Burkholderia gladioli | |
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Scientific classification ![]() | |
Domain: | Bacteria |
Phylum: | Pseudomonadota |
Class: | Betaproteobacteria |
Order: | Burkholderiales |
Family: | Burkholderiaceae |
Genus: | Burkholderia |
Species: | B. gladioli |
Binomial name | |
Burkholderia gladioli (Zopf 1885) Yabuuchi et al. 1993 | |
Type strain | |
ATCC 10248 CCUG 1782 CFBP 2427 CIP 105410 DSM 4285 HAMBI 2157 ICMP 3950 JCM 9311 LMG 2216 NBRC 13700 NCCB 38018 NCPPB 1891 NCTC 12378 NRRL B-793 | |
Synonyms | |
Pseudomonas gladioliSeverini 1913 Contents |
Burkholderia gladioli is a species of aerobic gram-negative rod-shaped bacteria [1] that causes disease in both humans and plants. It can also live in symbiosis with plants and fungi [2] and is found in soil, water, the rhizosphere, and in the microbiome of many animals. It was formerly known as Pseudomonas marginata.
Burkholderia gladioli synthesizes several inhibitory substances, among them gladiolin, bongkrek acid, enacyloxin, and toxoflavin. [3] [4] [5] [6] Those molecules might participate in antagonistic interactions with other microbes in the environment where they grow. [7] One pathovariety, growing on coconut pulp, produces the mitochondria disrupting toxin bongkrek acid which can cause fatal poisoning in humans.
The members of the genus Burkholderia were formerly classified as Pseudomonas, but Burkholderia was one of the seven genera that arose when Pseudomonas was divided based on rRNA differences. [8] Burkholderia gladioli is closely related to, and often mistaken for, a member of the Burkholderia cepacia complex. This includes ten closely related species, which are all plant pathogens.
Burkholderia gladioli is divided into several pathovars: [9]
The genus Burkholderia is named after scientist Walter H. Burkholder, who discovered an organism linked to disease in the skin of onions. [11]
Gladioli refers to the plant genus Gladiolus, which is grown ornamentally around the world, and where the fungus can cause rot. [12] The flower is named gladiolus "little sword" from gladius "sword", due to the shape of the leaves.
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, but do not ferment the lactose. Burkholderia gladioli can be distinguished from the other Burkholderia because it is oxidase negative [1] B. gladioli is indole negative, nitrate negative, and lysine decarboxylation negative. [13]
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. [14]
The primers used for the amplification of the 16S to 23S region in the B. gladioli genome 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 300 bp. [14]
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. [1]
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. [15]
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 °C. 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.
Test type | Test | Characteristics |
---|---|---|
Colony characters | Size | |
Type | Round | |
Color | Pale Yellow | |
Shape | ||
Morphological characters | Shape | Slightly Bent Rods |
Physiological characters | Motility | + |
Growth at 6.5% NaCl | ||
Biochemical characters | Gram staining | - |
Oxidase | d | |
Catalase | ||
Oxidative-Fermentative | ||
Motility | + | |
Methyl Red | ||
Voges-Proskauer | ||
Indole | ||
H2S Production | ||
Urease | ||
Nitrate reductase | ||
β-Galactosidase | ||
Hydrolysis of | Gelatin | + |
Starch | - | |
Casein | ||
Utilization of | Glycerol | |
Galactose | + | |
D-Glucose | + | |
D-Fructose | + | |
D-Mannose | + | |
Mannitol | + |
B. gladioli has been identified as a plant pathogen in onions, gladiolus, iris, and together with Burkholderia glumae affect the rice. 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. [2]
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. [16]
B. gladioli in humans is an opportunistic pathogen 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. [2] 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. [17]
Tempe bongkrèk, a variation of tempeh 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.[ citation needed ]
B. gladioli was implicated in the 2015 deaths of 75 people, in Mozambique, who had consumed a home-brewed beer made from corn flour that was contaminated with the bacterium. [18]
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. [19]
The primary system responsible for the disease caused by Burkholderia gladioli is a type two secretion pathway. [20] An experiment performed by Chowdhury and Heinemann revealed that six strains of B. gladioli that were avirulent still contained the capacity for mushroom growth inhibition without having the characteristics of mushroom tissue degradation. 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. [20]
Gladiolin, a novel macrolide produced by B. gladioli strain BCC0238, was found to have promising antibiotic activity against Mycobacterium tuberculosis in a 2017 study; the compound, which inhibits RNA polymerase, is structurally and functionally similar to etnangien, a macrolide synthesised by the bacterium Sorangium cellulosum which has also demonstrated potency against Mycobacterium, but is more unstable than gladiolin. In the study, gladiolin was found to have low mammalian cytotoxicity and good activity against M. tuberculosis isolates, suggesting that it may be a useful starting point in developing new antibiotics to treat multidrug resistant tuberculosis infections. [21]
Pseudomonas is a genus of Gram-negative bacteria belonging to the family Pseudomonadaceae in the class Gammaproteobacteria. The 313 members of the genus demonstrate a great deal of metabolic diversity and consequently are able to colonize a wide range of niches. Their ease of culture in vitro and availability of an increasing number of Pseudomonas strain genome sequences has made the genus an excellent focus for scientific research; the best studied species include P. aeruginosa in its role as an opportunistic human pathogen, the plant pathogen P. syringae, the soil bacterium P. putida, and the plant growth-promoting P. fluorescens, P. lini, P. migulae, and P. graminis.
