| [the immunochemical and biological properties of leptospira membranes]. | the immunochemical and biological properties of purified membrane fractions obtained from leptospira interrogans, serovar copenhageni, strain rat 2, and leptospira biflexa, strain patoc 1, were studied. the presence of genus-specific and group-specific antigens in leptospiral membranes was established by the methods of immunodiffusion analysis, the microagglutination (ma) and lysis tests. in animal experiments cell membrane preparations produced no toxic and allergic effects. leptospiral membran ... | 1992 | 1301663 |
| potency of leptospiral vaccines and protection against chronic infection in golden hamsters. | seven vaccines prepared from pathogenic strains of different origin of leptospira interrogans [serovars icterohaemorrhagiae (one strain) and copenhageni (6 strains)] were examined in protection tests on golden hamsters. two of the copenhageni strains were used for challenge. the organs (kidneys, spleen, liver) in the vaccinated animals surviving challenge were protected to a varying degree. low rates of survival were associated with a high incidence of leptospira-positive findings, partly connec ... | 1991 | 1959318 |
| efficacy of ciprofloxacin against leptospira interrogans serogroup icterohaemorrhagiae. | ciprofloxacin activity against leptospira interrogans serogroup icterohaemorrhagiae was studied in vitro and in an animal model. the mbc of ciprofloxacin was 0.6 microgram/ml. three of three syrian hamsters died 8 to 9 days after intraperitoneal challenge with 10(6) leptospires. in contrast, five of six animals given ciprofloxacin 3 or 5 days after challenge survived. | 1989 | 2751290 |
| [a polymerase chain reaction method for studying host persistence of pathogenic leptospira]. | polymerase chain reaction has for the first time been shown to be applicable to indication of leptospira interrogans in the organs of infected animals with acute or chronic leptospirosis (on the model of golden syrian hamsters). polymerase chain reaction is superior to microscopic and bacteriological analyses in identification of leptospirae in organ suspensions. the sensitivity of the technique is 1-10 cells per sample in studies of kidney or brain suspensions or 100-1000 cells in studies of li ... | 1994 | 8133845 |
| preliminary evaluation of antimicrobial agents for treatment of leptospira interrogans serovar pomona infection in hamsters and swine. | to evaluate antimicrobial agents for treatment of models of acute and persistent leptospirosis caused by leptospira interrogans serovar pomona. | 1996 | 8720239 |
| demonstration of leptospiral antigens on tissues using monoclonal antibodies and avidin-biotin peroxidase staining. | glycolipoprotein (glp) cytotoxin was extracted from leptospira interrogans serovar canicola. the silver staining profile of glp subjected to sds-page under denaturing conditions showed a number of bands in the mol. weight range of 14-66 kda. mouse monoclonal antibodies (mabs) igg3 recognizing a band near to 24 kda of leptospiral glp were produced (clone number mglp-01). the agglutinating property of mabs was established by microscopic agglutination test (mat) using 25 different serovars as antig ... | 1997 | 9495655 |
| the terminal portion of leptospiral immunoglobulin-like protein liga confers protective immunity against lethal infection in the hamster model of leptospirosis. | subunit vaccines are a potential intervention strategy against leptospirosis, which is a major public health problem in developing countries and a veterinary disease in livestock and companion animals worldwide. leptospiral immunoglobulin-like (lig) proteins are a family of surface-exposed determinants that have ig-like repeat domains found in virulence factors such as intimin and invasin. we expressed fragments of the repeat domain regions of liga and ligb from leptospira interrogans serovar co ... | 2007 | 17629368 |
| role of inducible nitric oxide synthase in the pathogenesis of experimental leptospirosis. | nitric oxide (no) produced by inducible nitric oxide synthase (inos) is a radical effector molecule of the innate immune system that can directly inhibit pathogen replication. in order to study subsequent inos kidney expression in experimental leptospirosis, golden syrian hamsters and c3h/hej mice were infected intraperitoneally with 10(2) or 10(7) virulent leptospira interrogans serovar copenhageni (lic) strain fiocruz l1-130. results showed increased levels of inos mrna and protein in kidneys ... | 2011 | 21497651 |
| a histopathological study of hearts and spleens of hamsters (mesocricetus auratus) infected with leptospira interrogans, serovar pyrogenes. | the effects of leptospira interrogans on the heart and spleen of hamsters were studied histopathologically. infected hamsters were sacrificed at 1 hour, 6 hours and on days 1, 2, 3, 4, 5 and 6 after inoculation with leptospira interrogans serovar pyrogenes. the heart and spleen of each of the sacrificed animals were removed and processed for routine conventional light microscopy. infected hearts showed degenerative change of the cardiac muscle cells composed of cellular swelling, condensation of ... | 2006 | 17121298 |
