Ralstonia pickettii
Cultural characteristics
Biochemical characters
Phylum Proteobacteria, Class Betaproteobacteria, Order  Burkholderiales, Family Burkholderiaceae, Genus Ralstonia,
Ralstonia pickettii  Yabuuchi et al. 1996.
Historical synonyms:
Pseudomonas pickettii, Ralston et al. 1973, Burkholderia pickettii Yabuuchi et al. 1993.

2 biovars: Va-1, Va-2. The third biovar ‘thomasii’ strains and at least some of the strains known as “Pseudomonas thomasii" where
moved to
Ralstonia mannitolilytica.
Gram-negative rods, 0.5-0.6 / 1.5-3.0 μm. Sometimes motile by a single polar
flagellum. Poli-beta-hydroxybutyrate inclusions are present.
Strictly aerobic, optimal temperature 35 ºC, variable growth at 42 ºC. Aerobic.
Grows on media: Trypticase Soy Agar  ± 5% sheep blood, Mueller-Hinton agar, Mac
Conkey agar (variable). Fluorescent diffusible pigments are not produced.
Isolated from soil, water, rarely from human clinical samples (pleural & ascitic fluid, pus, biopsy samples, blood samples).
Can cause pneumonia, meningitis, endocarditis, osteomyelitis, bacteremia, nosocomial infections, particularly in
immunocompromised patients (reports of biovar Va-1 acute meningitis, biovar Va-2 bacteremia &
P. thomasii hospital-acquired
colonization and infection).
  1. Ralston E., Palleroni N.J. & Dodoroff M.: Pseudomonas pickettii, a new species of clinical origin related to Pseudomonas
    solanacearum. International Journal of Systematic Bacteriology, 1973, 23, 15-19.
  2. Yabuuchi E., Kosako Y., Oyaizu H., Yano I., Hotta H., Hashimoto Y., Ezaki T. & Arakawa M.: Proposal of Burkholderia gen. nov. and
    transfer of seven species of the genus Pseudomonas homology group II to the new genus, with the type species Burkholderia
    cepacia (Palleroni and Holmes 1981) comb. nov. Microbiol. Immunol., 1992, 36, 1251-1275.
  3. Yabuuchi E., Kosako Y., Yano I., Hotta H., & Nishiuchi Y.: Transfer of two Burkholderia and an Alcaligenes species to Ralstonia
    gen. nov.: proposal of Ralstonia pickettii (Ralston, Palleroni and Doudoroff 1973) comb. nov., Ralstonia solanacearum (Smith
    1896) comb. nov. and Ralstonia eutropha (Davis 1969) comb. nov. Microbiol. Immunol., 1995, 39, 897-904.
  4. Mark R. Bruins, Sanjay Kapil and Frederick W. Oehme: Pseudomonas pickettii: A Common Soil and Groundwater Aerobic Bacteria
    with Pathogenic and Biodegradation Properties. Ecotoxicology and Environmental Safety Volume 47, Issue 2, October 2000,
    Pages 105-111.
  5. Ryan MP, Pembroke JT, Adley CC: Ralstonia pickettii: a persistent gram-negative nosocomial infectious organism. J Hosp Infect.
    2006 Mar;62(3):278-84. Epub 2005 Dec 6.
  6. Thierry De Baere, Sophia Steyaert, Georges Wauters, Paul De Vos,Johan Goris, Tom Coenye, Tetsushi Suyama, Gerda
    Verschraegen & Mario Vaneechoutte: Classification of Ralstonia pickettii biovar 3/‘thomasii’ strains (Pickett 1994) and of new
    isolates related to nosocomial recurrent meningitis as Ralstonia mannitolytica sp. nov. International Journal of Systematic and
    Evolutionary Microbiology (2001), 51, 547–558.
  7. Teizi Urakami, Chieko Ito-Yoshida, Hisaya Araki, Toshio Kijima, Ken-Ichiro Suzuki, and Kazuo Komagata: Transfer of
    Pseudomonas plantarii and Pseudomonas glumae to Burkholderia as Burkholderia spp. and Description of Burkholderia vandii
    sp. nov. Int J Syst Bacteriol April 1994 44:235-245.
  8. Eiko Yabuuchi, Yoshiaki Kawamura and Takayuki Ezaki: Genus VII. Ralstonia Yabuuchi, Kosako, Yano, Hotta and Nishiuchi 1996,
    625VP In: Bergey's Manual of Systematic Bacteriology, Second edition,Vol two, part C, George M. Garrity (Editor-in-Chief), pp. 609-
  9. Henry, D. A., Mahenthiralingam, E., Vandamme, P., Coenye, T., and Speert, D. P. (2001). Phenotypic methods for determining
    genomovar status of the Burkholderia cepacia complex. J. Clin. Microbiol. 39, 1073–1078. doi: 10.1128/JCM.39.3.1073-1078.2001
Can degrade chlorophenols, aromatic hydrocarbons, 2,4-dichlorophenoxyacetic acid
and pentacyclic triterpeniod compounds.

Positive results for alkaline reaction in OF base medium, catalase, denitrification, oxidase, phenylalanine deaminase, urease & acid
production from glucose. Can utilize: citrate, 2-ketogluconate, glucose, D-ribose, fructose, glycerol, xylose, adipate, DL-malate, D- and
L-alanine, L-histidine, urocanic acid, malonic acid, L-serine, acetic acid, L-asparagine, L-aspartic acid, L-glutamic acid,
beta-hydroxybutyric acid, DL-lactic acid, methylpyruvate, L-proline, L-pyroglutamic acid, propionic acid, tartrate, maleate & succinic acid.

Negative results for arginine dihydrolase, esculin hydrolysis, gelatin hydrolysis (positive in Bergey's Manual), H
2S production, indole
production, lecithinase, lysine decarboxylase, ONPG, starch hydrolysis & urease.
No utilization of adonitol, salicin, inositol, sorbitol, D- and L-arabinose, dulcitol, raffinose, rhamnose, melezitose, melibiose, inulin,
sucrose, trehalose, cellobiose, galactose, n-caprate, N-acetyl-D-glucosamine, phenylacetate, ethanol (3%), itaconic acid,
alpha-ketobutyric acid, L-leucine, quinic acid, D-saccharic acid, sebacic acid, D-serine, L-threonine, N-acetyl-D-galactosamine,
cellobiose, alpha-cyclodextrin, i-erythritol, glycyl-L-aspartic acid, inosine, D-raffinose, uridine, lactulose, D-melibiose,beta-methyl-D-
glucoside, L-rhamnose, D-trehalose, turanose, xylitol, D-arabitol, 2,3-butanediol, DL-carnitine, dextrin, L-fucose, gentiobiose,
glucose-1-phosphate, glucose-6-phosphate, D-glucosaminic acid, DL-alpha-glycerol phosphate, hydroxy-L-proline, m-inositol,
D-mannose, L-ornithine, putrescine, D-sorbitol, sucrose & thymidine.
(c) Costin Stoica
Culture media
Biochemical tests
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Nitrates reduction
P. thomasii /
R. mannitolilytica
Differentiating biovars