Mycobacterium tuberculosis, also known as Koch's bacillus, is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, M. tuberculosis has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid. This coating makes the cells impervious to Gram staining, and as a result, M. tuberculosis can appear weakly Gram-positive. Acid-fast stains such as Ziehl–Neelsen, or fluorescent stains such as auramine are used instead to identify M. tuberculosis with a microscope. The physiology of M. tuberculosis is highly aerobic and requires high levels of oxygen. Primarily a pathogen of the mammalian respiratory system, it infects the lungs. The most frequently used diagnostic methods for tuberculosis are the tuberculin skin test, acid-fast stain, culture, and polymerase chain reaction.
Mycobacterium is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy in humans. The Greek prefix myco- means 'fungus', alluding to this genus' mold-like colony surfaces. Since this genus has cell walls with a waxy lipid-rich outer layer containing high concentrations of mycolic acid, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types.
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 that range from mild, such as fever and skin changes, to severe with pneumonia, abscesses, and septic shock that could cause death. Approximately 10% of people with melioidosis develop symptoms that last longer than two months, termed "chronic melioidosis".
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). Burkholderia species is also found in marine environments. S.I. Paul et al. (2021) isolated and characterized Burkholderia cepacia from marine sponges of the Saint Martin's Island of the Bay of Bengal, Bangladesh.
Burkholderia cepacia complex (BCC) is a species complex consisting of Burkholderia cepacia and at least 20 different biochemically similar species of Gram-negative bacteria. They are catalase-producing and lactose-nonfermenting. Members of BCC are opportunistic human pathogens that most often cause pneumonia in immunocompromised individuals with underlying lung disease. Patients with sickle-cell haemoglobinopathies are also at risk. The species complex also attacks young onion and tobacco plants, and displays a remarkable ability to digest oil.
Dickeya dadantii is a Gram-negative bacillus that belongs to the family Pectobacteriaceae. It was formerly known as Erwinia chrysanthemi but was reassigned as Dickeya dadantii in 2005. Members of this family are facultative anaerobes, able to ferment sugars to lactic acid, have nitrate reductase, but lack oxidases. Even though many clinical pathogens are part of the order Enterobacterales, most members of this family are plant pathogens. D. dadantii is a motile, non-sporing, straight rod-shaped cell with rounded ends, much like the other members of the genus, Dickeya. Cells range in size from 0.8 to 3.2 μm by 0.5 to 0.8 μm and are surrounded by numerous flagella (peritrichous).
Burkholderia 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 Thailand and northern Australia. It was reported in 2008 that there had been an expansion of the affected regions due to significant natural disasters, and it could be found in Southern China, Hong Kong, and countries in the Americas. B. pseudomallei, amongst other pathogens, has been found in monkeys imported into the United States from Asia for laboratory use, posing a risk that the pathogen could be introduced into the country.
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 cepacia complex (Bcc) and is notable due to its virulence factors and inherent antibiotic resistance that render it a prominent opportunistic pathogen responsible for life-threatening, nosocomial infections in immunocompromised patients, such as those with cystic fibrosis or chronic granulomatous disease. The quorum sensing systems CepIR and CciIR regulate the formation of biofilms and the expression of virulence factors such as siderophores and proteases. Burkholderia cenocepacia may also cause disease in plants, such as in onions and bananas. Additionally, some strains serve as plant growth-promoting rhizobacteria.
Xanthomonas campestris is a gram-negative, obligate aerobic bacterium that is a member of the Xanthomonas genus, which is a group of bacteria that are commonly known for their association with plant disease. This species includes Xanthomonas campestris pv. campestris, the cause of black rot in brassicas, one of the most important diseases of brassicas worldwide.
Medical microbiology, the large subset of microbiology that is applied to medicine, is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies various clinical applications of microbes for the improvement of health. There are four kinds of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses, and one type of infectious protein called prion.
Pseudomonas syringae is a rod-shaped, Gram-negative bacterium with polar flagella. As a plant pathogen, it can infect a wide range of species, and exists as over 50 different pathovars, all of which are available to researchers from international culture collections such as the NCPPB, ICMP, and others.
Ralstonia is a genus of bacteria, previously included in the genus Pseudomonas. It is named after the American bacteriologist Ericka Ralston. Ericka Ralston was born in 1944 in Saratoga, California, and died in 2015 in Sebastopol, California. While in graduate school at the University of California at Berkeley, she identified 20 strains of Pseudomonas which formed a phenotypical homologous group, and named them Pseudomonas pickettii, after M.J. Pickett in the Department of Bacteriology at the University of California at Los Angeles, from whom she had received the strains. Later, P. pickettii was transferred to the new genus Ralstonia, along with several other species. She continued her research into bacterial pathogenesis under the name of Ericka Barrett while a professor of microbiology at the University of California at Davis from 1977 until her retirement in 1996.
Xanthomonas is a genus of bacteria, many of which cause plant diseases. There are at least 27 plant associated Xanthomonas spp., that all together infect at least 400 plant species. Different species typically have specific host and/or tissue range and colonization strategies.
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Xanthomonas vasicola pv. vasculorum (Xvv) is a gram-negative rod-shaped bacterium which has a single polar flagellum. It is a plant pathogen, causing both bacterial leaf streak of maize (corn) and sugarcane gumming disease. One outbreak in eucalyptus has been reported. Under experimental conditions it can infect sorghum, oats and some grass species. It is not currently a quarantine pathogen in any country, but it has already spread outside its native range and is highly adaptable to different environments.
Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and many are beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. By contrast, several thousand species are part of the gut flora present in the digestive tract.
Black rot, caused by the bacterium Xanthomonas campestris pv. campestris (Xcc), is considered the most important and most destructive disease of crucifers, infecting all cultivated varieties of brassicas worldwide. This disease was first described by botanist and entomologist Harrison Garman in Lexington, Kentucky, US in 1889. Since then, it has been found in nearly every country in which vegetable brassicas are commercially cultivated.
In biology, a pathogen, 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.
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