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[Spontaneous mixed infection in rodents with Borrelia and Leptospira].

This study was performed in a natural ITBB focus located in Perm' region of Russia. In 1993-1995, 73 root voles (Microtus oeconomus), collected in the forests, were examined by means of inoculation of internal organs on BSK-II medium. Borrelia were found in 13 animals (17.8%). According to the results in RLFP analysis 11 isolates were classified as B. garinii, 1 as B. afzelii and 1 as mixture of B. garinii and B. afzelii. In one case Leptospira, which was identified by PFGE analysis as grippotyphosa serovar, was found simultaneously with B. garinii in the BSK-II culture from urinary bladder. Our data testify to the fact of existence of mixed foci of leptospirosis and borreliosis. Moreover, one animal may serve as a reservoir host simultaneously of two different spirochetal agents.

Animals↗
PubMed1996

[The PCR amplification, cloning, sequencing, expression in E. coli of gene encoding endoflagella subunit protein (fla B) from Leptospira interrogans serovar lai].

A pair of oligonucleotide primers were designed by ourselves to amplify the endoflagella gene of L. interrogans serovar lai. A fragment about 840 bp was generated with PCR and inserted into plasmid pUC8 after the fragment and pUC8 were digested respectively with Bam HI and Pst I. A recombinant plasmid (designated as pLF1) was obtained. SDS-PAGE analysis indicated that a 33 kd was expressed in E. coli JM103 harboring pLF1 and the expression level of the protein was 11% of total bacterial soluble proteins. Western blot analysis showed that the protein band could be recognized by the antiserum against the endoflagella (Axiall filament) of Leptospira interrogans serovar lai. Nucleotide seguence data showed an open reading frame encoding 282 aminoacids residues, corresponding to a protein of molecular weight 33.6 kd. The G + C content of endoflagella subunit protein gene was 48 mol%. Therefore, the G + C content of the leptospiral fla B Gene is significantly higher than the reported 39 mol% G + C content of leptospiral genome of L.interrogans serovar lai but similar to the G + C of the Treponema pallidum genome. Comparison of the deduced endoflagellar subunit protein (fla B) amino acid sequence with flagellins from other bacteria revealed a high level of identity with the Treponema pallidum fla B proteins. Immunization/protection experiment was performed on the model of BALB/c mice and showed that the survival rate in the group JM103-pLF1 was higher than that in the group JM103-pUC8, but statistically the difference between them was significant (P < 0.05) and pLF1 did not induce significant levels of agglutinating antibodies against L.interrogans serovar lai.

Amino Acid Sequence↗
PubMed1977

Growth, virulence, and immunogenicity of Leptospira interrogans serotype szwajizak.

Leptospira interrogans serotype szwajizak was characterized by (1) its growth in polysorbate 80-bovine albumin medium, (2) its virulence and course of infection in laboratory animals, and (3) its immunogenicity. Growth of this organism was continuous and vigorous at 29 C and 37 C in liquid medium for 10 serial subcultures. Some specific lots of agar were superior to other agars if tested for the ability to support the growth of small inoculums. Individual colonies resulted from growth of small inoculums on solid polysorbate medium. Virulence of the organisms did not appear to be altered by 10 serial subcultures in liquid medium incubated at 29 C. The estimated median lethal dose of szwajizak for hamsters by the intraperitoneal route was 2 cells. Virulence, infectivity, and pathogenicity of szwajizak were shown in the hamster and the guinea pig. Protection results indicate the heat-inactivated szwajizak bacterin was a substantially better immunizing agent than the chemically inactivated bacterin. Serotype hardjo bacterins provided hamsters some protection against death if challenge exposed with szwajizak, but afforded no protection against infection.

Animals↗
PubMed1977

Potential variability of Leptospira serovars belonging to the same group.

3 clone strains of monjakov and pomona serovars were cultured with prolongation in a medium containing homologous immune sera. Separate subcultures were cloned in a solid medium, while isolated clones were typed in microagglutination test with whole and absorbed immune sera and in some cases in an absorption test. The results showed that the mutants of subcultures with the minimal and maximal time of contact with the immune serum turned out to differ greatly from each other in antigenic properties. While antigenic mutants of earlier subcultures were constantly connected with serovars of Pomona serogroup, mutants of subcultures adapted to immune serum were serologically more related to butembo serovar of Cynoptery serogroup. The results obtained showing potential variability of serovars belonging to Pomona serogroup could be significant from the viewpoint of classification and phylogeny of Leptospira.

Agglutination↗
PubMed1997

[Development of polymerase chain reaction-based test systems for detecting leptospira in polytypical leptospirosis foci].

Two highly sensitive test systems G and B, based on the polymerase chain reaction, were developed for indication of pathogenic Leptospira interrogans, including the serovariants appearing during outbreaks in polytypical foci of leptospirosis in the tropical zone of China. These test systems can be used for rapid diagnosis of leptospirosis in humans in foci with different etiological structure.

China↗
PubMed1978

[Observation on the antigenic affinity of Leptospira and Brucella in the serological examination of cattle].

