Bacteria

Question 1

Haemophilis influenzae

Answer 1

gram - coccobacilli, most common cause of community-acquired penumonia

Question 2

Strep

Answer 2

gram + cocci, diplococci and chains more common than clusters, catalase -, facultative anaerobe, pyogenes common for cellulitis

Question 3

Staph

Answer 3

gram + cocci in clusters, “aureus” golden/yellow color, catalase +, facultative anaerobe, aureus common for cellulitis

Question 4

Neisseria meningitidis

Answer 4

gram - cocci

Question 5

Mycoplasma pneumoniae

Answer 5

poorly gram stain surrounded by sterols, no cell wall, many shapes

Question 6

Borrelia recurrentis

Answer 6

spirochete, relapsing fever, transmitted via louse and epidemic in ethiopia

Question 7

Treponema pallidum

Answer 7

spirochete, syphilis

Question 8

Rickettsia rickettsia

Answer 8

gram -, intracellular coccobacilli, identified via Giemsa stain

Question 9

Babesia microti

Answer 9

intracellular protozoa, cause babesiosis, identified via Giemsa stain, low blood counts including low hematocrit and thrombocytopenia

Question 10

Serratia marcescens

Answer 10

red color

Question 11

Pseudomonas aeruginosa

Answer 11

blue-green pigment due to pyocyanin

Question 12

Actinomyces

Answer 12

filamentous bacteria “cement” together, yellow-orange appearance aka “sulfur granules”

Question 13

Gram stain dyes

Answer 13

fixation, crystal violet, iodine, decolorization, safranin

Question 14

Thayer-Martin growth media

Answer 14

Neisseria growth selective

Question 15

Blood Agar

Answer 15

non-selective, used to differentiate hemolysis pattern (beta = lysis, alpha = partial, gamma = no lysis), often used to differentiate species of streptococcus, Psuedomonas also beta hemolytic along with staph aureus

Question 16

Chocolate agar

Answer 16

H. Influenzae, contains rbcs that are lysed through heating,

Question 17

Bordet-Gengou agar

Answer 17

BORDetella pertussis

Question 18

Loeffler’s Media/Tellurite Plate

Answer 18

Loefflers media selevtive for corynebacterium diphtheriae and tellurite as well which produces gray-black colored colonies

Question 19

Lowenstein-jensen agar

Answer 19

Mycobacterium tuberculosis, slow growing (will also stain with Ziehl-Neelsen stain)

Question 20

Eaton’s agar

Answer 20

mycoplasma pneumonia, contains lots of cholesterol

Question 21

MacConkey’s agar

Answer 21

selective for gram -, contains bile salts that inhibits gram +, differential for lactose fermenters as well which turns agar pink, identify gram - rods

Question 22

Eosin-Methylene blue agar

Answer 22

inhibit gram + growth, also differential for lactose fermenters, if ferment lactose appear with green sheen look

Question 23

Sorbitol MacConkey agar

Answer 23

detection of E. Coli O157 strains grow colorless while other E. Coli produce pink colonies

Question 24

Buffered Charcoal Yeast

Answer 24

Legionella

Question 25

Sabouraud's agar

Answer 25

selective for fungi,

Question 26

Abd Abscess/perforation tx

Answer 26

Metronidazole, gram - agent, below diaphragm

Question 27

Aspiration pneumonia tx

Answer 27

clindamycin, above diaphragm, gram - agent

Question 28

obligate intracellular bacteria

Answer 28

Chlamydia, rickettsia (rocky mountain spotted fever), require extracellular ATP

Question 29

Pseudomonas

Answer 29

gram -, obligate aerobe, aeruginosa can cause "hot tub folliculitis",

Question 30

Obligate anaerobes

Answer 30

"Can't Breath Free Air", Clostridium/Bacteroides/Fusobacterium/Actinomyces israelii ATP through fermentation

Question 31

Virulence Factors

Answer 31

Protein A (staph aureus), IgA protease, M protein (binds factor H which is used to protect our own cells, and breaks down C3 convertase which prevent opsonization by C3b)

Question 32

Specific toxins

Answer 32

Exotoxin A, Shiga Toxin, EHEC, ETEC, Anthrax (edema toxin), Cholera Toxin, Pertussis toxin

Question 33

Shiga Toxin

Answer 33

Shigella causes infectionous diarrhea by binding to 60s ribosomal subunit and stopping protein synthesis

Question 34

EHEC

Answer 34

EHEC (enterohemorrhagic E. Coli) similar to shigatoxin E. coli O157:H7 but doesn't invade host cells and causes disease via toxin unlike shigatoxin,

Question 35

Exotoxin A

Answer 35

Pseudomonas aeruginosa secretes exotoxin A aka diphtheria toxin which stops protein synthesis

Question 36

ETEC

Answer 36

Heat Labile Toxin activates adenylate cyclase to increase camp, and heat stable activates guanylate cyclase to increase cGMP

Question 37

Anthrax (edema toxin)

Answer 37

mimics adenylate cyclase, lesions can have edematous border (surrounded swollen tissue)

Question 38

Cholera Toxin

Answer 38

"rice water diarrhea", permanently activates Gs and increases cAMP

Question 39

Pertussis Toxin

Answer 39

inhibits Gi proteins, increase cAMP

Question 40

neurotoxins

Answer 40

Clostrigium tetani (tetanus) inhibit inhibitory neurons meaning muscle is always on, botulinum prevents Ach release and creates floppy syndromes

Question 41

alpha toxin

Answer 41

phospholipase C ezyme degrades muscles, clostrigium perfringens