coevolution, evolution, and medicines - part 3

what are the two types of coevolution?

mutualistic and antagonistic

what is mutualistic coevolution?

when both species benefit

what is antagonistic coevolution?

changes in one species will decrease the fitness of the other

how do humans benefit from intestinal microbes?

they provide the microbes (bacteria) with various nutrients and good environment to grow and divide

what vitmanin is useful for blood clotting and cannot be produced by the human body?

vitamin E

what is bifidobacterium bifidum?

a gram-positive rod-shaped nonmotile abiquitous inhabitants of the human intestinal and vaginal tract (in infants and adults)

where can bifidobacterium bifidum be found in?

yogurts and probiotics

how is bifidobacterium bifidum helpful to humans?

they help discourage the growth of harmful gram-negative bacteria in intestinal tract

can produce bacterium

useful in metabolizing various food (fibers) and producing useful products (vitamins)

how do humans benefit soil microbes?

by providing them with food (organic matter)

create a stable habitat through minimal soil disturbance

ensure they have the right conditions (proper moisture, diverse range of plant life, etc.)

provide optimal environment for beneficial mutations to spread within a bacterial population

how do soil microbes benefit humans?

train the immune system

recycle nutrients

produce useful products (antibiotics)

what is Streptomyces sp.?

filamentous, gram-positive bacteria

has reproductive spores (whidia)

develop into new organisms under favorable conditions

primarily microbes, responsible for earthy odor of soil (geosmin)

what does Streptomyces sp have that is beneficial but not essential?

extracellular enzymes (secondary metabolites) from strict aerobes

what is streptomycin?

the first antibiotic ever reported from a bacterium (sS. griseus)

binds to the small bacterial ribosomal subunit to block translation

what is chlorumphenicol?

the first antibiotic to be manufactured synthetically on a large scale (S. venezuelae)

binds to the large bacterial ribosomal subunit to block translation

what is nystatin?

antifungal agent (S. noursei)

disrupts the fungal cell membrane to cause cell lysis

what is amycolatopsis sp.?

filamentous, gram-positive bacteria found in the soil

can also produce various secondary metabolites like streptomyces

what is vancomycin?

drug of choice to treat MRSA (A. orientalis)

target beta-lactam resistant gram-positive bacteria

blocks transpeptidation → cell wall destruction → cell lysis

what is rifamycin (A. mediterranei)?

drug of choice for treating tuberculosis

inhibit bacterial RNA polymerase

prevent RNA synthesis by physically blocking elongation

greater affinity for bacterial polymerases than human polymerases