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At least 883 records · Page 49Linked to original sources
PubMed1979

Isolation of Leptospira of the serotype hardjo from bovine kidneys.

Thirteen strains of Leptospira serotype hardjo were cultured from 200 bovine kidneys collected from an abattoir. All strains grew on primary isolation in EMJH medium 0.1 per cent Noble agar but most failed to grow in a variety of media containing neomycin or 5-fluorouracil as selective agents. Two of the cattle from which hardjo were isolated were seronegative by the microscopic agglutination test against hardjo, two had titres of 1/100, five of 1/400, three of 1/1600 and one of 1/6400.

Animals↗
PubMed1984

Differentiation of pathogenic and saprophytic leptospira strains.

Comparative studies of 249 pathogenic and 80 saprophytic leptospira strains, including 2 strains of the illini type, using the 8-azaguanine test, growth at 13 degrees C and growth on trypticase soy broth revealed their good differentiating potency if the recommended conditions were carefully observed. The same results were obtained by a simple hemolytic test using sheep and rat blood cells, having the advantage of providing results within 24 h. This test is suggested to replace the 8-azaguanine and the growth test at 13 degrees C. In these investigations, the first European strain of the illini type was recognized.

Animals↗
PubMed1983

[Preparation and use of solid culture medium for Leptospira isolation].

Recommendations on the preparation and use of a solid culture medium are given; age changes in the colonies of leptospires belonging to different serovars and serogroups have been studied in their dynamics; the absence of relationship between the form of the colonies, the serovar and serogroup of the cultures, their virulence, as well as the region, time and source of their isolation has been established, which makes it impossible to use these parameters for the differentiation of Leptospira strains belonging to different serovars on solid culture media.

Culture Media↗
PubMed1978

Experimental infection of calves with Leptospira interrogans serotype szwajizak.

This is a report on the experimental infection of cattle with Leptospira interrogans serotype szwajizak. The principal clinical features in three 4-week-old Holstein-Friesian heifers intravenously inoculated were fever, listlessness, anorexia, weakness, and diarrhea. Szwajizak was isolated from the blood for the first 5 to 8 days after inoculation. Leptospires were recovered from kidneys, but not from liver, spleen, brain, or urine. Two of the 3 calves produced homologous agglutinins, with maximum serum titers of 1:80 and 1:160. The sera of the 2 calves that developed szwajizak agglutinins showed cross reactivity with wolffi and hardjo antigens. There were not significant differences of plasma and urine constituents between the inoculated calves and the control calf. Endocardial hemorrhages and large soft black-red spleen were present in the 2 calves given the greatest numbers of leptospires. Histopathologically, kidney of all infected calves had multiple small foci of lymphoid cells, chiefly pasmacytes, which were present in periglomerular and interstitial areas.

Animals↗
PubMed1984

Enhancement of Leptospira hardjo agglutination titers in sheep and goat serum by heat inactivation.

Heat inactivation of sheep serum samples resulted in the detection of an additional 9% reactors to Leptospira hardjo that were negative on the initial test of fresh samples. Treatment with EDTA gave results generally similar to heat inactivation suggesting that complement was responsible for the inhibition of agglutination. Tests on heat inactivated serum from experimentally infected sheep and goats revealed enhanced titers or reactions which were not detected in fresh serum.

Agglutination Tests↗
PubMed1984

[Sensitivity of different morphological variants of Leptospira to the leptospirocidal activity of normal animal sera].

The leptospirocidal activity of normal animal sera with respect to 23 Leptospira strains was experimentally studied in vitro. 91.3% of the strains under study proved to be sensitive to the lytic action of cattle serum and 86.9%, to sheep serum. The uncinate variants of the pathogenic strains showed resistance to the action of the above sera, and their nonuncinate analogs were subject to agglutination with subsequent lysis, similarly to saprophytes.

Animals↗
PubMed1983

Exposure to Leptospira icterohaemorrhagiae in inner-city and suburban children: a serologic comparison.

This study explores the exposure of urban children to the spirochete Leptospira icterohaemorrhagiae. This organism is carried by 90 percent of the rats in Detroit. It is felt that these rats are a potential vehicle for childhood exposure to this organism. Strain-specific tests were performed comparing antibody levels in sera of inner-city (exposed) and suburban (unexposed) children. Study and control groups, numbering 124 and 113, respectively, showed significant serologic differences, with urban children having higher antibody titers. The findings are indicative of differential exposure rates and suggest that actual cases of leptospirosis may be present, yet undiagnosed.

