Gluconobacter morbifer G707
A Microbial Biorealm page on the genus Gluconobacter morbifer G707
Classification
Higher order taxa
Bacteria; Proteobacteria; Alphaproteobacteria; Rhodospirillales; Acetobacteraceae; Gluconobacter [1]
Species
Gluconobacter morbifer G707 [1]
Description and significance
Gluconobacter morbifer G707 is a non-motile, aerobic, rod-shaped bacteria found in Seoul, South Korea [2]. Isolated from the gastrointestinal tract of the fruit fly Drosophila melanogaster, this bacteria is described as being a commensal symbiont [2]; however, research on the fruit fly’s gut commensal community provides evidence that an abundance of G. morbifer causes apoptosis of gut cells and an early death to its host [3]. In immune-deregulated hosts, G. morbifer is associated with the unique trait of pathogenesis promotion, making this bacteria’s genome sequence particularly valuable in furthering scientific understanding of bacterial pathogenesis in varying host environs [4].
Genome structure
The G. morbifer G707 genome contains 2,899 genes, 50 of which are RNA genes [2]. G+C genome content is 59.04% over 19 DNA scaffolds, all of which are linear [2].
Cell and colony structure
G. morbifer are nonsporulating, rod-shaped bacteria measuring 0.7 by 1.8 to 2.0 um, with circular, pink colonies measuring 1.0 to 1.5 mm in diameter (at 25 degree C and aerobic conditions maintained over the course of a two day period on mannitol-agar) [3]. Some cells stain positive while others stain negative, making this a variable Gram staining bacteria [3]. 3.6 to 7.8 is the recognized optimal pH range for growth [3].
Metabolism
G. morbifer exhibits aerobic respiration using an Ubiquinol oxidation pathway with oxygen and proton transport [2]. G. morbifer is generally auxotrophic, meaning it is unable to manifest many of its own nutritional requirements—like metabolits and amino acids—for growth; however, it is prototrophic for L-aspartate and L-glutamate [2]. This bacteria also is characterized as having an incomplete Coenzyme A biosynthesis [2].
Ecology
G707, originally isolated in Seoul, South Korea, exhibit endosymbiotic extracellular physical interactions, living commensally within the intestinal microflora of the fruit fly Drosophila melanogaster [2]. Despite being described as commensal, the symbiotic relationship between G. morbifer and host is ultimately dependent upon the condition of the host’s immunity; the strain will display dominance when the host’s immune homeostasis is compromised, resulting in pathology and gradual host opportunistic infection [4].
Pathology
Rahnella aquatilis is pathogenic in humans. The organism can be diagnosed in patients via blood cultures, respiratory washings, and in wound cultures. Various infections, such as bacteremia (from renal infection), sepsis, respiratory infection, and urinary tract infection can be the result. One case involved an 11-month-old girl with congenital heart disease who developed infective endocarditis [8]. Another case involved a 76-year-old male who had prostatic hyperplasia presenting with acute pyelonephritis [9]. It is noted that R. aquatilis can potentially cause life-threatening infections in humans, infants and adults alike, especially the immunocompromised and organ transplant recipients. Treatments have included intravenous and oral levofloxacin therapy (and other members of the quinolone family).
References
[1] J Chemother. 2000 Feb;12(1):30-9. <http://www.ncbi.nlm.nih.gov/pubmed/10768513>
[2] R.J. Martinez. J Bacteriol. 2012 Apr;194(8):2113-4. <http://www.ncbi.nlm.nih.gov/genome/?term=Rahnella%20aquatilis>
[3] Robert Martinez, University of Alabama. <http://genome.jgi-psf.org/rahac/rahac.info.html>
[4] Park, Doo-Sang, Hyun-Woo Oh, Won-Jin Jeong, et al. "A Culture-Based Study of the Bacterial Communities within the Guts of Nine Longicorn Beetle Species and their Exo-enzyme Producing Properties for Degrading Xylan and Pectin." The Journal of Microbiology, October 2007, p. 394-401.
[5] Brenner, Don J., Hans E. Muller, Arnold G. Steigerwalt, et al. "Two new Rahnella genomospecies that cannot be phenotypically differentiated from Rahnella aquatilis." lnternstional Journal of Systematic Bacteriology (1 998), 48, 141 -149.
[6] Kim, Kil Yong, Diann Jordan, and Hari B. Krishnan. "Rahnella aquatilis, a bacterium isolated from soybean rhizosphere, can solubilize hydroxyapatite." FEMS Microbiology Letters Volume 153, Issue 2, 15 August 1997, Pages 273–277.
[7] Pintado, Manuela E., Ana I.E. Pintado, and F. Xavier Malcata. "Fate of Nitrogen During Metabolism of Whey Lactose by Rahnella aquatilis." Journal of Dairy Science, Volume 82, Issue 11, November 1999, Pages 2315-2326.
[8] Matsukura H., Katayama K., Kitano N., et al. "Infective endocarditis caused by an unusual gram-negative rod, Rahnella aquatilis." Pediatric Cardiology, 1996 Mar-Apr; 17(2): 108-11.
[9] Tash, Kaley. "Rahnella aquatilis Bacteremia from a Suspected Urinary Source." Journal of Clinical Microbiology. May 2005, vol. 43 no. 5, 2526-2528.
Edited by Christopher John Connor, student of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences, http://www.usm.maine.edu/bio
