Publications

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evaluation of the elastinolytic activity and protective effect of leptallo i, a protein composed by metalloprotease and fa5/8c domains, from leptospira interrogans copenhageni.leptospirosis is a re-emergent zoonosis, caused by pathogenic spirochetes from the genus lepstospira. to date, there is no protein described to be involved in leptospiral hemorrhagic manifestations, although several proteases have been reported for other bacterial infections. in this study we identified 12 putative metalloproteases from the genome of leptospira interrogans, and characterized for the first time a putative metalloprotease, here named leptallo i, as a potential zn(2+) dependent gly ...201323665291
[prokaryotic expression of leptospira interrogans groel gene and immunoprotection of its products in hamsters].to construct a prokaryotic expression system of groel gene of leptospira interrogans serogroup icterohaemorrhagia serovar lai strain lai, and to determine the immunoprotective effect of recombinant groel protein (rgroel) in lvg hamsters.201323585002
[expression changes of major outer membrane protein antigens in leptospira interrogans during infection and its mechanism].to determine expression changes of major outer membrane protein(omp) antigens of leptospira interrogans serogroup icterohaemorrhagiae serovar lai strain lai during infection of human macrophages and its mechanism.201323585001
detection of reactive canines to leptospira in campeche city, mexico.leptospira reactivity in stray and household dogs in campeche as well as associated risk factors to the seropositivity in household dogs have been herein determined. the survey included 323 dogs, 142 of which were stray dogs and 181 household dogs. nine leptospira interrogans serovars were tested by the microagglutination test. reactivity was 21.3 % (69/323), 17.2 % corresponded to household dogs and 26.7 % to stray dogs. leptospira canicola (29 %), leptospira hardjo (22.58 %), and leptospira ic ...201323560786
p53 signalling controls cell cycle arrest and caspase-independent apoptosis in macrophages infected with pathogenic leptospira species.pathogenic leptospira species, the causative agents of leptospirosis, have been shown to induce macrophage apoptosis through caspase-independent, mitochondrion-related apoptosis inducing factor (aif) and endonuclease g (endog), but the signalling pathway leading to aif/endog-based macrophage apoptosis remains unknown. here we show that infection of leptospira interrogans caused a rapid increase in reactive oxygen species (ros), dna damage, and intranuclear foci of 53bp1 and phosphorylation of h2 ...201323521874
molecular characterization of virulent leptospira interrogans serogroup icterohaemorrhagiae isolated from cavia aperea.leptospirosis is a worldwide zoonotic infection caused by pathogenic leptospira. synanthropic rodents are recognized carriers of leptospires; however, the role of wild rodents in the epidemiology of the disease is still incipient. in this work, we describe leptospira strain isolated from cavia aperea (brazilian guinea pig). the isolated strain was characterized by partial rpob gene sequencing, variable-number tandem-repeats and histopathological analysis. the strain was identified as leptospira ...201323435256
asymptomatic and chronic carriage of leptospira interrogans serovar pomona in california sea lions (zalophus californianus).since 1970, periodic outbreaks of leptospirosis, caused by pathogenic spirochetes in the genus leptospira, have caused morbidity and mortality of california sea lions (zalophus californianus) along the pacific coast of north america. yearly seasonal epizootics of varying magnitude occur between the months of july and december, with major epizootics occurring every 3-5 years. genetic and serological data suggest that leptospira interrogans serovar pomona is the infecting serovar and is enzootic i ...201323419822
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
synthesis, leptospirocidal activity and qsar analysis of novel quinoxaline derivatives.a simple and efficient method has been developed for the synthesis of series of n-mannich bases of (e)-3- (phenylimino/4-chlorophenylimino)-2,3-dihydro-1-[(n-substituted piperazinyl) methyl]quinoxaline-2-(1h)-one 3a-f and 4a-f. the requisite 2a and 2b were obtained by reaction between quinoxaline-2,3-dione 1 and aniline/p-chloroaniline. these compounds underwent nmannich reaction with various substituted piperazines to yield (title compounds 3a-f and 4a-f respectively. structures of synthesized ...201322779788
temporal trends in bulk milk antibodies to salmonella, neospora caninum, and leptospira interrogans serovar hardjo in irish dairy herds.bulk milk samples were collected from 309 irish dairy herds at four time points during 2009 and tested for antibodies to salmonella spp., n. caninum, and l. hardjo, three abortifacient agents in irish dairy herds. of the 312 study herds, 49% vaccinated against salmonella and 76% vaccinated against l. hardjo. in unvaccinated herds, the overall prevalence of antibody positive herds was 49% for salmonella, 19% for n. caninum and 86% for l. hardjo. there was no association between both testing posit ...201323117041
