Persistent isolation of an unusual Pseudomonas species from a phenolic disinfectant system.

A well-characterized unusual Pseudomonas species contaminated the piped disinfectant system of a newly-opened laminar air flow intensive care facility. This organism was frequently isolated (10(4)-10(6) cfu/ml) from phenolic diluted 1:256 in the system, and could also be recovered (0.01-0.2 cfu/ml) from undiluted phenolic. During the 20-month period when this unusual Pseudomonas was present, none of the severely compromised, granulocytopenic oncology patients treated in the intensive care facility were either colonized or infected with this Pseudomonas sp. Eradication of the organism from the system proved difficult and was accomplished by removing a contaminated reservoir of diluted phenolic disinfectant followed by transient cleansing of the system with very high concentrations (84,000 ppm) of chlorine. This experience demonstrates that phenolics should be added to the list of disinfectants which can harbor Pseudomonas spp. in the clinical setting.