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a call to order at the spirochaetal host-pathogen interface.as the lyme disease spirochaete borrelia burgdorferi shuttles back and forth between arthropod vector and vertebrate host, it encounters vastly different and hostile environments. major mechanisms contributing to the success of this pathogen throughout this complex transmission cycle are phase and antigenic variation of abundant and serotype-defining surface lipoproteins. these peripherally membrane-anchored virulence factors mediate niche-specific interactions with vector/host factors and prote ...201323750784
scrub typhus with sepsis and acute respiratory distress syndrome.scrub typhus is a major infectious threat in the asia-pacific region. we report an unusual case of scrub typhus in a patient in singapore who presented with sepsis and acute respiratory distress syndrome but lacked the pathognomonic eschar. the patient recovered after appropriate diagnosis and doxycycline treatment. rickettsial diseases should be included in the differential diagnosis of febrile illnesses in regions where the diseases are endemic, and absence of eschar should not be the criterio ...201323761149
characterization of streptococcal platelet-activating factor acetylhydrolase variants that are involved in innate immune evasion.human pathogen group a streptococcus (gas) has developed mechanisms to subvert innate immunity. we recently reported that the secreted esterase produced by serotype m1 gas (sse(m1)) reduces neutrophil recruitment by targeting platelet-activating factor (paf). sse(m1) and sse produced by serotype m28 gas (sse(m28)) have a 37% sequence difference. this study aims at determining whether sse(m28) is also a paf acetylhydrolase and participates in innate immune evasion. we also examined whether sse ev ...201323774595
leptospirosis in fox squirrels (sciurus niger) of larimer county, colorado, usa.leptospirosis is a zoonotic disease caused by the bacterium leptospira interrogans. the organism is typically maintained within a geographic region by colonizing renal tubules of carrier animals and shed into the environment in urine. we assessed whether l. interrogans was present in fox squirrels (sciurus niger) in larimer county, colorado, usa, and whether it is associated with disease. twenty-two squirrels were trapped from 29 november 2011 to 15 december 2011 for use in an unrelated study. t ...201323778614
automated target segmentation and real space fast alignment methods for high-throughput classification and averaging of crowded cryo-electron subtomograms.cryo-electron tomography allows the imaging of macromolecular complexes in near living conditions. to enhance the nominal resolution of a structure it is necessary to align and average individual subtomograms each containing identical complexes. however, if the sample of complexes is heterogeneous, it is necessary to first classify subtomograms into groups of identical complexes. this task becomes challenging when tomograms contain mixtures of unknown complexes extracted from a crowded environme ...201323812994
ecology of leptospira interrogans in norway rats (rattus norvegicus) in an inner-city neighborhood of vancouver, canada.leptospira interrogans is a bacterial zoonosis with a worldwide distribution for which rats (rattus spp.) are the primary reservoir in urban settings. in order to assess, monitor, and mitigate the risk to humans, it is important to understand the ecology of this pathogen in rats. the objective of this study was to characterize the ecology of l. interrogans in norway rats (rattus norvegicus) in an impoverished inner-city neighborhood of vancouver, canada.201323818996
ionic imbalance and lack of effect of adjuvant treatment with methylene blue in the hamster model of leptospirosis.leptospirosis in humans usually involves hypokalaemia and hypomagnesaemia and the putative mechanism underlying such ionic imbalances may be related to nitric oxide (no) production. we previously demonstrated the correlation between serum levels of no and the severity of renal disease in patients with severe leptospirosis. methylene blue inhibits soluble guanylyl cyclase (downstream of the action of any no synthase isoforms) and was recently reported to have beneficial effects on clinical and ex ...201323827990
expansion of the in vitro assay for leptospira potency testing to other serovars: case study with leptospira hardjo.evaluation of leptospiral vaccines for potency against leptospira interrogans serovars pomona, icterohaemorrhagiae, canicola, and grippotyphosa is accomplished using the hamster potency test method described in 9 cfr 113.101-104. applicability of this method to evaluation of bacterins developed for immunization against infection with l. interrogans serovar hardjo or leptospira borgpetersenii serovar hardjo is complicated by several issues. information from research on target host animal efficacy ...201323838569
monocyte human leukocyte antigen-dr expression-a tool to distinguish intestinal bacterial infections from inflammatory bowel disease?we sought to determine the quantitative expression of human leukocyte antigen-dr (hla-dr) on monocytes in patients with acute intestinal bacterial infections and inflammatory bowel disease (ibd).201323860582
bba70 of borrelia burgdorferi is a novel plasminogen-binding protein.the lyme disease spirochete borrelia burgdorferi lacks endogenous, surface-exposed proteases. in order to efficiently disseminate throughout the host and penetrate tissue barriers, borreliae rely on recruitment of host proteases, such as plasmin(ogen). here we report the identification of a novel plasminogen-binding protein, bba70. binding of plasminogen is dose-dependent and is affected by ionic strength. the bba70-plasminogen interaction is mediated by lysine residues, primarily located in a p ...201323861404
development of leptospira in vitro potency assays: eu/industry experience and perspectives.nobivac® lepto (msd animal health) is a non-adjuvanted canine leptospirosis vaccine containing inactivated whole cells of leptospira interrogans serogroup canicola serovar portlandvere and l. interrogans serogroup icterohaemorrhagiae serovar copenhageni. the current standard in vivo potency test is a hamster challenge test associated with major drawbacks such as animal suffering and poor reproducibility. here, the quantification of antigenic mass by elisa as a new in vitro potency test is descri ...201323867758
toll-like receptors in atherosclerosis.atherosclerosis, the leading cause of cardiovascular disease (cvd), is driven by inflammation. increasing evidence suggests that toll-like receptors (tlrs) are key orchestrators of the atherosclerotic disease process. interestingly, a distinct picture is being revealed for individual receptors in atherosclerosis. tlrs exhibit a complex nature enabling the detection of multiple motifs named danger-associated molecular patterns (damps) and pathogen-associated molecular patterns (pamps). activation ...201323880853
