Detección de proteínas de adhesión a fibronectina y colágeno presentesen Leptospira interrogans serovar Canicola / Detection of fibronectin and collagen binding-proteins from Leptospira interrogans serovar Canicola

Como parte de los estudios encaminados a la obtención de una formulación vacunal por subunidades contra laleptospirosis humana, se describe la purificación y caracterización de las proteínas de unión a fibronectina y a colágeno en Leptospira interrogans. Las proteínas de la membrana externa fueron extraídas mediante la solubilización con Tritón X-114 y se aplicaron en una columna de afinidad de IgG AntiBSA-Sepharose 2B CL, para eliminar la BSA, contaminante principal del medio de cultivo en que crece el microorganismo. La muestra libre de BSA (no fijado) se aplicó a una columna de afinidad de fibronectina Sepharose 4B-CNBr, que permitió la separación y detección de una fracción que contenía una proteína de unión a fibronectina presente en la cepa 87 de Leptospira interrogans serovar Canicola, cuyo peso molecular fue estimado en 40 kDa. La proteína aislada demostró ser antigénica y conservada en los serovares Canicola, Copenhageni y Mozdok, en el ensayo de inmunodetección utilizado en este estudio (Dot blot). Para ello se utilizaron sueros específicos obtenidos en ratas infectadas experimentalmente con cada serovar y una mezcla de sueros de humanos convalecientes de leptospirosis. Las proteínas de membrana externa solubilizadas conTritón X-114, libres de BSA, fueron aplicadas también a una columna de afinidad colágeno-Sepharosa 4B-CNBr, que permitió la purificación de una proteína de unión a colágeno con un peso molecular de aproximadamente 25 kDa, la cual resultó ser antigénica frente a sueros de humanos convalecientes de la enfermedad. Ambas proteínas seleccionadas (40 kD y 25 kD) podrían ser evaluadas como posibles inmunógenos en futuros estudios encaminados a la obtención denuevos antígenos vacunales(AU)

As part of the studies conducted to obtain a vaccine formulation by subunits against human leptospirosis, purification and characterization of fibronectin and collagen binding-proteins in Leptospira interrogans was developed. Outer membrane proteins from Leptospira were solubilized with Triton X-114 and were applied in a first step into an IgG AntiBSA- Sepharose 2B CL affinity chromatographic column to eliminate BSA as main contaminant of culture media for this microorganism. TheBSA free fraction was applied into a Fibronectin-Sepharose 4B CNBr affinity column. A fibronectin binding protein from Leptospira interrogans serovar Canicola strain 87, with a molecular weight of 40 kDa was obtained. For this, specific sera obtained from experimentally infected rats with each serovar and mixes of human sera of convalescent patients were used. Thisprotein showed to be antigenic and conserved in Canicola, Copenhageni and Mozdok serovars. Solubilized outer membrane protein by Triton X114 was applied into another affinity column of Collagen-Sepharose 4B CNBr to isolate collagen binding proteins from Leptospira interrogans serovar Canicola strain 87. A collagen binding protein with a molecular weight of 25 kDawhich showed to be antigenic when evaluated by Dot-Blot against human sera of convalescent patients was found(AU)

Leptospirosis en vampiros: desmodus rotundus (geoffroy saint hilaire) / Leptospirosis in ghoul: desmodus rotundus (geoffrou saint Hilaire)

Se realizó el estudio bacteriológico y serológico en 26 especínenes de Desmodus rotundus(Geoffroy Saint Hilaire), capturados en la localidad de Shansha, Huaráz-Ancash, a fin de determinar el posible rol de reservorios de Leptospiras de la especie Leptospira interrogans. Observaciones diresctas de tejido renal y hepático al microscópio de campo oscuro, mostraron la presencia de Leptospira en 6(23.07 por ciento)especímenes. Se detectaron anticuerpos contra Leptospira mediante la reacción de aglutinación microscópica (RAM)en 5(19.23 por ciento)vampiros investigados frente a L. javanica, L. pyrogenes, L. andamana y L. grippotyphosa. Del total de cultivos realizados, se aisló una cepa de Leptospira a partir del cultivo de hígado. Por los resultados obtenidos, se evidencia el rol de reservorios de Leptospira en este grupo de mamiferos, estudiados por primera vez en Perú. Se recomienda la investigación de un número mayor de especímenes, así como en otras especies de Chirópteros, principalmente para intentar el aislamiento de Leptospira y determinar la acción de los vampiros en la transmisión de esta espiroqueta al humano y animales domésticos

Fatty acid profiles in the family Leptospiraceae.

Fatty acid profiles of six leptospira strains representative of genera, species, and serogroups within the family Leptospiraceae were determined by gas liquid chromatography (GLC) of fatty acid methyl ester (FAME) derivatives. The influence of methodological and biological variables on FAME profiles of the same strain was tested. FAME profiles were sharply affected by the fatty acid composition of the culture medium but not by the growth phase. Twenty-four FAME peaks were selected on the basis of their presence in repeated gas chromatographic runs of single strains. Inter-strain divergences of FAME profiles were quantified by linear regression analysis (LR). Step-wise divergences in FAME profiles were observed between strains at serogroup, species, and genus levels.

