PHYSIOLOGICAL-ASPECTS OF DISINFECTION RESISTANCE IN PSEUDOMONAS-CEPACIA

A pseudomonas cepacia population was isolated which had reduced suscep tibility to iodine and maintained resistance when subcultured several times in phosphate buffer. This population was also resistant to iodin e after growth in a minimal medium containing glycerol but not glucose . Addition of cAMP to glucose-grown cells caused increased resistance to iodine. Iodine-resistant cultures also demonstrated reduced suscept ibility to chlorination but not to heat or metals (Cu/Ag). The results indicate that halogen resistance can be expressed in varying degrees, dependent on the carbon source, and cAMP may promote this expression. Thus, a catabolite repression-like mechanism may cause resistant cult ures grown in some media to become more sensitive to halogens.