''Burkholderia gladioli'' is a species of
aerobic
Aerobic means "requiring air," in which "air" usually means oxygen.
Aerobic may also refer to
* Aerobic exercise, prolonged exercise of moderate intensity
* Aerobics, a form of aerobic exercise
* Aerobic respiration, the aerobic process of cel ...
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 ...
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 '' Baci ...
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
that causes disease in both humans and plants. It can also live in
symbiosis
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
with plants and fungi
and is found in soil, water, the rhizosphere, and in many animals. It was formerly known as ''Pseudomonas marginata''.
''Burkholderia gladioli'' synthesizes several inhibitory substances, among them
gladiolin,
bongkrek acid,
enacyloxin, and
toxoflavin
Toxoflavin is a toxin produced by a variety of bacteria including ''Burkholderia gladioli''. It also has antibiotic properties.
Toxoflavin acts as a pH indicator
A pH indicator is a halochromic chemical compound added in small amounts to a ...
. Those molecules might participate in antagonistic interactions with other microbes in the environment where they grow. One
pathovar
A pathovar is a bacterial strain or set of strains with the same or similar characteristics, that is differentiated at infrasubspecific level from other strains of the same species or subspecies on the basis of distinctive pathogenicity to one o ...
iety, growing on
coconut pulp, produces the
respiratory
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies gre ...
toxin
A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849 ...
bongkrek acid which can cause fatal poisoning in humans.
Nomenclature
The members of the genus ''
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 ...
'' were formerly classified as ''Pseudomonas'', but ''Burkholderia'' was one of the seven genera that arose when ''Pseudomonas'' was divided based on
rRNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosoma ...
differences. ''Burkholderia gladioli'' is closely related to, and often mistaken for, a member of the
Burkholderia cepacia complex
''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. m ...
. This includes ten closely related species, which are all plant pathogens.
''Burkholderia gladioli'' is divided into several
pathovar
A pathovar is a bacterial strain or set of strains with the same or similar characteristics, that is differentiated at infrasubspecific level from other strains of the same species or subspecies on the basis of distinctive pathogenicity to one o ...
s:
* ''B. gladioli'' pv. ''gladioli'' causes
gladiolus
''Gladiolus'' (from Latin, the diminutive of ''gladius'', a sword) is a genus of perennial cormous flowering plants in the iris family (Iridaceae).
It is sometimes called the 'sword lily', but is usually called by its generic name (plural ''g ...
rot
* ''B. g.'' pv. ''alliicola'' causes onion
bulb rot
* ''B. g.'' pv.''agaricicola'' causes soft rot in
mushroom
A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans.
The standard for the name "mushroom" is ...
s
* ''B. g.'' pv. ''cocovenerans'' (sometimes written as ''cocovenenans'') spoils
coconut pulp
Etymology
Burkholderia - Named after the scientist (bacteriologist) that discovered an organism linked to disease in the skin of onions.
Gladioli - Small sword, of a lily; used within botany.
Identification
''Burkholderia'' are motile, Gram negative rods that may be straight or slightly curved. They are aerobic, catalase positive, urease positive, nonsporeformers. They grow on
MacConkey agar
MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate Gram-negative and enteric (normally found in the intestinal tract) bacteria and differentiate them based on lactose fermentation. ...
, but do not ferment the lactose. ''Burkholderia gladioli'' can be distinguished from the other ''Burkholderia'' because it is oxidase negative
''B. gladioli'' is indole negative, nitrate negative, and lysine decarboxylation negative.
On the molecular level, PCR can be used to distinguish between the different ''Burkholderia'' species. According to Furuya et al., the ribosomal RNA gene is highly conserved and universally distributed in all living things, and therefore difference in the DNA sequences between 16S and 23S rRNA genes can be used to differentiate between the species.
The
primers used for the amplification of the 16S to 23S region in the ''B. gladioli''
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding g ...
are as follows: GLA-f 5'-(CGAGCTAATACCGCGAAA)-3' and GLA-r 5'-(AGACTCGAGTCAACTGA)-3' Using these primers for PCR results in an amplicon of approximately 300bp.
All members of the genus ''Burkholderia'' have multireplicon genomes. They are able to keep "essential housekeeping" genes on the largest chromosome. This largest chromosome has a single origin of replication. The gene order and GC composition is conserved as well. Members of ''Burkholderia'' are able to capture and retain foreign DNA. The foreign DNA can be detected by looking for atypical GC context areas. One of the first foreign DNA segments detected this way encoded for virulence.
The ''B. gladioli'' genome consists of 6 major holders of genetic information: two chromosomes and four plasmids. The entire genome amounts to 9.06 Mb (Million Bases) with 89.64% of the genome - including non-coding regions - on the two chromosomes.
