Characterization of the MexC-MexD-OprJ Multidrug Efflux System in Δ mexA-mexB-oprM Mutants of Pseudomonas aeruginosa
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چکیده
منابع مشابه
Expression of Pseudomonas aeruginosa multidrug efflux pumps MexA-MexB-OprM and MexC-MexD-OprJ in a multidrug-sensitive Escherichia coli strain.
The mexCD-oprJ and mexAB-oprM operons encode components of two distinct multidrug efflux pumps in Pseudomonas aeruginosa. To assess the contribution of individual components to antibiotic resistance and substrate specificity, these operons and their component genes were cloned and expressed in Escherichia coli. Western immunoblotting confirmed expression of the P. aeruginosa efflux pump compone...
متن کاملsiRNA-mediated gene silencing of MexB from the MexA-MexB-OprM efflux pump in Pseudomonas aeruginosa
To gain insights into the effect of MexB gene under the short interfering RNA (siRNA), we synthesized 21 bp siRNA duplexes against the MexB gene. RT-PCR was performed to determine whether the siRNA inhibited the expression of MexB mRNA. Changes in antibiotic susceptibility in response to siRNA were measured by the E-test method. The efficacy of siRNAs was determined in a murine model of chronic...
متن کاملInteraction of the MexA and MexB components of the MexAB-OprM multidrug efflux system of Pseudomonas aeruginosa: identification of MexA extragenic suppressors of a T578I mutation in MexB.
A T578I mutation in MexB compromised the protein's contribution to antimicrobial resistance and negatively impacted its interaction with MexA. Mutations causing single amino acid changes in the C-terminal domain of MexA (R221H, L245F, E254K, and V259I) suppressed the antimicrobial susceptibility of a MexB(T578I)-expressing Pseudomonas aeruginosa strain and restored a MexA interaction with MexB(...
متن کاملExpression of the multidrug resistance operon mexA-mexB-oprM in Pseudomonas aeruginosa: mexR encodes a regulator of operon expression.
The region upstream of the multiple antibiotic resistance efflux operon mexA-mexB-oprM in Pseudomonas aeruginosa was sequenced, and a gene, mexR, was identified. The predicted MexR product contains 147 amino acids with a molecular mass of 16,964 Da, which is consistent with the observed size of the overexpressed mexR gene product. MexR was homologous to MarR, the repressor of MarA-dependent mul...
متن کاملSubstrate specificities of MexAB-OprM, MexCD-OprJ, and MexXY-oprM efflux pumps in Pseudomonas aeruginosa.
To find the exact substrate specificities of three species of tripartite efflux systems of Pseudomonas aeruginosa, MexAB-OprM, MexCD-OprJ, and MexXY-OprM, we constructed a series of isogenic mutants, each of which constitutively overproduced one of the three efflux systems and lacked the other two, and their isogenic mutants, which lacked all these systems. Comparison of the susceptibilities of...
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ژورنال
عنوان ژورنال: Antimicrobial Agents and Chemotherapy
سال: 1998
ISSN: 0066-4804,1098-6596
DOI: 10.1128/aac.42.8.1938