''Burkholderia'' is a genus of

Pseudomonadota Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The ...

whose pathogenic members include the ''Burkholderia cepacia'' complex, which attacks humans and ''

Burkholderia mallei ''Burkholderia mallei'' is a Gram-negative, bipolar, aerobic bacterium, a human and animal pathogen of genus ''Burkholderia'' causing glanders; the Latin name of this disease (''malleus'') gave its name to the species causing it. It is closely re ...

'', responsible for

glanders Glanders is a contagious zoonotic infectious disease that occurs primarily in horses, mules, and donkeys. It can be contracted by other animals, such as dogs, cats, pigs, goats, and humans. It is caused by infection with the bacterium ''Burkhol ...

, a disease that occurs mostly in

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million y ...

s and related animals; ''

Burkholderia pseudomallei ''Burkholderia pseudomallei'' (also known as ''Pseudomonas pseudomallei'') is a Gram-negative, bipolar, aerobic, motile rod-shaped bacterium. It is a soil-dwelling bacterium endemic in tropical and subtropical regions worldwide, particularly in T ...

'', causative agent of

melioidosis Melioidosis is an infectious disease caused by a gram-negative bacterium called ''Burkholderia pseudomallei''. Most people exposed to ''B. pseudomallei'' experience no symptoms; however, those who do experience symptoms have signs and symptoms t ...

; and ''

Burkholderia cepacia ''Burkholderia cepacia'' complex (BCC), or simply ''Burkholderia cepacia'', is a group of catalase-producing, lactose-nonfermenting, Gram-negative bacteria composed of at least 20 different species, including ''B. cepacia'', '' B. mul ...

'', an important

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

of pulmonary infections in people with

cystic fibrosis Cystic fibrosis (CF) is a rare genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. O ...

(CF). ''Burkholderia'' species is also found marine environment. S.I. Paul et al. (2021) isolated and characterized ''Burkholderia cepacia'' from marine sponges of the

Saint Martin's Island Saint Martin Island ( bn, সেন্টমার্টিন দ্বীপ) is a small island (area only 3 km2) in the northeastern part of the Bay of Bengal, about 9 km south of the tip of the Cox's Bazar-Teknaf peninsula, and fo ...

of the

Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line between ...

Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...

. The ''Burkholderia'' (previously part of ''

Pseudomonas ''Pseudomonas'' is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able ...

'') genus name refers to a group of virtually ubiquitous

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

, obligately aerobic,

rod-shaped A bacillus (), also called a bacilliform bacterium or often just a rod (when the context makes the sense clear), is a rod-shaped bacterium or archaeon. Bacilli are found in many different taxonomic groups of bacteria. However, the name ''Bacillu ...

bacteria that are

motile Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...

by means of single or multiple polar

flagella A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

, with the exception of ''

'', which is nonmotile. 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 In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

, 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 Chronic granulomatous disease (CGD), also known as Bridges–Good syndrome, chronic granulomatous disorder, and Quie syndrome, is a diverse group of hereditary diseases in which certain cells of the immune system have difficulty forming the reacti ...

) and its ability to degrade chlororganic pesticides and

polychlorinated biphenyl Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act in 1979 and internationally by t ...

s. The conserved RNA structure

anti-hemB RNA motif The anti-hemB RNA motif is a conserved RNA structure that was found in all known bacteria in the genus ''Burkholderia'', and in a variety of other betaproteobacteria. The anti-hemB RNA motif consists primarily of two stem-loops, followed by a pr ...

is found in all known bacteria in this genus. Due to their

antibiotic resistance Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. ...

and the high mortality rate from their associated diseases, '' B. mallei'' and '' B. pseudomallei'' are considered to be potential

biological warfare Biological warfare, also known as germ warfare, is the use of biological toxins or infectious agents such as bacteria, viruses, insects, and fungi with the intent to kill, harm or incapacitate humans, animals or plants as an act of war. Bio ...

agents, targeting livestock and humans.

History

The genus was named after Walter H. Burkholder, plant pathologist at

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

. The first species placed in the genus were transfers from ''

'', on the basis of various biochemical tests. Until recently, the genus ''Burkholderia'' was inclusive of all ''

Paraburkholderia ''Paraburkholderia'' is a genus of Pseudomonadota that are gram negative, slightly curved rods that are motile by means of flagella. They have been reported to colonize endophytic tissues of hybrid spruce (Picea glauca x engelmannii) and lodge ...

'' species. 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.

Taxonomy

''Burkholderia'' species form a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

group within the

Burkholderiales The Burkholderiales are an order of Pseudomonadota.George M. Garrity: '' Bergey's Manual of Systematic Bacteriology''. 2. Auflage. Springer, New York, 2005, Vol. 2: ''The Proteobacteria Part C: The Alpha-, Beta-, Delta-, and Epsilonproteabacteria ...

order of the

Betaproteobacteria Betaproteobacteria are a class of Gram-negative bacteria, and one of the eight classes of the phylum Pseudomonadota (synonym Proteobacteria). The ''Betaproteobacteria'' are a class comprising over 75 genera and 400 species of bacteria. Togeth ...

. Currently, the 48 validly named species can be distinguished from related genera (i.e. ''

'') and all other bacteria by

conserved signature indels Conserved signature inserts and deletions (CSIs) in protein sequences provide an important category of molecular markers for understanding phylogenetic relationships. CSIs, brought about by rare genetic changes, provide useful phylogenetic markers ...

in a variety of proteins. These indels represent exclusive common ancestry shared among all ''Burkholderia'' species. The genus has three distinct

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 ''. 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.

