Flashcards in Normal microbiota Deck (13):
Both organisms benefit from symbiosis
Neither organism benefits from symbiosis.
One organism benefits, the other derives neither benefit nor harm.
How are sterile body sites kept so?
Sterility maintained by barriers that allow uni-directional flow adjacent to non-sterile sites
Sterility maintained by physical separation from non-sterile sites
e.g. respiratory tract
Give examples of sterile sites where sterility is maintained by barriers.
Upper genital tract
Give examples of sterile sites where sterility in maintained by physical barriers
Give an example of skin flora.
Staph epidermidis. Staph aureus.
Give examples of nasopharyngeal commensals.
Streptococcus pyogenes (group A)
Neisseria meningitidis 7-34% in UK university students1
Why does vaginal flora change post-puberty?
Glycogen produced due to circulating antigens.
- Introduction of lactobacillus.
Give examples of aerobic GI bacteria?
Citrobacter spp. etc.
Give examples of anaerobic GI bacteria?
Bacteroides spp., Clostridium spp. Bifidobacteria spp
What are the benefits of normal flora?
Synthesis and excretion of vitamins
- e.g. vitamins K and B12 secreted by enteric bacteria
- e.g. pH
- e.g. colicins, bacteriocins, fatty acids, metabolic waste products
Induction of cross-reactive antibodies
May have a protective effect