A new microarray the size of a microscope slide holds 1,200 individual cultures of fungi or bacteriapaper in mBio this week. Scientists at the University of Texas at San Antonio and the U.S. Army Institute of Surgical Research at Fort Sam Houston have developed a microarray platform for culturing fungal biofilms, and validated one potential application of the technology to identify new drugs effective against Candida albicans biofilms. The nano-scale platform technology could one day be used for rapid drug discovery for treatment of any number of fungal or bacterial infections, according to the authors, or even as a rapid clinical test to identify antibiotic drugs that will be effective against a particular infection.
"Even though we have used the antifungal concept for development, it is a universal tool," says co-author Jose Lopez-Ribot of the University of Texas at San Antonio. "It opens a lot of possibilities as a new platform for microbial culture. Any time you need large numbers of cultures, this has a big advantage over other methods," Lopez-Ribot says.
"The possibility exists to use this same technology for pretty much any other organism," he says.
Now Trending: Tiny
Microbiology and medicine have become increasingly reliant on micro- and nano-scale technologies because of the increased speed and efficiency they can offer, but until now the cultivation of microorganisms has mostly been conducted on larger scales, in flasks and in micro-titer plates. The microarray technology developed by Srinivasan et al. enables the user to rapidly compare hundreds or thousands of individual cultures of bacteria or fungi, a big benefit in the search for new drugs to treat infections. And like many nano-scale techniques, the nano-culture approach described in the mBio study is also automated, a feature that saves time, improves reproducibility, and prevents some types of user error.
Does a 30 nanoliter culture actually work?
To test the technique, the authors embedded cells of the opportunistic pathogen C. albicans in each of the 1,200 tiny dots of alginate on the surface of the microarray. Under the microscope, these nano-biofilms of C. albicans, each of which was only 30 nanoliters, exhibited the same growth habits and other outward
"The antifungal screening results were similar to results in larger macroscale techniques. That gives us confidence that it could be used as a tool to replace existing techniques," says Ramasubramanian.
Going forward, Ramasubramanian says he and his colleagues are testing the microarrays with polymicrobial cultures to see whether the technology can be used to explore treatments for mixed infections. They are also exploring clinical applications for the technique, testing patient samples against an array of drugs or combinations of drugs to develop tailored therapies.
Lopez-Ribot says their microarray technique is just the latest development in a decades-long trend toward the tiny in science. "Things are moving toward smaller scale, more powerful techniques. You don't need millions of cells for these assays like we used to - maybe a few cells will do."