Showing papers on "Ralstonia pickettii published in 2008"
TL;DR: Cross-transmission of the pathogen, infusion of a putative contaminated intravenous solution, and persistent colonization of medical devices were the likely sources of R. pickettii BSI.
Abstract: We describe a series of Ralstonia pickettii bloodstream infections (BSI) that occurred in 19 oncohematologic patients admitted to a hospital for patients with cancer, in the city of Rio de Janeiro, from July 1999 to February 2006. Fifty-four R. pickettii isolates were recovered from blood and catheter-tip specimens (1–5 isolates per patient). Two patients eventually died of causes unrelated to R. pickettii BSI. Eight pulsed-field gel electrophoresis genotypes were resolved (A–H), with two detected in more than 1 patient: genotype B, in 2 patients (1.5%), and E, in 12 patients (63.2%). R. pickettii emerged as a new pathogen at our institution, causing at least one outbreak. Cross-transmission of the pathogen, infusion of a putative contaminated intravenous solution, and persistent colonization of medical devices were the likely sources of R. pickettii BSI.
23 citations
TL;DR: To the knowledge, this is the first record in the world of leaf spot and blight caused by R. pickettii, which is an ornamental perennial tropical plant grown in southern Italy.
Abstract: Bird of Paradise tree (Strelitzia alba (L. f.) Skeels) is an ornamental perennial tropical plant grown in southern Italy. In the summer of 2006 and 2007, a widespread, severe leaf disease was observed on seedlings and 1- to 2-year-old plants in two glasshouses located in eastern Sicily. Disease incidence ranged from 10 to 25%. Symptoms on the leaves consisted of dark brown-to-black stripes of varying length and found between the lateral veins. Lesions sometimes coalesced into a large area of necrotic tissue. Symptomatic tissues were ground in a drop of sterile distilled water (SDW) with a scalpel. Suspensions were streaked on King's medium B (KB), nutrient agar, and yeast extract nutrient agar (2). Isolated strains were gram negative and oxidase positive, non-levan, negative in tobacco hypersensitivity test, white and nonmucoid on yeast dextrose calcium carbonate agar, did not produce fluorescent pigments on KB, and utilized glucose, mannitol, trehalose, arabinose, mannose, and N-acetylglucosamine. Bacterial strains were identified as Ralstonia pickettii by using the Biolog Identification System (MicroLogTM System Release 4.2; Biolog, Inc., Hayward, CA) with a similarity index ranging from 0.52 to 0.67. For an additional confirmation of identity, the small subunit rRNA gene (SSUrDNA) was amplified with primers 530F and Uni 1492R (1). The resulting nucleotide sequence was compared with sequences deposited in GenBank and showed the highest identity (99%) to sequences of R. pickettii strains. Pathogenicity tests were performed on 20 cm tall potted plants. Four S. alba plants were inoculated by infiltrating leaf veins with bacterial suspensions for each of the four isolates (107 CFU ml-1 in SDW) with a 25-gauge needle and syringe. Plants were placed in polyethylene bags 1 day before inoculation and maintained there for 3 days after inoculation. Four control plants were inoculated with SDW. Water-soaked areas in the lateral veins of leaves were observed in all inoculated plants 4 days after inoculation. Within 10 days, dark brown-to-black stripes that coalesced into dark necrotic areas were observed. All isolates induced similar symptoms. Control plants did not show any symptoms. The pathogen was reisolated from symptomatic tissue and identified as R. pickettii by Biolog. A similar disease on S. reginae caused by a Pseudomonas sp. was previously reported from Florida (3). To our knowledge, this is the first record in the world of leaf spot and blight caused by R. pickettii. References: (1) D. J. Lane. 16S/23S rRNA sequencing. Page 115 in: Nucleic Acid Techniques in Bacterial Systematics. E. Stackebrandt and M. Goodfellow, eds. John Wiley and Sons, NY, 1991. (2) N. W. Schaad et al. Laboratory Guide for Identification of Plant Pathogenic Bacteria. The American Phytopathological Society, St. Paul, MN, 2001. (3) C. Wehlburg. Plant Dis. Rep. 55:447, 1971.
9 citations
TL;DR: It is indicated that histidine is a novel inducer of bacterial denitrification, and a shortage of amino acids in the medium limited it, among the 20 standard amino acids tested.