sporadic urban leptospirosis.severe leptospirosis (weil syndrome) was diagnosed in an otherwise healthy environmental worker in baltimore alleys in late november 2010. he developed multiple organ failure but responded to antibiotic therapy and experienced a full recovery within 4 weeks. his diagnosis was confirmed by a rise in indirect hemagglutinin titer (acute 0, convalescent 400). the subject had close contact with baltimore alley rats; a similar epidemiologic exposure and location reported in an outbreak 15 years ago.201123882321
extracellular proteome analysis of leptospira interrogans serovar lai.abstract leptospirosis is one of the most important zoonoses. leptospira interrogans serovar lai is a pathogenic spirochete that is responsible for leptospirosis. extracellular proteins play an important role in the pathogenicity of this bacterium. in this study, l. interrogans serovar lai was grown in protein-free medium; the supernatant was collected and subsequently analyzed as the extracellular proteome. a total of 66 proteins with more than two unique peptides were detected by ms/ms, and 33 ...201323895271
bridging the gap between systems biology and synthetic biology.systems biology is an inter-disciplinary science that studies the complex interactions and the collective behavior of a cell or an organism. synthetic biology, as a technological subject, combines biological science and engineering, allowing the design and manipulation of a system for certain applications. both systems and synthetic biology have played important roles in the recent development of microbial platforms for energy, materials, and environmental applications. more importantly, systems ...201323898328
prozone effects in microscopic agglutination tests for leptospirosis in the sera of mice infected with the pathogenic leptospira interrogans serovar canicola.mice experimentally infected with a pathogenic strain of leptospira interrogans serovar canicola produced false negative results (prozone effect) in a microscopic agglutination test (mat). this prozone effect occurred in several serum samples collected at different post-infection times, but it was more prominent in samples collected from seven-42 days post-infection and for 1:50 and 1:100 sample dilutions. this phenomenon was correlated with increased antibody titres in the early post-infection ...201323903987
a phylogenomic and molecular signature based approach for characterization of the phylum spirochaetes and its major clades: proposal for a taxonomic revision of the phylum.the spirochaetes species cause many important diseases including syphilis and lyme disease. except for their containing a distinctive endoflagella, no other molecular or biochemical characteristics are presently known that are specific for either all spirochaetes or its different families. we report detailed comparative and phylogenomic analyses of protein sequences from spirochaetes genomes to understand their evolutionary relationships and to identify molecular signatures for this group. these ...201323908650
leptospiral lrua is required for virulence and modulates an interaction with mammalian apolipoprotein ai.leptospirosis is a worldwide zoonosis caused by spirochetes of the genus leptospira. while understanding of pathogenesis remains limited, the development of mutagenesis in leptospira has provided a powerful tool for identifying novel virulence factors. lrua is a lipoprotein that has been implicated in leptospiral uveitis as a target of the immune response. in this study, two lrua mutants, m754 and m765, generated by transposon mutagenesis from leptospira interrogans serovar manilae, were charact ...201323918777
cryo-electron tomography: the challenge of doing structural biology in situ.electron microscopy played a key role in establishing cell biology as a discipline, by producing fundamental insights into cellular organization and ultrastructure. many seminal discoveries were made possible by the development of new sample preparation methods and imaging modalities. recent technical advances include sample vitrification that faithfully preserves molecular structures, three-dimensional imaging by electron tomography, and improved image-processing methods. these new techniques h ...201323918936
identification of novel adhesins of m. tuberculosis h37rv using integrated approach of multiple computational algorithms and experimental analysis.pathogenic bacteria interacting with eukaryotic host express adhesins on their surface. these adhesins aid in bacterial attachment to the host cell receptors during colonization. a few adhesins such as heparin binding hemagglutinin adhesin (hbha), apa, malate synthase of m. tuberculosis have been identified using specific experimental interaction models based on the biological knowledge of the pathogen. in the present work, we carried out computational screening for adhesins of m. tuberculosis. ...201323922800
complement-mediated opsonization of invasive group a streptococcus pyogenes strain ap53 is regulated by the bacterial two-component cluster of virulence responder/sensor (covrs) system.group a streptococcus pyogenes (gas) strain ap53 is a primary isolate from a patient with necrotizing fasciitis. these ap53 cells contain an inactivating mutation in the sensor component of the cluster of virulence (cov) responder (r)/sensor (s) two-component gene regulatory system (covrs), which enhances the virulence of the primary strain, ap53/covr(+)s(-). however, specific mechanisms by which the covrs system regulates the survival of gas in humans are incomplete. here, we show a key role fo ...201323928307
contribution of leptospira, neospora caninum and bovine viral diarrhea virus to fetal loss of beef cattle in new zealand.the profitability of beef breeding farms in new zealand depends principally on optimal reproductive performance. the aim of this study was to estimate the impact of four major pathogens, bovine viral diarrhea virus (bvdv), neospora caninum (n. caninum), leptospira borgpetersenii serovar hardjo (hardjo), and leptospira interrogans serovar pomona (pomona), on rates of fetal loss in commercial beef breeding herds. farms reporting fetal loss were recruited, and a blood sample from aborting cows (cas ...201323932894
genetic and molecular biological characterization of two homologous cher genes from leptospira interrogans.the leptospira interrogans genome encodes two copies of cher genes and each of them is able to complement for the swarming defective phenotype of escherichia coli cher null mutant rp1254 to certain extent, while over-expression of either of them inhibits the swarming of the chemotactic wild-type e. coli strain, rp437. therefore, both cher1 and cher2 ought to bear the methyltransferase activities, although cher1 has only one instead of two conserved basic amino acid residues located on the positi ...201323934012
