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Results for “LEPTOSPIRA INFECTIONS”

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At least 415 records · Page 23Linked to original sources
PubMed1998

Pneumonia due to Leptospira spp.: results of an epidemiological and clinical study.

OBJECTIVE: To evaluate the prevalence of Leptospira spp. infections in a population of in- and out-patients with community acquired pneumonia (CAP) and the incidence of leptospiral pneumonia. DESIGN AND RESULTS: Of 176 patients infected with CAP who were evaluated for the presence of Leptospira spp. as causative agent, 10 were found positive for leptospiral antibodies (prevalence rate: 5.7%), but seroconversion was observed in only one case (incidence rate: 0.6%). The patient had had recent contact with possibly contaminated water. She had pulmonary involvement and signs of mild hepatic damage, but recovered fully. CONCLUSION: The authors highlight the importance of testing for leptospirosis in case of pneumonia in endemic areas where the more common causative pathogens for CAP can not be documented and when initial empiric therapy is ineffective.

Adult↗
PubMed2004

Effect of bovine viral diarrhea virus infection on fertility of dairy heifers.

A prospective field study in heifers from birth to first breeding was undertaken on two commercial dairies to assess the effect of bovine viral diarrhea virus (BVDV) congenital and post-natal infection (PNI) on fertility. A high BVDV Type 2 antibody titer (1:4096) at 10 months of age was associated with 32 more days to conceive, compared with a low titer (1:128). Conversely, infection with BVDV by 5-6 months of age and high BVDV Type 2 titers 1 month before conception or breeding was associated with improved fertility. Heifers with evidence of congenital BVDV infection had lower fertility than non-infected heifers (15-42 days longer time-to-first AI), which depended on BVDV Type 2 titers at 10 months of age. Neospora caninum infection was associated with additional services per conception (SPC) and Leptospira interrogans infection was associated with a delay in the time-to-first breeding. It appears that under field conditions, the effect of subclinical BVDV infection on subsequent heifer fertility may be due to a complex of interrelationships among multiple BVDV infections that depend on the type and timing of infection relative to reproductive development and events.

Animals↗
PubMed1987

[Familial hemophagocytic lymphohistiocytosis (case report)].

This is the report of a female infant ten weeks of age, who was admitted to our hospital with hyperpyrexia, hemolytic anemia and disseminated intravascular coagulation. The further course of the disease was characterized by: continuing hemolysis resulting in severe normochromic, normocytic anemia, unrelenting disseminated intravascular coagulation, increasing hepato-splenomegaly with hyperbilirubinemia and ascites. No causative infectious organism could be identified. The infant died at the age of 14 weeks from respiratory insufficiency. Autopsy revealed massive hepato-splenomegaly, ascites and bilateral pneumonia. Histologic evaluation demonstrated lymphohistiocytic infiltrates of the periportal areas of the liver, the spleen and lymphnodes. Meninges were infiltered by macrophages with ingested erythrocytes. Differential diagnosis includes an infection with leptospira icterohemorrhagica (Weils disease) and erythrophagocytosis observed after various viral infections. Also histiocytosis X or malignant histiocytosis has to be taken into consideration. The most probable diagnosis in our patient is that of familiar hemophagocytic reticulosis although the familiarity in our patient was lacking. Intra vitam diagnosis can only be established by liver biopsy which could not be performed in our patient due to the severe coagulation disturbance.

Anemia, Hemolytic, Congenital↗
PubMed1989

Effect of vaccination with a bacterin containing Leptospira interrogans serovar bratislava on the breeding performance of swine herds.

Swine herds suspected to be infected with Leptospira interrogans serovar bratislava were vaccinated with bacterins containing 5 or 6 leptospiral serovars in which serovar bratislava was the unique component. The principal diagnostic feature indicating an infection by this organism was demonstration of antibody against serovar bratislava in sera from stillborn pigs. For 1 breeding cycle after vaccination of herds on 3 farms, 255 of 266 (95.9%) sows and gilts given the 6-serovar bacterin farrowed. In contrast, 233 of 311 (74.9%) sows and gilts given the 5-serovar bacterin farrowed. These results, as evaluated by analysis of variance techniques, showed a significant improvement (P less than 0.01) in reproductive performance for groups vaccinated against serovar bratislava.

