Stalheim, O. H. V. (University of Wisconsin, Madison) and J. B. Wilson. Leptospiral colonial morphology. J. Bacteriol. 86:482-489. 1963.-A sequence of apparent colonial types was observed with colonies of Leptospira pomona, L. canicola, L. icterohaemorrhagiae, and L. grippotyphosa in agar medium. Although some colonies of these serotypes had a different appearance initially, they eventually developed the mature or final appearance characteristic of the serotype. Colonies of freshly isolated, virulent cultures of L. pomona, L. canicola, and L. icterohaemorrhagiae were similar in appearance to colonies of avirulent strains of the same serotype. Additional studies of three stable and distinct colonial types of a laboratory strain of L. autumnalis revealed no differences in antigenicity, catalase activity, or mouse infectivity; however, differences in susceptibility to lysis by oleic acid were found. Although the colonial variants were stable during several in vitro variations, including growth in the presence of homologous antiserum and mutation to growth in a chemically characterized medium, rapid dissociation in vivo was found. (+info)
VIRULENCE-LINKED COLONIAL AND MORPHOLOGICAL VARIATION IN LEPTOSPIRA.
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Faine, S. (University of Sydney, Sydney, Australia), and J. van der Hoeden. Virulence-linked colonial and morphological variation in Leptospira. J. Bacteriol. 88:1493-1496. 1964.-Large-colony typical hooked Leptospira icterohaemorrhagiae was virulent for hamsters and guinea pigs. On cultivation, it was gradually replaced by a serologically identical small-colony avirulent straight mutant. The hooked virulent form was selected in vivo. (+info)
DIFFERENTIATION OF PATHOGENIC AND SAPROPHYTIC LEPTOSPIRES WITH 8-AZAGUANINE.
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Johnson, Russell C. (University of Minnesota, Minneapolis), and Palmer Rogers. Differentiation of pathogenic and saprophytic leptospires with 8-azaguanine. J. Bacteriol. 88:1618-1623. 1964.-The use of the purine analogue, 8-azaguanine, as a differential agent for the separation of pathogenic and saprophytic leptospires was investigated. Growth of strains of the saprophyte Leptospira biflexa was almost insensitive to the bacteriostatic action of 8-azaguanine at concentrations varying from 25 to 600 mug/ml; these saprophytic leptospires were serially transferred five times in media containing 225 mug without any change in growth rate or cell yield. In contrast, decreased growth rate and cell yield of the pathogenic serotypes were observed with 25 to 50 mug/ml of 8-azaguanine. Complete inhibition of growth occurred at concentrations of 100 mug/ml and above. A medium containing 225 mug/ml of 8-azaguanine was successfully used to differentiate 20 serotypes of pathogenic leptospires and 10 saprophytic strains. L. andaman CH11, L. semarang Veldrat S1 73, and L. andaman Correa, were classified with the L. biflexa strains on the basis of their growth response to 8-azaguanine. (+info)
Broth microdilution susceptibility testing for Leptospira spp.
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Leptospirosis in humans has traditionally been treated with penicillin or doxycycline. The choice of therapy offered at the time of initial patient presentation is often empirical, as definitive diagnosis can take weeks. Determining the activity of numerous antimicrobial agents against a wide range of Leptospira serovars may broaden empirical therapeutic options. Various antimicrobials have been shown to be active against a limited number of serovars in in vitro studies, chiefly by the use of broth macrodilution techniques. We developed a broth microdilution technique using the commercially available growth indicator alamarBlue. MICs produced by this technique were compared to MICs and minimal bactericidal concentrations produced by the traditional broth macrodilution technique. The internal validity of our methods was assessed with 11 runs over numerous days with a single isolate of Leptospira interrogans serovar Icterohaemorrhagiae. By either method, the MICs for these internal-validity runs fell within 2 dilutions of each other for more than 90% of antimicrobials. A broader application of these two techniques included 12 serovars (including seven species) of Leptospira and six antimicrobials (penicillin G, doxycycline, chloramphenicol, erythromycin, cefotaxime, and ciprofloxacin). Observed reproducibility fell within 2 dilutions for 99% of the duplicate result sets for the MIC microdilution method, compared to 89% for the MIC macrodilution method. The macrodilution method tended to have a higher MIC at which 90% of the isolates were inhibited (MIC(90)) than did the microdilution method, but the MIC(90)s of both methods were within 2 dilutions of each other for all six drugs. The macrodilution and microdilution techniques produced similar results, with microdilution allowing a faster, more streamlined method of producing MIC results. (+info)
Proposal to list ATCC 43642 as the type strain of Leptospira interrogans in the Approved Lists of Bacterial Names. Request for an opinion.
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ATCC 23581(T) has been cited as the type strain of Leptospira interrogans since 1980. In 1986, the Centers for Disease Control informed the ATCC that this strain was Leptospira interrogans serovar budapest, not serovar icterohaemorrhagiae as deposited originally. An authentic culture of the Leptospira interrogans serovar icterohaemorrhagiae RGA(T) strain was then submitted and assigned ATCC 43642, which was designated as the type strain of Leptospira interrogans in an article by Yasuda et al. [Yasuda et al. (1987). Int J Syst Bacteriol 37, 407-415]. In this Request for an Opinion to the Judicial Commission, it is proposed that a correction be made in the Approved Lists of Bacterial Names to acknowledge ATCC 43642 as the type strain of Leptospira interrogans. (+info)
Toll-like receptor 4 protects against lethal Leptospira interrogans serovar icterohaemorrhagiae infection and contributes to in vivo control of leptospiral burden.