Antibodies, Bacterial↗
PubMed1983

Morphological changes upon subculturing of freshly isolated strains of Leptospira interrogans serovar hardjo.

The morphology of freshly isolated strains of Leptospira interrogans serovar hardjo was studied by electron microscopy and was compared to that of established laboratory strains of the same serovar and to some other serovars within the Hebdomadis serogroup. Changes in the morphology of freshly isolated strains of serovar hardjo were observed when the isolates were subcultured in the laboratory. Cells of strains subcultured more than 20 times were longer and had longer wavelengths, and electron lucent inclusions were observed less frequently than in cells of strains subcultured less than 10 times. Upon hamster passage, cells subcultured 40 and 50 times became more similar to cells of low passage number than to those of the inoculate. The results are discussed and the importance of environmental factors for the growth of leptospires is emphasized.

Animals↗
PubMed1983

Growth of 10 Leptospira interrogans serovars using polyvinylpyrrolidone(PVP)-treated Tween in protein-free medium.

Polyvinylpyrrolidone (PVP)-treated Tween was used to prepare a protein-free medium for cultivation of leptospires. 6 out of 25 media were selected for culturing 10 serovars of leptospires. The best results were achieved in a medium containing Tween treated with PVP 25000. In several subcultures 8 out of 10 serovars reached a concentration of 10(8) leptospires/ml or more, when cultured in tubes without aeration.l Only in the case of 2 serovars (Leptospira interrogans serovars grippotyphosa and tarassovi) growth was not satisfactory. The results have shown that it is possible to detoxify Tween with the aid of polyvinylpyrrolidone. In the meantime the 40th subculture of 8 strains has been prepared.

Culture Media↗
PubMed1984

[Effect storage temperature on the biological properties of Leptospira].

No essential changes occurred in the morphology, viability and agglutinability of 212 Leptospira strains belonging to 20 serological groups during 2-year storage in ampoules at temperatures of -60 to -70 degrees C, and 18 to 24 degrees C. After storage lasting 3 and 4 years viability was retained, respectively, by 95.75 and 78.5% of the strains stored at a temperature of -60 to -70 degrees C and by 90.9 and 70% of the strains stored at room temperature. During 4 years of storage at room temperature the agglutinability of the strains decreased 2-8 times. Most of the strains retained their virulence unchanged for 2 years at a temperature of -60 to -70 degrees C.

Agglutination Tests↗
PubMed1980

Benign leptospirosis: the pathology of experimental infection of monkeys with Leptospira interrogans serovars balcanica and tarassovi.

Grivet monkeys experimentally infected with Leptospira interrogans serovars balcanica and tarassovi showed no clinical disease, but severe meningoencephalitis was demonstrated histologically in animals killed 26 and 33 days after infection. The meningeal and perivascular reactions were exclusively lymphocytic. Mild focal lesions of degeneration and cellular infiltration were also present in the kidneys and femoral musculature.

Animals↗
PubMed1980

[Demonstration of Leptospirae antibodies in the sera of immunized rabbits by the indirect immunofluorescence test (author's transl)].

Antibodies of Leptospirae were demonstrated in the sera of immunized rabbits by the indirect immunofluorescence test, only after a suitable dilution of the "anti-rabbit-gamma-globulin fluorescin conjugated" was carried out in a cross reference titration ("chessboard method"). A distinct crossreaction was observed when anti-icterohaemorrhagiae - and anti-bratislava-immunsera reacted with several serotypes out of the "interrogans complex". But only a weak crossreaction was found when both sera reacted with the serotyp patoc from the "biflexa complex". The evaluation of the indirect immunofluorescence test was complicated by a streaky background of fluorescence. The agargeldiffusion tests (Ouchterolony) exhibited four, three and two precipitation bands according to the conbination of antigens and immunsera.

Animals↗
PubMed1982

Infections with Encephalitozoon cuniculi and Leptospira interrogans, serovars grippotyphosa and ballum, in a kennel of foxhounds.

