In the next step, different antibiotics are pumped into the chambers. If the cells in a chamber stop reproducing, that indicates that a certain drug is likely to be effective at fighting the infection. The death of the bugs is confirmed by checking with a special dye.
Once the bacteria-carrying fluid is injected into the chip, the entire procedure is automatic-- including the counting of fluorescent-marked cells, which is done by a computer -- and takes less than eight hours.
One of the most difficult steps was to design a surface that would be hospitable to the bacteria but that would at the same time keep the antibodies and antibiotics from sticking to it, Lochhead said. While Accelr8 is working on finding a "universal" material that will allow virtually all pathogenic bacteria to stick to it, the company has so far focused on nine bacterial species that cause most of the cases of drug-resistant pneumonia, including Staphylococcus aureus (staph), Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli (E. coli). "If we can characterize the nine panel organisms, we'll cover 80 to 90 percent of hospital-acquired pneumonia cases," Lochhead said.
The company also hopes to apply the technology not just to identifying known strains but also to testing the efficacy of new drugs, or of existing drugs on unknown strains. "Even if you don't know the identity of an organism, if you know which drug works, it's still useful," Lochhead says.
Accelr8, a former software company that refashioned itself into a biotechnology company, plans to place development in
Source:American Institute of Physics