human hemorrhagic pulmonary leptospirosis: pathological findings and pathophysiological correlations.leptospirosis is a re-emerging zoonosis with protean clinical manifestations. recently, the importance of pulmonary hemorrhage as a lethal complication of this disease has been recognized. in the present study, five human necropsies of leptospirosis (weil's syndrome) with extensive pulmonary manifestations were analysed, and the antibodies expressed in blood vessels and cells involved in ion and water transport were used, seeking to better understand the pathophysiology of the lung injury associ ...201323951234
characterization of three novel adhesins of leptospira interrogans.we report cloning, expression, purification, and characterization of three predicted leptospiral membrane proteins (lic11360, lic11009, and lic11975). in silico analysis and proteinase k accessibility data suggest that these proteins might be surface exposed. we show that proteins encoded by lic11360, lic11009 and lic11975 genes interact with laminin in a dose-dependent and saturable manner. the proteins are referred to as leptospiral surface adhesions 23, 26, and 36 (lsa23, lsa26, and lsa36), r ...201323958908
transcriptional profiling of staphylococcus aureus during growth in 2 m nacl leads to clarification of physiological roles for kdp and ktr k+ uptake systems.staphylococcus aureus exhibits an unusually high level of osmotolerance and na(+) tolerance, properties that support survival in various host niches and in preserved foods. the genetic basis of these traits is not well understood. we compared the transcriptional profiles of s. aureus grown in complex medium with and without 2 m nacl. the stimulon for growth in high-osmolality media and na(+) included genes involved in uptake of k(+), other compatible solutes, sialic acid, and sugars; capsule bio ...201323963175
use of staged molecular analysis to determine causes of unexplained central nervous system infections.no agent is implicated in most central nervous system (cns) infections. to investigate cerebrospinal fluid samples from patients with cns infections of unknown cause in 1 hospital in taiwan, we used a staged molecular approach, incorporating techniques including multiplex masstag pcr, 16s rrna pcr, dna microarray, and high-throughput pyrosequencing. we determined the infectious agent for 31 (24%) of 131 previously negative samples. candidate pathogens were identified for 25 (27%) of 94 unexplain ...201323965845
bench-to-bedside review: platelets and active immune functions - new clues for immunopathology?platelets display a number of properties besides the crucial function of repairing damaged vascular endothelium and stopping bleeding; these are exploited to benefit patients receiving platelet component transfusions, which might categorize them as innate immune cells. for example, platelets specialize in pro-inflammatory activities, and can secrete a large number of molecules, many of which display biological response modifier functions. platelets also express receptors for non-self-infectious ...201323998653
[leptospirosis epidemic: 48 cases].the epidemic reported here took place from november 30, 2006, through january 3, 2007, in a rural area of tala-athmane and led to the hospitalization of 48 patients with leptospirosis. it was due to the proximity of homes to two uncontrolled garbage dumps invaded by rodents. all 48 hospitalized cases were confirmed serologically, and more than 60% were serogroup icterohaemorrhagiae. more than 14.5% of the patients were contaminated during occupational exposure. the authors describe the clinical ...201324001651
[renal manifestations of leptospirosis: 88 cases].this prospective study analyzes 173 patients, hospitalized between january 1, 2005, and december 31, 2008, for serologically confirmed leptospirosis. it describes the renal, clinical and laboratory manifestations in 88 (50.8%) of these cases. acute kidney failure was frequent in this group (68 cases = 77.3%). kidney damage was one of the multiple organs affected, with infection and hepatic and hemorrhagic signs predominant.201324001652
periplasmic flagellar export apparatus protein, flih, is involved in post-transcriptional regulation of flab, motility and virulence of the relapsing fever spirochete borrelia hermsii.spirochetes are bacteria characterized in part by rotating periplasmic flagella that impart their helical or flat-wave morphology and motility. while most other bacteria rely on a transcriptional cascade to regulate the expression of motility genes, spirochetes employ post-transcriptional mechanism(s) that are only partially known. in the present study, we characterize a spontaneous non-motile mutant of the relapsing fever spirochete borrelia hermsii that was straight, non-motile and deficient i ...201324009690
adhesins of leptospira interrogans mediate the interaction to fibrinogen and inhibit fibrin clot formation in vitro.we report in this work that leptospira strains, virulent l. interrogans serovar copenhageni, attenuated l. interrogans serovar copenhageni and saprophytic l. biflexa serovar patoc are capable of binding fibrinogen (fg). the interaction of leptospires with fg inhibits thrombin- induced fibrin clot formation that may affect the haemostatic equilibrium. additionally, we show that plasminogen (plg)/plasmin (pla) generation on the surface of leptospira causes degradation of human fg. the data suggest ...201324009788
role for cis-acting rna sequences in the temperature-dependent expression of the multiadhesive lig proteins in leptospira interrogans.the spirochete leptospira interrogans causes a systemic infection that provokes a febrile illness. the putative lipoproteins liga and ligb promote adhesion of leptospira to host proteins, interfere with coagulation, and capture complement regulators. in this study, we demonstrate that the expression level of the liga and ligb proteins was substantially higher when l. interrogans proliferated at 37°c instead of the standard culture temperature of 30°c. the rna comprising the 175-nucleotide 5' unt ...201324013626
prevalence of antibodies against leptospira sp. in snakes, lizards and turtles in slovenia.leptospiral infections in poikilothermic (cold blooded) animals have received very little attention and the literature concerning natural infections of these animals is limited. the aim of this study was to determine the prevalence of leptospiral antibodies in reptiles, imported into slovenia and intended to be pets in close contact with humans. a total of 297 reptiles (22 snakes, 210 lizards and 65 turtles) were tested for specific antibodies against serovars of leptospira interrogans sensu str ...201324020619
haemorrhagic pneumonia in sled dogs caused by streptococcus equi subsp. zooepidemicus - one fatality and two full recoveries: a case report.in spite of yearly vaccination, outbreaks of canine infectious respiratory disease are periodically seen amongst domestic dogs. these infections compromise host defense mechanisms, and, when combined with other stressful events, allow opportunistic pathogens like streptococcus equi subsp. zooepidemicus to create serious disease. early recognition and treatment are tremendously important for a successful outcome in these cases. a polyvalent vaccine was given to 22 racing dogs three days after a c ...201324020788
