SEARCH · PubMed Health

Results for “LEPTOSPIRA”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 109 records · Page 6Linked to original sources

PubMed2002

The Leptospira outer membrane protein LipL32 induces tubulointerstitial nephritis-mediated gene expression in mouse proximal tubule cells.

Tubulointerstitial nephritis is a main renal manifestation caused by pathogenic leptospira that accumulate mostly in the proximal tubules, thereby inducing tubular injury and tubulointerstitial nephritis. To elucidate the role of leptospira outer membrane proteins in tubulointerstitial nephritis, outer membrane proteins from pathogenic Leptospira shermani and nonpathogenic Leptospira patoc extracted by Triton X-114 were administered to cultured mouse proximal tubule cells. A dose-dependent increase of monocyte chemoattractant protein-1 (MCP-1), RANTES, nitrite, and tumor necrosis factor-alpha (TNF-alpha) in the culture supernatant was observed 48 h after incubating Leptospira shermani outer membrane proteins with mouse proximal tubule cells. RT competitive-PCR experiments showed that Leptospira shermani outer membrane proteins (0.2 microg/ml) increased the expression of MCP-1, nitric oxide synthase (iNOS), RANTES, and TNF-alpha mRNA by 3.0-, 9.4-, 2.5-, and 2.5-fold, respectively, when compared with untreated cells. Outer membrane proteins extract from avirulent Leptospira patoc did not induce significant effects. The pathogenic outer membrane proteins extract contain a major component of a 32-kD lipoprotein (LipL32), which is absent in the nonpathogenic leptospira outer membrane. An antibody raised against LipL32 prevented the stimulatory effect of Leptospira shermani outer membrane proteins extract on MCP-1 and iNOS mRNA expression in cultured proximal tubule cells, whereas recombinant LipL32 significantly stimulated the expression of MCP-1 and iNOS mRNAs and augmented nuclear binding of nuclear factor-kappaB (NF-kappaB) and AP-1 transcription factors in proximal tubule cells. An antibody raised against LipL32 also blunted the effects induced by the recombinant LipL32. This study demonstrates that LipL32 is a major component of pathogenic leptospira outer membrane proteins involved in the pathogenesis of tubulointerstitial nephritis.

Animals↗

PubMed2003

Low-stringency single specific primer PCR for identification of Leptospira.

Thirty-five Leptospira serovars from the species Leptospira interrogans, Leptospira borgpetersenii, Leptospira santarosai, Leptospira kirschneri, Leptospira weilii, Leptospira biflexa and Leptospira meyeri were characterized by the low-stringency single specific primer PCR (LSSP-PCR) technique. LSSP-PCR analysis was performed to detect DNA polymorphisms in a 285 bp DNA fragment amplified from genomic DNA with G1 and G2 selected primers. Similar LSSP-PCR profiles were obtained for serovars from the same genomic species, while serovars from non-related species produced distinct multiband patterns. Based on the data from sequence analysis, all genomic fragments amplified with G1 and G2 primers from distinct serovars of Leptospira were 285 bp in length, with nucleotide variation observed most frequently among different genomic species. The simplicity and accuracy of the LSSP-PCR technique were found to be suitable for identification of Leptospira species.

Base Sequence↗

PubMed2006

Characterization of the outer membrane proteome of Leptospira interrogans expressed during acute lethal infection.

