| Scanning electron micrograph of Leptospira interrogans.|
Scanning electron micrograph of Leptospira interrogans.
Leptospira (from the Greek leptos, meaning fine or thin, and the Latin spira, meaning coil) is a genus of spirochaete bacteria, including a small number of pathogenic and saprophytic species. Leptospira was first observed in 1907 in kidney tissue slices of a leptospirosis victim who was described as having died of "yellow fever."
Leptospira, together with the genera Leptonema and Turneria, is a member of the family Leptospiraceae. The genus Leptospira is divided into 17 genomospecies based on DNA hybridization studies. However, at least one additional species which is yet to be named has been identified.
Known pathogenic Leptospira
- Leptospira interrogans
- Leptospira kirschneri
- Leptospira noguchii
- Leptospira alexanderi
- Leptospira weilii
- Leptospira genomospecies 1,
- Leptospira borgpetersenii
- Leptospira santarosai
Intermediates or opportunistic Leptospira
- Leptospira inadai
- Leptospira fainei
- Leptospira broomii
- Leptospira biflexa
- Leptospira meyeri
- Leptospira wolbachii
- Leptospira genomospecies 3
- Leptospira genomospecies 4
- Leptospira genomospecies 5
Members of Leptospira are also grouped into serovars according to their antigenic relatedness. There are currently over 200 recognized serovars. A few serovars are found in more than one species of Leptospira.
At its 2002 meeting, the Committee on the Taxonomy of Leptospira of the International Union of Microbiological Societies approved the following nomenclature for serovars of Leptospira. Genus and species must of course be italicized, with the serovar name not italicized and with an upper case first letter.
- Genus species serovar Serovar_name
- Leptospira interrogans serovar Australis
- Leptospira biflexa serovar Patoc
Although over 200 serovars of Leptospira have been described, all members of the genus have similar morphology. Leptospira are spiral-shaped bacteria that are 6-20 μm long and 0.1 μm in diameter with a wavelength of about 0.5 μm. One or both ends of the spirochete are usually hooked. Because they are so thin, live Leptospira are best observed by darkfield microscopy.
The bacteria have a number of freedom degrees; when ready to proliferate via binary fission, the bacterium noticeably bends in the place of the future split.
Leptospira have a Gram-negative-like cell envelope consisting of a cytoplasmic and outer membrane. However, the peptidoglycan layer is associated with the cytoplasmic rather than the outer membrane, an arrangement that is unique to spirochetes. The two flagella of Leptospira extend from the cytoplasmic membrane at the ends of the bacteria into the periplasmic space and are necessary for the motility of Leptospira.
The outer membrane contains a variety of lipoproteins and transmembrane outer membrane proteins. As expected, the protein composition of the outer membrane differs when comparing Leptospira growing in artificial medium with Leptospira present in an infected animal. Several leptospiral outer membrane proteins have been shown to attach to the host extracellular matrix and to factor H. These proteins may be important for adhesion of Leptospira to host tissues and in resisting complement, respectively.
The outer membrane of Leptospira, like those of most other Gram-negative bacteria, contains lipopolysaccharide (LPS). Differences in the highly immunogenic LPS structure account for the numerous serovars of Leptospira.. Consequently, immunity is serovar specific; current leptospiral vaccines, which consist of one or several serovars of Leptospira endemic in the population to be immunized, protect only against the serovars contained in the vaccine preparation. Leptospiral LPS has low endotoxin activity.. An unusual feature of leptospiral LPS is that it activates host cells via TLR2 rather than TLR4. The unique structure of the lipid A portion of the LPS molecule may acccount for this observation. Finally, the LPS O antigen content of L. interrogans differs in an acutely infected versus a chronically infected animal. The role of O antigen changes in the establishment or maintenance of acute or chronic infection, if any, is unknown.
Leptospira, both pathogenic and saprotrophic, can occupy diverse environments, habitats and life cycles; it generally recognized these bacteria are virtually ubiquitous in terms of geographic distribution (present everywhere except Antarctica).
Most of Leptospira, however, are hydrophilic - high humidity and neutral (6.9-7.4) pH are essential for their survival in the environment, with stagnant water reservoirs - bogs, shallow lakes, ponds, puddles, etc - being natural placeholder for the bacteria.