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. In ''Burkholderia'' species, certain antibiotics such as

trimethoprim Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for ''Pneumocystis'' pneumonia in peop ...

has been shown to induce and upregulate a large amount of the

metabolome The metabolome refers to the complete set of small-molecule chemicals found within a biological sample. The biological sample can be a cell, a cellular organelle, an organ, a tissue, a tissue extract, a biofluid or an entire organism. The smal ...

, inducing over 100 silent secondary metabolite gene clusters in '' Burkholderia thailandensis.'' 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. It has been shown that closely related

-associated ''Burkholderia'' species respond to trimethoprim with differing levels of expression of various

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norm ...

s, highlighting the personalized nature of metabolomics in related bacterial strains. Research focused on interbacterial signaling using ''Burkholderia'' has shown that

contact-dependent growth inhibition Contact-dependent growth inhibition (CDI) is a phenomenon where a bacterial cell may deliver a polymorphic toxin molecule into neighbouring bacterial cells upon direct cell-cell contact, causing growth arrest or cell death. Discovery CDI is now ...

plays a significant role in mediating cell to cell communication specifically in ''B. thailandensis''. 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

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

s. This occurs even if the recipient cell was not of the same bacterial strain which highlights the importance of this system. 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 A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transpo ...

that can transfer between cells and is critical to communal aspect of the system. Thus, contact-dependent signaling plays a significant role in bacterial self recognition and community formation. ''Burkholderia'' species have been shown to be a potential source of beneficial products such as antimicrobials and

biosurfactant Biosurfactant usually refers to surfactants of microbial origin. Most of the biosurfactants produced by microbes are synthesized extracellularly and many microbes are known to produce biosurfactants in large relative quantities. Some are of commerc ...

s. Along with the related genus ''Pseudomonas'', ''Burkholderia'' can synthesize a particular class of biosurfactant called

rhamnolipid Rhamnolipids are a class of glycolipid produced by ''Pseudomonas aeruginosa'', amongst other organisms, frequently cited as bacterial surfactants. They have a glycosyl head group, in this case a rhamnose moiety, and a 3-(hydroxyalkanoyloxy)alkanoi ...

s. Rhamnolipids synthesized by ''Burkholderia'' have differing chemical characteristics (compared to those synthesized by ''Pseudomonas'') and thus have the potential for novel applications.

Species

List of species: *'' Burkholderia alpina'' *'' Burkholderia ambifaria'' *''

Burkholderia anthina ''Burkholderia anthina'' is a species of bacteria of the family Burkholderiaceae The Burkholderiaceae are a family of bacteria included in the order Burkholderiales.Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) ...

'' *'' Burkholderia arboris'' *''

Burkholderia cenocepacia ''Burkholderia cenocepacia'' is a Gram-negative, rod-shaped bacterium that is commonly found in soil and water environments and may also be associated with plants and animals, particularly as a human pathogen. It is one of over 20 species in the ...

'' *''

'' *'' Burkholderia contaminans'' *'' Burkholderia diffusa'' *'' Burkholderia dolosa'' *''

Burkholderia gladioli ''Burkholderia gladioli'' is a species of aerobic gram-negative rod-shaped bacteria that causes disease in both humans and plants. It can also live in symbiosis with plants and fungi and is found in soil, water, the rhizosphere, and in many anima ...

'' *''

Burkholderia glumae ''Burkholderia glumae'' is a Gram-negative soil bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorgani ...

'' *'' Burkholderia humptydooensis'' *'' Burkholderia lata'' *'' Burkholderia latens'' *''

'' *'' Burkholderia metallica'' *''

Burkholderia multivorans ''Burkholderia multivorans'' is a species in the phylum Pseudomonadota. The cells are Rod-shaped bacteria, rod-shaped. It is known to cause human disease, such as colonisation of the lung in cystic fibrosis. References External links ''Burkho ...

'' *'' Burkholderia oklahomensis'' *''

Burkholderia plantarii ''Burkholderia plantarii'' is a Gram-negative soil bacterium. Its specific name comes from the Latin ''plantarium'' (seedbed).Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual of Systematic Bacte ...

'' *''

'' *'' Burkholderia pseudomultivorans'' *'' Burkholderia puraquae'' *'' Burkholderia pyrrocinia'' *'' Burkholderia seminalis'' *'' Burkholderia singaporensis'' *'' Burkholderia singularis'' *'' Burkholderia stabilis'' *'' Burkholderia stagnalis'' *'' Burkholderia territorii'' *'' Burkholderia thailandensis'' *'' Burkholderia ubonensis'' *''

Burkholderia vietnamiensis ''Burkholderia vietnamiensis'' is a species of bacteria. It can be found as an opportunistic pathogen in patients with cystic fibrosis or other immunocompromising illnesses. It differs from most ''Burkholderia'' species in that it is often suscep ...

References

External links

Burkholderia
genomes and related information a
PATRIC
a Bioinformatics Resource Center funded b
NIAID

Pathema-''Burkholderia'' Resource

''Burkholderia'' Genome Database
{{Taxonbar, from=Q135239 Burkholderiaceae Bacteria genera Biological anti-agriculture weapons

History

Taxonomy

Research

Species

See also

References

External links