Leptospira interrogans serovars grippotyphosa and ballum were isolated from kidney and urine of an American Foxhound pup. The pup was from a litter of 12, all of which were unthrifty. Titers for serovar grippotyphosa in pups from the litter ranged from 200 to 6,400 and 23 of 36 adult dogs in the kennel had titers to that serovar. None of the sera was tested for antibodies to serovar ballum. Leptospires were not isolated from or observed in 2 littermates and 1 penmate, but gram-positive organisms morphologically compatible with Encephalitozoon cuniculi were detected in their brains and kidneys.

Animals↗
PubMed1983

Enzyme-linked immunosorbent assay for the detection of antibodies to Leptospira interrogans serovars hardjo and pomona in cattle.

An enzyme-linked immunosorbent assay (ELISA), which used the phenol phase of a hot phenol-water extraction as antigen, and the microscopic agglutination test were compared for the detection of antibodies to Leptospira interrogans serovars hardjo and pomona in cattle. Among serum samples from vaccinated cattle, the ELISA (using antiglobulin) was positive to 64% with hardjo antigen and to 78% with pomona antigen, whereas the microscopic agglutination test was positive to only 18% with hardjo and 23% with pomona. There were no ELISA reactions observed among known negative-control samples. The ELISA, using antiglobulin conjugate, was overall a more sensitive technique for the detection of leptospiral antibodies in cattle.

Agglutination Tests↗
PubMed1983

Growth, cultural characteristics, and antibacterial sensitivity of Leptospira interrogans serovar hardjo.

Nutrient requirements of Leptospira interrogans serovar hardjo were investigated using a 1% bovine serum albumin (BSA) medium, supplemented separately with polysorbates (Tweens) 80, 60, 40, 20, NH4Cl, and vitamins thiamine and cyanocobalamin (vitamin B12). L. hardjo was tested in vitro against 30 antibacterial compounds incorporated into semisolid medium (0.2% agar) at 3 compound concentrations. Growth was superior in polysorbate 80 (oleic acid rich) and polysorbate 40 (palmitic rich) media. A linear growth response to vitamin B12 could be shown. Hamster isolates all required thiamine and vitamin B12 for growth. The antibacterial compounds could be classed as: 100% bacteriocidal, bacteriocidal at the 2 highest concentrations, bacteriocidal at only 1 concentration, and completely noninhibitory. The tetracyclines were strongly bacteriocidal. The comparative growth rates of hamster isolates were much reduced when compared to the type strain hardjoprajitno. These studies were performed acknowledging that the polysorbates were mixtures of fatty acids. Nephelometry was used as an accepted method to monitor the synthesis of leptospiral cell mass.

Animals↗
PubMed1982

Isolations of Leptospira interrogans serovars hardjo, balcanica, and pomona from cattle at slaughter.

Kidneys were cultured for leptospires and blood was collected for leptospiral serologic examination from 306 cattle slaughtered in Florida during June, July, and August 1980. Leptospires were found in 82(36%) of 226 otherwise bacterial-free cultures. Forty-five isolates were identified as Leptospira interrogans serovar hardjo, 3 as serovar balcanica, and 3 as serovar pomona. Leptospiral antibodies were found in 218 (71%) of the cattle. Serum titers to hardjo were found in 162 cattle (53%) and to pomona in 28 (9%). Low titers to tarassovi were found in 14 cattle (4.5%).

Animals↗
PubMed1980

Effect of cyclophosphamide treatment on clinical and serologic response of rats to infection with Leptospira interrogans serovar icterohaemorrhagiae.

Young albino rats were immunosuppressed with cyclophosphamide and exposed to virulent and low-virulence Leptospira interrogans serovar icterohaemorrhagiae 820K. In rats exposed to virulent and low virulence leptospires, microscopic agglutinating antibody responses occurred later, and longer leptospiremic phase and more massive tissue invasion by the organisms were observed in immunosuppressed rats than in immunocompetent controls. Clinical and pathologic signs of illness were more severe in the immunosuppressed animals than in immunocompetent controls. When exposed to low-virulence leptospires, immunosuppressed rats became infected and developed signs of illness and 2 of 16 died. Immunocompetent rats rapidly developed a humoral response and did not develop any signs of illness, and with 1 exception, organisms were not recovered from any tissues.

Animals↗