Other Gram - Bacteria

Question 1

fermentation of lactose

Answer 1

• fermentation of lactose –> pink colonies on MacConkey agar
  
  • “lactose is key”
  • “test with MacConKEE’s agar”

Question 2

examples of lactose fermenting enteric bacteria

Answer 2

• Klebsiella
• E. coli
• Enterobacter
• Serratia (weak fermenter)

Question 3

what does E. coli produce, and how does that work as lactose?

Answer 3

• E. coli produces beta-galactosidase
  
  • beta galactosidase breaks fown lactose into glucose and galactose

Question 4

lactose fermenting enteric bacteria and EMB agar

Answer 4

• lactose fermenters grow as purple/black colonies
  
  • E. coli grows colonies with a green sheen

Question 5

properties of Neisseria

Answer 5

• gram - diplococci
• metabolic glucose
• produce IgA proteases

Question 6

is N. gonorrhoeae intra or extra cellular?

Answer 6

• intracellular
  
  • within neutrophils

Question 7

2 types of Neisseria and what they ferment

Answer 7

• Meningococci
  
  • “MeninGococci ferment Maltose and Glucose”
• Gonococci
  
  • “Gonococci ferment Glucose”

Question 8

properties of Gonococci Neisseria

Answer 8

• no polysaccharide capsule
• no maltose metabolized
• no vaccine due to antigenic variation of pilus proteins
• sexually or perinatally transmitted

Question 9

what does gonococci Neisseria cause?

Answer 9

• gonorrhea
• septic arthritis
• neonatal conjunctivitis
• pelvic inflammatory dz (PID)
• Fitz Hugh Curtis Syndrome

Question 10

how to prevent sexual transmission of gonococci Neisseria?

Answer 10

• condoms

Question 11

how to prevent neonatal blindness caused by gonococci Neisseria?

Answer 11

• erythromycin eye ointment

Question 12

gonococci Neisseria–treatment

Answer 12

• ceftriaxone
  
  • • (azithromycin or docycycline) for possible chlamydial coinfection

Question 13

properties of meningococci Neisseria

Answer 13

• polysaccharide capsule
• maltose fermentation
• vaccine–type B not widely available
• transmitted via respiratory and oral secretions

Question 14

what does meningococci Neisseria cause?

Answer 14

• meningococcemia with petechial hemorrhages and gangrene of toes
• meningitis
• Waterhouse Friderichsen syndrome
  
  • adrenal insufficiency
  • fever DIC
  • shock

Question 15

meningococci Neisseria–prophylaxis in close contacts

Answer 15

• rifampin
• ciprofloxacin OR
• ceftriaxone

Question 16

meningococci Neisseria–treatment

Answer 16

• ceftriaxone
• Penicillin G

Question 17

properties of Bordetella pertussis

Answer 17

• gram -
• aerobic
• coccobacillus

Question 18

Bordetella pertussis–virulence factors

Answer 18

• pertussis toxin–disable G_i
• tracheal cytotoxin

Question 19

what does Berdetella pertussis cause?

Answer 19

• whooping cough

Question 20

how to prevent bordetella pertussis?

Answer 20

• Tdap, DTaP vaccines

Question 21

what may Bordetella pertussis be mistaken as, and why?

Answer 21

• may be mistaken as viral infection due to lymphocytic infiltrate resulting from immune response

Question 22

properties of Campylobacter jejuni

Answer 22

• gram -
• comma or S shaped with polar flagella
• oxidase +
• grows at 42 deg C)
  
  • “Campylobacter likes the hot campfire”
• fecal oral transmission through person to person contact or via ingestion of undercooked contaminated poultry or meat, unpasteurized milk

Question 23

what does Campylobacter jejuni cause?

Answer 23

• bloody diarrhea especially in children

Question 24

what is a risk factor for Campylobacter jejuni?

Answer 24

• contact with infected animals (dogs, cats, pigs) is also a risk factor

Question 25

what is Camphylobacter jejuni a common antecedent of?

Answer 25

• Guillain Barre Syndrome
• reactive arthritis

Question 26

properties of Vibrio cholerae

Answer 26

• gram -
• flagellated
• comma shaped
• oxidase +
• grows in alkaline media
• requires large incoculum (high ID50) unless host has dec gastric acidity

Question 27

where is Vibrio cholerae endemic?

Answer 27

• developing countries

Question 28

what does Vibrio cholerae cause and by what mechanism?

Answer 28

• produces profuse rice water diarrhea
  
  • via enterotoxin that permanently activates G_s –> inc cAMP

Question 29

what is Vibrio cholerae sensitive to?

Answer 29

• stomach acid–acid labile

Question 30

what is necessary with a Vibrio cholerae infection?

Answer 30

• prompt oral rehydration