
lyme disease (ixodes)
|
|
What type of immunoglobin is reacting in M. pneumoniae croagglutinins?
|
IgM
|
|
What do WBC casts indicate?
|
pyelonephritis
|
|
what cell is deficient in someone with tetany and candidiasis. With hypocalcemia and immunosuppresion?
|
DiGeorge- T cell
|
|
Thorn prick from a rose, with ulcers along lymph drainage?
|
Sporothrix schenckii
|
|
What causes cauliflower lesions by yeast?
|
the broad based budding blasto
|
|
What would cause redness and swelling of the breast after breast feeding, fluctuant mass?
|
S. Aureus causing Mastitis
|
|
Young child has recurrent lung infections and granulomatous lesions. What is the defect?
|
Neutrphils lack NADPH oxidase
|
|
20 y/o college student presents with lymphadenopathy, fever, hepatospleno. Serum agglutinates in Sheep RBCs?
|
EBV infection, B Cell is infected
|
|
What organism would cause endocarditis 3 wks after getting a heart valve replacement?
|
S. aureus or S. epidermidis
|
|
Why would someone get megacolon and diarrhea after a round of clindamycin?
|
C. difficile overgrowth
|
|
What bug can be grown in 6.5% NaCl?
|
Enterococci
|
|
What is the change made for vancomycin resistance?
|
d-ala-d-ala is now d-ala-lactate preventing vanco binding
|
|
What cancer is associated with S. bovis?
|
colon cancer
|
|
Which strep are paired up?
|
S. pneumoniae
|
|
What is the Quellung reaction?
|
helps identify pneumococcus- anti serum, the capsule will swell.
|
|
Which one is optochin sensitive: viridans or pneumo?
|
pneumo
|
|
What is the role of Protein A?
|
Staph
bidn the Fc portion of IgG, protects from opsonization |
|
How does coagulase protect the bacteria?
|
forms fibrin around the bacteria protecting from phagocytosis
|
|
What does staph aureus cause?
|
Inflammatory- skin infections, organ abscesses, pneumonia
Toxin- TSST, SSS TSST is a superantigetn |
|
What is the toxin involved in scalded skin syndrom
|
Exfoliatin
|
|
Which toxin causes food poinsoning?
|
enterotoxins (heat stabile)
|
|
What is the role of hyaluronidase?
|
breaks down proteoglycans in CT
|
|
What is the role of staphylokinase?
|
lyses formed fibrin clots
|
|
What are the symptoms of Toxic Shock Syndrome?
|
high fever, nausea, vomiting, watery diarrhea are sudden
diffuse erythema comes on a little later |
|
When is Staph epidermidis a problem?
|
Hospitalized patients with IVs or Catheters.
|
|
Who gets S. Saprophyticus?
|
women, common community aquired UTI.
|