sphingomyelinase activity of trichomonas vaginalis extract and subfractions.trichomoniasis is one of the most common acute sexually transmitted curable diseases, and it is disseminated worldwide generating more than 170 million cases annually. trichomonas vaginalis is the parasite that causes trichomoniasis and has the ability to destroy cell monolayers of the vaginal mucosa in vitro. sphingomyelinases (smase) are enzymes that catalyze the hydrolysis of sphingomyelin into ceramide and phosphorylcholine. ceramide appears to be a second messenger lipid in programmed apopt ...201324024206
isolation and characterization of leptospira interrogans from pigs slaughtered in são paulo state, brazil.with the aim of isolating leptospira spp., blood serum, kidney, liver and genital tract of 137 female swine (40 sows and 97 gilts) and also urine samples from 22 sows were collected in a slaughterhouse in the state of são paulo, from april 2003 to august 2004. four isolates were obtained from animals that presented microagglutination test (mat) titers ≥ 100 for the serovar pomona and one was obtained from an animal negative by mat in which leptospira was isolated from the liver and reproductive ...200824031254
isolation of leptospira serovars canicola and copenhageni from cattle urine in the state of paraná, brazil.in 2001, 698 urine samples were randomly collected from cattle at a slaughterhouse in the state of paraná, brazil. direct examination using dark field microscopy was carried out immediately after collection. five putative positive samples were cultured in modified emjh medium, yielding two positive cultures (lo-14 and lo-10). typing with monoclonal antibodies revealed that the two isolates were similar to canicola (lo-14) and copenhageni (lo-10). microscopic agglutination test results show that ...200824031301
production of reactive oxygen (h2o2) and nitrogen (no) intermediates and tnf-α in mice genetically selected for high (h) and low (l) antibody response and experimentally infected with leptospira serovar pomona.the aim of the present study was to evaluate the activity of macrophages, and the production of tnf-α and antibodies against experimental infection by leptospira serovar pomona in mice genetically selected for high (h) or low (l) humoral immune response. to evaluate macrophagic activity, peritoneal and splenic lavages were performed for determination of oxygen (h2o2) and nitrogen (no) intermediates. the production of the tumor necrosis factor (tnf-α) was investigated through bioassays in serum a ...201124031688
diagnosis of canine leptospirosis using an immunomagnetic separation-pcr method.diagnosis of leptospirosis by pcr is hampered due to the presence of substances on biological fluids. here, we report an immunomagnetic separation step prior to pcr which improved the detection of leptospira spp. in blood and urine samples from dogs. it resulted in a significant improvement on sensitivity for diagnosis of canine leptospirosis.201224031870
detection of human leptospirosis as a cause of acute fever by capture elisa using a leptospira interrogans serovar copenhageni (m20) derived antigen.leptospirosis is a potentially lethal zoonosis mainly affecting low-resource tropical countries, including peru and its neighbouring countries. timely diagnosis of leptospirosis is critical but may be challenging in the regions where it is most prevalent. the serodiagnostic gold standard microagglutination test (mat) may be technically prohibitive. our objective in this study was to assess the sensitivity, specificity, and predictive value of an igm antibody capture enzyme-linked immunoassay (ma ...201324053555
a new tetravalent canine leptospirosis vaccine provides at least 12 months immunity against infection.a key success factor in the vaccination of dogs against leptospirosis is long term protection against establishment of the renal carrier state, in order to protect other dogs, as well as humans, against this re-emerging zoonotic disease. in this paper, we describe the ability of a new european tetravalent vaccine containing antigen from leptospira interrogans (sensu lato) serogroups icterohaemorrhagiae, canicola, grippotyphosa and australis to control infection and renal excretion in dogs at 12 ...201424054091
molecular characterization, serotyping, and antibiotic susceptibility profile of leptospira interrogans serovar copenhageni isolates from brazil.leptospira interrogans serogroup icterohaemorrhagiae is the major serogroup infecting humans worldwide, and rodents and dogs are the most significant transmission sources in urban environments. knowledge of the prevalent serovars and their maintenance hosts is essential to understand the epidemiology of leptospirosis. in this study, 20 leptospira isolates were evaluated by pulsed-field gel electrophoresis (pfge), variable number tandem-repeat analysis (vntr), serotyping, and determination of ant ...201324054736
assessment of persistence of bartonella henselae in ctenocephalides felis.bartonella henselae (rhizobiales: bartonellaceae) is a gram-negative fastidious bacterium of veterinary and zoonotic importance. the cat flea ctenocephalides felis (siphonaptera: pulicidae) is the main recognized vector of b. henselae, and transmission among cats and humans occurs mainly through infected flea feces. the present study documents the use of a quantitative molecular approach to follow the daily kinetics of b. henselae within the cat flea and its excreted feces after exposure to infe ...201324056468
species loss on spatial patterns and composition of zoonotic parasites.species loss can result in the subsequent loss of affiliate species. though largely ignored to date, these coextinctions can pose threats to human health by altering the composition, quantity and distribution of zoonotic parasites. we simulated host extinctions from more than 1300 host-parasite associations for 29 north american carnivores to investigate changes in parasite composition and species richness. we also explored the geography of zoonotic parasite richness under three carnivore compos ...201324068356
cytokine response signatures in disease progression and development of severe clinical outcomes for leptospirosis.the role of the immune response in influencing leptospirosis clinical outcomes is not yet well understood. we hypothesized that acute-phase serum cytokine responses may play a role in disease progression, risk for death, and severe pulmonary hemorrhage syndrome (sphs).201324069500
discovery of a camp deaminase that quenches cyclic amp-dependent regulation.an enzyme of unknown function within the amidohydrolase superfamily was discovered to catalyze the hydrolysis of the universal second messenger, cyclic-3',5'-adenosine monophosphate (camp). the enzyme, which we have named cadd, is encoded by the human pathogenic bacterium leptospira interrogans. although cadd is annotated as an adenosine deaminase, the protein specifically deaminates camp to cyclic-3',5'-inosine monophosphate (cimp) with a kcat/km of 2.7 ± 0.4 × 10(5) m(-1) s(-1) and has no acti ...201324074367