Leptospira are typically cultivated at 30 °C in Ellinghausen-McCullough-Johnson-Harris (EMJH) medium, which can be supplemented with 0.2-1% rabbit serum to enhance growth of fastidious strains. Growth of pathogenic Leptospira in an artificial nutrient environment such as EMJH becomes noticeable in 4-7 days; growth of saprophytic strains occur within 2-3 days. The minimal growth temperature of pathogenic species is 13-15 °C. Because the minimal growth temperature of the saprophytes is 5-10 °C, the ability of Leptospira to grow at 13 °C can be used to distinguish saprophytic from pathogenic Leptospira species. The optimal pH for growth of Leptospira is 7.2-7.6.
Leptospira are aerobes whose major carbon and energy source during in vitro growth is long-chain fatty acids, which are metabolized by beta-oxidation. Fatty acids are provided in EMJH in the form of Tween. Fatty acid molecules are bound by albumin in EMJH and are released slowly into the medium to prevent its toxic accumulation.
Like most bacteria, Leptospira require iron for growth. L. interrogans and L. biflexa have the ability to acquire iron in different forms. A TonB-dependent receptor required for utilization of the ferrous form of the iron has been identified in L. biflexa, and an ortholog of the receptor is encoded in the genome of L. interrogans. L. interrogans can also obtain iron from heme, which is bound to most of the iron in the human body. The HbpA hemin-binding protein, which may be involved in the uptake of hemin, has been identified on the surface of L. interrogans Although other pathogenic species of Leptospira and L. biflexa lack HbpA, yet another hemin-binding protein, LipL41, may account for their ability to use hemin as a source of iron. Although they do not secrete siderophores, L. biflexa and L. interrogans may be capable of obtaining iron from siderophores secreted by other microorganisms.
The genome of pathogenic Leptospira consists of two chromosomes. The size of the genomes of L. interrogans serovars Copenhageni and Lai is approximately 4.6 Mb. However, the genome of L. borgpetersenii serovar Hardjo is only 3.9 Mb in size with a large number of pseudogenes, gene fragments, and insertion sequences relative to the genomes of L. interrogans. L. borgpetersenii serovar Hardjo is usually transmitted by direct exposure to infected tissues, whereas L. interrogans is often acquired from water or soil contaminated by the urine of carrier animals harboring Leptospira in their kidneys. The high number of defective genes and insertion sequences in L. borgpetersenii Hardjo together with the poor survival outside of the host and difference in transmission patterns compared to L. interrogans suggest that L. borgpetersenii is undergoing insertion-sequence mediated genomic decay, with ongoing loss of genes necessary for survival outside of the host animal.
- ↑ leptospirosis. American Heritage® Dictionary of the English Language: Fourth Edition. Bartleby.com (2000). Retrieved on 2007-05-13.
- ↑ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0-8385-8529-9.
- ↑ Stimson AM (1907). "Note on an organism found in yellow-fever tissue." Public Health Reports 22:541.
- ↑ Brenner DJ, Kaufmann AF, Sulzer KR, Steigerwalt AG, Rogers FC, Weyant RS (1999). "Further determination of DNA relatedness between serogroups and serovars in the family Leptospiraceae with a proposal for Leptospira alexanderi sp. nov. and four new Leptospira genomospecies". Int. J. Syst. Bacteriol. 49 Pt 2: 839–58. PMID 10319510.
- ↑ Bharti AR, Nally JE, Ricaldi JN, Matthias MA, Diaz MM, Lovett MA, Levett PN, Gilman RH, Willig MR, Gotuzzo E, Vinetz JM (2003). "Leptospirosis: a zoonotic disease of global importance". The Lancet infectious diseases 3 (12): 757–71. PMID 14652202.
- ↑ Levett PN, Morey RE, Galloway RL, Steigerwalt AG (2006). "Leptospira broomii sp. nov., isolated from humans with leptospirosis". Int. J. Syst. Evol. Microbiol. 56 (Pt 3): 671–3. doi:10.1099/ijs.0.63783-0. PMID 16514048.
- ↑ Ganoza CA, Matthias MA, Collins-Richards D, Brouwer KC, Cunningham CB, Segura ER, Gilman RH, Gotuzzo E, Vinetz JM (2006). "Determining risk for severe leptospirosis by molecular analysis of environmental surface waters for pathogenic Leptospira". PLoS Med. 3 (8): e308. doi:10.1371/journal.pmed.0030308. PMID 16933963.
