Clinical Vignettes

Front 1

Lag phase

Back 1

detoxifying medium
turning on enzymes to utilize medium
# cells at beginning = # at end

Front 2

Log phase

Back 2

exponential growth
generation time (time for one cell to divide) is determined during this phase

Front 3

Stationary phase

Back 3

nutrients used up
toxic products accumulate
new cells=dying cells

Front 4

Cysteine required for growth

Back 4

Four sisters 'ella' worship in cysteine chapel
francisella, brucella, legionella, pasteurella

Front 5

Obligate anaerobes

Back 5

ABCs of anaerobiosis
actinomyces, bacteroides, clostridium

Front 6

Gm +, catalase +, Coagulase +, B-hemolysis, acute endocarditis, abscesses, TSS, gastroenteritis (salty foods, custards), pyoderma, impetigo, osteomyelitis (#1 cause unless HbS mentioned), PNA (nosocomial, typical, acute)

Back 6

S. aureus

Front 7

gram +, Catalase +, coagulase -, g-hemolysis, novobiocin sensitive, endocarditis, catheter/artificial heart valve infxns

Back 7

Staph. epidermidis

Front 8

gram +, Catalase +, Coagulase -, g-hemolysis, novobiocin resistant, UTIs in newly sexually active females (honeymoon cystitis)

Back 8

Staph. saprophyticus

Front 9

gram +, catalase -, coagulase -, B-hemolysis, bacitracin sensitive, pharyngitis, scarlet fever, pyoderma/impetigo, rheumatic fever (inc ASO titer >200), acute glomerulonephritis post infxn

Back 9

Strep. pyogenes (group A)

Front 10

gram +, catalase -, coagulase -, B hemolysis, bacitracin resistant, CAMP test +, neonatal septicemia

Back 10

Strep. agalactiae (Group B)

Front 11

gram +, catalase -, coagulase -, a-hemolysis, optochin sensitive, CAP (most common cause, rusty/bloody sputum), adult meningitis, otitis media and sinusitis in kids (most common cause)

Back 11

Strep. pneumoniae

Front 12

gram +, catalase -, coagulase -, a-hemolysis, optochin resistant, endocarditis, dental caries

Back 12

strep. viridians

Front 13

gram +, catalase -, coagulase -, a, B, or g hemolysis, endocarditis s/p GU/GI surgery, urinary and biliary infxns

Back 13

enterococcus sp. (Group D)
faecalis/faecium

Front 14

productive nosocomial PNA, rapid onset, ventilator, post influenza, CF, CGD, salmon colored sputum---> CA?

Back 14

Staph. aureus

Front 15

Typical PNA with pain and fever, lobar PNA, with productive cough. Grows on blood agar, responds well to PCN---> CA?

Back 15

Strep. pneumoniae

Front 16

gram + rods

Back 16

Bacillus, clostridium, listeria, corynebacterium, actinomyces, nocardia, mycobacterium

Front 17

gram +, spore forming, aerobic rods, contact with animal hides or postal worker; eschar or life threatening PNA

Back 17

bacillus anthracis

Front 18

Rapid-onset gastroenteritis, fried rice, Chinese restuarants

Back 18

Bacillus cereus

Front 19

Gram + spore forming rod, Dirty puncture wound, rigid paralysis

Back 19

clostridium tetani

Front 20

gram +, spore forming rod, Home-canned alkaline veggies, floppy baby syndrome/floppy paralysis

Back 20

clostridium botulinum

Front 21

gram +, spore forming rod, double zone of hemolysis, Contaminated wound, pain, edema, gas, fever, tachycardia, food poisoning: reheated meats, noninflammatory diarrhea

Back 21

clostridium perfringens

Front 22

Hospitalized pt. on Abx (esp. clindamycin), pseudomembranous colitis, diarrhea

Back 22

Clostridium difficile

Front 23

Gram + rod, B hemolytic, cold growth, facultative intracellular, foodborne (deli foods), transplacental, neonatal septicemia/meningitis, most common cause of meningitis in renal transplant or cancer patients

Back 23

Listeria monocytogenes

Front 24

Gram +, aerobic, non-spore forming rod, bull neck, myocarditis, nerve palsies, airway obstruction (gray pseudomembrane), heart/nerve damage

