We have previously identified a gene in Staphylococcus aureus, agr, whose activity is required for high-level post-exponential-phase expression of series secreted proteins. In this paper, we describe the cloning Escherichia coli by using an inserted transposon (Tn551) as probe. The cloned gene, consisting 241-codon open reading frame containing site insertion, was recloned to S. aureus vector, pSK265, and shown be functional aureus. Activity evaluated determinations alpha-hemolysin,...

A lobule-mimetic cell-patterning technique for on-chip reconstruction of centimetre-scale liver tissue heterogeneous hepatic and endothelial cells via an enhanced field-induced dielectrophoresis (DEP) trap is demonstrated reported. By mimicking the basic morphology tissue, classic lobule, lobule-mimetic-stellate-electrodes array was designed cell patterning. Through DEP manipulation, well-defined spatial electric field gradients were created in-parallel manipulation massive individual cells....

ABSTRACT Sequence analysis of the large virulence plasmid pLVPK in Klebsiella pneumoniae CG43 revealed presence another mucoid factor encoding gene rmpA besides rmpA2 . Promoter activity measurement indicated that deletion reduced K2 capsular polysaccharide (CPS) biosynthesis, resulting decreased colony mucoidy and mice. Introduction a multicopy carrying restored CPS production or mutant but not rcsB mutant. Transformation with an -carrying also failed to enhance production, suggesting...

Abstract Background The cationic peptide antibiotic polymyxin has recently been reevaluated in the treatment of severe infections caused by gram negative bacteria. Methods In this study, genetic determinants for capsular polysaccharide level and lipopolysaccharide modification involved B resistance opportunistic pathogen Klebsiella pneumoniae were characterized. expressional control genes responsible was assessed a LacZ reporter system. PmrD connector-mediated regulation expression pmr also...

Abstract Background The opportunistic enterobacterium, Morganella morganii , which can cause bacteraemia, is the ninth most prevalent of clinical infections in patients at Changhua Christian Hospital, Taiwan. KT strain M. was isolated during postoperative care a cancer patient with gallbladder stone who developed sepsis caused by bacteraemia. sometimes encountered nosocomial settings and has been causally linked to catheter-associated bacteriuria, complex urinary and/or hepatobiliary tracts,...

The rmpA2 gene, which encodes an activator for capsular polysaccharide (CPS) synthesis, was isolated from a 200-kb virulence plasmid of Klebsiella pneumoniae CG43. Based on the sequence homology with LuxR at carboxyl-terminal DNA-binding motif, we hypothesized that RmpA2 exerts its effect by activating expression cps genes are responsible CPS biosynthesis. Two luxAB transcriptional fusions, each containing putative promoter region K. K2 genes, were constructed and found to be activated in...

A novel and disposable microchip (K-kit) with SiO2 nano-membranes was developed used as a specimen kit for in situ imaging of living organisms an aqueous condition using transmission electron microscopy (TEM) without equipment modification. This K-kit enabled the successful TEM observation Escherichia colicells tellurite reduction process Klebsiella pneumoniae. The K. pneumoniae Saccharomyces cerevisiae can stay alive after continuous up to 14 s 42 s, respectively. Besides, different...

Certain bacterial two-component sensor kinases possess a histidine-containing phosphotransfer (Hpt) domain to carry out multistep phosphotransferring reaction cognate response regulator. Pseudomonas aeruginosa PAO1 contains three genes that encode proteins with an Hpt but lack kinase domain. To identify the coupled these proteins, phosphorelay profiling assay was performed. Among 12 recombinant orphan tested, 4 of sensors (PA1611, PA1976, PA2824, and RetS) transferred phosphoryl group HptB...

ABSTRACT Klebsiella pneumoniae is the predominant pathogen of primary liver abscess. However, our knowledge regarding molecular basis how K. causes infection in limited. We established an oral model that recapitulated characteristics abscess and conducted a genetic screen to identify genes required for development mice. Twenty-eight mutants with attenuated growth or spleen samples out 2,880 signature-tagged produced wild-type capsule were identified, loci which disrupted these identified...

The ferric uptake regulator Fur has been reported to repress the expression of rmpA , a regulatory gene for mucoid phenotype, leading decreased capsular polysaccharide (CPS) biosynthesis in Klebsiella pneumoniae CG43. Here, quantitative real-time PCR (qRT-PCR) analyses and electrophoretic mobility shift assays showed that also repressed CPS genes rmpA2 rcsA . Interestingly, deletion or but not from Δ fur strain was able suppress effect Fur. availability extracellular iron affected amount...

Abstract PmrA, an OmpR/PhoB family response regulator, manages genes for antibiotic resistance. Phosphorylation of regulator induces the formation a symmetric dimer in N-terminal receiver domain (REC), promoting two C-terminal DNA-binding domains (DBDs) to recognize promoter DNA elicit adaptive responses. Recently, determination KdpE–DNA complex structure revealed REC–DBD interface upstream protomer that may be necessary transcription activation. Here, we report 3.2-Å-resolution crystal...