urban leptospirosis in africa: a cross-sectional survey of leptospira infection in rodents in the kibera urban settlement, nairobi, kenya.leptospirosis is a widespread but under-reported cause of morbidity and mortality. global re-emergence of leptospirosis has been associated with the growth of informal urban settlements in which rodents are thought to be important reservoir hosts. understanding the multi-host epidemiology of leptospirosis is essential to control and prevent disease. a cross-sectional survey of rodents in the kibera settlement in nairobi, kenya was conducted in september-october 2008 to demonstrate the presence o ...201324080637
enzymatic characterization of a type ii isocitrate dehydrogenase from pathogenic leptospira interrogans serovar lai strain 56601.leptospira interrogans, a gram-negative pathogen, could cause infections in a wide variety of mammalian hosts, but due to their fastidious cultivation requirements and the lack of genetic systems, the pathogenic factor is still not clear. isocitrate dehydrogenase (idh) is a key enzyme in the tricarboxylation (tca) cycle, which could have an important impact on the growth and pathogenesis of the bacteria. in the present study, we first report the cloning, heterologous expression, and detailed cha ...201424092452
leptospira interrogans serovar copenhageni harbors two lexa genes involved in sos response.bacteria activate a regulatory network in response to the challenges imposed by dna damage to genetic material, known as the sos response. this system is regulated by the reca recombinase and by the transcriptional repressor lexa. leptospira interrogans is a pathogen capable of surviving in the environment for weeks, being exposed to a great variety of stress agents and yet retaining its ability to infect the host. this study aims to investigate the behavior of l. interrogans serovar copenhageni ...201324098496
pathogenomic inference of virulence-associated genes in leptospira interrogans.leptospirosis is a globally important, neglected zoonotic infection caused by spirochetes of the genus leptospira. since genetic transformation remains technically limited for pathogenic leptospira, a systems biology pathogenomic approach was used to infer leptospiral virulence genes by whole genome comparison of culture-attenuated leptospira interrogans serovar lai with its virulent, isogenic parent. among the 11 pathogen-specific protein-coding genes in which non-synonymous mutations were foun ...201324098822
characterization of a bifunctional enzyme with (p)ppgpp-hydrolase/synthase activity in leptospira interrogans.alarmone guanosine 5'-diphosphate (or 5'-triphosphate) 3'-diphosphate [(p)ppgpp] is the key component that globally regulates stringent control in bacteria. there are two homologous enzymes, rela and spot in escherichia coli, which are responsible for fluctuations in (p)ppgpp concentration inside the cell, whereas there exists only a single rela/spot enzyme in gram-positive bacteria. we have identified a bifunctional enzyme with (p)ppgpp-hydrolase/synthase activity in leptospira interrogans. we ...201324111633
identification of leptospira interrogans phospholipase c as a novel virulence factor responsible for intracellular free calcium ion elevation during macrophage death.leptospira-induced macrophage death has been confirmed to play a crucial role in pathogenesis of leptospirosis, a worldwide zoonotic infectious disease. intracellular free ca(2+) concentration ([ca(2+)]i) elevation induced by infection can cause cell death, but [ca(2+)]i changes and high [ca(2+)]i-induced death of macrophages due to infection of leptospira have not been previously reported.201324124502
responses of murine and human macrophages to leptospiral infection: a study using comparative array analysis.leptospirosis is a re-emerging tropical infectious disease caused by pathogenic leptospira spp. the different host innate immune responses are partially related to the different severities of leptospirosis. in this study, we employed transcriptomics and cytokine arrays to comparatively calculate the responses of murine peritoneal macrophages (mpms) and human peripheral blood monocytes (hbms) to leptospiral infection. we uncovered a series of different expression profiles of these two immune cell ...201324130911
identification of seroreactive proteins of leptospira interrogans serovar copenhageni using a high-density protein microarray approach.leptospirosis is a widespread zoonotic disease worldwide. the lack of an adequate laboratory test is a major barrier for diagnosis, especially during the early stages of illness, when antibiotic therapy is most effective. therefore, there is a critical need for an efficient diagnostic test for this life threatening disease.201324147173
feline leptospirosis serosurvey from a quebec referral hospital.epidemiologic studies have linked interactions with cats as a risk factor for human leptospirosis, but serosurveys of feline leptospira spp. infection are scarce in the veterinary literature. the objective of this study was to conduct a serosurvey of leptospira spp. infection in cats presenting to an eastern canadian veterinary teaching hospital (vth). all serum samples collected from cats presented to the vth were tested by the microscopic agglutination test (mat) for the leptospira serovars ca ...201324155435
diagnostic ophthalmology. anterior uveitis of the right eye. 201324155500
characterization of a virulent leptospira interrogans strain isolated from an abandoned swimming pool.pathogenic leptospira spp. are the etiological agents of leptospirosis, an important disease of both humans and animals. in urban settings, l. interrogans serovars are the predominant cause of disease in humans. the purpose of this study was to characterize a novel leptospira isolate recovered from an abandoned swimming pool. molecular characterization through sequencing of the rpob gene revealed 100% identity with l. interrogans and variable-number tandem-repeat (vntr) analysis resulted in a ba ...201324159300
functional and immunological evaluation of two novel proteins of leptospira spp.this work shows the production and characterization of two novel putative lipoproteins encoded by the genes lic10645 and lic10731 identified in the genome sequences of leptospira interrogans. in silico conservation analysis indicated that the proteins are well conserved among pathogenic leptospiral serovars and species. recombinant proteins were obtained in escherichia coli bl21(de3) star plyss strain, purified by metal-affinity chromatography, and used for characterization and immunological eva ...201424162609
leptospira interrogans enolase is secreted extracellularly and interacts with plasminogen.leptospira interrogans is the agent for leptospirosis, an important zoonosis in humans and animals across the globe. surface proteins of invading pathogens, such as l. interrogans, are thought to be responsible for successful microbial persistence in vivo via interaction with specific host components. in particular, a number of invasive infectious agents exploit host proteolytic pathways, such as one involving plasminogen (pg), which aid in efficient pathogen dissemination within the host. here ...201324205133
