The emergence of multidrug-resistant Klebsiella pneumoniae is a worldwide problem. K. possesses numerous resistant genes in its genome. We isolated mutants to various antimicrobials vitro and investigated the importance intrinsic acquired resistance. isolation frequency was 10-7-10-9. Of mutants, hyper-multidrug-resistant (EB256-1, EB256-2, Nov1-8, Nov2-2, OX128) were identified, accelerated efflux activity ethidium from inside outside cells observed these mutants. Therefore, we hypothesized...

A structure-guided molecular design approach was used to optimize quercetin diacylglycoside analogues that inhibit bacterial DNA gyrase and topoisomerase IV show potent antibacterial activity against a wide spectrum of relevant pathogens responsible for hospital- community-acquired infections. In this paper, such novel 3,7-diacylquercetin, 6''-acylgalactoside, 2'',6''-diacylgalactoside lead compound 1 were prepared assess their target specificities preferences in bacteria. The significant...

muxA-muxB-muxC-opmB (formerly PA2528-PA2527-PA2526- opmB ), encoding a putative resistance nodulation cell division (RND)-type multidrug efflux pump system, was cloned from Pseudomonas aeruginosa PAO1. Introduction of muxABC-opmB into P. YM64, drug-hypersusceptible strain, led to elevated MICs aztreonam, macrolides, novobiocin and tetracycline. Since muxB muxC , both which encode RND components, were essential for function, MuxABC-OpmB is thought be drug with four components. One...

Serratia sp. ATCC 39006 (Serratia 39006) is a Gram-negative bacterium which produces the secondary metabolite antibiotics, prodigiosin and 1-carbapen-2-em-3-carboxylic acid secretes plant cell wall degrading enzymes. In this study we have identified mutations in genes, pigX, rap rsmA, caused increased production of previously unidentified surfactant flagella-dependent swarming phenotype 39006. Analysis both biosynthesis regulation swarming, revealed FlhC, quorum sensing, GGDEF/EAL domain...

We cloned genes, designated smdAB, that encode a multidrug efflux pump from the chromosomal DNA of clinically isolated Serratia marcescens NUSM8906. For cells drug-hypersensitive strain Escherichia coli KAM32 harboring recombinant plasmid carrying structurally unrelated antimicrobial agents such as norfloxacin, tetracycline, 4',6-diamidino-2-phenylindole (DAPI), and Hoechst 33342 showed elevated MICs. The deduced amino acid sequences both SmdA SmdB exhibited similarities to ATP-binding...

We found that an extract from Laurus nobilis L. (Lauraceae) leaves showed antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). purified two flavonoids as the effective compounds and identified them kaempferol 3-O-α-L-(2″,4″-di-E-p-coumaroyl)-rhamnoside (C2) 3-O-α-L-(2″-Z-p-coumaroyl-4″-E-p-coumaroyl)-rhamnoside (C3). Both strong not only MRSA but also vancomycin-resistant enterococci (VRE). There was low or no of C2 C3 for Streptococcus pneumoniae, Pseudomonas...

In a previous study, we reported that two kaempferol glycosides isolated from Laurus nobilis L., kaempferol-3-O-α-L-(2″,4″-di-E-p-coumaroyl)-rhamnoside (C2) and kaempferol-3-O-α-L-(2″-E-p-coumaroyl-4″-Z-p-coumaroyl)-rhamnoside (C3), showed strong antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA) vancomycin-resistant enterococci. Thereafter found these compounds greatly reduced the minimum inhibitory concentrations (MICs) of some fluoroquinolones in MRSA....

We previously described the cloning of genes related to drug resistance from Klebsiella pneumoniae MGH78578. Of these, we identified a putative gene encoding MATE-type multidrug efflux pump, and named it ketM. Escherichia coli KAM32 possessing ketM on plasmid showed increased minimum inhibitory concentrations for norfloxacin, ciprofloxacin, cefotaxime, acriflavine, Hoechst 33342, 4',6-diamidino-2-phenyl indole (DAPI). The active DAPI was observed in E. plasmid. expression mRNA K. cells,...

Klebsiella pneumoniae MGH78578, a clinical isolate, showed high level of resistance to many antimicrobial agents. We cloned genes responsible for drug from chromosomal DNA K. MGH78578 by shotgun method using Escherichia coli KAM32, hypersensitive strain, as host. obtained 43 hybrid plasmids that made host cells resistant several classified them into 17 groups based on growth properties in the presence each one 9 agents and restriction patterns plasmid. Analysis must be very useful...

Abstract There are six putative genes for multidrug and toxic compound extrusion (MATE) family efflux pumps in the chromosome of Vibrio cholerae . We have so far analyzed two MATE V. non‐O1 NCTC4716. Here we cloned four remaining by PCR method from this microorganism designated them as vcmB, vcmD, vcmH vcmN Each one was introduced expressed drug hypersusceptible host Escherichia coli KAM32 cells. observed elevated MICs multiple antimicrobial agents, such fluoroquinolones, aminoglycosides,...