36,9% bovine serums which showed a non-specific reaction in examination for brucellosis had titre greater than or equal to 1:400 leptospirosis agglutinins. 15.1% of the serums showed a positive reaction (greater than 1:800), mostly those against L. sejroe and L. grippotyphosa. The cross reactions, found in individual cases within up to 39 days since the first reaction to brucellosis in cattle may signalize early Leptospira infections.

Agglutination Tests↗
PubMed1998

Leptospira borgpetersenii serovar hardjo type hardjobovis in bovine embryos fertilized in vitro.

The association of Leptospira borgpetersenii serovar hardjo type hardjobovis with bovine embryos produced by in vitro fertilization was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Morula stage embryos with an intact zona pellucida (ZP) were exposed to this spirochete for 24 h in culture medium, washed by the standard washing procedure as recommended by the International Embryo Transfer Society, and then examined. SEM showed typical helicoid leptospires on the surface and in the pores of the ZP. TEM showed cross and longitudinal sections of leptospires in the matrix and channels of the ZP, in the perivitelline and intercellular spaces, on the vitellus and in the embryonic cells. Some of the embryos that were penetrated showed damage to the membranes and the cytoplasm. The ineffectiveness of the washing procedure, for the removal of hardjobovis from exposed embryos may be of importance to the industry.

Animals↗
PubMed1997

[Investigation on the rate of urinary excretion of leptospires among cattle naturally infected with Leptospira interrogans].

Urine samples of Leptospires from cattle were detected by polymerase chain reaction (PCR) and isolation. Positive rates by Southern-blot and agarose gel electrophoresis of PCR amplification productions were 13% and 11% respectively. Positive rate of isolation was 3.1%. Various positive rates by PCR for cattle urine from different areas were discovered. Average rate of urinary excretion of Leptospires among cattle that naturally infected with Leptospira interrogans was 13.2%. Data showed that cattle was a major source of infection of Leptospirosis in some parts of China. According to the comparsion of results between PCR and isolation, we believe that PCR is a sensitive, rapid and simple method for the investigation on source of infection of Leptospirosis.

Animals↗
PubMed1983

Leptospira interrogans serovar Hardjo: an abortifacient in New Zealand? A review of the literature.

From experimental and clinical evidence, Leptospira interrogans serovar hardjo has been suspected as an abortifacient in cattle overseas. Early reports from North America and Australia described clinical disease with abortions occurring up to 12 weeks later associated with hardjo infections. Recent studies in the United Kingdom have found hardjo infections in nearly 69 percent of aborted foetuses from problem farms, and a prospective epidemiological study determined a relationship between hardjo infection and abortion on one property. In New Zealand, although the epidemiology of hardjo infections has been studied, little attention has been paid to the potential abortifacient role of this organism. In part this is due to the impracticality of using serology to diagnose infections that may have occurred months prior to the abortion. Future research to resolve this question should therefore revolve around hardjo isolation, cohort studies, and the examination of pathogenic mechanisms by which hardjo may induce abortion in cattle.

Journal Article↗
PubMed1986

Haemolytic disease associated with Leptospira interrogans serovar pomona in red deer calves (Cervus elaphus).

Three red deer calves (Cervus elaphus) died with a haemolytic disease associated with infection by Leptospira interrogans serovar pomona. Infection within the herd was more prevalent than disease. Sera from 16 herd mates were tested by the microscopic agglutination test (MAT) and 12 had leptospiral titres, the majority to serovar pomona. A few calves had titres to balcunica and hardjo. Urine was obtained for culture from six of these calves and serovar pomona was isolated from five with titres to pomona, and hardjo from one with a titre to hardjo but not pomona. A fourth calf died with severe nephritis but a diagnosis of leptospirosis was not confirmed in this case.

Journal Article↗
PubMed1992

Antibodies in dogs against Leptospira interrogans serovars copenhageni, ballum and canicola.

In a nationwide survey carried out during 1990-91 of more than 5800 dogs to detect antibodies against Leptospira interrogans serovars copenhageni, ballum and canicola, only one weak reactor against serovar canicola was found. Reactors of varying titre were found against serovar ballum in 0.7% of dogs tested, indicating sporadic infection with this serovar. Reactors (0.9%) to serovar copenhageni came mainly from the Waikato, Northland and the Auckland region. This was in agreement with the reported occurrence of the clinical syndrome and with the results of a smaller survey in urban Auckland, in which more than 5% of dogs tested were seropositive to serovar copenhageni.

Journal Article↗
PubMed1996

The efficacy of a Leptospira interrogans serovars pomona and copenhageni and L. borgpetersenii serovar hardjo vaccine in cattle.

An experimental, trivalent, bovine, leptospiral vaccine, containing inactivated Leptospira interrogans serovars pomona and copenhageni and L. borgpetersenii serovar hardjo Hardjobovis, was developed. The experimental vaccine was shown to protect hamsters against virulent challenge with each of the component serovars. In a serological efficacy test in cattle, the experimental vaccine was compared for bioequivalence with a similar product, registered in New Zealand for veterinary use. The experimental vaccine induced higher titres in cattle than the latter mentioned product.