molecular and serological characterization of leptospira interrogans serovar canicola isolated from dogs, swine, and bovine in brazil.the identification of leptospira clinical isolates through genotyping and serotyping, besides the recognition of its reservoirs, are important tools for understanding the epidemiology of leptospirosis, and they are also keys for identifying new species and serovars. fourteen clinical isolates from animals were characterized by means of single enzyme amplified length polymorphism, variable number of tandem repeat analysis, pulsed field gel electrophoresis, and serotyping. all isolates were identi ...201322610538
[preservation for vaccinal strains of leptospira at liquid nitrogen].leptospira interrogans strains of cuban vaccine vax-spiral are preserved in fletcher's semi-solid medium, which guarantees the preservation of the cell viability for a few months.201323431625
molecular serovar characterization of leptospira isolates from animals and water in colombia.leptospirosis is a bacterial disease transmitted directly or indirectly from animals to humans that may result in severe hemorrhagic, hepatic/renal and pulmonary disease. there are 20 known leptospira species and hundreds of serovars, some of which belong to different species. it is essential to identify pathogenic leptospira serovars and their potential reservoirs to prepare adequate control strategies.201324652261
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
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
identification of epitopes in leptospira borgpetersenii leucine-rich repeat proteins.leptospirosis is considered to be a re-emerging disease that has impacts on public health both globally and in and thailand. the leptospires outbreak in thailand during 1999 was largely due to the etiologic agent leptospira borgpetersenii serogroup sejroe. this had a related immunity profile in cows from thailand, which serovars tarassovi and sejroe were prevalent. development of a vaccine protecting against leptospiral infection in livestock has been considered. one family of proteins being tar ...201323201041
a serological survey of leptospiral antibodies in dogs in new zealand.to investigate the prevalence of titres to four endemic leptospiral serovars in dog sera from the lower half of the north island, and the south island of new zealand submitted to diagnostic laboratories, and to explore the association between the prevalence of seropositive samples to leptospirosis and breed group, age group and sex.201323013160
factors associated with probable cluster of leptospirosis among kennel workers in abuja, nigeria.between february and october 2009 an increase in morbidity and mortality in dogs in a national kennel in abuja, nigeria, was observed with signs indicative of leptospirosis. concurrent illness was observed in some kennel workers which had high titres of leptospira antibodies.201324711882
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
veillonella, firmicutes: microbes disguised as gram negatives.the firmicutes represent a major component of the intestinal microflora. the intestinal firmicutes are a large, diverse group of organisms, many of which are poorly characterized due to their anaerobic growth requirements. although most firmicutes are gram positive, members of the class negativicutes, including the genus veillonella, stain gram negative. veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerob ...201324976898
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
metaid: a novel method for identification and quantification of metagenomic samples.advances in next-generation sequencing (ngs) technology has provided us with an opportunity to analyze and evaluate the rich microbial communities present in all natural environments. the shorter reads obtained from the shortgun technology has paved the way for determining the taxonomic profile of a community by simply aligning the reads against the available reference genomes. while several computational methods are available for taxonomic profiling at the genus- and species-level, none of thes ...201324564518
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
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
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
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
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
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
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
cloning and sequence analysis of lipl32, a surface-exposed lipoprotein of pathogenic leptospira spp.leptospirosis is a worldwide zoonosis caused by pathogenic leptospira species. a major challenge of this disease is the application of basic research to improve diagnostic methods and related vaccine development. outer membrane proteins of leptospira are potential candidates that may be useful as diagnostic or immunogenic factors in treatment and analysis of the disease.201324719688
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
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
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
androgenic anabolic steroid, cocaine and amphetamine abuse and adverse cardiovascular effects.anabolic-androgenic steroids (aas), a synthetic derivate of testosterone, have become a popular drug among athletes and bodybuilders to enhance muscle mass and improve the athletic performance. many pathological effects such as hepatic and endocrine dysfunction, behavioural changes and cardiovascular complications have been reported.201324719633
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
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