Resistance nodulation cell division (RND)-type efflux transporters play the main role in intrinsic resistance to various antimicrobial agents many gram-negative bacteria. Here, we estimated 12 RND-type transporter genes Vibrio parahaemolyticus. Because VmeAB has already been characterized, cloned other 11 and characterized them Escherichia coli KAM33 cells, a drug hypersusceptible strain. expressing either VmeCD, VmeEF, or VmeYZ showed increased minimum inhibitory concentrations (MICs) for...

Abstract Resistance Nodulation cell Division (RND) efflux transporters are thought to be involved in mediating multidrug resistance Gram‐negative bacteria, including Vibrio cholerae non‐O1. There six operons for putative RND‐type present the chromosome of V. O1 two operons, vexAB and vexCD , which had already been identified. All were cloned from non‐O1, NCTC4716 by PCR method, introduced, expressed cells drug hypersusceptible Escherichia coli KAM33 ( AacrAB, AydhE ). Only vexEF conferred...

We cloned a gene responsible for multidrug resistance from the chromosomal DNA of Klebsiella pneumoniae MGH78578 that showed resistance. designated kmrA. The deduced amino acid sequence KmrA was similar to SmvA is methyl viologen-resistance in Salmonella enterica sv. Typhi and Typhimurium. Introduction kmrA into drug-hypersensitive Escherichia coli KAM32 cells made them resistant acriflavine, 4′,6-diamidino-2-phenylindole (DAPI), Hoechst 33342, tetraphenylphosphonium chloride (TPPCl),...

We cloned a gene related to multidrug resistance from drug-resistant Klebsiella pneumoniae strain MGH78578. designated the kdeA, which encodes protein possessing 12 hydrophobic regions. The deduced amino acid sequence of KdeA is similar that MdfA, well-characterized efflux pump Escherichia coli. Introduction kdeA into cells drug-hypersusceptible E. coli KAM32 resulted in elevated minimum inhibitory concentrations chloramphenicol, norfloxacin, acriflavine, and ethidium bromide. observed...

Genes vmeA and vmeB, encoding a multidrug efflux transporter in the halophilic bacterium Vibrio parahaemolyticus, have been cloned using drug-hypersusceptible Escherichia coli strain as host. Cells of E. KAM33 (DeltaacrAB DeltaydhE) carrying vmeAB region from V. parahaemolyticus conferred much higher MICs for variety antimicrobial agents than did control cells. possessing VmeAB under energized conditions maintained very low intracellular concentrations ethidium. This was expected an...

We previously reported that we had cloned genes responsible for multidrug resistance from the chromosomal DNA of Klebsiella pneumoniae MGH78578 using a drug-hypersusceptible Escherichia coli strain as host. One recombinant plasmids pETV6 conferred to host cells against wide range antimicrobial agents, dyes and detergents. It was revealed this plasmid carried acrBKp gene part acrAKp coding efflux pump belonging RND family. whole acrAKpBKp operon K. characterized pump. The AcrAB utilized TolC...

We cloned a gene responsible for multidrug resistance from chromosomal DNA of Serratia marcescens, and determined the nucleotide sequence. designated as ssmE. The deduced amino acid sequence SsmE showed high similarity with small (SMR)-type efflux pumps. Cells Escherichia coli KAM32, drug hyper-susceptible mutant, transformed plasmid pESM437 carrying ssmE elevated minimum inhibitory concentrations structurally unrelated antimicrobial agents. E. KAM32/pESM437 energy dependent ethidium....

We cloned a gene smfY for multidrug efflux pump from chromosomal DNA of Serratia marcescens using drug-hypersensitive Escherichia coli KAM32 as the host, and characterized pump. E. KAM32/pESM42 carrying showed significantly increased MICs various drugs including DAPI, norfloxacin, benzalkonium chloride, acriflavine ethidium bromide, compared with control. also detected energy-dependent due to SmfY. Sequence analysis revealed that SmfY was MF (Major Facilitator) superfamily transporters. This...

A DNA fragment responsible for resistance to antimicrobial agents was cloned from chromosomal of Enterococcus faecium FN-1, a clinically isolated strain. Escherichia coli KAM32, drug-hypersusceptible mutant, used as host gene cloning. Cells E. KAM32 harboring recombinant plasmid (pTFM8) carrying the became resistant fluoroquinolones, macrolides, ethidium bromide, 4′,6-diamidino-2-phenylindole (DAPI) and tetraphenylphosphonium chloride (TPPCl). Three complete open reading frames (ORFs) were...

ABSTRACT We cloned a gene ( sstT ) for the Na + /serine symporter from chromosome of Escherichia coli by using low-copy-number vector and sequenced it. According to deduced amino acid sequence, transporter (SstT) consists 414 residues. Hydropathy analysis suggested that SstT protein possesses 9, instead 12, hydrophobic domains.

A gene encoding Na+/serine symporter (SstT) of Escherichia coli has been cloned and sequenced in our laboratory [Ogawa et al. (1998) J. Bacteriol. 180, 6749–6752). In an attempt to overproduce the protein purify it, we first constructed a plasmid pTSTH which modified sstT (sstT with 8 successive codons for His at 3'-terminus) is located downstream from trc promoter. Upon induction by IPTG, Histagged SstT was overproduced (about 15% total membrane proteins), showed activity as high wild type...