Deoxycholate agar (DCA) is useful for the isolation of which group of bacteria?

Deoxycholate agar (DCA) is a selective medium primarily designed for the isolation of enteric gram-negative bacteria, particularly members of the Enterobacteriaceae family. The composition of DCA inhibits the growth of many gram-positive bacteria while allowing for the growth of gram-negative organisms. The selective components, including sodium deoxycholate, suppress the growth of non-enteric bacteria, which makes it an effective medium for isolating pathogens such as Salmonella and Shigella, both of which are members of the Enterobacteriaceae family.

Additionally, the differential aspect of DCA allows for the identification of lactose fermenters, which produce acid and result in color change. Understanding the specific use of DCA reinforces one's knowledge of microbiological media and highlights the significance of selective and differential media in the laboratory environment. Other bacterial groups listed may not grow well on DCA or may not be the target organisms for isolation using this particular medium.