Pathogenic Leptospira species adapt to a wide range of environmental conditions during disease transmission and infection. While the proteome of in vitro cultivated Leptospira has been characterized in several studies to date, relatively little is known of the proteome as expressed by Leptospira during disease processes. Isolates of Leptospira obtained from patients suffering the severe pulmonary form of leptospirosis cause acute lethal infection in guinea pigs and chronic asymptomatic infection in rats. Recent studies have demonstrated that protein and lipopolysaccharide constituents of Leptospira recovered from acutely infected guinea pig tissue differ from that of Leptospira in chronically infected rat tissue and in vitro cultivated Leptospira (J. E. Nally, E. Chow, M. C. Fishbein, D. R. Blanco, and M. A. Lovett, Infect. Immun. 73:3251-3260, 2005). In the current study, the proteome of Leptospira expressed during disease processes was characterized relative to that of in vitro cultivated Leptospira (IVCL) after enrichment for hydrophobic membrane proteins with Triton X-114. Protein samples were separated by two-dimensional gel electrophoresis, and antigens expressed during infection were identified by immunoblotting with monospecific antiserum and convalescent rat serum in addition to mass spectrometry. Results suggest a significant increase in the expression of the outer membrane protein Loa22 during acute infection of guinea pigs relative to other outer membrane proteins, whose expression is generally diminished relative to expression in IVCL. Significant amounts of LipL32 are also expressed by Leptospira during acute infection of guinea pigs.

Adaptation, Physiological↗

PubMed2003

An evaluation of the serological and epidemiological effects of the outer envelope vaccine to leptospira.

BACKGROUND: The Shanghai Institute of Biological Products manufactured successfully a new outer envelope vaccine for leptospira in 1978. It has been confirmed by using animal tests and a number of human body trials that this vaccine is safe and effective, However, results regarding serological and epidemiological effects of the vaccine in population has not been reported. The objective of this study was to evaluate serological and epidemiological effects of this vaccine. METHODS: From May 1998 to May 1999, an evaluation of the serological and epidemiological effects of the outer envelope vaccine for leptospira made by Shanghai Institute of Biological Products was conducted among agricultural population aged 5 to approximately 60 years in an epidemic area of leptospirosis, in Jingzhou District, Jingzhou City, Hubei Province, China by microscopic agglutination test (MAT), cohort study, matched case-control study and screening method. RESULTS: The serological surveillance results of 77 students immunized showed that the successful rates of vaccination with the outer envelope vaccine of L. icterohaemorrhagiae sero-group and L. hebdomadis sero-group leptospira were 79.22% and 77.92%, respectively, the antibody geometric mean titer (GMT) of the two groups were 1:106.71 and 1:63.31, respectively, with 6.7-fold and 4.7-fold rises comparing with the group of those of the antibody before inoculation, and the antibody protective rates of the two groups of outer membrane protein vaccine of leptospira all were 100% at one month after immunization. Higher level antibody against L. icterohaemorrhagiae sero-group leptospira was still maintained at one year after injection. The results of cohort analysis showed that the protective rate of the outer envelope vaccine of leptospira for the same serological groups of leptospira was 75.17%, and the effective index of the vaccine was 4.03. The protective rate of vaccines obtained from 1:2 matched case-control studies was 81.25%, while that estimated by screening method was 75%. CONCLUSIONS: The study results showed that the serological and epidemiological efficiencies of leptospira vaccine all were ideal. In addition, this vaccine had partly protective effect against other sero-groups of leptospira.

Adolescent↗

PubMed1963

EFFECTS OF CARBON DIOXIDE ON THE COLONIAL GROWTH OF PATHOGENIC LEPTOSPIRAE.

Yanagawa, R. (National Institute of Animal Health, Kodaira, Tokyo, Japan), T. Hiramune, and J. Fujita. Effects of carbon dioxide on the colonial growth of pathogenic leptospirae. J. Bacteriol. 85:875-880. 1963.-The growth of colonies of pathogenic leptospirae was examined in air of various CO(2) concentrations, ranging from air from which CO(2) was absorbed to air with 20% CO(2) added, and was compared with the growth of other microorganisms of the genera Mycoplasma, Brucella, Vibrio, Erysipelothrix, Staphylococcus, Micrococcus, Sarcina, Klebsiella, Salmonella, Escherichia, and Bacillus. The colonial growth of the 24 strains of pathogenic leptospirae examined was similar to that of other organisms in that the growth was negative in air from which naturally contained CO(2) had been absorbed, the growth tended to be inhibited in 5 to 20% CO(2) in proportion to the CO(2) concentration, and good colonial growth of leptospirae was obtained in a relatively narrow range of CO(2) concentration (from the normal amount in air to around 1%). The growth of some leptospirae was accelerated in 1% CO(2), but not that of the strains of Leptospira icterohaemorrhagiae, which required a lower range of CO(2), and of L. canicola. The CO(2) requirement of pathogenic leptospirae was similar, to some extent, to that of Mycoplasma mycoides, but was not so high as that of Brucella abortus. Incorporation of C(14)O(2) was demonstrated in leptospirae.