Journal Article↗
PubMed1997

Effects of experimental infection with Leptospira interrogans serovar balcanica on the health of brushtail possums (Trichosurus vulpecula).

Data on changes in the condition and feeding behaviour of captive brushtail possums (Trichosurus vulpecula) following an experimental infection with Leptospira interrogans serovar balcanica are presented. The daily food intake of nine experimentally infected possums was recorded for 47 days before and 24 days after balcanica inoculation (0.5 ml intraperitoneally containing about 10(8) organisms). Body weight was recorded seven times between 42 days before and 96 days after inoculation. The mean daily food intake of infected possums decreased significantly throughout the 24-day recording period after infection with balcanica. The mean body weight of infected possums had decreased significantly by day 26 after inoculation but had fully recovered by day 96 after inoculation. Uninfected and control possums showed no significant changes in mean daily food intake or mean body weight over the experimental period. These data suggest that the health of possums is temporarily affected by infection with balcanica, but that overt disease caused by balcanica is unlikely. These findings support previous research suggesting that balcanica has only subclinical effects on possums.

Journal Article↗
PubMed2001

Protective killed Leptospira borgpetersenii vaccine induces potent Th1 immunity comprising responses by CD4 and gammadelta T lymphocytes.

Leptospira borgpetersenii serovar hardjo is the most common cause of bovine leptospirosis and also causes zoonotic infections of humans. A protective killed vaccine against serovar hardjo was shown to induce strong antigen-specific proliferative responses by peripheral blood mononuclear cells (PBMC) from vaccinated cattle by 2 months after the first dose of vaccine. This response was absent from nonvaccinated control cattle. The mean response peaked by 2 months after completion of the two-dose vaccination regimen, and substantial proliferation was measured in in vitro cultures throughout the 7 months of the study period. Variations in magnitude of the response occurred among the vaccinated animals, but by 7 months postvaccination there was a substantial antigen-specific response with PBMC from all vaccinated animals. Up to one-third of the PBMC from vaccinated animals produced gamma interferon (IFN-gamma) after 7 days in culture with antigen, as ascertained by flow cytometric analysis, and significant levels of IFN-gamma were measured in culture supernatants by enzyme-linked immunosorbent assay. Two-color immunofluorescence revealed that one-third of the IFN-gamma-producing cells were gammadelta T cells, with the remaining cells being CD4(+) T cells. The significance of this study is the very potent Th1-type immune response induced and sustained following vaccination with a killed bacterial vaccine adjuvanted with aluminum hydroxide and the involvement of gammadelta T cells in the response. Moreover, induction of this Th1-type cellular immune response is associated with the protection afforded by the bovine leptospiral vaccine against L. borgpetersenii serovar hardjo.

Animals↗
PubMed1969

Benign leptospirosis: first reported outbreak in British Isles due to strains belonging to the Hebdomadis serogroup of Leptospira interrogans.

The clinical and epidemiological features associated with the first reported outbreak in the British Isles of benign anicteric leptospirosis, due to strains belonging to the hebdomadis subgroup, are described. Four cowherdsmen working in two dairy farms in Surrey developed a febrile illness which was not associated with jaundice, but aseptic meningitis was a feature. Microscopic agglutination tests with formolized antigen suspensions revealed a significant rise in the agglutinin titres against various serotypes belonging to the hebdomadis serogroup of Leptospira interrogans. The probable source was eventually traced to the cattle, which showed serological evidence of infection with the same serogroup.

Adult↗
PubMed1989

Severe disease in a dairy herd associated with acute infection with bovine virus diarrhoea virus, Leptospira harjo and Coxiella burnetii.

Between November 1984 and February 1985, a serious outbreak of pyrexia, diarrhoea, agalactia, metritis and severe weight loss affected most of the recently calved cows in a 183-cow dairy herd in Norfolk. Fifteen cows died and 20 were culled. Forty cows aborted during or after the outbreak, and many of them produced mummified fetuses; 18 calves were stillborn and three others died soon after birth. Necropsy of three affected cows revealed ulceration of the gastrointestinal tract similar to that seen in cases of mucosal disease. Bovine virus diarrhoea virus was isolated from the intestines of one cow that died soon after the onset of illness. The virus was also isolated from the blood of four acutely ill cows and seroconversion was demonstrated in three of those that survived. The virus was isolated from three aborted fetuses, a stillborn calf and a live neonatal calf. Body fluids from two aborted fetuses were seropositive for the virus as were sera from all the aborting cows tested. In addition to widespread seroconversion to bovine virus diarrhoea virus during the outbreak, there was serological evidence of recent infection with Leptospira interrogans serovar hardjo and Coxiella burnetii in a high proportion of cows. It was concluded that this was primarily an acute outbreak of bovine virus diarrhoea but its unprecedented clinical severity was probably associated with the concurrent introduction of L hardjo and C burnetii into an immunologically naive herd during the main calving period. Epidemiological analysis suggested that the source of the virus and L hardjo was down-calving heifers returning from communal marsh grazing.

Abortion, Veterinary↗