- ↑ 8.0 8.1 8.2 Levett PN (2001). "Leptospirosis". Clin. Microbiol. Rev. 14 (2): 296–326. doi:10.1128/CMR.14.2.296-326.2001. PMID 11292640.
- ↑ Picardeau M, Brenot A, Saint Girons I (2001). "First evidence for gene replacement in Leptospira spp. Inactivation of L. biflexa flaB results in non-motile mutants deficient in endoflagella". Mol. Microbiol. 40 (1): 189–99. PMID 11298286.
- ↑ Cullen PA, Cordwell SJ, Bulach DM, Haake DA, Adler B (2002). "Global analysis of outer membrane proteins from Leptospira interrogans serovar Lai". Infect. Immun. 70 (5): 2311–8. PMID 11953365.
- ↑ Haake DA, Martinich C, Summers TA, Shang ES, Pruetz JD, McCoy AM, Mazel MK, Bolin CA (1998). "Characterization of leptospiral outer membrane lipoprotein LipL36: downregulation associated with late-log-phase growth and mammalian infection". Infect. Immun. 66 (4): 1579–87. PMID 9529084.
- ↑ Palaniappan RU, Chang YF, Jusuf SS, Artiushin S, Timoney JF, McDonough SP, Barr SC, Divers TJ, Simpson KW, McDonough PL, Mohammed HO (2002). "Cloning and molecular characterization of an immunogenic LigA protein of Leptospira interrogans". Infect. Immun. 70 (11): 5924–30. PMID 12379666.
- ↑ Nally JE, Whitelegge JP, Bassilian S, Blanco DR, Lovett MA (2007). "Characterization of the outer membrane proteome of Leptospira interrogans expressed during acute lethal infection". Infect. Immun. 75 (2): 766–73. doi:10.1128/IAI.00741-06. PMID 17101664.
- ↑ Verma A, Hellwage J, Artiushin S, Zipfel PF, Kraiczy P, Timoney JF, Stevenson B (2006). "LfhA, a novel factor H-binding protein of Leptospira interrogans". Infect. Immun. 74 (5): 2659–66. doi:10.1128/IAI.74.5.2659-2666.2006. PMID 16622202.
- ↑ Barbosa AS, Abreu PA, Neves FO, Atzingen MV, Watanabe MM, Vieira ML, Morais ZM, Vasconcellos SA, Nascimento AL (2006). "A newly identified leptospiral adhesin mediates attachment to laminin". Infect. Immun. 74 (11): 6356–64. doi:10.1128/IAI.00460-06. PMID 16954400.
- ↑ Choy HA, Kelley MM, Chen TL, Møller AK, Matsunaga J, Haake DA (2007). "Physiological osmotic induction of Leptospira interrogans adhesion: LigA and LigB bind extracellular matrix proteins and fibrinogen". Infect. Immun. 75 (5): 2441–50. doi:10.1128/IAI.01635-06. PMID 17296754.
- ↑ Werts C, Tapping RI, Mathison JC, Chuang TH, Kravchenko V, Saint Girons I, Haake DA, Godowski PJ, Hayashi F, Ozinsky A, Underhill DM, Kirschning CJ, Wagner H, Aderem A, Tobias PS, Ulevitch RJ (2001). "Leptospiral lipopolysaccharide activates cells through a TLR2-dependent mechanism". Nat. Immunol. 2 (4): 346–52. doi:10.1038/86354. PMID 11276206.
- ↑ Que-Gewirth NL, Ribeiro AA, Kalb SR, Cotter RJ, Bulach DM, Adler B, Girons IS, Werts C, Raetz CR (2004). "A methylated phosphate group and four amide-linked acyl chains in Leptospira interrogans lipid A. The membrane anchor of an unusual lipopolysaccharide that activates TLR2". J. Biol. Chem. 279 (24): 25420–9. doi:10.1074/jbc.M400598200. PMID 15044492.
- ↑ Nally JE, Chow E, Fishbein MC, Blanco DR, Lovett MA (2005). "Changes in lipopolysaccharide O antigen distinguish acute versus chronic Leptospira interrogans infections". Infect. Immun. 73 (6): 3251–60. doi:10.1128/IAI.73.6.3251-3260.2005. PMID 15908349.
