Effect of nutrient depletion on the sensitivity of Pseudomonas cepacia to antimicrobial agents.

Pseudomonas cepacia depleted of various nutrients showed marked variation in sensitivity to cetrimide, chlorhexidine, and benzalkonium chloride. In all cases cells depleted of magnesium were the most resistant. It is proposed that these observations may be due to alterations of the envelope of P. cepacia in response to changes in the growth environment. This may have profound implications for investigations of the resistance of this organism both in vivo and in vitro.