|Ring stage malaria parasites in red blood cells|
Last semester, I rotated in a lab at Columbia University that focuses on malaria; specifically, my mini-projects had to do with drug resistance. In the wet lab, the way we approached this subject was by taking a given amount of parasite and growing it in a certain concentration of drug.
Now, when you first give the drug to the parasites, a lot of them will die, as expected. When you look under the microscope, it'll seem like there are no more parasites at all!
If your starting dose is too high, you will likely continue seeing nothing, as all parasites really will have died. However, you will likely eventually see the parasites 'come back' -- it's really only possible to start seeing them once they hit a concentration of 0.1% infection, or 1 parasite for every 1000 red blood cells -- after a few days or weeks depending on the drug. These parasites will be resistant. You can make really resistant parasites by continuously ramping up the drug pressure - i.e. start with 5nM concentration; get resistant parasites; up to 10nM; etc. Once one acquires the drug-resistant parasite of choice,
This process is really interesting, but time-consuming and a bit bothersome. When I did this, I grew three wells each of five different starting concentrations of parasite per trial, with three trials in total. There is a risk of contamination. It's incredibly frustrating to come in one day to see a portion of your samples have gone to waste after three weeks! Additionally, parasites have to be checked every two days, and blood has to be changed every week. These are lots of man-hours and, while it's a fascinating field, one can't help but feel like a monkey with a pipette once in a while.
Why am I writing about this? A team of researchers from Harvard, Harvard Medical School and Sabanaci University (Istanbul, Turkey) have created an automated device to investigate the development of drug resistance. While they focus on E. coli, the principle is similar: grow the bacteria in a variety of different concentrations, sequence, and identify the genes leading to resistance.
Now, there are no details out yet - the team is presenting details this week at a conference - but I'm curious to see what the details of this device are.
(This post was not completed at the time of writing, but is being published for the sake of linking to the article.)