Environmental monitoring in a laboratory animal facility

A study was made of the microbial environmental status of an animal facility. Cultures were made of animal and surgical room floors; the germicidal effectiveness of the phenolic disinfectant-detergent employed in the facility was tested against standard test organisms as well as against other microorganisms isolated from the facility, and killing power of the disinfectant-detergent was evaluated during various steps of the usual cleaning procedures, ie, mops and mop bucket solutions were tested before, during, and after mopping a room. It was found that colony counts for animal rooms cleaned with a chlorhexidine disinfectant were much lower than those cleaned with a phenolic disinfectant. The phenolic disinfectant killed some organisms after 10 min exposure, but no others. Pseudomonads were the most resistant organisms. Contaminated mops and mop bucket solutions appeared responsible for the high counts on floors cleaned with the phenolic disinfectant. Guidelines for achievable levels of cleanliness were suggested.