Outer membrane changes in Pseudomonas stutzeri resistant to chlorhexidine diacetate and cetylpyridinium chloride

Changes in outer membrane proteins (OMP) and lipopolysaccharide (LPS) in ce lls of strains of Pseudomonas stutzeri sensitive and resistant to chlorhexi dine diacetate (CHA) or cetylpyridinium chloride (CPC) have been examined. Four of five CHA-resistant strains had alterations in OMP profiles, includi ng the expression of two additional protein bands. All the: CPC-resistant s trains had altered OMP profiles but the changes varied from strain to strai n. Loss of the fastest-migrating bands was observed in the LPS from CHX-res istant strains. In strain JM 302R with high-level CHX resistance (minimal i nhibitory concentration 100 mg/l as opposed to 2.5 mg/l in the parent-strai n, JM 302), all the fast-migrating bands were lost and the strain showed 'c ross-resistance' to polymyxin, gentamicin and ethylenediamine tetraacetic a cid. It is however, possible that the altered LPS patterns reflect a respon se to alterations in other components rather than being directly associated per se with the enhanced resistance. (C) 2000 Elsevier Science B.V. and In ternational Society of Chemotherapy. All rights reserved.