- ↑ Madigan M; Martinko J (editors). (2005). Brock Biology of Microorganisms, 11th ed., Prentice Hall. ISBN 0-13-144329-1.
- ↑ 21.0 21.1 21.2 Johnson RC, Harris VG (1967). "Differentiation of pathogenic and saprophytic letospires. I. Growth at low temperatures". J. Bacteriol. 94 (1): 27–31. PMID 6027998.
- ↑ Johnson RC, Gary ND (1963). "Nutrition of Leptospira pomona. II. Fatty acid requirements". J. Bacteriol. 85: 976–82. PMID 14044026.
- ↑ Henneberry RC, Cox CD (1970). "Beta-oxidation of fatty acids by Leptospira". Can. J. Microbiol. 16 (1): 41–5. PMID 5415967.
- ↑ Faine S (1959). "Iron as a growth requirement for pathogenic Leptospira". J. Gen. Microbiol. 20 (2): 246–51. PMID 13654718.
- ↑ 25.0 25.1 Louvel H, Bommezzadri S, Zidane N, Boursaux-Eude C, Creno S, Magnier A, Rouy Z, Médigue C, Saint Girons I, Bouchier C, Picardeau M (2006). "Comparative and functional genomic analyses of iron transport and regulation in Leptospira spp". J. Bacteriol. 188 (22): 7893–904. doi:10.1128/JB.00711-06. PMID 16980464.
- ↑ 26.0 26.1 Asuthkar S, Velineni S, Stadlmann J, Altmann F, Sritharan M (2007). "Expression and characterization of an iron-regulated hemin-binding protein, HbpA, from Leptospira interrogans serovar Lai". Infect. Immun. 75 (9): 4582–91. doi:10.1128/IAI.00324-07. PMID 17576761.
- ↑ Ren SX, Fu G, Jiang XG, Zeng R, Miao YG, Xu H, Zhang YX, Xiong H, Lu G, Lu LF, Jiang HQ, Jia J, Tu YF, Jiang JX, Gu WY, Zhang YQ, Cai Z, Sheng HH, Yin HF, Zhang Y, Zhu GF, Wan M, Huang HL, Qian Z, Wang SY, Ma W, Yao ZJ, Shen Y, Qiang BQ, Xia QC, Guo XK, Danchin A, Saint Girons I, Somerville RL, Wen YM, Shi MH, Chen Z, Xu JG, Zhao GP (2003). "Unique physiological and pathogenic features of Leptospira interrogans revealed by whole-genome sequencing". Nature 422 (6934): 888–93. doi:10.1038/nature01597. PMID 12712204.
- ↑ Nascimento AL, Ko AI, Martins EA, Monteiro-Vitorello CB, Ho PL, Haake DA, Verjovski-Almeida S, Hartskeerl RA, Marques MV, Oliveira MC, Menck CF, Leite LC, Carrer H, Coutinho LL, Degrave WM, Dellagostin OA, El-Dorry H, Ferro ES, Ferro MI, Furlan LR, Gamberini M, Giglioti EA, Góes-Neto A, Goldman GH, Goldman MH, Harakava R, Jerônimo SM, Junqueira-de-Azevedo IL, Kimura ET, Kuramae EE, Lemos EG, Lemos MV, Marino CL, Nunes LR, de Oliveira RC, Pereira GG, Reis MS, Schriefer A, Siqueira WJ, Sommer P, Tsai SM, Simpson AJ, Ferro JA, Camargo LE, Kitajima JP, Setubal JC, Van Sluys MA (2004). "Comparative genomics of two Leptospira interrogans serovars reveals novel insights into physiology and pathogenesis". J. Bacteriol. 186 (7): 2164–72. PMID 15028702.
- ↑ 29.0 29.1 Bulach DM, Zuerner RL, Wilson P, Seemann T, McGrath A, Cullen PA, Davis J, Johnson M, Kuczek E, Alt DP, Peterson-Burch B, Coppel RL, Rood JI, Davies JK, Adler B (2006). "Genome reduction in Leptospira borgpetersenii reflects limited transmission potential". Proc. Natl. Acad. Sci. U.S.A. 103 (39): 14560–5. doi:10.1073/pnas.0603979103. PMID 16973745.
- Leptospira page at Kenyon College MicrobeWiki.
- Pasteur Institute - Leptospira Molecular Genetics Serverca:Leptospirath:เล็บโตสไปร่า
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