[Comparative study of outer envelope protein and LPS of five strains of leptospires by SDS-PAGE and 2D-PAGE].

We applied SDS-PAGE, 2D-PAGE and Western blot to analyse the outer envelopes protein and LPS of five strains of leptospires. The work would lay foundations for taxonomy, the development of vaccination regimens and the elucidation of pathogenic mechanisms. The outer envelope proteins of leptospires were analyzed by SDS-PAGE and silver staining. We found that the protein profiles of the pathogenic leptospires were basically identical. A comparison of the protein profiles of the pathogenic L. with those exhibited by two nonpathogenic L. indicated that there was no obvious relationship between these organisms and any of the L. interrogans strains examined. The quantity of 21.5 kd protein of strain 017 was greater than that of strain 601 and 156. Approximately 200, 225, 238 distinct polypeptides were detected in the strain 017, 601 and 156 in 2D-PAGE by silver staining respectively. The profiles of 2D-PAGe showed obvious differences in pI. The pI of strain 017, 601 and 156 were mainly 6.68-7.4, 6.55-6.9, 5.85-7.1 respectively. The 21.5 kd protein of strain 017 was made up of six polypeptides. Our immunoblots revealed that McAb (LB1) reacted with a 41 kd antigen, which was common to the three virulent leptospires tested. SDS-PAGE profiles of silver stained outer envelope LPS of pathogenic L. differed greatly from those of the nonpathogenic L. There was a distinct differences between strain Patoc I and 3055. Our studies showed that each of the five strains of leptospires possessed characteristic outer envelope LPS, which may be used to identify the genus, species and serovars of a strain of L.

[Electrophoretic study of the outer membrane proteins of leptospirae]. / Elektroforeticheskoe issledovanie belkov naruzhnoi obolochki leptospir.

The outer membranes of pathogenic and saprophytic leptospires have been isolated. The spectrum of outer membrane proteins in three saprophytic and one pathogenic Leptospira strains has been studied by means of electrophoresis in polyacrylamide gel. In Leptospira strains VGNKI-6 (pathogenic) and G-80 (saprophytic) identical proteins, as well as proteins similar in their Rf value, have been detected. The possibility of using strain G-80 for the development of leptospiral vaccine against serovars having common surface antigens with this strain has been suggested.

[Purification and SDS-page analysis of axial filaments from leptospires].

A modified method, differential centrifugation followed by sucrose density centrifugation, was used to purify axial filaments from three strains of Leptospires. Ultrastructure of the axial filaments was studied and profiles of the axial filaments were characterized and compared. The results have shown that all the three strains of Leptospires, i.e., L. interrogsans serovar Lai strain 017, L. biflexa serovar patoc strain Patoc I and L. illini strain 3055, have two axial filaments in one cell. The axial filament is 20 nm in diameter. It is the first observation that the end which inserts the cytoplasms cylinder is wider in diameter than the free one. An insertion pore structure is observed. The new method yields 1.5mg axial filaments from 12 g leptospires cells. SDS-PAGE was first employed in the analysis of axial filaments of leptospires. The results have also shown that there are 6 proteins in the axial filaments of strain 017, MW 26,000-50,000 while 7 proteins in the axial filaments of strain Patoc I and strain 3055. MW 29,000-80,000 and 28,500-80,000 respectively. Interestingly, all the axial filaments of the three strains have a common protein band of MW 31,500. The possibility of using axial filament proteins as a new criterion for typing and a serodiagnosis antigen is discussed.

Copurification of Leptospira interrogans serovar pomona hemolysin and sphingomyelinase C.

The hemolytic and sphingomyelinase C activities of supernatants of cultures of Leptospira interrogans serovar pomona tended to copurify when isoelectric fractionation was carried out. Both activities focused primarily at pH 8.1. Considered in conjunction with other circumstantial evidence, the results led to the conclusion that sphingomyelinase C is responsible for hemolysis.

Heterogeneity of lipopolysaccharide banding patterns in Leptospira spp.

Strains of Leptospira interrogans and Leptospira biflexa, examined by electrophoresis after whole cell lysis and protein digestion, revealed the presence of 2-keto-3-deoxyoctonate and an heterogeneous lipopolysaccharide electrophoretic banding pattern, which was characteristic of the species.

Differentiation of reference strains of leptospires of the Pomona serogroup by cross-agglutination absorption and restriction endonuclease analysis.

The serological classification of all reference strains that have been described as representing separate serovars of Leptospira interrogans within the Pomona serogroup was investigated using cross-agglutination absorption and bacterial restriction endonuclease analysis (BRENDA). Comparative cross-agglutination absorption studies indicated that cornelli CB, monjakov Monjakov and kennewicki LT1026 were homologous with pomona Pomona, and dania K1 and tsaratsova B81/7 were homologous with mozdok 5621. BRENDA confirmed these results, except that pomona Pomona and monjakov Monjakov showed a difference in the high molecular weight region. It is proposed that four serovars be currently recognised within the Pomona serogroup: pomona, mozdok, proechimys and tropica. The relative merits of the use of cross-agglutination absorption and BRENDA with respect to identification of Pomona serogroup isolates are discussed.

