CH4A

• How do humans and microflora display mutualism?

  Humans give microflora food and shelter from our bodies. Microflora make low-pH environments where pathogens cannot inhabit, and provide essential vitamins.
• Commensialism


  A: Benefitted

  B: Unaffected
• Mutualism


  Both populations A and B benefit
• Amensalism


  A: Harmed

  B: Unaffected
• Parasitism


  A: Harmed

  B: Benefitted
• Neutralism


  Both populations A and B unaffected
• Vaginal microflora doesn't develop fully until puberty, when estrogen changes the vaginal metabolism to house Lactobacillus species.
• Why is Lactobacillus important for the vagina?

  It helps keep the vaginal pH low, preventing pathogens like C. albicans from colonizing.
• Clostridium difficile is a spore.
• What does C. difficile do when ingested?

  It produces a toxin that kills intestinal cells, forming pseudomembranous colitis.
• How do microflora protect against C. difficile?

  They take up space, impairing C. difficile's growth. They compete for nutrients to stunt their germination. They'll also influence the immune system to produce antibodies and antimicrobial peptides against the pathogens.