This image depicts what is known as a Moore swab, which can be used to monitor a sewage system, or other flowing water for the presence of Vibrio cholerae-O1. The swab consists of a bundle of sterile, cotton gauze secured to the end of a wire. Placed into a water supply suspected V. cholerae contamination, the bacteria adhere to the gauze fibers. Then in a laboratory setting, they’re grown to a high titer during the enrichment process, which takes place in an alkaline peptone broth. Thereafter, the organisms can then be isolated using a thiosulfate-citrate-bile-sucrose (TCBS) agar medium.