Back 24

Corynebacterium diptheriae

Front 25

Mycetoma on jawline or spread from IUD, sulfur granules in pus grow anaerobic, gram +, non-acid fast branching rods

Back 25

actinomyces israelii

Front 26

Gram +, filamentous bacilli, aerobic, partially acid fast, cavitary bronchopulmonary disease, mycetomas

Back 26

Nocardia asteroides and nocardia brasiliensis

Front 27

High risk pt (poverty, HIV, IV drugs), chronic cough, wt. loss, Ghon complex, acid fast bacilli in sputum, produce niacin, heat-sensitive catalase, PPD+, intracellular

Back 27

mycobacterium tuberculosis

Front 28

acid fast bacilli in punch biopsy, immigrant patient with sensory loss in extremities, intracellular

Back 28

mycobacterium leprae

Front 29

Tuberculoid leprosy

Back 29

TH1 response, lepromin test +, low number of organisms, fewer lesions

Front 30

Lepromatous leprosy

Back 30

TH2 response, Lepromin test -, high number of organisms, numerous lesions

Front 31

1st line tx for localized MRSA

Back 31

trimethoprim-sulfamethoxazole (Bactrim) (PO)
clindamycin (PO)
doxycycline or minocycline (PO)

Front 32

1st line tx for soft tissue/systemic MRSA

Back 32

1st line: vancomycin (IV), others includelinezolid (IV, PO after discharge)
daptomycin (IV)
quinupristin-dalfopristin (Synercid) (IV)
telavancin (IV)
ceftaroline (IV)

Front 33

Strep virulence factors

Back 33

M protein (interferes with phagocytosis), Streptokinase (clot buster), Streptolysin (dx RF), C5a peptidase, hyaluronidase, toxins

Front 34

fever, rash, carditis and arthritis 2-3 wks after pharyngitis---> CA?, MOA

Back 34

cross-reactivity between Strep Ags (M protein) and heart and joint tissue. prevent with Abx

Front 35

Acute pharyngitis CA?, tx?

Back 35

most commonly strep. pyogenes (Group A), PCN

Front 36

Hot tub folliculitis, swimmer's ear, PNA in CF pts, necrotizing enterocolitis in IC pt

Back 36

P. aeruginosa

Front 37

Gram + rod, obligate anaerobe, necrotizing fascitis, food poisoning

Back 37

Clostridium perfringens

Front 38

Tx for P. aeruginosa

Back 38

Cephalosporin: ceftazidime (Ceftaz) IV
Penicillins: ticarcillin (Ticar), ticarcillin-clavulanate (Timentin), piperacillin (Piracil) or piperacillin-tazobactam (Zosyn) (IV)
Aminoglycosides: tobramycin (IV/IM) or gentamicin (IV/IM)
Fluoroquinolones: ciprofloxacin (Cipro) (IV, PO)

Front 39

Tx. of C. perfringens necrotizing fascitis

Back 39

remove dead tissue, O2 exposure, PCN G, doxycycline, broad spectrum abx to cover a mixture of species

Front 40

TSS tx

Back 40

strep: pcn G plus clindamycin
Staph: oxacillin, nafcillin or cefazolin

Front 41

Tx scarlet fever

Back 41

PCN G

Front 42

focal erythema (redness), warmth, edema and pain
May have fever, mildly elevated WBC with left shift. Usually follows some discernible wound,
Tinea pedis can be portal of entry. DZ and CA and TX?

Back 42

cellulitis group A streptococcus and S. aureus in healthy adults, Cephalexin

Front 43

with pain, redness, swelling of external ear with hx of maceration from water, surgery/trauma, or upper ear cartilage piercing---> DZ, CA, TX?

Back 43

Acute otitis externa, P. aeruginosa, hydrocortisone, neomycin, polymyxin B otic solution

Front 44

pain, erythema, edema, cellulitis, fever
clues: pain out of proportion to physical findings, dusky blue/back color of skin, gas in tissue (crepitus, seen on imaging)---> DZ, CAs, and TX

Back 44

necrotizing fascitis, strep. pyogenes, clostridium perfringens, surgically remove dead tissue, broad spectrum Abx

Front 45

A 72 year old man presents with a two month history of fever, fatigue, anorexia, and weight loss. His past medical history is significant for a mitral valve replacement with a porcine valve 5 years ago and he underwent a dental extraction about 3 months ago.
What infectious disease are you most concerned about?
What infectious organism is the most likely cause?
Risk factors?
Prophylaxis?

