Microbiology Flashcards
Gram positive stain what color? what about negative?
Purple/red
Lipoteichoic acid is a property of gram + or - bacteria?
Gram +
Why can’t Vanco work on Gram - bacteria?
External membrane blocks it
Chlamydia lacks what kind of acid in its cell wall?
Muramic acid
What is transformation regarding bacterial genetics?
Uptake of free DNA from the environment
What does transposons do?
They transfer DNA between chromosome and plasmid
What kind of cells is capable of conjugating with another cell?
F+/Hfr
What’s the difference between F+ and Hfr cells?
F+ cells have the F factor in the plasmid/F factor is integrated into the chromosomes in Hfr cells
What is the difference of conjugation between F+ and Hfr cells?
During conjugating of Hfr cells—>the entire genome would be transferred instead of just the F factor plasmid of F+ cells
What kind of cells are responsible for transduction of bacteria?
Phage virus
What is the only kind of gram + cells that have LPS?
Listeria
Which toxin is heat stable, endotoxin or exotoxin? and what is the exception?
Endotoxin is heat stable/S aureus produces exotoxin that is heat stable
Which toxin is immunogenic (can produce an vaccine against it), endo or exo?
Exotoxin is immunogenic
What are superantigens and what are the 2 examples?
Antigens that unselectively activate everything in your immune system—>cytokine storms
S. aureus—>TSST-1
S. pyogenes—>exotoxin A
What are 2 examples of toxin that are cAMP inducers?
Cholera and anthrax toxin
What kind of agar is Pertussis grows on?
Bordet-Gengou agar
Fungi grows on ___ agar?
Sabouraud agar
What are the 3 bacteria that cause atypical pneumonia?
Mycoplasma/Chlamydia/Legionella
Barking kind of cough (seal?) with inspiratory stridor, is it pharyngitis or epiglottis?
Epiglottis
Sinusitis usually occurs after?
Viral infection
What to give first to food poisoning pts?
Fluid, antibiotics are not always necessary
Gastritis presents with ___ enteritis presents with ____?
Vomiting/diarrhea
Campylobacter presents with? and its from?
Bloody diarrhea/spoiled chicken
Get food poisoning from reheated rice, think what bacteria?
Bacillus cereus
Pt with pyelonephritis/high fever/”swarming” on agar/struvite stones, think what bacteria?
Proteus
Young pt with arthritis in one knee, think what bacteria?
Gonnorrhea
Which one can kill, viral or bacterial meningitis?
Bacterial
Signs in babies with meningitis?
Lethargy/irritable/not able to feed well
Why do pregoes shouldn’t have unpasteurized milk?
It might contain Listeria—>cross placenta—>meningitis
Swap vagina, see clue cells and have a positive whiff test, diagnosis?
Gardenella
Itchy vagina/strawberry cervix/parasite swims on wet mount, what kind of parasite is it?
Trichomonas vaginitis
What is chandelier sign?
Tender cervix—>caused by PID from gonnorrhea or chlamydia
Only gram + or - bacteria can form spores? and what is responsible for that?
Gram +/teichoic acid pumps water out of the cell
What does catalase do?
Break hydrogen peroxide into water and O2—>protect bacteria from oxidative damage
What do staph and strep look like under microscopy?
Cluster/chain
Coagulase + means the bacteria will form ___?
Abscess
What is the second most common bacteria that causes UTI?
S. saprophyticus
What is the significance of protein A on the surface of S. aureus?
It binds to the Fc (handle part) part of IgG—>prevent opsonization
What bacteria seeds prothetic valves?
S. epidermidis
How do alpha and beta hemolytic bacteria present on blood agar?
Green/clear
What group of bacteria cause subacute endocarditis?
Viridian group
What does the M protein of S. pyogenes do?
Cleave C3 convertease—>prevent complement
What are the 2 gram + gamma hemolytic bacteria?
enterococcus/S. bovis
How does autoclave work?
High pressure putting water into spores and burst them
Gram + rods in chain with poly-D-gluatmate capsule, think?
B. anthracis
Gram + or - has an outer membrane in their cell wall?
Gram -
What is Fitz Hugh Curtis disease? and what causes it?
Infection of liver capsule from N. Gonorrhea (violin adhesion between the peritoneum and the liver)
What are the 3 antigen of enterobacteriaceae?
O antigen of the LPS/H antigen on the flagella/K antigen on capsule
What are the 3 non lactose fermenting enterobacteriaceae?
Proteus/Salmonella/shigella
How to distinguish Salmonella from Shigella on Hektoen agar?
Salmonella: black
Shigella: green
What cell does Shigella invade through?
M cell in the GI
Bacillary dysentery is caused by what bacteria? and what do you find in the stool sample?
Shigella/blood and pus
What is EUEC and what does it cause? and what virulent fact does it have?
One strain of E. coli—>causes UTI/fimbriae
Which serotype of E. coli causes infant meningitis?
K
What does urease do? what does it do for bacteria?
Break urea into ammonia and CO2/decrease acidity to invade
How does vibrio cholera causes watery diarrhea?
It stimulate Gs—->increase cAMP—>increase water secretion into the intestinal lumen—>watery diarrhea
What is the number 1 bacteria that causes diarrhea?
Campylobacter