Biofilms Flashcards
Are anaerobes or aerobes more present in human body? What is the ratio?
anaerobes more present; 1000:1
Mouth and GI have appx 10^x number of organisms per gram of tissue?
10^9
2 main categories of gram + bacteria?
Bacteroidetes and Firmicutes
Makeup of gut microbiota?
48% bacteroidetes, 51% firmicutes, 1% proteobacteria
What is colonization resistance?
good bacteria “occupy” all the available space (parking lot analogy)
How does C. difficile become infectious in the gut if it’s there normally and not harming us?
Abx tx wipes out normal gut flora, so C. diff spores can vegetate and cause infection
4 main functions of gut microbes?
digest food, produce vitamins B and K, occupy niches and exclude pathogens, train our immune systems
What is meant by fecal transplants being a “double edged sword?”
can replenish the microbiome and have therapeutic effects, but can also transmit drug resistant germs/bad stuff
Staphylococcus epidermis is found where?
skin
S. aureus is found where?
nose
Lactobacillus is found where?
vagina
Bacteroidetes and Firmicutes are found where?
GI
E. coli and Clostridium are found where?
GI
Difference between sessile and planktonic?
Sessile bacteria are settled down and living in a biofilm or on a surface; planktonic are free-floating
What are exopolysaccharides?
sugars secreted beyond the bacterial envelope into the environment; unattached to individual bacteria
