Burkholderia

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Burkholderia
Burkholderia pseudomallei 01.jpg
B. pseudomallei colonies on a blood agar plate.
Scientific classification
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Betaproteobacteria
Order: Burkholderiales
Family: Burkholderiaceae
Genus: Burkholderia

Burkholderia is a genus of Proteobacteria whose pathogenic members include Burkholderia mallei, responsible for glanders, a disease that occurs mostly in horses and related animals; Burkholderia pseudomallei, causative agent of melioidosis; and Burkholderia cepacia, an important pathogen of pulmonary infections in people with cystic fibrosis (CF).[1]


The Burkholderia (previously part of Pseudomonas) genus name refers to a group of virtually ubiquitous Gram-negative, obligately aerobic, rod-shaped bacteria that are motile by means of single or multiple polar flagella, with the exception of Burkholderia mallei which is nonmotile. Members belonging to the genus do not produce sheaths or prosthecae and are able to utilize poly-beta-hydroxybutyrate (PHB) for growth. The genus includes both animal and plant pathogens, as well as some environmentally important species. In particular, B. xenovorans (previously named Pseudomonas cepacia then B. cepacia and B. fungorum) is renowned for being catalase positive (affecting patients with chronic granulomatous disease) and its ability to degrade chlororganic pesticides and polychlorinated biphenyls (PCBs).

Due to their antibiotic resistance and the high mortality rate from their associated diseases, B. mallei and B. pseudomallei are considered to be potential biological warfare agents, targeting livestock and humans.

History[edit]

The genus was named after Walter H. Burkholder, plant pathologist at Cornell University. The first species to receive membership to the genus were transfers from the Pseudomonas genus, on the basis of various biochemical tests. [2][3]

Until recently, the Burkholderia genus was inclusive of all Paraburkholderia species.[4] However, the Paraburkholderia genus is phylogenetically distinct, and can be distinguished from all Burkholderia species on the premise of molecular signatures that are uniquely found for each genus.[5]

Taxonomy[edit]

Burkholderia species form a monophyletic group within the Burkholderiales order of the Betaproteobacteria. There are currently 48 validly named species that can be distinguished from neighbouring genera (i.e. Paraburkholderia) and all other bacteria by conserved signature indels in a variety of proteins.[5][6] These indels represent exclusive common ancestry shared among all Burkholderia species.

Within the genus, there are three distinct monophyletic clusters. One group consists of all species belonging to the Burkholderia cepacia complex, another clade comprises B. pseudomallei and closely related species, and the last clade encompasses of most of the phytogenic species within the genus, including B. glumae and B. gladioli .[5] Conserved signature indels have also been discovered that are specific for each of these subgroups within the genus that aid in demarcating members of this extremely large and diverse genus.[5][7]

Species[edit]

List of species:[8]

Note: Several Burkholderia species not listed here have been reclassified as Paraburkholderia

List of Candidatus species (proposed but unculturable)

References[edit]

  1. ^ Woods, Donald E., and Pamela A. Sokol.(2006) The genus Burkholderia. In: The prokaryotes, pp. 848-860. Springer-: New York.
  2. ^ Yabuuchi E, Kosako Y, Oyaizu H, Yano I, Hotta H, Hashimoto Y, Ezaki T, Arakawa M (1992). "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. 36 (12): 1251–1275. doi:10.1111/j.1348-0421.1992.tb02129.x. PMID 1283774. 
  3. ^ Yabuuchi E, Kosako Y, Oyaizu H, Yano I, Hotta H, Hashimoto Y, Ezaki T, Arakawa M (1993). "Burkholderia gen. nov.validation of the publication of new names and new combinations previously effectively published outside the IJSB". Int J Syst Bacteriol. 43: 298–399. doi:10.1099/00207713-43-2-398. 
  4. ^ Oren A, Garrity GM (2015). "List of new names and new combinations previously effectively, but not validly, published". Int J Syst Evol Microbiol. 65: 2017–2025. doi:10.1099/ijs.0.000317. 
  5. ^ a b c d Sawana A, Adeolu M, Gupta RS (2014). "Molecular signatures and phylogenomic analysis of the genus Burkholderia: proposal for division of this genus into the emended genus Burkholderia containing pathogenic organisms and a new genus Paraburkholderia gen. nov. harboring environmental species". Front Genet. 5: 429. doi:10.3389/fgene.2014.00429. PMC 4271702Freely accessible. PMID 25566316. 
  6. ^ "List of prokaryotic names with standing in nomenclature". Retrieved 21 October 2016. 
  7. ^ Gupta RS (2016). "Impact of genomics on the understanding of microbial evolution and classification: the importance of Darwin's views on classification". FEMS Microbiol Rev. 40 (4): 520–53. doi:10.1093/femsre/fuw011. PMID 27279642. 
  8. ^ Sayers; et al. "Burkholderia". National Center for Biotechnology Information (NCBI) taxonomy database. Retrieved 2016-10-24. 

External links[edit]