title: Molecular cloning and characterization of the Salmonella enterica Serovar Paratyphi B rma Gene, which confers multiple drug resistance in Escherichia coli.
abstract: A genomic library from a strain of Salmonella enterica serovar Paratyphi B that exhibits multiple drug resistance (MDR) was constructed in Escherichia coli. Two of the recombinant plasmids, pNOR5 and pNOR5, conferred resistance only to fluoroquinolones in E. coli, whereas the third, pNCTR4, conferred the MDR phenotype. Sequence and subcloning analysis showed that it is the presence of RecA on the first two plasmids which confers resistance to fluoroquinolones in E. coli. A similar analysis established that the MDR phenotype conferred by pNCTR4 is due to a gene, rma (resistance to multiple antibiotics), which encodes a 13.5-kDa polypeptide. The derived sequence for Rma exhibits a high degree of similarity to those of a group of MarA-like activators that confer MDR in E. coli. A MalE-Rma fusion protein was purified to near homogeneity and was shown to interact with a DNA fragment carrying a MarA operator sequence. Furthermore, overexpression of rma in E. coli caused changes in the outer membrane protein profile that were similar to those reported for MarA. These results suggest that Rma might act as a transcriptional activator of the marA regulon.
authors.affiliation: Department of Microbiology and Immunology, Faculty of Pharmacy, Ain-Shams University, Cairo, Egypt.
authors.forename: Mahmoud A
authors.initials: MA
authors.lastname: Yassien
authors.forename: Hosam E
authors.initials: HE
authors.lastname: Ewis
authors.forename: Chung-Dar
authors.initials: CD
authors.lastname: Lu
authors.forename: Ahmed T
authors.initials: AT
authors.lastname: Abdelal
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D018432:Drug Resistance, Multiple / Q000235:genetics* / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000502:physiology; D058619:Maltose-Binding Proteins; D026901:Membrane Transport Proteins; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D009643:Norfloxacin / Q000494:pharmacology; D033902:Periplasmic Binding Proteins; D018272:Porins / Q000378:metabolism; D011938:Rec A Recombinases / Q000096:biosynthesis / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D019779:Salmonella enterica / Q000187:drug effects / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012703:Serotyping
chemical_list: D018528:ATP-Binding Cassette Transporters; D000890:Anti-Infective Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C461619:MalE protein, E coli; D058619:Maltose-Binding Proteins; D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; C109237:OmpF protein; D033902:Periplasmic Binding Proteins; D018272:Porins; D011993:Recombinant Fusion Proteins; C461599:maltose transport system, E coli; C453342:rma protein, Salmonella; C073126:tolC protein, E coli; D011938:Rec A Recombinases; D009643:Norfloxacin