Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LEPTOSPIRA INFECTIONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources
PubMedDate not supplied

[The epidemiological and epizootiological characteristics of leptospirosis in the Republic of Sakha (Yakutia)].

Among zoonotic infections with natural foci in the Republic of Sakha (Yakutia), leptospiroses have assumed greater importance. Their morbidity is sporadic, mainly afflicting rural adults. The serogroups pomona, grippotyphosa, and icterohaemorrhagiae are prevalent in the etiological structure of leptospiras. An epizootiological survey has revealed natural and anthropurgic leptospirosis foci which present a hazard primarily to rural inhabitants who deal with animal husbandry, fur-bearer breeding, hunting, and fishing. The vole (Microtis) and root vole (Microtis oeconomus) serve as the major reservoir and source of leptospiroses in the natural foci, while cattle and caged Arctic foxes do in the anthropurgic ones. High sizes of house and grey mice which are carriers of the Leptospira javanica and icterohaemorrhagiae, have been recorded in the residential and domestic constructions of localities. A complex of antileprospirotic measures that limits the influence of the leading factors of infection transmission and the risk of human infection is substantiated.

Adult↗
PubMed1976

The effect of Leptospira hardjo vaccine in a northern Queensland beef herd.

In a northern Queensland beef herd where there was serological evidence of L. hardjo infection, lactation failure or wastage between pregnancy diagnosis and branding was 11.9% in animals vaccinated with a single dose of a L. hardjo vaccine and 19.4% in unvaccinated controls. This difference was statistically significant (P less than 0.05). Vaccination caused a significant (P less than 0.05) reduction in rate of lactation failure in heifers but not in other classes of cows.

Animals↗
PubMed2004

The etiology of febrile illness in adults presenting to Patan hospital in Kathmandu, Nepal.

In Nepal, many infections remain poorly characterized, partly due to limited diagnostic facilities. We studied consecutive febrile adults presenting to a general hospital in Kathmandu, Nepal. Of the 876 patients enrolled, enteric fever and pneumonia were the most common clinical diagnoses. Putative pathogens were identified in 323 (37%) patients, the most common being Salmonella enterica serotype Typhi and S. enterica serotype Paratyphi A (117), Rickettsia typhi (97), Streptococcus pneumoniae (53), Leptospira spp. (36), and Orientia tsutsugamushi (28). Approximately half of the Salmonella isolates were resistant to nalidixic acid. No clinical predictors were identified to reliably distinguish between the different infections. These findings confirm the heavy burden of enteric fever and pneumonia in Kathmandu, and highlight the importance of murine typhus, scrub typhus, and leptospirosis. Given the lack of reliable clinical predictors, the development of cheap and accurate diagnostic tests are likely to be of great clinical utility in this setting.

Adolescent↗
PubMed1984

Epidemiological aspects of canine leptospirosis in the Netherlands.

The epidemiology of canine leptospirosis has been examined in a limited study in the Netherlands from 1969 through 1982. Leptospira interrogans serotype icterohaemorrhagiae and canicola were found to be the only serotypes causing clinical leptospirosis. However, positive agglutination titres to the serotypes grippotyphosa, bratislava, poi and ballum have also been detected. The incidence of infection caused by serotype icterohaemorrhagiae was highest during summer and autumn. Infections with serotype canicola were more evenly distributed over the year with only a slight increase during summer and autumn. Infections caused by serotype canicola were significantly more prevalent in male dogs, whereas infections with serotype icterohaemorrhagiae were found both in males and females in almost equal numbers. The incidence of infections with serotype icterohaemorrhagiae was highest in immature dogs. Infections with serotype canicola were detected in young as well as older animals. In contrast to the situation in the past, infections with serotype icterohaemorrhagiae are now more common than those caused by serotype canicola, which have become rare. The highest incidence of infection was found in the western part of the country. The majority of infections was demonstrated in guard-dogs and sporting-dogs. Dogs proved to be of minor importance as a source of human infection in the Netherlands.

Age Factors↗
PubMed1975

Dependence of pathogenic properties of leptospires on animal subspecies.

