00:02
The thumb rule in microbiology is that we use pure cultures, right, for antimicrobial susceptibility tests, right? if you want to assess the effect of antimicrobials in a particular or against a particular strain of microorganisms, say staphiloccus are rare, right? you'll first grow these staphilococcus earth, right? you'll first isolate them.
00:38
And then you're going to get mixed cultures, for instance, right? of different strains.
00:48
And then you're going to pick pure isolates of staphylopokas areas and then grow them on specific media.
01:02
For susceptibility tests.
01:06
Remember, we're going to use pure cultures.
01:11
Pure culture is a culture from a single cell, right? which results in clones, right? so what happens is a single clone of cells means all these cells possess similar features of parental cycle, which means they'll all react.
01:38
Same to a given antibiotic.
01:41
All right? if you're testing the effect of ampicillin on staphilocococcus areas, you definitely grow staphocococcal cells on mullah hinton agra, right? and then spread it uniformly.
01:59
So this is one strain you've spread, then you place skillfully placed your antibiotic discs evenly distributed or through the plate.
02:11
So you see what happens is after isolation from fewer cultures, individual antibiotics will have effect against a particular strain of bacteria in line with a particular infection...