Micro Gram -

Question 1

Gram - diplococci, ferment maltose and glucose, polysaccharide capsule

Answer 1

Neisseria meningitidis

Question 2

Gram - diplococci, ferments glucose but not maltose, no polysaccharide capsule

Answer 2

Neisseria gonorrhoeae

Question 3

What can neisseria gonorrhoeae cause?

Answer 3

Gonorrhea, septic arthritis, neonatal conjunctivitis (2-4 days after birth), PID, and Fitz-Hugh-Curtis syndrome

Question 4

Treatment for neisseria gonorrhoeae

Answer 4

Ceftriaxone (+ azithromycin or doxycycline, for possible chlamydia coinfection)

Question 5

What can neisseria meningitidis cause?

Answer 5

Meningococcemia with petechial hemorrhages and gangrene of toes, meningitis, Waterhouse-Friderichsen syndrome

Question 6

How is neisseria meningitidis treated?

Answer 6

Ceftriaxone or penicillin G

Question 7

How are close contacts to neisseria meningitis patient treated?

Answer 7

Rifampin, ciprofloxacin, or ceftriaxone

Question 8

Small gram - coccobacillary rod. Aerosol transmission

Answer 8

Haemophilus influenza

Question 9

What can H influenzae cause?

Answer 9

Epiglottitis, meningitis, otitis media, pneumonia

Question 10

What kind of media is needed to grow H influenzae?

Answer 10

Chocolate agar - contains factors V (NAD+) and X (hematin) for growth. Can also be cultured with S aureus

Question 11

How is H influenzae treated?

Answer 11

Amoxicillin +/- clavulonate for mucosal infections, ceftriaxone for meningitis, rifampin prophylaxis for close contacts

Question 12

Gram - aerobic coccobacillus

Answer 12

Bordetella pertussis

Question 13

What are the virulence factors for bordetella pertussis?

Answer 13

Pertussis toxin (disables Gi), adenylate cyclase toxin (increases cAMP), and tracheal cytotoxin

Question 14

What are the 3 clinical stages of pertussis?

Answer 14

Catarrhal - low grade fevers, coryza
Paroxysmal - paroxysms of intense coughing followed by inspiratory whoop, posttussive vomiting
Convalescent - gradual recovery of chronic cough

Question 15

Gram - rod, grams stain poorly so silver stain is used. Grows on charcoal yeast extract medium with iron and cysteine

Answer 15

Legionella

Question 16

How is legionella pneumophila transmitted?

Answer 16

Aerosol transmission from environmental water source habitat. No person-person transmission

Question 17

How is legionella pneumophila treated?

Answer 17

Macrolide or quinolone

Question 18

Legionnaire’s Disease

Answer 18

Severe pneumonia (often unilateral and lobar), fever, GI and CNS symptoms. Common in smokers and in chronic lung disease

Question 19

Aerobic, motile, gram - rod. Non-lactose fermenting. Oxidase +. Mucoid polysaccharide capsule

Answer 19

Pseudomonas aeruginosa

Question 20

What infections/disease is pseudomonas associated with?

Answer 20

Pneumonia, sepsis, ecthyma gangrenosum, UTIs, diabetes, osteomyelitis, otitis externa, nosocomial infections, addicts, skin infections

Question 21

What do pseudomonas produce?

Answer 21

Phospholipase C (degrades cell membranes)
Endotoxin (fever, shock)
Exotoxin A (inactivates EF-2)
Pigments: pyoverdine and pyocyanin (blue green)
Reactive oxygen species

Question 22

What drugs are used to treat pseudomonas?

Answer 22

Carbapenems, aminoglycosides, monobactams, polymyxins, fluoroquinolones (ciprofloxacin, levofloxacin), third and fourth generation cephalosporins (ceftazidime, cefepime), extended spectrum penicillins (piperacillin, ticarcillin)

Question 23

Gram - rods, non-lactose fermenters, oxidase -, can invade the GI tract via M cells of Peyer patches

Answer 23

Salmonella and Shigella

Question 24

What do antibiotics do against Salmonella infection?

Answer 24

Prolong duration

Question 25

Which bacteria ferment lactose?

Answer 25

Pink colonies on MacConkey agar | Citrobacter, Klebsiella, E. coli, Enterobacter

Question 26

E. coli virulence factors

Answer 26

Fimbriae, K capsule, LPS endotoxin

Question 27

What can the shiga like toxin in O157:H7 E. coli cause?

Answer 27

Hemolytic uremic syndrome - anemia, thrombocytopenia, and acute renal failure due to microthrombi forming on damaged endothelium leading to mechanical hemolysis (schistocytes), platelet consumption, and decreased renal blood flow

Question 28

Currant jelly sputum

Answer 28

Klebsiella

Question 29

Intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated

Answer 29

Klebsiella

Question 30

Gram -, comma or S shaped, oxidase +, grows at 42 degrees C

Answer 30

Campylobacter jejuni

Question 31

What part of the stomach does H pylori colonize?

Answer 31

Antrum

Question 32

How is H pylori treated?

Answer 32

Amoxicillin, clarithromycin, proton pump inhibitor