Animals↗
PubMed1985

Bovine leptospirosis: some clinical features of serovar hardjo infection.

During an investigation of natural in utero infection of cattle by Leptospira interrogans strains, infection (almost entirely caused by serovar hardjo) was diagnosed in 57 per cent of 505 calves (472 aborted fetuses, 20 stillborn calves and 13 perinatal deaths) examined over a six-year period. The prevalence of leptospire-infected fetuses showed a seasonal increase in September, October and December and was significantly higher in fetuses aborted by dairy cows than in fetuses aborted by beef cows. The majority of infected fetuses were aborted from the sixth month of gestation onwards. Cows which aborted infected fetuses had not previously exhibited overt signs of agalactia. There was an association between leptospiral infection and retention of fetal membranes.

Abortion, Veterinary↗
PubMed1997

[Immunogenecity of expressed protein p68 from recombinant plasmid rpDJt in L. interrogans serovar lai].

There are two types of infection caused by pathogenic microorganisms, intracellular infection and intercellular infection. Infection of pathogenic leptospira is an intercellular infection. The immunological reaction of host to intercellular infection is unique. The potential immunogen of an expressed protein should meet three criteria: it can be degraded (by antigen-present cells in the host); it should have antigenic epitope which can be recognized by specific antibodies and have at least one epitope that can be recognized by an MHC II protein and T cell receptor. In this study we report the cloning of an L. interrogans protein in plasmid rpDJt and the immunogencity of the expressed protein derivative. A genomic library of L. interrogans serovar lai strain 017 was constructed with the plasmid vector pUC18. Recombinant plasmids, designated pDJH2 and pDJ8 were screened from the bank. EcoRI-inserted fragment of 1. 9 kb recombinant DNA of pDJH2 was ligated into T7 RNA polymerase/promoter vectors (pT7-7). Then they were transformed into E. coli JM109 (De3), one of subclones, designated rpDJt was achieved. SDS-PAGE showed that the molecular weights of expression proteins were 68 kd and 23 kd respectively, designated p68 and p23. Purifying and isolating p68 and p23, we separated them from SDS-Polyacrylamide gels by using Side-Strip method. After fragmenting and electroeluting, p68 and p23 were injected into guinea pigs and rabbits. An extremely strong immune response to p68 was obtained since an anti-p68 antibody response could be detected to a dilution 1:524,288 (guinea pigs) and 1:262,144 (rabbits) by ELISA while anti-P23 antibody being 1:1024 (the same to guinea pigs and rabbits). The results of improved MTT and conA 3HTdR transformation methods showed the activities and proliferation of Th-cells were increased in guinea pigs after p68 immunization (IL-6, 83.25 IU/ml, IL-2, 28.75 IU/ml; RPI, 2.04, SI, 65.62%) Thlymphocyte existed in two subclasses, the Th1- and Th2-cells. A major role of Th2-cells is to "help" B-cells differentiate, replicate, and secrete antibody. The properties of these interactions explain why p68 makes good antigen and p23 does not. The antigens responsible for eliciting the production of protective antibodies are not known; however, several outer membrane proteins on L. interrogans are candidates for vaccine. Our results suggest that expresion protein p68 from recombinants (rpDJt) may be a candidate for gene engineered subunit vaccine for Leptospirosis.

Animals↗
PubMedDate not supplied

[High resolution light microscopy: adaptation of the method and its use in the study of experimental leptospirosis in guinea pigs].

Morphological lesions in parenchimal and mesenchimal structures of liver and kidney were studied in guinea-pigs experimentally infected with Leptospira interrogans serogroup icterohaemorrhagiae in comparison with a group of non-infected guinea-pigs. All specimens were submitted to conventional light microscopy as well as to high resolution light microscopy, in one micrometer sections of tissue embedded in glycolmethacrylate. High resolution light microscopy, applied for the first time in leptospirosis, was proved very useful, since it enabled us to visualize cellular structures in the same slide used for panoramic view. Cell cohesion, brush borders, pynocytotic vesicles and organellae distributions were parameters especially suitable for analysis at this low-cost, highly precise procedure in microscopy.

Animals↗
PubMed1998

Sanitary status of oocytes and embryos collected from heifers experimentally exposed to Leptospira borgpetersenii serovar hardjobovis.