a 26-year-old man with a blind spot in his left eye. 201324453936
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
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
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
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
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
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
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
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
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
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
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
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
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
development of an enzyme-linked immunosorbent assay using a recombinant liga fragment comprising repeat domains 4 to 7.5 as an antigen for diagnosis of equine leptospirosis.leptospira immunoglobulin (ig)-like (lig) proteins are a novel family of surface-associated proteins in which the n-terminal 630 amino acids are conserved. in this study, we truncated the liga conserved region into 7 fragments comprising the 1st to 3rd (ligacon1-3), 4th to 7.5th (ligacon4-7.5), 4th (ligacon4), 4.5th to 5.5th (ligacon4.5-5.5), 5.5th to 6.5th (ligacon5.5-6.5), 4th to 5th (ligacon4-5), and 6th to 7.5th (ligacon6-7.5) repeat domains. all 7 recombinant lig proteins were screened usin ...201323720368
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
precipitation of iron on the surface of leptospira interrogans is associated with mutation of the stress response metalloprotease htpx.high concentrations of free metal ions in the environment can be detrimental to bacterial survival. however, bacteria utilize strategies, including the activation of stress response pathways and immobilizing chemical elements on their surface, to limit this toxicity. in this study, we characterized la4131, the htpx-like m48 metalloprotease from leptospira interrogans, with a putative role in bacterial stress response and membrane homeostasis. growth of the la4131 transposon mutant strain (l522) ...201323709510
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
seroprevalence of leptospiral antibodies in canine population in and around namakkal.leptospirosis is a reemerging and a complex zoonotic bacterial disease, caused by pathogenic serovars of leptospira interrogans. a total of 124 sera samples of dogs belonging to different categories like vaccinated, unvaccinated-semiowned, and stray dogs were subjected to sampling. microscopic agglutination test (mat) was conducted by using leptospira culture. out of 42 vaccinated dogs, 24 (57%) were positive to one or more serovars. of the 24, 22 (52.3%), 11 (26.19%), 4 (9.5%), 1 (3%), and 2 (4 ...201326464917
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
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
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
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
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
acyltransferases in bacteria.long-chain-length hydrophobic acyl residues play a vital role in a multitude of essential biological structures and processes. they build the inner hydrophobic layers of biological membranes, are converted to intracellular storage compounds, and are used to modify protein properties or function as membrane anchors, to name only a few functions. acyl thioesters are transferred by acyltransferases or transacylases to a variety of different substrates or are polymerized to lipophilic storage compou ...201323699259
the mtb proteome library: a resource of assays to quantify the complete proteome of mycobacterium tuberculosis.research advancing our understanding of mycobacterium tuberculosis (mtb) biology and complex host-mtb interactions requires consistent and precise quantitative measurements of mtb proteins. we describe the generation and validation of a compendium of assays to quantify 97% of the 4,012 annotated mtb proteins by the targeted mass spectrometric method selected reaction monitoring (srm). furthermore, we estimate the absolute abundance for 55% of all mtb proteins, revealing a dynamic range within th ...201323684311
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
incidence of leptospirosis infection in the east zone of sao paulo city, brazil.leptospirosis is a zoonosis which is spread through contamined running water. this contaminations is seriously affected by the flooding which occurs in the area surrounding the aricanduva river. the transmission of the disease results mainly from the contact of water with soil contaminated by the urine of infected animals. we aimed to conduct an epidemiological survey on leptospirosis cases in sao paulo east zone area.201323672682
a chimeric udp-glucose pyrophosphorylase produced by protein engineering exhibits sensitivity to allosteric regulators.in bacteria, glycogen or oligosaccharide accumulation involves glucose-1-phosphate partitioning into either adp-glucose (adp-glc) or udp-glc. their respective synthesis is catalyzed by allosterically regulated adp-glc pyrophosphorylase (ec 2.7.7.27, adp-glc ppase) or unregulated udp-glc ppase (ec 2.7.7.9). in this work, we characterized the udp-glc ppase from streptococcus mutans. in addition, we constructed a chimeric protein by cutting the c-terminal domain of the adp-glc ppase from escherichi ...201323648478
