Burkholderia

Burkholderia is a genus of Pseudomonadota whose pathogenic members include the Burkholderia cepacia complex, which attacks humans and 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).^[3] Burkholderia species is also found in marine environments. S.I. Paul et al. (2021)^[4] isolated and characterized Burkholderia cepacia from marine sponges of the Saint Martin's Island of the Bay of Bengal, Bangladesh.^[4]

Burkholderia
B. pseudomallei colonies on a blood agar plate.
Scientific classification
Domain:	Bacteria
Phylum:	Pseudomonadota
Class:	Betaproteobacteria
Order:	Burkholderiales
Family:	Burkholderiaceae
Genus:	Burkholderia Yabuuchi et al. 1993[1][2]
Type species
Burkholderia cepacia (Palleroni and Holmes 1981) Yabuuchi et al. 1993
Species
See text

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.^[4] Members belonging to the genus do not produce sheaths or prosthecae and are able to use 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. The conserved RNA structure anti-hemB RNA motif is found in all known bacteria in this genus.^[5]

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

The genus was named after Walter H. Burkholder, plant pathologist at Cornell University. The first species placed in the genus were transfers from Pseudomonas, on the basis of various biochemical tests.^[1][2]

Until recently, the genus Burkholderia was inclusive of all Paraburkholderia species.^[6] However, the genus Paraburkholderia is phylogenetically distinct, and can be distinguished from all Burkholderia species on the basis of molecular signatures that are uniquely found for each genus.^[7]

Taxonomy

Burkholderia species form a monophyletic group within the Burkholderiales order of the Betaproteobacteria.^[4] Currently, the 48 validly named species can be distinguished from related genera (i.e. Paraburkholderia) and all other bacteria by conserved signature indels in a variety of proteins.^[7] These indels represent exclusive common ancestry shared among all Burkholderia species.

The genus has 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 .^[7] Conserved signature indels are specific for each of these subgroups within the genus that aid in demarcating members of this extremely large and diverse genus.^[7][8]

Research

Recently, research in Burkholderia species has investigated a range of topics and characteristics including metabolomic response to antibiotics, contact-dependent interactions between bacterial communities, and genomic potential to yield beneficial products.^[9][10][11]

In Burkholderia species, certain antibiotics such as trimethoprim has been shown to induce and upregulate a large amount of the metabolome, inducing over 100 silent secondary metabolite gene clusters in Burkholderia thailandensis.^[9] These global activators can be used as a source of investigation into how the metabolomes of pathogenic bacterial species respond to antibiotic stress and how bacterial species can vary in response to them.^[9] It has been shown that closely related cystic fibrosis-associated Burkholderia species respond to trimethoprim with differing levels of expression of various secondary metabolites, highlighting the personalized nature of metabolomics in related bacterial strains.^[12]

Research focused on interbacterial signaling using Burkholderia has shown that contact-dependent growth inhibition plays a significant role in mediating cell to cell communication specifically in B. thailandensis.^[10] In this interaction, cells release protein toxins to the surrounding environment, and only those with a corresponding protective protein (usually bacteria of the same strain) will not have its growth inhibited or die. Furthermore, recipient cells that have the corresponding protein then undergo changes to gene expression and phenotype that promotes community formation in the form of biofilms. This occurs even if the recipient cell was not of the same bacterial strain which highlights the importance of this system.^[10] The genes that encode the protein toxins and the rest of the contact-dependent inhibition system can become mobile in the form of a transposon that can transfer between cells and is critical to communal aspect of the system.^[13] Thus, contact-dependent signaling plays a significant role in bacterial self recognition and community formation.^[10][13]

Burkholderia species have been shown to be a potential source of beneficial products such as antimicrobials and biosurfactants.^[11][14] Along with the related genus Pseudomonas, Burkholderia can synthesize a particular class of biosurfactant called rhamnolipids. Rhamnolipids synthesized by Burkholderia have differing chemical characteristics (compared to those synthesized by Pseudomonas) and thus have the potential for novel applications.^[14][15]

Species

List of species:^[16]

• Burkholderia alpina
• Burkholderia ambifaria
• Burkholderia anthina
• Burkholderia arboris
• Burkholderia cenocepacia
• Burkholderia cepacia
• Burkholderia contaminans
• Burkholderia diffusa
• Burkholderia dolosa
• Burkholderia gladioli
• Burkholderia glumae
• Burkholderia humptydooensis
• Burkholderia lata
• Burkholderia latens
• Burkholderia mallei
• Burkholderia metallica
• Burkholderia multivorans
• Burkholderia oklahomensis
• Burkholderia plantarii
• Burkholderia pseudomallei
• Burkholderia pseudomultivorans
• Burkholderia puraquae
• Burkholderia pyrrocinia
• Burkholderia seminalis
• Burkholderia singaporensis
• Burkholderia singularis
• Burkholderia stabilis
• Burkholderia stagnalis
• Burkholderia territorii
• Burkholderia thailandensis
• Burkholderia ubonensis
• Burkholderia vietnamiensis

