BP: Helicobacter, Clostridium + Bacillus anthracis

Helicobacter pylori

Gram-negative, helical, microaerophilic stomach colonizer associated with gastritis, ulcers, and gastric cancer

What part of the body does H. pylori colonize?

The stomach

What enzyme helps H. pylori survive stomach acid?

Urease

What toxin causes vacuole formation in host cells?

VacA

What major virulence factor is delivered by a type IV secretion system?

CagA

What major diseases are associated with H. pylori?

Chronic gastritis, peptic ulcers, gastric cancer, and MALT lymphoma

Why does H. pylori’s helical shape matter?

It helps the bacterium move through mucus

What did Chen 2022 show about O-glycan?

It reduced H. pylori adhesion and epithelial injury

Clostridium

Gram-positive, anaerobic, spore-forming rods with major themes of exotoxins and endospore formation

Which Clostridium species causes botulism?

C. botulinum

What kind of paralysis does botulinum toxin cause?

Flaccid paralysis

Which Clostridium species causes tetanus?

C. tetani

What kind of paralysis does tetanospasmin cause?

Spastic paralysis

Which Clostridium species is associated with gas gangrene?

C. perfringens

Which Clostridium species causes pseudomembranous colitis after antibiotics?

C. difficile

What special trigger is important for C. difficile spore germination?

Bile salts such as taurocholate

What did Collins 2019 show about trehalose and C. difficile?

Trehalose metabolism helped certain epidemic strains grow and become more virulent

Bacillus anthracis

Gram-positive, spore-forming bacterium that causes anthrax

What disease does it cause?

Anthrax

What are the three main forms of anthrax?

Cutaneous, inhalational, and gastrointestinal

What are the two biggest virulence factors of B. anthracis?

Capsule and anthrax toxin

Which plasmid carries anthrax toxin genes?

pXO1

Which plasmid carries capsule genes?

pXO2

What are the three toxin components of anthrax toxin?

PA, EF, and LF

What does edema factor do?

Acts as an adenylate cyclase

What does lethal factor do?

Acts as a protease that disrupts MAPK signaling

What did Hagan 2018 show about petrobactin?

It helped with sporulation and stress protection, not just iron acquisition