climate variability and outbreaks of infectious diseases in europe.several studies provide evidence of a link between vector-borne disease outbreaks and el niño driven climate anomalies. less investigated are the effects of the north atlantic oscillation (nao). here, we test its impact on outbreak occurrences of 13 infectious diseases over europe during the last fifty years, controlling for potential bias due to increased surveillance and detection. nao variation statistically influenced the outbreak occurrence of eleven of the infectious diseases. seven diseas ...201323639950
a conserved region of leptospiral immunoglobulin-like a and b proteins as a dna vaccine elicits a prophylactic immune response against leptospirosis.the leptospiral immunoglobulin-like (lig) proteins liga and ligb possess immunoglobulin-like domains with 90-amino-acid repeats and are adhesion molecules involved in pathogenicity. they are conserved in pathogenic leptospira spp. and thus are of interest for use as serodiagnostic antigens and in recombinant vaccine formulations. the n-terminal amino acid sequences of the liga and ligb proteins are identical, but the c-terminal sequences vary. in this study, we evaluated the protective potential ...201323486420
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
sex bias in infectious disease epidemiology: patterns and processes.infectious disease incidence is often male-biased. two main hypotheses have been proposed to explain this observation. the physiological hypothesis (ph) emphasizes differences in sex hormones and genetic architecture, while the behavioral hypothesis (bh) stresses gender-related differences in exposure. surprisingly, the population-level predictions of these hypotheses are yet to be thoroughly tested in humans.201323638062
a ubiquitous method for street scale spatial data collection and analysis in challenging urban environments: mapping health risks using spatial video in haiti.fine-scale and longitudinal geospatial analysis of health risks in challenging urban areas is often limited by the lack of other spatial layers even if case data are available. underlying population counts, residential context, and associated causative factors such as standing water or trash locations are often missing unless collected through logistically difficult, and often expensive, surveys. the lack of spatial context also hinders the interpretation of results and designing intervention st ...201323587358
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
isolation and molecular characterization of leptospira interrogans and leptospira borgpetersenii isolates from the urban rat populations of kuala lumpur, malaysia.rats are considered the principal maintenance hosts of leptospira. the objectives of this study were isolation and identification of leptospira serovars circulating among urban rat populations in kuala lumpur. three hundred urban rats (73% rattus rattus and 27% r. norvegicus) from three different sites were trapped. twenty cultures were positive for leptospira using dark-field microscopy. r. rattus was the dominant carrier (70%). polymerase chain reaction (pcr) confirmed that all isolates were p ...201323358635
detection of lipl32-specific igm by elisa in sera of patients with a clinical diagnosis of leptospirosis.successful treatment of leptospirosis is heavily dependent on early diagnosis and prompt initiation of antibiotic therapy. an elisa test to detect specific igm antibodies against lipl32 for early diagnosis of leptospirosis is described and evaluated here. one thousand one hundred and eighty sera from clinically suspected leptospirosis cases were enrolled together with 109 healthy volunteers selected from an endemic area between october 2007 and january 2010. patients were categorized based on th ...201323683367
serosurvey of dogs for human, livestock, and wildlife pathogens, uganda. 201323750507
crystallographic study to determine the substrate specificity of an l-serine-acetylating enzyme found in the d-cycloserine biosynthetic pathway.dcse, one of the enzymes found in the d-cycloserine biosynthetic pathway, displays a high sequence homology to l-homoserine o-acetyltransferase (hat), but it prefers l-serine over l-homoserine as the substrate. to clarify the substrate specificity, in the present study we determined the crystal structure of dcse at a 1.81-å resolution, showing that the overall structure of dcse is similar to that of hat, whereas a turn region to form an oxyanion hole is obviously different between dcse and hat: ...201323396912
leptospirosis risk increases with changes in species composition of rat populations.rats are major reservoirs of leptospirosis and considered as a main threat to biodiversity. a recent introduction of rattus rattus to the island of futuna (western polynesia) provided the opportunity to test if a possible change in species composition of rat populations would increase the risk of leptospirosis to humans. we trapped rodents on wallis and futuna and assessed leptospira carriage in 357 rodents (rattus norvegicus, r. rattus, rattus exulans, and mus domesticus) from 2008 to 2012. whi ...201323535996
multiple single-cell genomes provide insight into functions of uncultured deltaproteobacteria in the human oral cavity.despite a long history of investigation, many bacteria associated with the human oral cavity have yet to be cultured. studies that correlate the presence or abundance of uncultured species with oral health or disease highlight the importance of these community members. thus, we sequenced several single-cell genomic amplicons from desulfobulbus and desulfovibrio (class deltaproteobacteria) to better understand their function within the human oral community and their association with periodontitis ...201323555659