Animals↗

PubMed1968

Water strains of Leptospira in the serodiagnosis of human and animal leptospirosis.

The most widely used serological reaction for the diagnosis of leptospirosis is the agglutination test. This test, however, cannot be carried out in many laboratories because special equipment and special experience are required. It is also necessary to maintain live Leptospira cultures belonging to all the serotypes present in the country where the test is made. Consequently, it would be extremely useful to be able to diagnose leptospirosis by means of a single antigen, regardless of the serotype to which the Leptospira responsible for the infection belonged. This is particularly important for countries in which the antigenic pattern of the local leptospirae is not well known and in which it would thus be necessary to use a large number of Leptospira serotypes for each test.Observations made in the last 11 years have suggested that the problem may be solved with the use of some non-pathogenic, water strains of Leptospira which seem to be agglutinated by human sera containing antibodies against pathogenic leptospirae. This paper reports the results of studies from 1960 to 1968 on the possibility of using water strains for serodiagnosis.The results over the 8-year period show that the non-pathogenic strain Patoc 1 is agglutinated by a high percentage of human sera positive for pathogenic leptospirae: these results indicate that Patoc 1 would be useful for serodiagnosis. However, a high percentage of animal sera positive for pathogenic leptospirae gave negative results with the strains Patoc 1 and Sao Paulo, and thus these strains cannot be used for serodiagnosis in animals.

Agglutination Tests↗

PubMed1996

[Leptospira antibodies in small mammals in Eastern Slovakia].

During the five years (1991-1995) mostly free living small mammals were examined serologically for the presence of antibodies to leptospira. Serological examinations were used by Kmety and Bakoss (1978). Altogether, 2493 individuals of 22 species were examined, an important part of host material (69.6%) was caught in two lowland areas which are intensively cultivated landscapes (East Slovakian Lowland and Kosická kotlina basin). The remaining material comes from submontane areas with less agricultural activities. Apodemus flavicollis, A. agrarius, Clethrionomys glareolus were the most frequently examined species. Antibodies to leptospira were demonstrated in 123 mammals (i. e. in 5.0% of hosts) of eleven species. The highest percentage of positive hosts were recorded in 1993 (8.8%) and the lowest (2.6%) in 1995, but the examined samples were different in size and structure of host species. In six most dominant species higher values of antibodies to leptospira were detected in Microtus arvalis (9.2%), followed by Apodemus flavicollis (5.6%), A. agrarius (5.4%) and A. microps (4.9%). The lowest values were found in Clethrionomys glareolus (2.5%) and Sorex araneus (2.3%). In examined hosts we found antibodies to six serovars of leptospira. The most frequently observed antibodies were to leptospira of the serovar L. grippotyphosa (63.2%) and leptospira of the serovar L. sejroe (26.4%). We recorded nonsignificant differences between the values of prevalence to antibodies in small mammal communities from lowland and submontane areas, resp. Our results confirmed differences in the leptospira serovar structure in small mammals of Bohemia and Slovakia, they were connected with different historical development of both areas. Comparing our results with previous examinations (about 20 years ago) in small mammals from eastern Slovakia, a decline of positivity and lower number of leptospira serovars were recorded.

Animals↗

PubMed1964

CULTIVATION OF LEPTOSPIRAE. II. GROWTH AND LYSIS IN SYNTHETIC MEDIUM.

