LRMoore, Univ of Southern Maine: Difference between revisions

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===Higher order taxa===
===Higher order taxa===


Domain (Bacteria); Phylum (Spirochaetes); Class (Spirochaetes); Order (Spirochaetales); Family (Borreliaceae); Genus (Borrelia)
Domain (Bacteria); Phylum (Proteobacteria); Class (Gammaproteobacteria); Order (Enterobacteriales); Family (Enterobacteriaceae); Genus (Rahnella)


===Species===
===Species===
[[Image:Adbacterial.jpg‎|frame|right|150px|PUT FIGURE LEGEND HERE ALONG WITH THE REFERENCE]]
Species (aquatilis)


''Borrelia recurrentis''
''Rahnella aquatilis''


==Description and significance==
==Description and significance==
Borrelia recurrentis is the causative agent of louse borne relapsing fever (LBRF) and is closely related to the bacteria B. duttonii, the source of tick borne relapsing fever. A recent genomic study of the two strains of bacteria found that B. recurrentis is actually a subset of B. duttonii in which the genes of the latter underwent a decaying process that gave rise to B. recurrentis. This process could be due to the inactivation of genes encoding for DNA repair mechanisms (recA and mutS), causing an accumulation of errors in the genome [5]. B. recurrentis is the cause of systemic inflammatory disease, characterized by one to five fever relapses, distinctive hemorrhagic syndrome, a high rate of spontaneous abortion in pregnant women, and a 2-4% mortality rate despite modern antibiotics. B.recurrentis is unlike its counter part (B. duttonii), which produces more relapses and a lower mortality rate [5,6].B. recurrentis is a slender, pathogenic spirochete whose habitat is usually associated with humans and is vector borne via lice. LBRF was once a world wide epidemic, but over the last century has since been eradicated due to better personal hygiene and way of living [1]. Now the disease is prevalent in areas that have major lice problems such as the Andean foothills, the highlands of eastern Africa, southern Sudan, and Rwanda [1,2]. The lice become infected by feeding on humans that are infected by the spirochetes. When the lice are transferred to another human, the infection spreads by the contact of the hemolymph (the fluid found in the circulatory system of arthropods) with abraded skin. This contact can occur by scratching, which then opens the skin and crushes the body of the lice, exposing the hemolymph. New evidence suggests that another means of infection can occur through contact with infected feces [2,4].
Rahnella aquatilis is a relatively rare gram-negative rod-shaped bacteria which has been found in fresh water, soil, certain animals such as snails [5] and certain beetles, [4] and isolated human clinical specimens. [2] This bacterium is of importance because of its abundance and its disease-causing ability in humans. Many different strains have been isolated, and presumably more will be disocvered.


==Genome structure==
==Genome structure==
According to JGI Genome encyclopedia, the fully sequenced bacteria Borrelia recurrentis has a genome with 1025 genes and 1,242,163 base pairs which contain 8 linear fragments ranging from 6,131 bp to 930,981bp [3, 5].This is quite atypical of prokaryotes since they are normally seen having a single, circular chromosome.  B. recurrentis contains a linear chromosome with a size of approximately 1Mb (27.5 GC%) along with both linear (7) and circular plasmids. All strains contain one large plasmid anywhere from 183 to 194kb as well a small one (11kb). Strains have 5 main differences in the pattern of the other plasmids, which range in size from 25kb to 62kb [2].
As of the year 2000, at least 70 strains of Rahnella aquatilis have been identified [1].  According to the National Center for Biotechnology Information (NCBI), the whole genome has been sequenced for R. aquatilis Strain Y9602.  This particular strain has a genome consisting of 4,864,217 basepairs, with two identified plasmids [2]. Another strain, Rahnella aquatilis CUETM 77-115, was shown to have a genome consisting of 5,440,269 basepairs, and had a G-C content of 52.1% [3].