toll-like receptors as therapeutic targets for autoimmune connective tissue diseases.autoimmune connective tissue diseases (actds) are a family of consistent systemic autoimmune inflammatory disorders, including systemic lupus erythematosus (sle), rheumatoid arthritis (ra), systemic sclerosis (ssc) and sjögren's syndrome (ss). il-1r-like receptors (tlrs) are located on various cellular membranes and sense exogenous and endogenous danger-associated molecular patterns (damps) and pathogen-associated molecular patterns (pamps), playing a critical role in innate immune responses. du ...201323531543
evolutionary history of the plant pathogenic bacterium xanthomonas axonopodis.deciphering mechanisms shaping bacterial diversity should help to build tools to predict the emergence of infectious diseases. xanthomonads are plant pathogenic bacteria found worldwide. xanthomonas axonopodis is a genetically heterogeneous species clustering, into six groups, strains that are collectively pathogenic on a large number of plants. however, each strain displays a narrow host range. we address the question of the nature of the evolutionary processes--geographical and ecological spec ...201323505513
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
a case of mixed infections in a patient presenting with acute febrile illness in the tropics.concurrent infections with more than one etiological agent can result in an illness with overlapping symptoms, resulting in a situation where the diagnosis and management of such a patient could be challenging. we report a case of vivax malaria in a patient who was also serologically positive for leptospirosis and dengue.201323533853
protein analysis by shotgun/bottom-up proteomics. 201323438204
the origin of 8-amino-3,8-dideoxy-d-manno-octulosonic acid (kdo8n) in the lipopolysaccharide of shewanella oneidensis.lipopolysaccharide (lps; endotoxin) is an essential component of the outer monolayer of nearly all gram-negative bacteria. lps is composed of a hydrophobic anchor, known as lipid a, an inner core oligosaccharide, and a repeating o-antigen polysaccharide. in nearly all species, the first sugar bridging the hydrophobic lipid a and the polysaccharide domain is 3-deoxy-d-manno-octulosonic acid (kdo), and thus it is critically important for lps biosynthesis. modifications to lipid a have been shown t ...201323413030
pancreatitis and myocarditis followed by pulmonary hemorrhage, a rare presentation of leptospirosis- a case report and literature survey.leptospirosis is a potentially fatal disease which can cause multi-organ dysfunction. it can rarely present as acute pancreatitis. this is the first ever report of leptospirosis presenting with acute pancreatitis and myocarditis followed by diffuse pulmonary hemorrhages to the best of our knowledge.201323347428
solution structure of the big domain from streptococcus pneumoniae reveals a novel ca2+-binding module.streptococcus pneumoniae is a pathogen causing acute respiratory infection, otitis media and some other severe diseases in human. in this study, the solution structure of a bacterial immunoglobulin-like (big) domain from a putative s. pneumoniae surface protein sp0498 was determined by nmr spectroscopy. sp0498 big domain adopts an eight-β-strand barrel-like fold, which is different in some aspects from the two-sheet sandwich-like fold of the canonical ig-like domains. intriguingly, we identified ...201323326635
risk factors and predictors of severe leptospirosis in new caledonia.leptospirosis is a major public health concern in new caledonia (nc) and in other tropical countries. severe manifestations of the disease are estimated to occur in 5-15% of all human infections worldwide and factors associated with these forms are poorly understood. our objectives were to identify risk factors and predictors of severe forms of leptospirosis in adults.201323326614
comparative analysis of leptospira strains isolated from environmental soil and water in the philippines and japan.there have been few reports on the epidemiological analysis of environmental leptospira isolates. this is probably because the isolation of leptospires from the environment was usually unsuccessful due to the overgrowth of contaminants and the slow growth of leptospira. in this study, we collected a total of 88 samples of soil and water from three sites: metro manila and nueva ecija, philippines (an area where leptospira is now endemic), and fukuoka, japan (an area where leptospira was once ende ...201323144130
rapid isolation and susceptibility testing of leptospira spp. using a new solid medium, lvw agar.pathogenic leptospira spp., the causative agents of leptospirosis, are slow-growing gram-negative spirochetes. isolation of leptospira from clinical samples and testing of antimicrobial susceptibility are difficult and time-consuming. here, we describe the development of a new solid medium that facilitates more-rapid growth of leptospira spp. and the use of this medium to evaluate the etest's performance in determining antimicrobial mics to drugs in common use for leptospirosis. the medium was d ...201323114772
