Involvement of outer membrane of Pseudomonas cepacia in aminoglycoside and polymyxin resistance.

AUTOR(ES)

Moore, R A

RESUMO

Pseudomonas cepacia was found to be resistant to the outer membrane-permeabilizing effects of aminoglycoside antibiotics, polymyxin B, and EDTA. Permeabilization of P. cepacia to the fluorescent probe 1-N-phenylnaphthylamine was not achieved at concentrations 100- to 1,000-fold above those required to permeabilize Pseudomonas aeruginosa. Furthermore, in contrast to P. aeruginosa cells, intact cells of P. cepacia did not bind the fluorescent probe dansyl-polymyxin. However, purified lipopolysaccharide (LPS) from P. cepacia bound dansyl-polymyxin with approximately the same affinity as did LPS from P. aeruginosa. Also, binding of dansyl-polymyxin to P. cepacia (and P. aeruginosa) LPS was inhibited by polymyxin B, streptomycin, gentamicin, and Mg2+. These data suggest that P. cepacia does not utilize the self-promoted pathway for aminoglycoside uptake and that the outer membrane is arranged in a way that conceals or protects cation-binding sites on LPS which are capable of binding polycations such as aminoglycosides or polymxyin.

Documentos Relacionados

• Aminoglycoside Efflux in Pseudomonas aeruginosa: Involvement of Novel Outer Membrane Proteins
• Outer membrane protein H1 of Pseudomonas aeruginosa: involvement in adaptive and mutational resistance to ethylenediaminetetraacetate, polymyxin B, and gentamicin.
• Nucleotide sequence analysis of a gene from Burkholderia (Pseudomonas) cepacia encoding an outer membrane lipoprotein involved in multiple antibiotic resistance.
• Resistance of Spheroplasts and Whole Cells of Pseudomonas cepacia to Polymyxin B
• Fatty acid alterations and polymyxin B binding by lipopolysaccharides from Pseudomonas aeruginosa adapted to polymyxin B resistance.