ceg: a database of essential gene clusters.essential genes are indispensable for the survival of living entities. they are the cornerstones of synthetic biology, and are potential candidate targets for antimicrobial and vaccine design.201324209780
the serological response of working farm dogs to a vaccine containing leptospira interrogans serovars copenhageni and pomona, and l. borgpetersenii serovar hardjo.to evaluate the serological response in dogs to a commercial vaccine for use in cattle containing cultured strains of leptospira interrogans serovars copenhageni and pomona, and l. borgpetersenii serovar hardjo.201424228620
disease control through fertility control: secondary benefits of animal birth control in indian street dogs.we sought to (1) survey sexually intact street dogs for a wide range of diseases in three cities in rajasthan, india and (2) evaluate links between the health of non-treated dogs and both the presence and duration of animal birth control (abc) programs. abc regimes sterilize and vaccinate stray dogs in an attempt to control their population and the spread of rabies. they are commonly suggested to improve the health of those dogs they serve, but here we provide evidence that these benefits also e ...201424239212
leptospirosis in pigs, dogs, rodents, humans, and water in an area of the colombian tropics.leptospirosis is a reemerging zoonosis of global distribution and is one of the causes of hemorrhagic fevers in the tropics. we sought to determine seroprevalence in humans and animals and isolate leptospira interrogans sensu lato in domestic animals, rodents, and water sources. the study was conducted in a tropical area of the middle sinú in cordoba, colombia. in a prospective descriptive study, we collected blood and urine from pigs and dogs, sera from rural human workers, sera and kidney mace ...201424254419
statistical approach to protein quantification.a major goal in proteomics is the comprehensive and accurate description of a proteome. this task includes not only the identification of proteins in a sample, but also the accurate quantification of their abundance. although mass spectrometry typically provides information on peptide identity and abundance in a sample, it does not directly measure the concentration of the corresponding proteins. specifically, most mass-spectrometry-based approaches (e.g. shotgun proteomics or selected reaction ...201324255132
statistical approach to protein quantification.a major goal in proteomics is the comprehensive and accurate description of a proteome. this task includes not only the identification of proteins in a sample, but also the accurate quantification of their abundance. although mass spectrometry typically provides information on peptide identity and abundance in a sample, it does not directly measure the concentration of the corresponding proteins. specifically, most mass-spectrometry-based approaches (e.g. shotgun proteomics or selected reaction ...201324255132
high virulence in hamsters of four dominant leptospira serovars isolated from rats in the philippines.leptospirosis is caused by pathogenic species of leptospira. the aim of this study was to determine and characterize the pathogenicity of four dominant leptospira isolates prevailing among rats in the philippines. the isolates were leptospira interrogans serovar manilae strain k64, l. interrogans serovar losbanos strain k37, l. interrogans serovar ratnapura strain k5 and leptospira borgpetersenii serovar javanica strain k6. pathogenicities were studied using hamsters, which reproduce severe huma ...201424257815
leptospirosis in the republic of korea: historical perspectives, current status and future challenges.leptospirosis is an important public health problem in the republic of korea (rok), occurring sporadically or in outbreaks during the autumn season. wild rodents, apodemus agrarius, have been mainly involved in human leptospirosis. the majority of carrier animals are infected with leptospira interrogans serovar lai. the characteristic pulmonary involvement or hemorrhage may increase the clinical severity or result in fatal outcomes, and these aspects continue to be a threat to people in endemic ...201324265962
differential response of orthologous l,l-diaminopimelate aminotransferases (dapl) to enzyme inhibitory antibiotic lead compounds.l,l-diaminopimelate aminotransferase (dapl) is an enzyme required for the biosynthesis of meso-diaminopimelate (m-dap) and l-lysine (lys) in some bacteria and photosynthetic organisms. m-dap and lys are both involved in the synthesis of peptidoglycan (pg) and protein synthesis. dapl is found in specific eubacterial and archaeal lineages, in particular in several groups of pathogenic bacteria such as leptospira interrogans (lidapl), the soil/water bacterium verrucomicrobium spinosum (vsdapl) and ...201424268540
identification of collagenase as a critical virulence factor for invasiveness and transmission of pathogenic leptospira species.leptospirosis is a global zoonotic disease. transmission of leptospira from animals to humans occurs through contact with water contaminated with leptospire-containing urine of infected animals. however, the molecular basis for the invasiveness of leptospira and transmission of leptospirosis remains unknown.201424277745
targeting toll-like receptors: promising therapeutic strategies for the management of sepsis-associated pathology and infectious diseases.toll-like receptors (tlrs) are pattern recognition receptors playing a fundamental role in sensing microbial invasion and initiating innate and adaptive immune responses. tlrs are also triggered by danger signals released by injured or stressed cells during sepsis. here we focus on studies developing tlr agonists and antagonists for the treatment of infectious diseases and sepsis. positioned at the cell surface, tlr4 is essential for sensing lipopolysaccharide of gram-negative bacteria, tlr2 is ...201324302927
the multifunctional role of the pallilysin-associated treponema pallidum protein, tp0750, in promoting fibrinolysis and extracellular matrix component degradation.the mechanisms that facilitate dissemination of the highly invasive spirochaete, treponema pallidum, are incompletely understood. previous studies showed the treponemal metalloprotease pallilysin (tp0751) possesses fibrin clot degradation capability, suggesting a role in treponemal dissemination. in the current study we report characterization of the functionally linked protein tp0750. structural modelling predicts tp0750 contains a von willebrand factor type a (vwfa) domain, a protein-protein i ...201424303899
interaction of leptospira elongation factor tu with plasminogen and complement factor h: a metabolic leptospiral protein with moonlighting activities.the elongation factor tu (ef-tu), an abundant bacterial protein involved in protein synthesis, has been shown to display moonlighting activities. known to perform more than one function at different times or in different places, it is found in several subcellular locations in a single organism, and may serve as a virulence factor in a range of important human pathogens. here we demonstrate that leptospira ef-tu is surface-exposed and performs additional roles as a cell-surface receptor for host ...201324312361