Back 45

endocarditis, Strep. viridans. Risk factors are heart valve and dental procedure
Amoxicillin 3g PO 1 hr b4 procedure and 1.5g 6h s/p procedure

Front 46

A 61 year old woman presents with a two day history of a bright red, swollen and tender area on her left anterior lower leg. She denies fever and trauma to the site.
What is your diagnosis?
What are the most likely organisms to cause this presentation?
What treatment do you recommend?

Back 46

Cellulitis,
staph. aureus, strep. pyogenes
cephalexin (keflex), dicloxacillin

Front 47

A 54 year old man develops increased redness, swelling and purulent drainage at excision site on his right ear four days after surgery to remove basal cell carcinoma. You are concerned about bacterial infection.
What organisms do you need to cover with your antibiotic choice?
Which antibiotic would you prescribe?

Back 47

staph, strep, psuedomonas
ciprofloxacin PO is DOC

Front 48

A 64 year old man presents with redness, swelling, tenderness and warm on the bilateral lower extremities. No history of trauma. Afebrile.
What is your diagnosis?

Back 48

Not cellulitis b/c it's bilateral, more likely d/t stasis dermatitis
Key to diagnosis is pre-existing edema and two distant sites

Front 49

gm + rod, severe pain
Progression to edema, pallor, tenderness
Crepitance (50%)
Hemorrhagic bullae
Fever, tachycardia, diaphoresis
Muscle Necrosis---> DZ, CA, TX

Back 49

gas gangrene
clostridium perfringens
surgical debridement, PCN, hyperbaric O2

Front 50

gm + rod, Associated with malnutrition, high protein meals (pig-bel), sweet potatoes, nematode infections---> DZ, CA, TX
Upper abdominal pain, vomiting, bloody diarrhea
Surgery and antibiotic treatment

Back 50

enteritis necrocans, c. perfringens, Surgery and Abx

Front 51

Diarrhea, cramps, vomiting, nausea
Spontaneous resolution in 24 hours---> DZ, CA

Back 51

Food poisoning, Clostridium perfringens Enterotoxin

Front 52

Gram positive anaerobic rod with terminal spore, Puncture wounds and lacerations
IV drug use
Opisthotonic posturing
Flexion of arms, extension of legs
Painful muscle spasms
Upper airway obstruction
Diaphragmatic compromise---> DZ, CA, TX

Back 52

tetanus, C. tetani, artificial ventilation
Benzodiazepines
Neuromuscular junction blockade
Vecuronium
Human tetanus immunoglobulin (antitoxin)
Antibiotics (metronidazole, penicillin), prevent with vaccine

Front 53

Anaerobic gram positive rod with subterminal spore, flaccid paralysis, Foodborne starts 12 to 36 hrs after ingestion, Initially cranial nerve involvement
Ptosis
Pupils fixed or dilated (50%)
Diploplia, dysarthria, dysphagia
Descending paralysis, respiratory
No fever---> DZ, CA, TX

Back 53

botulinism, C. botulinum, Intensive care (mechanical ventilation)
Debridement
Antitoxin
Penicillin or metronidazole

Front 54

Infant eats honey and has
Constipation
Difficulty feeding
Hypotonia
Weak cry
Airway obstruction, Respiratory weakness---> DZ, CA, TX

Back 54

botulism, C. botulinum, Intensive care (mechanical ventilation)
Debridement
Antitoxin
Penicillin or metronidazole

Front 55

Gram positive anaerobic rod, post abx diahrrea (esp clindamycin, ampicillin/amoxicillin, 3rd gen cephalosporin)---> DZ, CA, DX, TX

Back 55

pseudomembranous colitis, clostridium dificile, Diagnosis
Endoscopy
Enzyme immunoassay
Latex agglutination
Cytotoxic assay (HELA cells)
PCR, Treatment
ORAL Vancomycin
ORAL Metronidazole
fidaxomicin (gm + but not gm - so you still have nl flora)
Stopping antibiotic treatment if possible, prevent with handwashing