| immunoprotection of recombinant leptospiral immunoglobulin-like protein a against leptospira interrogans serovar pomona infection. | we previously reported the cloning and characterization of leptospiral immunoglobulin-like proteins liga and ligb of leptospira interrogans. liga and ligb are conserved at the amino-terminal region but are variable at the carboxyl-terminal region. here, we evaluate the potential of recombinant liga (rliga) as a vaccine candidate against infection by l. interrogans serovar pomona in a hamster model. rliga was truncated into conserved (rligacon) and variable (rligavar) regions and expressed in esc ... | 2006 | 16495547 |
| [growth, virulence and antigenecity of leptospira interrogans serovar mozdok in modified emjh medium]. | the effect of higher tween 80 concentrations in emjh synthetic medium on the growth, virulence and antigenecity of leptospira interrogans serovar mozdok was evaluated for increasing the performances and making a full use of the detoxifying capacity of bovine serum albumin. the growth was spectrophotographically evaluated by the analysis of the bacterial growth kinetics; the obtained biomass performance and the consumption of the carbon source. the virulence was estimated in syrian hamster model ... | 2002 | 15846938 |
| quantitative pcr assay to evaluate ampicillin, ofloxacin, and doxycycline for treatment of experimental leptospirosis. | the susceptibility of leptospira interrogans serovar icterohaemorrhagiae strain verdun to selected antibiotics used in medical practice (ampicillin, doxycycline, and ofloxacin) was evaluated in a syrian hamster model, to determine the efficacy of these antibiotics during the course of the disease. a quantitative pcr assay was used to monitor the density of leptospires in blood and in target organs (liver, kidney, lung, heart, and spleen). our results demonstrated the ability of ampicillin at a h ... | 2002 | 11850271 |
| pathology of acute leptospira interrogans serotype icterohaemorrhagiae infection in the syrian hamster. | the pathology of acute leptospira interrogans serotype icterohaemorrhagiae infection in the syrian hamster was investigated up to 7 days after infection using histology, electron microscopy and an indirect fluorescence test for leptospires. the disease was characterized by the presence of many leptospires in the tissues, jaundice, leukocytosis, haemorrhages, endothelial alteration and thrombotic glomerulopathy. the leptospires were present intravascularly, in the interstitium penetrating between ... | 1986 | 3538643 |
| biological activities and endotoxic activities of protective antigens (pags) of leptospira interrogans. | the biological and endotoxic activities of protective antigens (pags) prepared by the chloroform-methanol-water method from leptospira interrogans serovars lai, copenhageni and canicola were examined. the pag preparations did not show a local shwartzman reaction in the rabbits at doses of 100 micrograms and 50 micrograms/site and lethal toxicity to galactosamine-sensitized mice at the dose of 12.5 micrograms to 50 micrograms/mouse. pags exhibited a weak cytotoxic action on peritoneal exudate mac ... | 1990 | 2261063 |
| [in vitro and in vivo activity of tiamulin against leptospires (author's transl)]. | the minimal growth inhibiting concentration of tiamulin, a derivative of the diterpen antibiotic pleuromutilin, was evaluated in vitro against 11 different serogroups of leptospira interrogans by twofold serial dilution technique, in comparison to tetracyclin, dihydrostreptomycin and tylosin. the range of the mic values of tiamulin is between 0.07 and 2.5 microgram/ml and thus comparable to the activities of the standard antibiotics tested (see table 1). the chemotherapeutic efficacy (ed50) of t ... | 1977 | 74926 |
| immunoprotective properties of recombinant liga and ligb in a hamster model of acute leptospirosis. | leptospirosis is the most widespread zoonosis and is considered a major public health problem worldwide. currently, there is no widely available vaccine against leptospirosis for use in humans. a purified, recombinant subunit vaccine that includes the last six immunoglobulin-like (ig-like) domains of the leptospiral protein liga (liga7'-13) protects against lethal infection but not renal colonization after challenge by leptospira interrogans. in this study, we examined whether the addition of th ... | 2017 | 28704385 |
| male-specific pulmonary hemorrhage and cytokine gene expression in golden hamster in early-phase leptospira interrogans serovar hebdomadis infection. | leptospirosis causes severe clinical signs more frequently in men than in women, but the mechanism underlying the gender differences in leptospirosis remains unclear. in this study, petechial hemorrhage was observed in male but not in female hamster lung tissues infected with leptospira interrogans serovar hebdomadis at 120 h pi, demonstrating that male hamsters were more susceptible to the development of a severe disease upon leptospira infection. no leptospiral dna was detected in the lung tis ... | 2017 | 28811249 |