1. Leptospires of mozdok serotype of the Pomona serogroup possessed specific pathogenic properties for a definite subspecies of Apodemus agrarius. They caused carriership in rodents of a European population, but were unable to cause such a process in Far East mice. However, leptospires of monjakov and pomona types were also unable to provoke leptospiruria in these small mammals. 2. The intensity of the formation of antibody to leptospires in different subspecies of Apodemus agrarius was dependent on the degree of their susceptibility, determined by the presence of renal leptospirosis. Leptospira-carriers among animals reacted by antibody formation 6-40 times more intensive than in those not susceptible to the infection. 3. Leptospires of pomona, monjakov and mozdok serotypes of the Pomona group taxonomically can be designated as separate subspecies, on the basis of differences in biological properties as related to their natural animal reservoirs.

Animals↗
PubMed2004

Dna probes for identification of leptospires and disease diagnosis.

A newly identified 1 kb DNA fragment amplified by PCR using (AG)8T inter-simple sequence repeats (ISSR) primer and a 631 bp segment of 16S rRNA ribosomal gene amplified by PCR using reported primers were labeled with a alpha32P dCTP for use as DNA probes. These probes were hybridized with DNA extracted from 19 standard pathogenic serovars, 3 standard saprophytic serovars, 33 pathogenic isolates (12 from patients, 1 from a tapwater source, and 20 from rodents), and 22 saprophytic isolates from environmental sources. The pathogen-specific 16S rRNA DNA probe specifically hybridized all 33 standard pathogenic serovars, to 13 pathogenic isolates. Similarly, the saprophyte specific 1 kb ISSR DNA probe specifically hybridized the 3 standard saprophytic serovars and the 22 saprophytic Leptospira isolates. The sensitivity of the 1 kb labeled saprophytic Leptospira specific DNA probe was 1.95 ng, and for the 16S rRNA pathogen specific probe 3.90 ng. The 16S rRNA gene segment DNA probe could also identify the leptospiremic stage in mice or guinea pigs infected experimentally with the pathogenic serovars australis, autumnalis or icterohaemorrhagiae. DNA probes therefore, owing to their high specificity and sensitivity, appear useful for easy, rapid, and reliable differentiation of pathogenic Leptospira strains and also hold promise for direct identification of organisms in blood samples to diagnose leptopsirosis.

Animals↗
PubMed1998

Retinal immunopathology in horses with uveitis.

BACKGROUND: Equine uveitis is a spontaneous disorder of horses that can serve as a model for the study of human uveitis. Although the initial presentation is that of an anterior uveitis, retinal involvement has been noted in some cases. We report here the immunohistopathology of retinas from horses with uveitis. METHODS: Sections of eyes recovered from horses with naturally occurring uveitis and from Shetland ponies with experimental leptospira-induced uveitis were stained by hematoxylin and eosin for histopathological evaluation. Immunohistochemistry was used to evaluate retinas for MHC Class II antigen expression and infiltration of T and B lymphocytes. RESULTS: Histopathological abnormalities in retinas from horses with uveitis ranged from minimal to total loss of retinal tissue. MHC Class II antigen-positive round and dendritiform cells were seen in these retinas, but were not seen in retinas from horses without uveitis. There was no significant reactivity noted in the retinal pigment epithelial cells or Muller cells. Numbers of MHC Class II antigen-expressing cells and T lymphocytes correlated with the extent of retinal histopathology. B lymphocytes were seen primarily in retinas from horses that were seroreactive for Leptospira interrogans serovar pomona. Retinas from ponies with experimental uveitis had changes similar to those from horses with spontaneous uveitis. CONCLUSIONS: These results suggest that retinal pathology may be a primary immunological event in equine uveitis, provide evidence that leptospira-associated uveitis may be a distinct subset of equine uveitides, underscore the relevance of the study of equine uveitis to human uveitis, and support the plausibility of a post-infectious immunopathogenesis of some naturally occurring uveitides in both humans and horses.

Animals↗
PubMed2005

[Phospholipase C activity and alteration of intracellular free Ca2+ levels during internalization of Leptospira interrogans].