eco-genetic structure of bacillus cereus sensu lato populations from different environments in northeastern poland.the bacillus cereus group, which includes entomopathogens and etiologic agents of foodborne illness or anthrax, persists in various environments. the basis of their ecological diversification remains largely undescribed. here we present the genetic structure and phylogeny of 273 soil b. cereus s.l. isolates from diverse habitats in northeastern poland, with samplings acquired from the last european natural forest (białowieża national park), the largest marshes in europe (biebrza national park), ...201324312460
refseq microbial genomes database: new representation and annotation strategy.the source of the microbial genomic sequences in the refseq collection is the set of primary sequence records submitted to the international nucleotide sequence database public archives. these can be accessed through the entrez search and retrieval system at http://www.ncbi.nlm.nih.gov/genome. next-generation sequencing has enabled researchers to perform genomic sequencing at rates that were unimaginable in the past. microbial genomes can now be sequenced in a matter of hours, which has led to a ...201324316578
refseq microbial genomes database: new representation and annotation strategy.the source of the microbial genomic sequences in the refseq collection is the set of primary sequence records submitted to the international nucleotide sequence database public archives. these can be accessed through the entrez search and retrieval system at http://www.ncbi.nlm.nih.gov/genome. next-generation sequencing has enabled researchers to perform genomic sequencing at rates that were unimaginable in the past. microbial genomes can now be sequenced in a matter of hours, which has led to a ...201324316578
carriage of clostridium difficile by wild urban norway rats (rattus norvegicus) and black rats (rattus rattus).clostridium difficile is an important cause of enteric infections in humans. recently, concerns have been raised regarding whether animals could be a source of c. difficile spores. although colonization has been identified in a number of domestic species, the ability of commensal pests to serve as a reservoir for c. difficile has not been well investigated. the objective of this study was to determine whether urban rats (rattus spp.) from vancouver, canada, carry c. difficile. clostridium diffic ...201424317079
seroprevalence of leptospira hardjo in cattle and african buffalos in southwestern uganda.leptospirosis, caused by the spirochete bacterium leptospira spp. is a zoonosis, distributed worldwide and classified as an emerging infectious disease. fatal outcomes to leptospiral infection do occur and the disease can cause abortion and other reproductive problems in cattle, goats, and pigs. in humans the symptoms range from subclinical infection to acute febrile illness, pulmonary hemorrhage and renal failure. leptospirosis has never been officially reported to the world health organization ...201424323512
usefulness of real-time pcr assay targeting lipl32 gene for diagnosis of human leptospirosis in uruguay.assays based on dna amplification can provide information that contributes to the initial management of patients with leptospirosis. however, these have not been adopted in uruguay. our aim was to evaluate the performance of the lipl32 real-time pcr (qpcr) for diagnosis of leptospirosis.201324334940
lipl41, a hemin binding protein from leptospira santarosai serovar shermani.leptospirosis is one of the most widespread zoonotic diseases in the world. it is caused by the pathogen leptospira that results in multiple-organ failure, in particular of the kidney. outer membrane lipoprotein is the suspected virulence factor of leptospira. in leptospira spp lipl41 is one major lipoprotein and is highly conserved. previous study suggests that lipl41 bears hemin-binding ability and might play a possible role in iron regulation and storage. however, the characterization of hemi ...201324349474
seroprevalence and exposure to risk factors for leptospirosis among veterinary students at massey university.to determine the seroprevalence and quantify putative risk factors for exposure to leptospirosis both within and outside the veterinary curriculum among undergraduate veterinary students at massey university, new zealand.201424350827
leptospirosis: a silent epidemic disease.this special issue of international journal of environmental research and public health is dedicated to leptospirosis, an endemic zoonotic disease that is a cause of many acute undifferentiated fevers, especially in tropical countries. while it can be debated whether leptospirosis is an emerging disease, it is evident that it is becoming an emerging public health problem. it is recognized as a disease of epidemic potential that has a significant health impact in many parts of the world.201324351743
infections by leptospira interrogans, seoul virus, and bartonella spp. among norway rats (rattus norvegicus) from the urban slum environment in brazil.norway rats (rattus norvegicus) are reservoir hosts for zoonotic pathogens that cause significant morbidity and mortality in humans. studies evaluating the prevalence of zoonotic pathogens in tropical norway rat populations are rare, and data on co-infection with multiple pathogens are nonexistent. herein, we describe the prevalence of leptospiral carriage, seoul virus (seov), and bartonella spp. infection independently, in addition to the rates of co-infection among urban, slum-dwelling norway ...201424359425
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.201424361944
a multi-part matching strategy for mapping loinc with laboratory terminologies.to address the problem of mapping local laboratory terminologies to logical observation identifiers names and codes (loinc). to study different ontology matching algorithms and investigate how the probability of term combinations in loinc helps to increase match quality and reduce manual effort.201324363318
a multi-part matching strategy for mapping loinc with laboratory terminologies.to address the problem of mapping local laboratory terminologies to logical observation identifiers names and codes (loinc). to study different ontology matching algorithms and investigate how the probability of term combinations in loinc helps to increase match quality and reduce manual effort.201324363318
high-temperature protein g is an essential virulence factor of leptospira interrogans.leptospira interrogans is a global zoonotic pathogen and is the causative agent of leptospirosis, an endemic disease of humans and animals worldwide. there is limited understanding of leptospiral pathogenesis; therefore, further elucidation of the mechanisms involved would aid in vaccine development and the prevention of infection. htpg (high-temperature protein g) is the bacterial homolog to the highly conserved molecular chaperone hsp90 and is important in the stress responses of many bacteria ...201424366253