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The roles of innate immune responses in protection from or pathogenesis of severe leptospirosis remain unclear. We examined the role of Toll-like receptors (TLRs) in mouse infection and macrophage responses to Leptospira. C3H/HeJ mice (TLR4 deficient) and C3H/HeJ-SCID mice, but not C3H/OuJ mice (TLR4 intact), died after intraperitoneal infection with Leptospira interrogans serovar Icterohaemorrhagiae. Death in both C3H/HeJ mouse strains was associated with jaundice and pulmonary hemorrhage, similar to the patient from whom the isolate was obtained. In chronic sublethal infection, TLR4-deficient mice harbored more leptospires in liver, lung, and kidney than control mice. Heat-killed Leptospira stimulated macrophages to secrete proinflammatory cytokines, tumor necrosis factor alpha, interleukin-6, and macrophage inflammatory protein 2 not inhibited by polymyxin B, suggesting that leptospiral lipopolysaccharide (LPS) did not drive these responses. Anti-TLR4 and anti-MD-2 but not anti-CD14 monoclonal antibodies inhibited cytokine production. Peritoneal macrophages from CD14-/- and TLR2-/- mice exhibited no defect in cytokine responses to Leptospira compared to controls. Macrophages from C3H/HeJ, TLR4-/-, and MyD88-/- mice secreted far-lower levels of cytokines than wild-type macrophages in response to Leptospira. TLR4 plays a crucial role in protection from acute lethal infection and control of leptospiral burden during sublethal chronic infection. Cytokine responses in macrophages correlated with leptospiral clearance. These TLR4-dependent but CD14/TLR2-independent responses are likely mediated by a leptospiral ligand(s) other than LPS. (+info)
Leptospirosis-induced meningitis and acute renal failure in a 19-month-old male child.
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An unusual case of leptospirosis is described in a 19-month-old male child presenting with meningitis and acute renal failure without jaundice. Some aspects concerning the pathogenesis and treatment of this potentially life-threatening disease are also discussed. Leptospirosis was diagnosed on the basis of history and serological tests. (+info)
Proteome and immunome of pathogenic Leptospira spp. revealed by 2DE and 2DE-immunoblotting with immune serum.
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In this study, proteomes of two pathogenic Leptospira spp., namely L. interrogans, serogroup Icterohaemorrhagiae, serovar Copenhageni and L. borgpetersenii, serogroup Tarassovi, serovar Tarassovi, were revealed by using two dimensional gel electrophoresis (2DE)-based-proteomics. Bacterial cells were disrupted in a lysis buffer containing 30 mM Tris, 2 M thiourea, 7 M urea, 4% CHAPS, 2% IPG buffer pH 3-10 and protease inhibitors and then subjected to sonication in order to solubilize as much as possible the bacterial proteins. The 2DE-separated components of both Leptospira homogenates were blotted individually onto membranes and antigenic components (immunomes) were revealed by probing the blots with immune serum of a mouse readily immunized with the homogenate of L. interrogans, serogroup Icterohaemorrhagiae, serovar Copenhageni. The immunogenic proteins of the two pathogenic Leptospira spp. could be grouped into 10 groups. These are: 1) proteins involved in the bacterial transcription and translation including beta subunit transcription anti-termination protein of DNA polymerase III, elongation factors Tu and Ts, and tRNA (guanine-N1)-methyltransferase; 2) proteins functioning as enzymes for metabolisms and nutrient acquisition including acetyl-Co-A acetyltransferase, putative glutamine synthetase, glyceraldehyde-3-phospahte dehydrogenase, NifU-like protein, 3-oxoacyl-(acyl-carrier-protein) reductase, oxidoreductase, sphingomyelinase C precursor, spermidine synthase, beta subunit of succinyl-CoA synthetase, and succinate dehydrogenase iron-sulfur subunit; 3) proteins/enzymes necessary for energy and electron transfer, i.e. electron transfer flavoprotein, and proton-translocating transhydrogenase; 4) enzymes for degradation of misfolded proteins, i.e. ATP-dependent Clp protease; 5) molecular chaperone, i.e. 60 kDa chaperonin; 6) signal transduction system, i.e. response regulator; 7) protein involved in immune evasion in host, i.e. peroxiredoxin; 8) cell structure proteins including MreB (cytoskeletal) and flagellin/ periplasmic flagellin; 9) lipoproteins/outer membrane proteins: LipL32, LipL41, LipL45 and OmpL1; and 10) various hypothetical proteins. Many immunogenic proteins are common to both Leptospira spp. These proteins not only are the diagnostic targets but also have potential as candidates of a broad spectrum leptospirosis vaccine especially the surface exposed components which should be vulnerable to the host immune effector factors. (+info)