In the genome of Klebsiella pneumoniae NTUH-K2044, nine fimbrial gene clusters were identified. Besides type 1 and 3 fimbriae, others are novel named Kpa, Kpb, Kpc, Kpd, Kpe, Kpf Kpg fimbriae. Prevalence analysis among 105 K. clinical isolates revealed that kpc genes highly associated with K1 serotype isolates. Induced expression recombinant kpcABCD in Escherichia coli resulted Kpc fimbriation increased biofilm formation. A putative site-specific recombinase encoding kpcI a 302 bp intergenic...

In this study, the feasibility using atomic force microscopy (AFM) to study interaction between bacteriophages (phages) and bacteria in situ was demonstrated here. Filamentous phage M13 specifically infects male Escherichia coli, which expresses F-pili. After infection, E. coli become fragile grows at a slower rate. AFM provides powerful tool for investigating these changes near-physiological environment. Using high-resolution phosphate-buffered saline, damage lipopolysaccharide (LPS) layer...

Abstract Background The capsular polysaccharide (CPS) and iron acquisition systems are important determinants of Klebsiella pneumoniae infections, we have previously reported that the ferric uptake repressor (Fur) can play dual role in CPS biosynthesis. In many bacteria, Fur negatively controls transcription small non-coding RNA RyhB to modulate cellular functions virulence. However, K. , played by regulon has not been characterised. This study investigated regulation ryhB functional ....

Type 3 fimbriae play a crucial role in Klebsiella pneumoniae biofilm formation, but the mechanism of regulation type fimbrial operon is largely unknown. In K. CG43, three regulatory genes, mrkH, mrkI and mrkJ, are located downstream genes mrkABCDF. The production major pilin MrkA abolished by deletion mrkH or slightly increased mrkJ. Additionally, quantitative RT-PCR promoter–reporter assay mrkHI verified that transcription was activated MrkI, suggesting autoactivation transcription....

This study shows that the expression of yjcC, an in vivo (IVE) gene, and stress response regulatory genes soxR, soxS, rpoS are paraquat inducible Klebsiella pneumoniae CG43. The deletion or soxRS decreased yjcC expression, implying RpoS- SoxRS-dependent control. After H2O2 treatment, reduced bacterial survival. These effects could be complemented by introducing ΔyjcC mutant with YjcC-expression plasmid pJR1. recombinant protein containing only YjcC-EAL domain exhibited phosphodiesterase...

Klebsiella pneumoniae is the predominant pathogen isolated from liver abscesses of diabetic patients in Asian countries. However, effects elevated blood glucose levels on virulence this remain largely unknown. Type 3 fimbriae, encoded by mrkABCDF genes, are important factors K. pathogenesis. In study, exogenous and intracellular cyclic AMP (cAMP) signaling pathway type fimbriae expression regulation were investigated. The production MrkA, major subunit was increased glucose-rich medium,...

ABSTRACT A novel in vivo expression technology (IVET) was performed to identify Klebsiella pneumoniae CG43 genes that are specifically expressed during infection of BALB/c mice. The IVET employed a UDP glucose pyrophosphorylase ( galU )-deficient mutant K. which is incapable utilizing galactose and synthesizing capsular polysaccharide, as demonstrated by its low virulence mice white nonmucoid colony morphology on MacConkey-galactose agar. By using functional gene the reporter, an IVE...

The histidine-containing phosphotransfer protein-B (HptB; PA3345) is an intermediate protein involved in transferring a phosphoryl group from multiple sensor kinases to the response regulator PA3346 Pseudomonas aeruginosa PAO1. objective of this study was elucidate biological significance HptB-PA3346 interaction and regulatory mechanisms thereafter. transcription profiling analysis hptB knock-out mutant showed that expression number motility-related genes altered consistent with non-swarming...

Klebsiella pneumoniae is a common cause of septicemia and urinary tract infections. The PCR-supported genomic subtractive hybridization was employed to identify genes specifically present in virulent strain K. pneumoniae. Analysis 25 subtracted DNA clones has revealed 19 distinct nucleotide sequences. Two the sequences were found be encoding transposase Tn3926 capsule polysaccharide exporting enzyme. Three displayed moderate homology with bvgAS, which encodes two-component signal...

Glycan-bound nanoprobes have been demonstrated as suitable sensing probes for bacteria containing glycan binding sites. In this study, we a facile approach generating glycan-bound gold nanoclusters (AuNCs). The generated AuNCs were used corresponding target bacteria. Mannose-capped (AuNCs@Mann) and the model sensors A one-step synthesis was employed to generate AuNCs@Mann. approach, an aqueous solution of tetrachloroauric acid mannoside that functionized with thiol group (Mann-SH) stirred at...