loop-mediated isothermal amplification for rickettsia typhi (the causal agent of murine typhus): problems with diagnosis at the limit of detection.murine typhus is a flea-borne disease of worldwide distribution caused by rickettsia typhi. although treatment with tetracycline antibiotics is effective, treatment is often misguided or delayed due to diagnostic difficulties. as the gold standard immunofluorescence assay is imperfect, we aimed to develop and evaluate a loop-mediated isothermal amplification (lamp) assay. lamp assays have the potential to fulfill the who assured criteria (affordable, sensitive, specific, user friendly, robust an ...201424371248
human leptospirosis: an emerging risk in europe?leptospirosis has been reemerging in both developed and developing countries including europe, where, this phenomenon has notably been associated with urban transmission. however, the comprehensive data that are needed to fully understand the ongoing epidemiological trends are lacking. in this article, we report surveillance data from throughout europe, especially in france, to have an overview of this neglected disease in temperate countries. our results underline the important role of wild rod ...201424388481
pyruvate protects pathogenic spirochetes from h2o2 killing.pathogenic spirochetes cause clinically relevant diseases in humans and animals, such as lyme disease and leptospirosis. the causative agent of lyme disease, borrelia burgdorferi, and the causative agent of leptospirosis, leptospria interrogans, encounter reactive oxygen species (ros) during their enzootic cycles. this report demonstrated that physiologically relevant concentrations of pyruvate, a potent h2o2 scavenger, and provided passive protection to b. burgdorferi and l. interrogans against ...201424392147
b-cell-specific peptides of leptospira interrogans liga for diagnosis of patients with acute leptospirosis.leptospirosis is a reemerging infectious disease that is underdiagnosed and under-recognized due to low-sensitivity and cumbersome serological tests. rapid reliable alternative tests are needed for early diagnosis of the disease. considering the importance of the pathogenesis-associated leptospiral liga protein expressed in vivo, we have evaluated its application in the diagnosis of the acute form of leptospirosis. the c-terminal coding sequence of liga (liga-c) was cloned into pet15b and expres ...201424403522
serologic and urinary pcr survey of leptospirosis in healthy cats and in cats with kidney disease.although there is serologic evidence of exposure of cats to leptospira spp., clinical disease is rarely reported in cats.201424417764
acute interstitial nephritis due to leptospira grippotyphosa in the absence of weil's disease.anicteric leptospirosis is a self-limited flu-like disease, whereas the icteric form is a severe illness characterized by multiple organ involvement or even failure. a case involving a patient with rapidly progressing renal insufficiency requiring intermittent renal replacement therapy due to leptospira grippotyphosa in the absence of a weil's disease is reported.201324421798
biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from glucose with elevated 3-hydroxyvalerate fraction via combined citramalate and threonine pathway in escherichia coli.the biosynthesis of polyhydroxyalkanoate copolymers in escherichia coli from unrelated carbon sources becomes attractive nowadays. we previously developed a poly(hydroxybutyrate-co-hydroxyvalerte) (phbv) biosynthetic pathway from an unrelated carbon source via threonine metabolic route in e. coli (chen et al., appl environ microbiol 77:4886-4893, 2011). in our study, a citramalate pathway was introduced in recombinant e. coli by cloning a cima gene from leptospira interrogans. by blocking the py ...201424425304
a method for molecular analysis of catalase gene diversity in seawater.catalase plays an important role in the metabolism of marine bacteria and has potential impact on the marine environment. four pcr primers were designed to amplify the catalase gene fragments in marine bacteria by applying metagenomic dna from yellow sea surface water as the template. of the four reproducible target pcr products, the longest one with 900 bp were chosen for catalase gene library construction by the t-vector and the white escherichia coli colonies in the library was screened throu ...201324426153
human leptospirosis on reunion island: past and current burden.since 1953, leptospirosis has been recognized as a public health problem on reunion island. in 2004, was implemented a specific surveillance system that included systematic reporting and the realization of environmental investigations around hospitalized cases. here, we present the synthesis of historical data and the assessment of 9 years of leptospirosis surveillance. from 2004 to 2012, 414 hospitalized cases were reported. cases of leptospirosis occurred mostly during the rainy season from de ...201424434593
central cavity of fructose-1,6-bisphosphatase and the evolution of amp/fructose 2,6-bisphosphate synergism in eukaryotic organisms.the effects of amp and fructose 2,6-bisphosphate (fru-2,6-p2) on porcine fructose-1,6-bisphosphatase (pfbpase) and escherichia coli fbpase (efbpase) differ in three respects. amp/fru-2,6-p2 synergism in pfbpase is absent in efbpase. fru-2,6-p2 induces a 13° subunit pair rotation in pfbpase but no rotation in efbpase. hydrophilic side chains in efbpase occupy what otherwise would be a central aqueous cavity observed in pfbpase. explored here is the linkage of amp/fru-2,6-p2 synergism to the centr ...201424436333
serodiagnosis of equine leptospirosis by enzyme-linked immunosorbent assay using four recombinant protein markers.leptospirosis, caused by leptospira spp., is one of the most common zoonotic diseases in the world. we tested four recombinant proteins of leptospira interrogans, namely, rlipl21, rloa22, rlipl32, and rligacon4-8, to evaluate their potential for use as antigens for the diagnosis of equine leptospirosis. we employed equine sera (n = 130) that were microscopic agglutination test (mat) negative and sera (n = 176) that were mat positive for the 5 serovars that most commonly cause equine leptospirosi ...201424451330
a 26-year-old man with a blind spot in his left eye. 201324453936
regional differences of leptospirosis in sri lanka: observations from a flood-associated outbreak in 2011.leptospirosis is known to be an important cause of weather disaster-related infectious disease epidemics. in 2011, an outbreak of leptospirosis occurred in the relatively dry district of anuradhapura, sri lanka where diagnosis was resisted by local practitioners because leptospirosis was not known in the area and the clinical presentation was considered atypical. to identify the causative leptospira associated with this outbreak, we carried out a cross-sectional study. consecutive clinically sus ...201424454971
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