See also

• MAEB RNA motif

References

1. Yabuuchi E, Kosako Y, Oyaizu H, Yano I, Hotta H, Hashimoto Y, et al. (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". Microbiology and Immunology. 36 (12): 1251–75. doi:10.1111/j.1348-0421.1992.tb02129.x. PMID 1283774.
2. "Validation of the publication of new names and new combinations previously effectively published outside the IJSB—List No. 45". Int J Syst Bacteriol. 43 (2): 298–399. 1993. doi:10.1099/00207713-43-2-398.
3. Woods DE, Sokol PA (2006). "The genus Burkholderia". In Dworkin M, Falkow S, Rosenberg E, Schleifer KH, Stackebrandt E (eds.). The Prokaryotes—A Handbook on the Biology of Bacteria (3 ed.). New York: Springer–Verlag. pp. 848–860. doi:10.1007/0-387-30745-1_40. ISBN 978-0-387-25495-1.
4. Paul, Sulav Indra; Rahman, Md. Mahbubur; Salam, Mohammad Abdus; Khan, Md. Arifur Rahman; Islam, Md. Tofazzal (December 2021). "Identification of marine sponge-associated bacteria of the Saint Martin's island of the Bay of Bengal emphasizing on the prevention of motile Aeromonas septicemia in Labeo rohita". Aquaculture. 545: 737156. Bibcode:2021Aquac.54537156P. doi:10.1016/j.aquaculture.2021.737156. ISSN 0044-8486.
5. Weinberg Z, Barrick JE, Yao Z, Roth A, Kim JN, Gore J, et al. (2007). "Identification of 22 candidate structured RNAs in bacteria using the CMfinder comparative genomics pipeline". Nucleic Acids Research. 35 (14): 4809–19. doi:10.1093/nar/gkm487. PMC 1950547. PMID 17621584.
6. Oren A, Garrity GM (September 2017). "List of new names and new combinations previously effectively, but not validly, published". International Journal of Systematic and Evolutionary Microbiology. 67 (9): 3140–3143. doi:10.1099/ijs.0.000317. PMC 5817221. PMID 28891789.
7. 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". Frontiers in Genetics. 5: 429. doi:10.3389/fgene.2014.00429. PMC 4271702. PMID 25566316.
8. Gupta RS (July 2016). "Impact of genomics on the understanding of microbial evolution and classification: the importance of Darwin's views on classification". FEMS Microbiology Reviews. 40 (4): 520–53. doi:10.1093/femsre/fuw011. PMID 27279642.
9. Okada BK, Wu Y, Mao D, Bushin LB, Seyedsayamdost MR (August 2016). "Mapping the Trimethoprim-Induced Secondary Metabolome of Burkholderia thailandensis". ACS Chemical Biology. 11 (8): 2124–30. doi:10.1021/acschembio.6b00447. PMC 6786267. PMID 27367535.
10. Garcia EC, Perault AI, Marlatt SA, Cotter PA (July 2016). "Interbacterial signaling via Burkholderia contact-dependent growth inhibition system proteins". Proceedings of the National Academy of Sciences of the United States of America. 113 (29): 8296–301. Bibcode:2016PNAS..113.8296G. doi:10.1073/pnas.1606323113. PMC 4961174. PMID 27335458.
11. Kunakom S, Eustáquio AS (July 2019). "Burkholderia as a Source of Natural Products". Journal of Natural Products. 82 (7): 2018–2037. doi:10.1021/acs.jnatprod.8b01068. PMC 6871192. PMID 31294966.
12. McAvoy AC, Jaiyesimi O, Threatt PH, Seladi T, Goldberg JB, da Silva RR, Garg N (May 2020). "Burkholderia spp. Bacteria Metabolomes after Exposure to the Antibiotic Trimethoprim". ACS Infectious Diseases. 6 (5): 1154–1168. doi:10.1021/acsinfecdis.9b00513. PMID 32212725. S2CID 214682246.
13. Ocasio AB, Cotter PA (January 2019). Blokesch M (ed.). "CDI/CDS system-encoding genes of Burkholderia thailandensis are located in a mobile genetic element that defines a new class of transposon". PLOS Genetics. 15 (1): e1007883. doi:10.1371/journal.pgen.1007883. PMC 6350997. PMID 30615607.
14. Wittgens A, Santiago-Schuebel B, Henkel M, Tiso T, Blank LM, Hausmann R, et al. (February 2018). "Heterologous production of long-chain rhamnolipids from Burkholderia glumae in Pseudomonas putida-a step forward to tailor-made rhamnolipids". Applied Microbiology and Biotechnology. 102 (3): 1229–1239. doi:10.1007/s00253-017-8702-x. PMID 29264775. S2CID 9690461.
15. Victor IU, Kwiencien M, Tripathi L, Cobice D, McClean S, Marchant R, Banat IM (August 2019). "Quorum sensing as a potential target for increased production of rhamnolipid biosurfactant in Burkholderia thailandensis E264". Applied Microbiology and Biotechnology. 103 (16): 6505–6517. doi:10.1007/s00253-019-09942-5. PMC 6667413. PMID 31222386.
16. "List of prokaryotic names with standing in nomenclature". Retrieved 21 October 2016.

External links

• Burkholderia genomes and related information at PATRIC, a Bioinformatics Resource Center funded by NIAID
• Pathema-Burkholderia Resource
• Burkholderia Genome Database