Gram Negative Bacteria

Question 1

Prominent diseases caused by Neisseria meningitidis?

Answer 1

Leading cause of meningitis in 2-18 year olds and can also cause a meningococcemia (sepsis + meningitis)

Question 2

Route of infection of Neisseria meningitidis?

Answer 2

respiratory route

Question 3

Who is most susceptible to Neisseria meningitidis?

Answer 3

military personnel and dorm residents (those living in close quarters)

Question 4

Virulence factors of Neisseria meningitidis?

Answer 4

polysaccharide capsule, endotoxin (Lipid A)

Question 5

Prominent diseases caused by Neisseria gonorrheae?

Answer 5

gonorrhea-purulent urethritis or cervicitis, pelvic inflammatory disease, frequently occurs simultaneously w chlamydia

Question 6

Virulence factors of Neisseria gonorrheae?

Answer 6

Pili, IgA protease

Question 7

Prominent diseases caused by Moraxella catarrhalis?

Answer 7

sinusitis, otitis media, bronchitis, pneumonia

Question 8

Neisseria species and Moraxella catarrhalis are what category of bacteria?

Answer 8

Gram negative cocci

Question 9

Prominent diseases caused by Escherichia coli?

Answer 9

UTIs (top cause), neonatal meningitis, sepsis, diarrheal disease (traveler’s diarrhea=ETEC and enterohemorrhagic diarrhea=EHEC)

Question 10

E coli virulence factors?

Answer 10

UTIs: P-type pilus allows adherence to upper urinary tract epithelium
Neonatal meningitis: K1 capsule, LPS
Sepsis: capsule, LPS
Diarrhea: exotoxins, shiga toxin, type III secretion system

Question 11

Prominent diseases caused by Salmonella Enteriditis and Salmonella typhimurium?

Answer 11

enterocolitis from consumption of contaminated food; Top cause of food poisoning

Question 12

Virulence factors of Salmonella enteriditis and salmonella typhimurium?

Answer 12

type III secretion system and the ability to kill macrophages

Question 13

Prominent diseases caused by Salmonella typhi?

Answer 13

typhoid (enteric) fever; death can occur by hemorrhage at ruptured Peyer’s patches

Question 14

Salmonella typhi virulence factors?

Answer 14

Vi antigen that inhibits phagocytosis by neutrophils and the ability to replicate in macrophages

Question 15

What is typhoid fever associated with?

Answer 15

wars & poverty

Question 16

Prominent diseases caused by Shigella (Shigella sonnei= most common in US, Shigella dysenteriae=more severe)

Answer 16

bloody diarrhea (dysentery)

Question 17

Virulence factor of Shigella?

Answer 17

Shiga toxin

Question 18

What is the most common bacterial GI infection in developed countries?

Answer 18

Campylobacter jejuni

Question 19

Prominent diseases caused by Campylobacter jejuni?

Answer 19

watery diarrhea that progresses to inflammatory/bloody diarrhea

Question 20

Prominent diseases caused by Vibrio cholera?

Answer 20

Cholera: most prolific watery diarrhea (“rice water stool”) from fecal contamination of water and food

Question 21

Virulence factors of Vibrio cholera?

Answer 21

cholera toxin, pilus

Question 22

Prominent diseases caused by Vibrio parahaemolyticus?

Answer 22

watery diarrhea from consumption of fecal-contaminated shellfish

Question 23

Prominent diseases caused by Helicobacter pylori?

Answer 23

GI ulcers; chronic ulcers can lead to MALT B-cell tumors

Question 24

Virulence factors of Helicobacter pylori?

Answer 24

urease, 2 toxins introduced into cells via a type III secretion system

Question 25

Prominent diseases caused by bacteroides?

Answer 25

intra-abdominal abscesses when they escape the GI tract due to surgery or trauma

Question 26

Virulence factor of bacteroides?

Answer 26

polysaccharide capsule and tissue-destroying enzymes (collagenases, lipases)

Question 27

Prominent diseases caused by pseudomonas aeruginosa?

Answer 27

skin infection of burn patients, pulmonary infection of cystic fibrosis patients, nosocomial pneumonia associated with ventilators, sepsis

Question 28

Virulence factors of pseudomonas aeruginosa?

Answer 28

LPS endotoxin, numerous degradative enzymes (proteases and elastases), exotoxin A, pyocyanin (blue enzyme damaging lung cilia), Type III secretion system

Question 29

Prominent diseases caused by Klebsiella pneumoniae?

Answer 29

Nosocomial pneumonia, aspiration pneumonia

Question 30

Virulence factor of Klebsiella pneumoniae?

Answer 30

thick polysaccharide capsule

Question 31

What causes acute diarrhea vs chronic diarrhea?

Answer 31

90% of acute diarrheas are caused by viruses and chronic diarrhea is likely a parasite infection

Question 32

Prominent diseases caused by haemophilus influenzae?

Answer 32

meningitis, otitis media and sinusitis, epiglottitis, pneumonia in elderly

Question 33

Virulence factor of haemophilus influenzae?

Answer 33

type b capsule

Question 34

Prominent diseases caused by Bordetella pertussis?

Answer 34

pertussis (whooping cough)

Question 35

Virulence factors of Bordetella pertussis?

Answer 35

pertussis toxin, cytotoxin (kills cilia in lung)

Question 36

Prominent diseases caused by Legionella pneumophilia?

Answer 36

community- and hospital-acquired atypical pneumonia

Question 37

Virulence factor of Legionella pneumophilia?

Answer 37

LPS