Burkholderia gladioli

Taxobox
color = lightgrey
name = "Burkholderia gladioli"
regnum = Bacteria
phylum = Proteobacteria
classis = Beta Proteobacteria
ordo = Burkholderiales
familia = Burkholderiaceae
genus = Burkholderia
species = "B. gladioli"
binomial = "Burkholderia gladioli"
binomial_authority = (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 gladioli" Severini 1913
"Burkholderia cocovenenans" (van Damme "et al". 1960) Gillis "et al".
"Pseudomonas cocovenenans" van Damme "et al". 1960
"Pseudomonas antimicrobica" Attafuah and Bradbury 1990
"Pseudomonas marginata" (McCulloch) Stapp
"Pseudomonas farinofermentans" Naixin
"Pseudomonas alliicola" (Burkholder 1942) Starr and Burkholder 1942

Formally "Pseudomonas marginata"

Introduction

The genus "Burkholderia" was previously named "Pseudomonas". The genus "Burkholderia" is one of the seven genera that arose when the "Pseudomonas" genus was divided based on rRNA differences. [Prescott, L. M., Harley, J. P., & Klein, D. A. (2005). Bacteria: The Proteobacteria. In Microbiology, 6th Edition (pp. 482-483). New York: McGraw-Hill. ] . "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 three pathovars: pv. "gladioli", pv. "allicola", and pv. "agaricicola". "B. gladioli" pv. "gladioli" causes gladiolus rot, "B. gladioli" pv. "alliicola" causes onion bulb rot, and "B. gladioli" pv. "agaricicola" causes soft rot in mushrooms [Jiao, Zhenquan, et al. (2003). Need to Differentiate Lethal Toxin-Producing Strains of Burkholderia gladioli, Which Cause Seere Food Poisoning: Description of B. gladioli Pathovar cocovenenans and an Emended Description of B. gladioli. Microbiol. Immunol, 915-925. ]

Habitat

"Burkholderia" can be found in the soil, in water, in the rhizosphere, in animals, and in humans. Many are either plant or animal pathogens, and some live in symbiosis with plants and fungi. Stoyanova, M., Pavlina, I., Moncheva, P., & Bogatzevska, N. (2007, March). Biodiversity and Incidence of Burkholderia Species. Biotechnol. & Biotechnol. Eq., 47: 306-310. ]

Identification

"Burkholderia" are motile, Gram negative rods that may be straight of slightly curved. The 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 Coenye, Tom, and Vandamme, Peter. (2007). Burkholderia: Molecular Microbiology and Genomics. Horizon Bioscience] "B. gladioli" is indole negative, nitrate negative, and lysine decorboxylation negative [ Graves, Margot, et al. (1997, October). Four Additional Cases of Burkholderia gladioli Infection with Microbiological Correlates and Review. CID. 838-842.]

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. Furuya, Naruto. (2002). Specific Oligonucleotide Primers Based on Sequences of the 16S-23S rDNA Spacer Region for the Detection of Burkholderia gladioli by PCR. J. Gen. Plant Pathol. 68:220-224 ]

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 300bp.

Genomics

All members of the "Burkholderia" genus 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 the "Burkholderia" genus 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 ditected this way encoded for virulence.

Phytopathology

"Burkholderia gladioli" is a plant pathogen. Strains have been isolated from onions, Gladiolus, Iris, and rice. It was originally described to have caused rot of gladiolus corms. The bulbs can become watersoaked and decay.

Some other common symptoms of infected plants can be seen in the leaves. The leaves contain brown legions, 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 "Burkholderia 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. [http://web.aces.uiuc.edu/vista/pdf_pubs/651.pdf]

Human Pathogenesis

"Burkholderia gladioli" is an opportunistic pathogen that has become an important agent for nosocomial infections. It has recently appeared as a severe pathogen in patients with cystic fibrosis, causing severe pulmonary infections , and it has also colonized in the respiratoy tracts of patients with granulomatous disease. These infections can be lethal.

"B. gladioli" colonization in the airways of lung transplant patients can be fatal. Patients have developed bacteremia and sterile wound infections as a result. [www.chestjournal.org/cgi/reprint/114/2/658.pdf]

Links

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=88710

http://www.emedicine.com/med/topic3459.htm

References