Fighting Superbugs in Water: Detecting Tough Bacteria

Water can be a hidden reservoir for Pseudomonas aeruginosa, a nasty bug that can make people sick. One type of this bacteria, called CRPA, is extra tough due to carbapenem resistance. This makes it hard to treat infections caused by it. Currently, we mostly know how to find CRPA in hospitals, but not so much in water. Scientists wanted to change that. They tested different ways to find CRPA in water, both from wastewater and surface water. They used different types of agar plates, which are like petri dishes, and added different antibiotics to see which works best. They also tried adding antibiotics to a liquid called broth to see if that helps.The best results came from using M-PA-C agar plates with imipenem. This method was great at finding CRPA and not other bacteria. But, they found that directly plating the water samples didn't work well because there were too many other bacteria growing. So, they suggested using a special broth first, called asparagine proline broth with vancomycin, to make the CRPA stand out more. They also found that using both a non-selective broth and selective plates with imipenem was the best way to find even small amounts of CRPA. Adding imipenem to the broth instead of the plates didn't work as well. It made it harder to find CRPA and the results weren't as reliable.