Stalheim, O. H. V. (University of Wisconsin, Madison), and J. B. Wilson. Cultivation of leptospirae. II. Growth and lysis in synthetic medium. J. Bacteriol. 88:55-59. 1964.-Differences were found in the ability of leptospirae to grow in a synthetic medium; 43 strains, consisting of 16 serotypes, were tested and designated as either type I or type II. Type I leptospirae did not grow; type II grew and could be subcultured. The lytic effect of several lipids was measured with Leptospira pomona and L. canicola as representatives of type I and II leptospirae, respectively. L. pomona organisms were rapidly lysed by the monoolein of the synthetic medium and by other lipids as well; L. canicola cells were consistently more resistant. Although both organisms incorporated similar amounts of label when incubated in the presence of oleic-1-C(14) acid, only L. canicola grew in a modified, nonlytic synthetic medium. No differences were found in susceptibility to lysis between virulent and avirulent L. canicola organisms. Mutant type I leptospirae grown in synthetic medium had increased resistance to lysis by surface-active agents; they were poorly agglutinated by antiserum. The role of protein in the growth and antigenicity of type I leptospirae is discussed.

Bacteriolysis↗

PubMed1985

[Fatty acid composition of Leptospira lipids as a taxonomic criterion].

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.

Chromatography, Thin Layer↗

PubMed2006

PCR detection of pathogenic Leptospira genomospecies targeting putative transcriptional regulator genes.

The genus Leptospira comprises multiple genomospecies that demonstrate varied pathogenic potential. The availability of rapid and precise diagnostic procedures to differentiate pathogenic from nonpathogenic Leptospira spp. is therefore essential to prevent an otherwise easily treatable malaise from developing into a life-threatening disease. In this report, we conducted an investigation on the diagnostic potential of Leptospira genes encoding putative transcriptional regulators. While PCR primers derived from transcriptional regulator gene la1137 recognized all 24 pathogenic Leptospira strains representing seven species, those from la1937, la3231, la3825, and la4130 detected 19 of the 24 Leptospira strains. However, none of these primers reacted with four nonpathogenic Leptospira species or other common bacteria. The putative transcriptional regulator genes la1137, la1937, la3231, la3825, and la4130 are present in pathogenic Leptospira strains, making them potential targets for diagnostic applications. Further characterization of these genes and their proteins may help elucidate the molecular mechanisms of leptospiral virulence and pathogenicity and pave the way for potential development of novel control strategies against leptospirosis.

Genes, Regulator↗

PubMed2006

Identification of pathogenic Leptospira species by conventional or real-time PCR and sequencing of the DNA gyrase subunit B encoding gene.

BACKGROUND: Leptospira is the causative genus of the disease, leptospirosis. Species identification of pathogenic Leptospira in the past was generally performed by either DNA-DNA hybridisation or 16s rRNA gene sequencing. Both methods have inherent disadvantages such as the need for radio-labelled isotopes or significant homology between species. A conventional and real-time PCR amplification and sequencing method was developed for an alternate gene target: DNA gyrase subunit B (gyrB). Phylogenetic comparisons were undertaken between pathogenic Leptospira 16srRNA and gyrB genes using clustering and minimum evolution analysis. In addition 50 unidentified Leptospira isolates were characterised by gyrB sequencing and compared with conventional 16s rRNA sequencing. RESULTS: A conventional and real-time PCR methodology was developed and optimised for the amplification of the gyrB from pathogenic Leptospira species. Non pathogenic and opportunistic Leptospira species such as L. fainei and L. broomi were not amplified. The gyrB gene shows greater nucleotide divergence (3.5% to 16.1%) than the 16s rRNA gene (0.1% to 1.4%). Minimum evolution analysis reveals that the gyrB has a different evolution topology for L. kirschneri and L. interrogans. When the two genes were compared for the identification of the 50 unknown isolates there was 100% agreement in the results. CONCLUSION: This research has successfully developed a methodology for the identification of pathogenic Leptospira using an alternate gene to 16s rRNA. The gyrB encoding gene shows higher nucleotide/evolutionary divergence allowing for superior identification and also the potential for the development of DNA probe based identification.

Base Sequence↗

PubMed1975

Nucleic acid content and nucleotide composition of DNA in leptospirae.