Identification by cross-agglutination absorption and restriction endonuclease analysis of leptospires of the Pomona serogroup isolated in the United Kingdom.

Five strains of Leptospira interrogans isolated in the United Kingdom and belonging to the Pomona serogroup were subjected to cross-agglutination absorption and bacterial restriction endonuclease DNA analysis (BRENDA) for their identification. British isolates were compared with reference strains representing the known serovars in the Pomona serogroup and also with isolates of the Pomona serogroup obtained from other countries. Three strains isolated from wildlife in England produced equivocal results when the cross-agglutination absorption and BRENDA results were compared. According to the World Health Organisation definition of a serovar the three English strains represented two new serovars, whereas by BRENDA all three had DNA electrophoresis patterns indistinguishable from serovar mozdok. Serovar pomona has not as yet been isolated in Great Britain and the epidemiology of the Pomona serogroup infections that have been detected by serology suggests that a serovar such as mozdok, maintained by wildlife, may be the causal agent. Two strains isolated in Northern Ireland were identified as pomona by the cross-agglutination absorption test. Further studies are needed to investigate the homogeneity of field and reference strains that are designated as pomona using the cross-agglutination absorption test.

New method for classification of leptospiral isolates belonging to serogroup pomona by restriction endonuclease analysis: serovar kennewicki.

The genomes of leptospiral field isolates belonging to serogroup Pomona were analyzed and compared with those of type strains by cleavage with restriction endonucleases. This new classification method shows differences among these organisms not indicated by the conventional serological typing method. No differences were observed among isolates from the United States, Canada, and New Zealand. Although all isolates selected for this study had been serologically typed as belonging to serovar pomona, the restriction endonuclease analysis indicates that they belong to serovar kennewicki. kennewicki, a serovar of North American origin, has recently been eliminated from the official serovar list because it was found to be indistinguishable from serovar pomona by the serological method.

[Fatty acid composition of Leptospira lipids as a taxonomic criterion]. / Zhirnokislotnyi sostav lipidov leptospir kak taksonomicheskii kriterii.

The fatty-acid composition of microbial cells in 17 pathogenic and saprophytic Leptospira strains, comprising 14 serovars and 10 serogroups, has been studied. The strains under investigation have proved to fall into 3 groups differing by this characteristic. The group of saprophytic strains is characterized by a comparatively high level of myristic acid and, consequently, by the ratio of saturated and unsaturated fatty acids with 14 carbon atoms approaching 1:1; besides, it is also characterized by a lower, in comparison with the pathogenic Leptospira strains belonging to the serogroups Icterohaemorrhagiae, Canicola, Ballum has a higher level of unsaturated fatty acids. The second group of pathogenic Leptospira strains including the serogroups Grippotyphosa, Hebdomadis, Pomona, Tarassovi, Pyrogenes, Australia has been found to occupy an intermediate position between the first group of pathogenic Leptospira strains and the group of saprophytic ones. As the difference in the content of myristic acid in pathogenic and saprophytic Leptospira strains is a stable characteristic, it can be used for the differentiation of these strains. The present investigation has revealed that the distribution of the main fatty acids in Leptospira phospholipids is similar to their distribution in Leptospira neutral lipids with the exception of unsaturated fatty acid with 14 carbon atoms, occurring mainly in phospholipids.

Isolation of Leptospira from desert rodents of west Texas.

Urine, blood and tissue samples from 369 rodents of 13 species were cultured for Leptospira. Four serogroups, including ballum, isterohaemorrhagiae, pomona, and grippotyphosa, were isolated from 70 rodents (19%) of 9 species.

Gas-liquid-chromatography of trimethylsilyl derivatives from whole cell methanolysates of Leptospira : preliminary evaluation of its applicability to the taxonomy of the genus.

Gas-liquid-chromatography of trimethylsilyl derivatives from whole cell methanolysates was investigated as a supplmentary means for taxonomical classification within the genus Leptospira. Reproducibility of this technique was assessed through the peak height variations occurring in chromatograms of strain Patoc 1, serotype patoc, when samples either from the same or different batches of culture were used. From each chromatogram seven peaks were selected. Their heights were measured and calculated as percent values of the seven peaks total height. The values of relative standard deviation reported show that the reproducibility of this technique lies within the usual limits of biological methods. Four out of seven different serotypes analyzed gave elution patterns dissimilar enough to allow a clear distinction among them by the simple visual examination. Differentiation of the other three had to be done comparing the relative heights of the seven selected peaks. One not yet classified new strain was submitted to this technique; results seemed to confirm available serological information about it. Data reported encourage further research in order to evaluate the potential of GLC as an useful aid in the taxonomy of genus Leptospira.