leptospira interrogans survey by pcr in wild rodents coming from different urban areas of palermo, italy.dna extracted from the kidneys of rodents captured in different urban areas of palermo, italy, had been analysed for the presence of pathogenic l. interrogans sensu latu dna. pcr analysis had shown that in rodents captured close to green areas and small river up to 40 % animals give positive pcr results. not many cases of human leptospirosis are reported in sicilian island in which hot season is usually dry. but considering climate change toward subtropical aspect in sicily, with hot humid summe ...201323427420
detection of severe fever with thrombocytopenia syndrome virus by reverse transcription-cross-priming amplification coupled with vertical flow visualization.a virus known as severe fever with thrombocytopenia syndrome virus (sftsv) was recently identified as the etiological agent of severe fever with thrombocytopenia syndrome (sfts) in china. reliable laboratory detection and identification of this virus are likely to become clinically and epidemiologically desirable. we developed a nearly instrument-free, simple molecular method which incorporates reverse transcription-cross-priming amplification (rt-cpa) coupled with a vertical flow (vf) visualiza ...201222993179
a novel tetravalent leptospira bacterin protects against infection and shedding following challenge in dogs.recent evidence based on the current epidemiological situation suggests that vaccines against canine leptospirosis in europe should be directed against infection with leptospira interrogans (sensu lato) serogroups canicola, icterohaemorrhagiae, grippotyphosa and australis. in the eight studies presented here, dogs were vaccinated with nobivac l4 (msd animal health), a new tetravalent inactivated vaccine containing antigen from four strains representing these four serogroups. the dogs were then c ...201223180149
a novel tetravalent leptospira bacterin protects against infection and shedding following challenge in dogs.recent evidence based on the current epidemiological situation suggests that vaccines against canine leptospirosis in europe should be directed against infection with leptospira interrogans (sensu lato) serogroups canicola, icterohaemorrhagiae, grippotyphosa and australis. in the eight studies presented here, dogs were vaccinated with nobivac l4 (msd animal health), a new tetravalent inactivated vaccine containing antigen from four strains representing these four serogroups. the dogs were then c ...201223180149
structure determination of lpxa from the lipopolysaccharide-synthesis pathway of acinetobacter baumannii.acinetobacter baumannii is a gram-negative pathogenic bacterium which is resistant to most currently available antibiotics and that poses a significant health threat to hospital patients. lpxa is a key enzyme in the biosynthetic pathway of the lipopolysaccharides that are components of the bacterial outer membrane. it is a potential target for antibacterial agents that might be used to fight a. baumannii infections. this paper describes the structure determination of the apo form of lpxa in spac ...201223192027
serosurveillance for livestock pathogens in free-ranging mule deer (odocoileus hemionus).routine disease surveillance has been conducted for decades in mule deer (odocoileus hemionus) in california for pathogens shared between wildlife and domestic ruminants that may have implications for the animal production industry and wildlife health. deer sampled from 1990 to 2007 (n = 2,619) were tested for exposure to six pathogens: bluetongue virus (btv), epizootic hemorrhagic disease virus (ehdv), bovine viral diarrhea virus (bvdv), leptospira spp., anaplasma spp. and brucella spp. we eval ...201223209790
accuracy of a dual path platform (dpp) assay for the rapid point-of-care diagnosis of human leptospirosis.diagnosis of leptospirosis by the gold standard serologic assay, the microscopic agglutination test (mat), requires paired sera and is not widely available. we developed a rapid assay using immunodominant leptospira immunoglobulin-like (lig) proteins in a dual path platform (dpp). this study aimed to evaluate the assay's diagnostic performance in the setting of urban transmission.201223133686
quantification of bacterial indicators and zoonotic pathogens in dairy wastewater ponds.zoonotic pathogens in land-applied dairy wastewaters are a potential health risk. the occurrence and abundance of 10 pathogens and 3 fecal indicators were determined by quantitative real-time pcr (qpcr) in samples from 30 dairy wastewaters from southern idaho. samples tested positive for campylobacter jejuni, stx(1)- and eaea-positive escherichia coli, listeria monocytogenes, mycobacterium avium subsp. paratuberculosis, and salmonella enterica, with mean recoveries of genomic dna corresponding t ...201222983964
leptospirosis outbreaks in nicaragua: identifying critical areas and exploring drivers for evidence-based planning.leptospirosis is an epidemic-prone zoonotic disease that occurs worldwide. in central america, leptospirosis outbreaks have been reported in almost all countries; nicaragua in particular has faced several outbreaks. the objective of this study was to stratify the risk and identify "critical areas" for leptospirosis outbreaks in nicaragua, and to perform an exploratory analysis of potential "drivers". this ecological study includes the entire country (153 municipalities). cases from 2004 to 2010 ...201223202822
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