The contents of DNA and RNA were studied in 9 strains of leptospirae and the composition of nitrogen bases of DNA in 20 strains of pathogenic and saprophytic leptospirae. It has been found that leptospirae contain a high per cent ration of nucleic acids. According to the nucleotide composition, the family of Leptospira as a whole belongs to the AT-type. According to overall guanine and cytosine contents, the investigated strains of pathogenic leptospirae fall into 3 groups and differ from the seprophytic strains. With respect to the limited number of the investigated strains, the DNA nucleotide composition of leptospirae can be used as a supplementary biochemical criterion in the classification of leptospirae.

Chromatography, Paper↗

PubMed2003

[Distribution of virulence associated genes among strains of Leptospira].

OBJECTIVE: To analyze factors related to the virulence associated genes of Leptospires. METHODS: Twelve putative virulence associated genes were detected by polymerase chain reaction (PCR) method in 38 reference strains, 81 field strains of Leptospira interrogans isolated from patients or animals, and 12 avirulent strains of Leptospira biflexa. RESULTS: These putative virulent genes were widely distributed among the strains of Leptospira interrogans, but only few of them were detected in Leptospira biflexa. Gene lipL32 was detected in all strains of Leptospira interrogans. Distribution of gene lipL36 was varied significantly with detected rates from 0 to 90.91%. Gene la1608 had a positive rate of 87.50% for strains of serogroup Icterohaemorrhagiae, but was only detected in few strains of other serogroups with a range from 0 to 25.00%. Rate of detection on gene sphA was 17.65% in Leptospira interrogans, and was absent in serovar hardjo reference strain. CONCLUSION: Results indicated that these genes might be of importance for the virulence and pathogenicity of Leptospira interrogans, while gene lipL32 might be one of the common antigens. Gene lipL36 might be involved in serogroup specificity with genetic diversity, but gene la1608 was as one of the genes with specificity for serogroup Icterohaemorrhagiae. However, serovar hadjo might hold quite different genetic characteristics when compared with the other serovars of Leptospires.

Bacterial Outer Membrane Proteins↗

PubMed1993

[Occurrence of Leptospira antibodies in the blood of game animals].

The blood serum of game was examined for the presence of antibodies to Leptospiras in 1987-1989. A total of 792 blood sera from animals belonging to 14 zoo-species were examined (Tab. I). The blood serum of red deer (Cervus elephus) was examined the most often within the group of animals, in 398 cases, i.e. 50.2%, followed by 165 blood sera of wild boar (Sus scrofa), representing 20.8%, and by 136 blood sera of roedeer (Capreolus capreolus), representing 18.6%. Small numbers of blood sera of the other animals were examined. A serological reaction of microagglutination-lysion revealed the antibodies to Leptospiras in fifty examined samples, i.e. 6.31%, of the six examined zoo-species: muskrat (Ondatra zibethica) 14.28%, wild boar (Sus scrofa) 13.93%, roedeer (Capreolus capreolus) 6.76%, fox (Vulpes vulpes) 5.26%, red deer (Cervus elephus) 3.76%, mouflon (Ovis musimon) 2.50%. No antibodies to Leptospiras were found in the blood serum of the other animal species (Tab. I). Twelve strains of Leptospira were used for serological examination according to the standard method (Sebek, 1979). The examined blood sera of game reacted only with Leptospiras of the serotype L. grippotyphosa. No reaction with other Leptospira serotypes was observed. Our results have demonstrated, in comparison with the results of foreign authors, great susceptibility of the game to infection with different serotypes of Leptospira. But it is possible to say that with certain exceptions these game species do not play an important role in the epidemiology of Leptospirosis.

Animals↗

PubMed2006

Partial rpoB gene sequencing for identification of Leptospira species.