==Cell and colony structure==
==Cell and colony structure==
Electron microscopy has revealed B. recurrentis as a spirochetal cell with pointed ends containing 8-10 periplasmic flagella, an average wavelength of 1.8 pm and an amplitude of 0.8 pm (fig 1)[2]. Because of the flagella, this is a motile bacterium which leads to greater spreading in the bloodstream of the host. Contrary to most pathogenic bacteria, B. recurrentis is gram negative.
Rahnella aquatilis is gram-negative rod-shaped bacterium, about 2-3 microns in length. Strain ISL 19 was isolated from soybean rhizosphere, and was seen to have several flagella for motility [6]. The bacterium can be readily cultured in the laboratory.  


==Metabolism==
==Metabolism==
This microaerophilic microbe is also mesophilic (it prefers moderate temperatures of 68-113o F), where the human host provides perfect conditions for the bacteria to thrive [3]. It is also an auxotroph for most amino acids, meaning that it is unable to produce them itself and absorbs them from the environment instead [3].
Rahnella aquatilis is a facultative anaerobe (it can live in the absence or presence of oxygen) that fixes Nitrogen [2]. R. aquatilis metabolizing whey lactose produces high levels of organic acids (except for lactic acid) [7].      


==Ecology==
==Ecology==
B. recurrentis is known for its inhabitance in human hosts and has only successfully been able to infect primates.
Rahnella aquatilis is named so because of its prevalence in fresh water.  It has been found around the globe in places like the United States, Korea, Japan, Russia, the Ukraine, and Egypt.  R. aquatilis has also been found in humans, soil,  and snails [5]. One of the most unusual places for the the microbe to have been found was inside the gut of certain speicies of longicorn beetles in Korea [4].
 


==Pathology==
==Pathology==
These spirochaetes normally cause a blood infection but they can also infect the nervous system along with other tissues [5]. There are no known virulence factors, but there are a few novel ways that this sneaky pathogen evades the host immune system [5]. The body has its way of recognizing and enhancing the recognition of foreign invaders called opsonization, which targets them for destruction through a cascade of reactions known as the complement system. Recent studies show that B. recurrentis expresses a multifunctional surface lipoprotein, termed HcpA, that exploits the host’s proteins and offers resistance to complement attack and opsonization while increasing the potential to invade the host’s tissues [6]. Since HcpA outlines the high virulence potential of B. recurrentis, it makes a good target for therapeutic treatment of LBRF, however, none have been created yet. It was also found that this spirochete binds to the PLG(human plasminogen/Plasmin) receptor on endothelium cells and exploits their increased proteolytic capacity to breach tight junctions of endothelium, cross basement membranes, and to initiate patho-physiological processes in the affected organs [6]. Another novel approach is its ability to undergo antigenic variation, meaning that once the innate immune system is able to identify and start fighting off the first antigenic type, another antigenic type appears. This impairs the host immunes system from being able to clear the infection and explains why there are multiple recurrences of fever [6]. To treat LBRF, tetracyclines and penicillins are commonly used and are usually quite effective; however they may cause a severe Jarisch-Herxheimer reaction, which can be fatal [1] . This reaction causes fever, chills, rigor, hypotension, headache, tachycardia, hyperventilation, vasodilation with flushing, myalgia (muscle pain), and exacerbation of skin lesions because the death of the bacteria causes the release of harmful endotoxins faster than the body can get rid of them.
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==
==References==
[1] Houhamdi, Linda, and Didier Raoult. "Excretion Living Borrelia recurrentis in Feces of Infected Human Body Lice." Journal of Infectious Diseases. 191.11 (2005): 1898-1906.  
[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.  


[2] Cutler, S.J, J. Moss, M. Fukunaga, D.J.M. Wright, D. Fekade, and D. Warrel. "Borrelia recurrentis Characterization and Comparison with Relapsing-Fever, Lyrne-Associated, and Other Borrelia spp.." International Journal of Systematic Bacteriology. 47.4 (1997): 958-968.  
[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.


