TY - JOUR
T1 - Ciprofloxacin, salicylate, and 2,4-dinitrophenol decrease production of AmpC-type β-lactamase in two Citrobacter freundii clinical isolates
AU - Tavío, María M.
AU - Perilli, Mariagrazia
AU - Vila, Jordi
AU - Becerro, Pino
AU - Ruiz, Joaquím
AU - Amicosante, Gianfranco
AU - Jiménez De Anta, María T.
PY - 2005/9
Y1 - 2005/9
N2 - The effect of ciprofloxacin and two marRAB inducers on the susceptibility to β-lactam antibiotics in two AmpC β-lactamase semiconstitutive producer Citrobacter freundii clinical isolates (the DM1 and DM2 strains) was studied. Possible changes in outer membrane protein expression, permeability to cephaloridine, active efflux, and hydrolytic activity of β-lactamase-crude extracts were evaluated under the influence of ciprofloxacin, sodium salicylate, and 2,4-dinitrophenol. Results were compared with those of the effect of the same three chemicals on a normally β-lactamase-inducible wild-type C. freundii strain. The three assayed compounds decreased β-lactamase hydrolysis on cephaloridine in both the two clinical isolates as well as in the wild-type strain. However, only the DM1 and DM2 strains showed increased susceptibility to β-lactams. Sodium salicylate and 2,4-dinitrophenol, but not ciprofloxacin, reduced the expression of a 45-kDa outer membrane protein in the three studied strains, which was accompanied by a 4- to 20-fold diminution in permeability to cephaloridine. In conclusion, two marRAB inducers and ciprofloxacin induced the Mar phenotype and repressed AmpC β-lactamase synthesis in the DM1 and DM2 clinical isolates.
AB - The effect of ciprofloxacin and two marRAB inducers on the susceptibility to β-lactam antibiotics in two AmpC β-lactamase semiconstitutive producer Citrobacter freundii clinical isolates (the DM1 and DM2 strains) was studied. Possible changes in outer membrane protein expression, permeability to cephaloridine, active efflux, and hydrolytic activity of β-lactamase-crude extracts were evaluated under the influence of ciprofloxacin, sodium salicylate, and 2,4-dinitrophenol. Results were compared with those of the effect of the same three chemicals on a normally β-lactamase-inducible wild-type C. freundii strain. The three assayed compounds decreased β-lactamase hydrolysis on cephaloridine in both the two clinical isolates as well as in the wild-type strain. However, only the DM1 and DM2 strains showed increased susceptibility to β-lactams. Sodium salicylate and 2,4-dinitrophenol, but not ciprofloxacin, reduced the expression of a 45-kDa outer membrane protein in the three studied strains, which was accompanied by a 4- to 20-fold diminution in permeability to cephaloridine. In conclusion, two marRAB inducers and ciprofloxacin induced the Mar phenotype and repressed AmpC β-lactamase synthesis in the DM1 and DM2 clinical isolates.
UR - http://www.scopus.com/inward/record.url?scp=26444432340&partnerID=8YFLogxK
U2 - 10.1089/mdr.2005.11.225
DO - 10.1089/mdr.2005.11.225
M3 - Artículo
C2 - 16201924
AN - SCOPUS:26444432340
SN - 1076-6294
VL - 11
SP - 225
EP - 231
JO - Microbial Drug Resistance
JF - Microbial Drug Resistance
IS - 3
ER -