OBJECTIVE: To determine the effects of leptospiral strains with different virulence on intracellular free Ca(2+)level and its relation with phospholipase C (PLC) activity of L.interrogans. METHODS: L.interrogans-j infection cell modals were established with Vero and J774A.1 cell lines. Vero and J774A.1 cells were co-incubated with L.interrogans serogroup Icterohaemorrhagiae serovar lai strain 56601 (strong virulence) and serogroup Pomona serovar pomona strain 56608 (weak virulence) and L.biflexa serogroup Samaranga serovar patoc strain Patoc I (non-virulence). Intracellular free Ca(2+)levels were detected by laser scanning confocal microscopy with specific fluorescence labeling of fluoj3/AM. Using [(3)H] PIP2 as the substrate, the PLC activities in the culture supernatant, and cytoplasma and cytomembrane of the three strains of Leptospira were measured by isotope assay. RESULTS: The baseline intracellular free Ca(2+)levels in the normal Vero and J774A.1 cells were (102.3+/-8.2)% and (105.9+/-7.3)%,respectively. The fluorescence intensity in the two cell lines incubated with L.biflexa strain Patoc I were fluctuated in range of (102.3+/-8.2)%approximate, equals(102.2+/-8.3)% during the observation period. The intracellular free Ca(2+)levels in the two cell lines infected with L.interrogans strain 56601 showed elevation with double peak patterns, with first peaks of (430.5+/-35.7)%, (747.5+/-18.5)% and the second peak of (380.6+/-17.4)%, (804.6+/-22.4)%, respectively. When the cells were infected with L.interrogans strain 56608, the intracellular free Ca(2+)levels were rising slowly with a single slope-like pattern, with the maximal of (235.0+/-19.3)% in Vero cells and (402.4+/-17.4)% in J774A.1 cells, which were significantly lower than those in the cells infected with L.interrogans strain 56601 (P<0.01). The culture supernatants, and cytoplasma and cytomembrane proteins of all three strains displayed PLC activities (P<0.05). CONCLUSION: The cells infected with L.interrogans of different virulence show distinct intracellular free Ca(2+)levels and peak patterns. The different host cell lines can affect the intracellular free Ca(2+)levels, which is not related to the PLC activity in the leptospiral strains.

Animals↗
PubMed2006

Evaluation of LSSP-PCR for identification of Leptospira spp. in urine samples of cattle with clinical suspicion of leptospirosis.

We evaluated the use of low-stringency single specific primer PCR (LSSP-PCR) for genetically typing Leptospira directly from urine samples of cattle with clinical suspicion of leptospirosis. Urine samples obtained from 40 cattle with clinical suspicion of leptospirosis were amplified by specific PCR using the following primers: Internal 1/Internal 2 and G1/G2. The internal primers were designed from the gene sequence of the outer membrane lipoprotein Lip32 from Leptospira kirschneri, strain RM52. The PCR products were amplified with these two pairs of primers, which had approximately 497 and 285bp, respectively, and were subsequently used as a template for LSSP-PCR analysis. The genetic signatures from the leptospires which were present in the urine samples allowed us to make a preliminary identification of the leptospires by comparing the LSSP-PCR profiles obtained directly from urine samples with those from reference leptospires. The LSSP-PCR profiles obtained with the Internal 1 primer or with the G1 primer allowed the grouping of the leptospires into serogroups. LSSP-PCR was found to be a useful and sensitive approach capable of identifying leptospires directly from biological samples without the need for prior bacterial isolation. In conclusion, the LSSP-PCR technique may still be helpful in discriminating serogroups of Leptospira from different animal reservoirs, since the early identification of carrier animals and information on the shedding state are crucial to prevent the spread of leptospiral infection to other animals and humans.

Animals↗
PubMed1975

Immunity to leptospirosis: antiserums in dogs and hamsters.

Resistance to clinical and renal leptospirosis in dogs injected with antiserum to Leptospira interrogans serotype canicola and Leptospira interrogans serotype icterohaemorrhagiae was demonstrated. The relationship between resistance induced in serum-injected hamsters was also demonstrated, using criteria of leptospiremia, renal infection, leptospiruria, and clinical signs of disease in dogs and death in hamsters.

Animals↗
PubMed1982

Leptospiral vaccines in dogs: immunogenicity of whole cell and outer envelope vaccines prepared in protein-free medium.

The immunogenicity of leptospires cultivated in modified bovine albumin-polysorbate 80 medium and those cultivated in protein-free medium were quantitatively evaluated in the dog. Vaccine preparations, whole cell or outer envelope, prevented leptospiremia; however, kidney culture data revealed that 1 of 4 dogs vaccinated with 0.1 to 1 mg of whole cell prepared from leptospires cultivated in the modified bovine albumin-polysorbate 80 medium was positive for Leptospira, whereas dogs vaccinated with whole cells prepared in protein-free medium were not. Dogs vaccinated with greater than or equal to 0.5 mg of outer envelope were refractory to infection after challenge exposure.