Abstract: Ralstonia pickettii K50 (strain K50) is a denitrifying bacterium that produces low levels of N(2)O under aerobic conditions. In this study, we found that co-culturing of strain K50 with Streptomyces griseus significantly enhanced the denitrification activity of strain K50 in an artificial wastewater (AWW) system. Most factors that enhance denitrification activity were in the high molecular weight fraction of the cell-free broth of S. griseus, and were suggested to be extracellular proteases. Further investigation revealed that the cultivation of strain K50 in protease-treated AWW medium fully enhanced denitrification, and that a shortage of amino acids in the medium limited it. Among the 20 standard amino acids tested, only histidine had a significant effect in inducing denitrification by strain K50. Our results indicate that histidine is a novel inducer of bacterial denitrification.
7 citations
TL;DR: It was found that poly(3-hydroxybutyrate) depolymerase was secreted by the Type II pathway and had the four cysteines highly conserved in most prepilin peptidases at the same positions.
Abstract: The extracellular poly(3-hydroxybutyrate) depolymerase from Ralstonia pickettii T1 has been purified, its function and character investigated in detail, and its gene cloned and sequenced. However, the mechanism by which this enzyme is secreted has not been elucidated. A mutant unable to degrade poly(3-hydroxybutyrate), N17, was obtained with the random insertion of a mini-transposon, Tn5. Western analysis using antiserum against the poly(3-hydroxybutyrate) depolymerase of Ralstonia pickettii T1, revealed that N17 accumulated the poly(3-hydroxybutyrate) depolymerase in the periplasm and cytoplasm, and did not secrete the enzyme into the external medium. It was also found that 3-hydroxybutyrate-oligomer hydrolase was secreted but inactive. The disrupted gene in N17, depO, was analyzed by Southern hybridization and its nucleotide sequence was determined. One complete open reading frame was found in the cloned 2.3-kbp DNA fragment. From a BLAST search, this gene product was found to be homologous to PulO of Ralstonia eutropha JMP134 (60% identity) and XcpA of Pseudomonas aeruginosa (60% identity). These proteins are prepilin peptidase/N-metyltransferases, a component of the Type II secretion pathway. DepO also had the four cysteines highly conserved in most prepilin peptidases at the same positions. The transcript of depO was examined by Northern hybridization using depO as a probe. In the total RNA of Ralstonia pickettii T1 in the early stationary phase, a band at 2.6-kb was detected, suggesting depO to be a functional gene. In this study, it was found that poly(3-hydroxybutyrate) depolymerase was secreted by the Type II pathway.
7 citations
01 Jan 2008
TL;DR: A case of catheter-related R. pickettii bacteremia and septic pneumonia in a patient with breast cancer is presented, successfully treated with intravenous antibiotics and removal of the infected chemoport.
Abstract: Ralstonia pickettii is a non-fermentative, gram-negative bacillus, rarely associated with human infections. It can cause bacteremia, mainly following the use of contaminated solutions, e.g. distilled water, water for injection and aqueous chlorhexidine solutions in patients with underlying diseases or conditions. Several cases of nosocomial infections with this organism have been reported in the literature, but there have been few reports in Korea. We present a case of catheter-related R. pickettii bacteremia and septic pneumonia in a patient with breast cancer, successfully treated with intravenous antibiotics and removal of the infected chemoport. (Korean J Med 74:S149-S152, 2008)
Journal Article•
TL;DR: It was shown that a novel BDH besides BDH1 and BDH2 was present in R. pickettii T1, a bacterium growing on extracellular poly-3-hydroxybutyrate (PHB), and the third BDH (BDH3) was partially purified by column chromatography, and the enzyme had the N-terminal amino acid sequence different from those of BDH one and two.
Abstract: We previously reported that Ralstonia pickettii T1, a bacterium growing on extracellular poly-3-hydroxybutyrate (PHB), have two 3-hydroxybutyrate dehydrogenases (BDH1 and BDH2). By analysis of knockout mutants of bdh1 or bdh2 using anion- exchange column chromatography, it was shown that a novel BDH besides BDH1 and BDH2 was present in R. pickettii T1. The third BDH (BDH3) was partially purified by column chromatography, and the enzyme had the N-terminal amino acid sequence different from those of BDH1 and BDH2. In Southern blotting with bdh2 as a probe, bdh3 was detected and cloned, and the purified gene product of bdh3 expressed in Escherichia coli showed higher specific activity than those of BDH1 and BDH2.