In a preliminary trial and three experiments, a total of 30 Holstein heifers were experimentally infected with a culture of Leptospira borgpetersenii serovar hardjobovis via one or more routes (uterine, cervical supraconjunctival, intranasal) and oviductal and uterine fluids recovered post-mortem or in vivo following superovulation with FSH. All routes of administration were effective in establishing Leptospira infection in the reproductive tract and Leptospira were identified in the oviductal and uterine fluids of all 30 heifers by microscopy. The incidence of infection was confirmed by positive identification of serum antibodies by the microscopic agglutination test (MAT). Twenty-one samples of the embryos (n = 59) recovered were cultured using bacteriological procedures and all tested negative for the infectious microorganism. Using polymerase chain reaction (PCR) assay, however, showed that 29% (7/24) of morula and blastocyst stage embryos, and one out of 29 oocytes tested positive for the presence of leptospiral DNA. A single oocyte or embryo collected from the infected heifers was inoculated intravenously to 26 test heifers. None of the test heifers developed antibody titers to Leptospira. It was concluded that, despite the presence of leptospires in the reproductive tract of donor animals and the association of leptospiral DNA with uterine stage embryos, the transmission of this disease is unlikely to occur by transfer of in vivo produced embryos in the bovine.

Animals↗
PubMed2006

A model of Leptospirosis infection in an African rodent to determine risk to humans: seasonal fluctuations and the impact of rodent control.

Human leptospirosis (Leptospira spp. infection) is a worldwide public health problem that is of greatest concern for humid tropical and subtropical regions. The magnitude of the problem in these areas is larger because of the climatic and environmental conditions the bacterium face outside their hosts but also because of the frequency of contacts between people and sources of infection. Rodents are thought to play the most important role in the transmission of human leptospirosis. We here model the dynamics of infection in an African rodent (Mastomys natalensis) that is thought to be the principal source of infection in parts of Tanzania. Our model, representing the climatic conditions in central Tanzania, suggests a strong seasonality in the force of infection on humans with a peak in the abundance of infectious mice between January and April in agricultural environments. In urban areas the dynamics are predicted to be more stable and the period of high numbers of infectious animals runs from February to July. Our results indicate that removal of animals by trapping rather than reducing the suitability of the environment for rodents will have the greater impact on reducing human cases of leptospirosis.

Animals↗
PubMed1986

Bovine leptospirosis: experimental serovar hardjo infection.

Almost the full range of clinical signs observed in pregnant cattle naturally infected with Leptospira interrogans serovar hardjo was observed in this experimental study in which 22 heifers were infected by intraplacentome inoculation with serovar hardjo strains. These features included abortion, mummification, stillbirth, premature and term birth of weak calves and full-term birth of live apparently healthy calves. Leptospires were demonstrated in all but three calves by culture and or immunofluorescence.

Animals↗
PubMed1992

[The significance of small mammals in the epizootiology of leptospirosis in livestock].

1. Favourite species of rodents in sheds and their surroundings are rats (Rattus norvegicus, R. rattus) and house mouse (Mus musculus). From the epizootiological point of view only R. norvegicus is important as the maintenance host of L. copenhageni. 2. In surrounding of sheds vole (Microtus arvalis) and back-striped field mouse (Apodemus agrarius) are sources of infection for livestock. 3. Transmission of leptospira occurs via infected environment. The tenacity of Leptospira mozdok and L. grippotyphosa under field conditions suffices to maintain the chain of infections.

Animals↗
PubMed1985

Experimental infection of lactating goats with Leptospira interrogans serovars pomona and hardjo.

Pathogenesis of Leptospira interrogans serovars pomona and hardjo was evaluated in 14 lactating goats. Although mild clinical signs of leptospiral infection characterized by pyrexia and reduction in milk yield appeared in some animals, a consistent clinical pattern was not observed in the inoculated animals. The pomona serovar was isolated from the kidney of 1 of the 4 goats inoculated with serovar pomona. The hardjo serovar (strain UI 750) was isolated in the rabbit serum-supplemented bovine albumin polysorbate-80 liquid medium only from the mammary gland of 1 of 4 goats at 13 days after inoculation with serovar hardjo. The positive culture was detected after an 8-month incubation period.

Animals↗