Animals↗
PubMed1983

Leptospirosis in rodents from an arid environment.

Rodents (n = 358) were trapped from 6 locations in Arizona, including 2 dairies, 2 swine raising operations, and 2 areas where domestic animal access was limited. Isolates of Leptospira interrogans serovar ballum were obtained from 3 house mice (Mus musculus) trapped in dairies. Leptospira were seen in silver-stained kidney sections of 10.4% of the rodents. The usefulness of serologic data in detecting leptospiral infection in these rodents was uncertain because so few animals yielded isolates that valid comparisons of culture positives to serologic positives were not possible. Titers greater than or equal to 1:160 were obtained to serovars autumnalis, ballum, bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona. Nearly 60% of the rodents had microscopic lesions in kidneys, including 20 of 34 (59%) of those in which leptospira were seen.

Animals↗
PubMed1984

Adhesion of leptospires to mouse fibroblasts (L929) and its enhancement by specific antibody.

The adhesion of leptospires (Leptospira interrogans serovar. copenhageni L45) to mouse L-cells was studied by microscopic observations. Within 3 h of infection of monolayers many leptospires adhered to 95-100% of the cells, and intracellular leptospires were demonstrated by electron microscopy. No specific site of attachment on the cells or the leptospires was observed. Avirulent or dead leptospires adhered poorly but attachment of the saprophytic leptospire L. biflexa serovar. patoc occurred on cell and glass surfaces. After adhesion, microvilli on the cell surfaces disappeared within 6 h of infection and cell damage was observed after 12 h. The adhesion was greatly enhanced by the presence of specific antiserum at a subagglutinating concentration. No direct penetration by leptospires of the host cells was observed with transmission and scanning electron microscopy. It appears that (1) adhesion of leptospires to L-cells precedes cell damage, and (2) leptospires may enter cells either through damaged membranes, or by a phagocytosis-like mechanism.

Adhesiveness↗
PubMed1975

Leptospira fort-bragg isolated from a rat in Barbados.

Leptospira fort-bragg was isolated from the kidney tissue of a rat (Rattus rattus) trapped on a plantation in St. Philip Parish, Barbados. This constitutes the first reported isolation of this Autumnalis group serotype outside of the United States and its first known isolation from an animal species. Serologic evidence is presented which indicates that this serotype may be the cause of leptospiral infections in Barbadian cattle.

Animals↗
PubMed1990

Lesions and immune responses produced in hamsters and guinea pigs inoculated with some strains of leptospira.

Pathogenic lesions and immune responses in hamsters and guinea pigs produced by three leptospiral serovars, viz. autumnalis, grippotyphosa, and pomona, and their pool were experimentally studied. Hepatic lesions precede renal localisation. The infections were documented by the demonstration of leptospires and histopathological study. The 2-Me sensitive IgM was responsible for MAT titres in the early immune response.

Animals↗
PubMed2003

[Leptospiral infection and subclinical presentation among children in Salvador, Bahia].

The purposes of this investigation were to identify the frequency and risk factors of leptospiral infection among children aged between 2 and 15 years in Salvador, Bahia, household contacts of patients (index-cases) hospitalized at Couto Maia Hospital due to Leptospira interrogans (ELISA IgM positive). Among 148 household contacts from 25 selected index-cases, clinical and epidemiological data were collected and ELISA IGM and IgG were performed in paired sera (between 20 days) from 73 (49.3%). This diagnostic method divided the 73 household contacts into three groups: group A (acute or recent leptospiral infection), 30 (41.1%) children, group B (not- infected ) 34 (46.6%) and group C, (past infection) nine (12.3%) children. In group A five (16.7%) had cold syndrome simile. No statistically significant difference was found between groups A and B for sex, race, age and presence of pet dog. However, in group A there was a statistically significant predominance (p < 0.05%) of: contact with natural water courses; index-case sibling aged under fifteen years; female sex and over 9 years old; and principally lack of appropiate trash disposal in the residential area. In conclusion, leptospiral infection in children (from 2 to 15 years of age) in Salvador is underestimated, because it is asymptomatic or presents as a cold syndrome simile.

Adolescent↗