Characteristics
All species of the genus ''Burkholderia -'' except for ''B. mallei -'' display a form of motility when suspended within liquid. Being Gram-Negative, ''B. gladioli'' will not be stained by the Crystal Violet - Iodine complex, but will be counter stained red by Safranin. The optimal growth temperature on a Nutrient Agar plate is 30-35 degree Celsius. The Genus ''Burkholderia'' (including ''B. gladioli'') shows a remarkable amount of diversity of metabolism of carbohydrates and other organic compounds. ''B. gladioli'' is able to more acids than is typical for its genus.
Pathology
In plants
''B. gladioli'' has been identified as a plant pathogen in
onion
An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onio ...
s,
gladiolus
''Gladiolus'' (from Latin, the diminutive of ''gladius'', a sword) is a genus of perennial cormous flowering plants in the iris family (Iridaceae).
It is sometimes called the 'sword lily', but is usually called by its generic name (plural ''g ...
,
iris
Iris most often refers to:
*Iris (anatomy), part of the eye
*Iris (mythology), a Greek goddess
* ''Iris'' (plant), a genus of flowering plants
* Iris (color), an ambiguous color term
Iris or IRIS may also refer to:
Arts and media
Fictional ent ...
, and together with ''
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 ...
'' affect the
rice
Rice is the seed of the grass species '' Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera '' Zizania'' and '' Porteresia'', both wild and domesticat ...
. It was originally described to have caused rot of gladiolus corms. The bulbs can become water soaked and decay.
Some other common symptoms of infected plants can be seen in the leaves. The leaves contain brown lesions, and they may become watersoaked. Other symptoms are the wilting and/or rot of roots, stems, and petals. ''B. gladioli'' has also been identified as the causative agent in leaf-sheath browning in gladiolas and onions. Sometimes, the whole plant decays.
One widespread plant disease caused by ''B. gladioli'' is called scab. It can be seen on gladiolus corms as water-soaked brown spots, outlined in yellow. Eventually, they can become hollow and surrounded by scabs. If the scabs fall off, they leave behind cavities or lesions.
In humans
''B. gladioli'' in humans is an
opportunistic pathogen
An opportunistic infection is an infection caused by pathogens (bacteria, fungi, parasites or viruses) that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immune ...
that is an important agent for
hospital-associated infections. It has recently appeared as a severe pathogen in patients with
cystic fibrosis, causing severe pulmonary infections.
Though it is still a fairly uncommon pathogen, its presence is associated with a poor
prognosis. It has also colonized the respiratory tracts of patients with granulomatous disease. In lung
transplant patients, infection can be fatal as patients have developed
bacteremia and sterile wound infections as a result.
''Tempe bongkrèk'', a variation of
tempeh
Tempeh or tempe (; jv, ꦠꦺꦩ꧀ꦥꦺ, témpé, ) is a traditional Indonesian food made from fermented soybeans. It is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form. A fungus, '' Rhiz ...
prepared with coconut, is susceptible to ''B. gladioli'' pathovar. ''cocovenenans'' contamination. Contaminated ''tempe bongkrèk'' can contain lethal amounts of highly toxic
bongkrek acid and
toxoflavin
Toxoflavin is a toxin produced by a variety of bacteria including ''Burkholderia gladioli''. It also has antibiotic properties.
Toxoflavin acts as a pH indicator
A pH indicator is a halochromic chemical compound added in small amounts to a ...
.
''B. gladioli'' was implicated in the
2015 deaths of 75 people, in
Mozambique
Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...
, who had consumed a home-brewed beer made from corn flour that was contaminated with the bacterium.
A 3-year long study period of neonatal and nosocomial sepsis yielded 14 patients (out of approximately 3784) with isolated positive colonies of ''B. gladioli'' from blood cultures. During this time, symptoms of the sepsis caused by the ''B. gladioli'' infection included congenital leukemia, pneumonia, and several other respiratory malfunctions. A mortality rate of 7% is linked to the ''B. gladioli'' infections present during the time of study.
Systems of Pathology
The primary system responsible for the disease caused by ''B. gladioli sp''. is a
type two secretion pathway.
An experiment performed by Chowdhury and Heinemann revealed that six strains of Burkholderia gladioli that were avirulent still contained the capacity for mushroom growth inhibition without having the characteristics of mushroom tissue degradations. This led the two to believe the genetic factors that cause the microbe to have the ability to generate the cavity disease within an organism can be separated from the factors that inhibit mycelium growth within said mushrooms.
References
External links
PubMed article on PCR identification of ''Burkholderia''Type strain of ''Burkholderia gladioli'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q3308486
Burkholderiaceae
Bacteria described in 1885
Taxa named by Friedrich Wilhelm Zopf