The usual target for sequence-based identification of Leptospira species is the 16S rRNA gene. However, because the 16S rRNA gene is not polymorphic enough, it is necessary to sequence a 1500 bp segment of this gene for accurate identification. Based on the alignment of previously determined rpoB of three Leptospira strains, we designed and tested a primer pair that enabled us to amplify and sequence a 600 bp segment of Leptospira rpoB. This segment was species-specific for the 16 species tested, but was unable to separate Leptospira interrogans serovars accurately. For the 11 L. interrogans serovars tested, only seven genotypes could be determined. We thus think that analysis of partial rpoB may be useful as an initial screening test for the identification of a new isolate of Leptospira and detection or identification of Leptospira in clinical or environmental samples, but not for serovar determination.

Bacterial Typing Techniques↗

PubMed2005

The vitamin K-dependent carboxylase has been acquired by Leptospira pathogens and shows altered activity that suggests a role other than protein carboxylation.

Leptospirosis is an emerging infectious disease whose pathology includes a hemorrhagic response, and sequencing of the Leptospira interrogans genome revealed an ortholog of the vitamin K-dependent (VKD) carboxylase as one of several hemostatic proteins present in the bacterium. Until now, the VKD carboxylase was known to be present only in the animal kingdom (i.e. metazoans that include mammals, fish, snails, and insects), and this restricted distribution and high sequence similarity between metazoan and Leptospira orthologs strongly suggests that Leptospira acquired the VKD carboxylase by horizontal gene transfer. In metazoans, the VKD carboxylase is bifunctional, acting as an epoxidase that oxygenates vitamin K to a strong base and a carboxylase that uses the base to carboxylate Glu residues in VKD proteins, rendering them active in hemostasis and other physiologies. In contrast, the Leptospira ortholog showed epoxidase but not detectable carboxylase activity and divergence in a region of identity in all known metazoan VKD carboxylases that is important to Glu interaction. Furthermore, although the mammalian carboxylase is regulated so that vitamin K epoxidation does not occur unless Glu substrate is present, the Leptospira VKD epoxidase showed unfettered epoxidation in the absence of Glu substrate. Finally, human VKD protein orthologs were not detected in the L. interrogans genome. The combined data, then, suggest that Leptospira exapted the metazoan VKD carboxylase for some use other than VKD protein carboxylation, such as using the strong vitamin K base to drive a new reaction or to promote oxidative damage or depleting vitamin K to indirectly inhibit host VKD protein carboxylation.

Amino Acid Sequence↗

PubMed2001

flaB-polymerase chain reaction (flaB-PCR) and its restriction fragment length polymorphism (RFLP) analysis are an efficient tool for detection and identification of Leptospira spp.

For establishment of a rapid-identification method of Leptospira species, a flaB gene of Leptospira was investigated and the following results were obtained. 1) HaeIII- or HindIII-restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products (793 bp) of flaB gene was effectual for the classification of species of Leptospira. 2) Twenty cells of Leptospira in 1 ml of coagulated blood and 100 cells of Leptospira in 1 ml of anti-coagulated blood could be detected by flaB-PCR. These results suggested that PCR-RFLP based on the flaB gene was an efficient tool for rapid detection and identification of species of infected Leptospira from clinical specimens.

DNA Primers↗

PubMed2005

Serological evidence of Leptospira interrogans serovar Bratislava infection and its association with abortions in cattle in northern Spain.

A cross-sectional study was carried out in the Basque Country of Spain to determine the seroprevalence of 10 Leptospira serovars in a population of dairy cattle with poor fertility, and a case-control study was carried out in another northern area to investigate the role of Leptospira interrogans serovar Bratislava in abortions. L. Bratislava was the most prevalent serovar in the cross-sectional study, with 25.4 per cent of the cows testing positive in the microagglutination test when a cut-off of 1:10 or higher was applied, followed by Leptospira Hardjo (8.2 per cent), Leptospira Pomona (7.7 per cent), Leptospira Autumnalis (0.7 per cent) and Leptospira Copenhageni (0.1 per cent). In the case-control study the seroprevalence of L. Bratislava was significantly higher among the cows which had aborted when a titre of 1:300 or more was used as a cut-off (9.7 per cent v 3.4 per cent, P=0.008); 69 per cent of the L. Bratislava-infected cows that had aborted apparently aborted as a result of the infection.

Abortion, Veterinary↗