| in vivo gene expression and immunoreactivity of leptospira collagenase. | pulmonary hemorrhage is an increasing cause of death of leptospirosis patients. bacterial collagenase has been shown to be involved in lung hemorrhage induced by various infectious agents. according to leptospira whole genome study, cola, a gene suggested to code for bacterial collagenase has been identified. we investigated cola gene expression in lung tissues of leptospira infected hamsters. golden syrian hamsters were injected intraperitoneally with leptospira interrogans serovar pyrogenes. t ... | 2013 | 23305770 |
| immunomodulatory treatment with thalidomide in experimental leptospirosis in golden syrian hamsters (mesocricetus auratus). | the benefit of antibiotics in leptospirosis is limited when treatment is started four days after symptoms appear, and new adjuvant therapeutic options are urgently needed. | 2014 | 24361944 |
| the use of halloysite clay and carboxyl-functionalised multi-walled carbon nanotubes for recombinant lipl32 antigen delivery enhanced the igg response. | we studied the feasibility of using halloysite clay nanotubes (hnts) and carboxyl-functionalised multi-walled carbon nanotubes (cooh-mwcnts) as antigen carriers to improve immune responses against a recombinant lipl32 protein (rlipl32). immunisation using the hnts or cooh-mwcnts significantly increased the rlipl32-specific igg antibody titres (p < 0.05) of golden syrian hamsters. none of the vaccines tested conferred protection against a challenge using a virulent leptospira interrogans strain. ... | 2015 | 25626458 |
| real-time pcr reveals rapid dissemination of leptospira interrogans after intraperitoneal and conjunctival inoculation of hamsters. | the pathogen leptospira interrogans is a highly motile spirochete that causes acute and fulminant infections in humans and other accidental hosts. hematogenous dissemination is important for infection by the pathogen but remains poorly understood because few animal model studies have used sensitive tools to quantify the bacteria. we evaluated the kinetics of leptospiral infection in golden syrian hamsters by a sensitive quantitative real-time pcr (taqman) with lipl32 as the target gene. the diss ... | 2016 | 27141082 |
| the use of halloysite clay and carboxyl-functionalised multi-walled carbon nanotubes for recombinant lipl32 antigen delivery enhanced the igg response. | we studied the feasibility of using halloysite clay nanotubes (hnts) and carboxyl-functionalised multi-walled carbon nanotubes (cooh-mwcnts) as antigen carriers to improve immune responses against a recombinant lipl32 protein (rlipl32). immunisation using the hnts or cooh-mwcnts significantly increased the rlipl32-specific igg antibody titres (p < 0.05) of golden syrian hamsters. none of the vaccines tested conferred protection against a challenge using a virulent leptospira interrogans strain. ... | 2015 | 25742273 |
| comparison of bacterial burden and cytokine gene expression in golden hamsters in early phase of infection with two different strains of leptospira interrogans. | leptospirosis, a zoonotic infection with worldwide prevalence, is caused by pathogenic spirochaetes of leptospira spp., and exhibits an extremely broad clinical spectrum in human patients. although previous studies indicated that specific serovars or genotypes of leptospira spp. were associated with severe leptospirosis or its outbreak, the mechanism underlying the difference in virulence of the various leptospira serotypes or genotypes remains unclear. the present study addresses this question ... | 2015 | 26146835 |
| mouse model for sublethal leptospira interrogans infection. | although leptospira can infect a wide range of mammalian species, most studies have been conducted in golden syrian hamsters, a species particularly sensitive to acute disease. chronic disease has been well characterized in the rat, one of the natural reservoir hosts. studies in another asymptomatic reservoir host, the mouse, have occasionally been done and have limited infection to mice younger than 6 weeks of age. we analyzed the outcome of sublethal infection of c3h/hej mice older than age 10 ... | 2015 | 26416909 |
| oral immunization with escherichia coli expressing a lipidated form of liga protects hamsters against challenge with leptospira interrogans serovar copenhageni. | leptospirosis is a potentially fatal zoonosis transmitted by reservoir host animals that harbor leptospires in their renal tubules and shed the bacteria in their urine. leptospira interrogans serovar copenhageni transmitted from rattus norvegicus to humans is the most prevalent cause of urban leptospirosis. we examined l. interrogans liga, domains 7 to 13 (liga7-13), as an oral vaccine delivered by escherichia coli as a lipidated, membrane-associated protein. the efficacy of the vaccine was eval ... | 2014 | 24478102 |
| methylation and in vivo expression of the surface-exposed leptospira interrogans outer membrane protein ompl32. | recent studies have revealed that bacterial protein methylation is a widespread post-translational modification that is required for virulence in selected pathogenic bacteria. in particular, altered methylation of outer membrane proteins has been shown to modulate the effectiveness of the host immune response. in this study, two-dimensional gel electrophoresis combined with matrix-assisted laser desorption/ionization-time of flight mass spectrometry identified a leptospira interrogans serovar c ... | 2011 | 22174381 |