[3] "Borrelia recurrentis A1." Genomic Encyclopedia of Bacteria and Archaea Genomes. 3.5. California: Doe Joint Genome Institute, 2012. 1 Mar 2012. <http://img.jgi.doe.gov/cgi-bin/m/main.cgi>
[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.


[4] Cutler, J.S, A. Abdissa, and J.F. Trape. "New concepts for the old challenge of African relapsing fever borreliosis." Clinical Microbiology & Infection. 15.5 (2009): 400-406. 5 Mar. 2012. DOI:10.1111/j.1469-0691.2009.02819.x
[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.
[5] Magali, Lescot, Stephane Audic, Catherine Robert, et al. "The Genome of Borrelia recurrentis, the Agent of Deadly Louse- Borne Relapsing Fever, Is a Degraded Subset of Tick-Borne Borrelia duttonii." PLoS Genetics. 4.9 (2008): 1-12. 5 Mar. 2012. DOI:10.1371/journal.pgen.1000185


[9] Tash, Kaley. "Rahnella aquatilis Bacteremia from a Suspected Urinary Source." Journal of Clinical Microbiology. May 2005, vol. 43 no. 5, 2526-2528.


[6] Grosskinsky, Sonja, Melanie Schott, Christiane Brenner, et al. "Borrelia recurrentis Employs a Novel Multifunctional Surface Protein with Anti-Complement, Anti-Opsonic and Invasive Potential to Escape Innate Immunity." PLoS ONE. 4.3 (2009): 1-13. 5 Mar. 2012. DOI:10.1371/journal.pone.0004858






Edited by Cassandra Terry of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences, http://www.usm.maine.edu/bio
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

Revision as of 05:18, 3 May 2012

This student page has not been curated.

A Microbial Biorealm page on the genus LRMoore, Univ of Southern Maine

Classification

Higher order taxa

Domain (Bacteria); Phylum (Proteobacteria); Class (Gammaproteobacteria); Order (Enterobacteriales); Family (Enterobacteriaceae); Genus (Rahnella)

Species

Species (aquatilis)

Rahnella aquatilis

Description and significance

Rahnella aquatilis is a relatively rare gram-negative rod-shaped bacteria which has been found in fresh water, soil, certain animals such as snails [5] and certain beetles, [4] and isolated human clinical specimens. [2] This bacterium is of importance because of its abundance and its disease-causing ability in humans. Many different strains have been isolated, and presumably more will be disocvered.

Genome structure

As of the year 2000, at least 70 strains of Rahnella aquatilis have been identified [1]. According to the National Center for Biotechnology Information (NCBI), the whole genome has been sequenced for R. aquatilis Strain Y9602. This particular strain has a genome consisting of 4,864,217 basepairs, with two identified plasmids [2]. Another strain, Rahnella aquatilis CUETM 77-115, was shown to have a genome consisting of 5,440,269 basepairs, and had a G-C content of 52.1% [3].

Cell and colony structure

Rahnella aquatilis is gram-negative rod-shaped bacterium, about 2-3 microns in length. Strain ISL 19 was isolated from soybean rhizosphere, and was seen to have several flagella for motility [6]. The bacterium can be readily cultured in the laboratory.

Metabolism

Rahnella aquatilis is a facultative anaerobe (it can live in the absence or presence of oxygen) that fixes Nitrogen [2]. R. aquatilis metabolizing whey lactose produces high levels of organic acids (except for lactic acid) [7].

Ecology

Rahnella aquatilis is named so because of its prevalence in fresh water. It has been found around the globe in places like the United States, Korea, Japan, Russia, the Ukraine, and Egypt. R. aquatilis has also been found in humans, soil, and snails [5]. One of the most unusual places for the the microbe to have been found was inside the gut of certain speicies of longicorn beetles in Korea [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