Publications

genome-wide identification of francisella tularensis virulence determinants.	francisella tularensis is a gram-negative pathogen that causes life-threatening infections in humans and has potential for use as a biological weapon. the genetic basis of the f. tularensis virulence is poorly understood. this study screened a total of 3,936 transposon mutants of the live vaccine strain for infection in a mouse model of respiratory tularemia by signature-tagged mutagenesis. we identified 341 mutants attenuated for infection in the lungs. the transposon disruptions were mapped to ...	2007	17420240
plasmids and rickettsial evolution: insight from rickettsia felis.	the genome sequence of rickettsia felis revealed a number of rickettsial genetic anomalies that likely contribute not only to a large genome size relative to other rickettsiae, but also to phenotypic oddities that have confounded the categorization of r. felis as either typhus group (tg) or spotted fever group (sfg) rickettsiae. most intriguing was the first report from rickettsiae of a conjugative plasmid (prf) that contains 68 putative open reading frames, several of which are predicted to enc ...	2007	17342200
epidemiology and control of neosporosis and neospora caninum.	neospora caninum is a protozoan parasite of animals. until 1988, it was misidentified as toxoplasma gondii. since its first recognition in dogs in 1984 and the description of the new genus and species neospora caninum in 1988, neosporosis has emerged as a serious disease of cattle and dogs worldwide. abortions and neonatal mortality are a major problem in livestock operations, and neosporosis is a major cause of abortion in cattle. although antibodies to n. caninum have been reported, the parasi ...	2007	17428888
pathogenesis of leptospirosis: interaction of leptospira interrogans with in vitro cultured mammalian cells.	interactions of virulent leptospira interrogans with murine monocyte-macrophage-like j774a.1 cells and vero (african green monkey kidney fibroblasts) cells from attachment to internalization were investigated by a series of morphological analysis. fontana silver staining revealed that only the pathogenic leptospires were able to attach to host cells and the attachment pattern varied depending on cell types that they interacted with. transmission electron microscopy (tem) analysis confirmed the f ...	2007	17429690
enzymology and evolution of the pyruvate pathway to 2-oxobutyrate in methanocaldococcus jannaschii.	the archaeon methanocaldococcus jannaschii uses three different 2-oxoacid elongation pathways, which extend the chain length of precursors in leucine, isoleucine, and coenzyme b biosyntheses. in each of these pathways an aconitase-type hydrolyase catalyzes an hydroxyacid isomerization reaction. the genome sequence of m. jannaschii encodes two homologs of each large and small subunit that forms the hydrolyase, but the genes are not cotranscribed. the genes are more similar to each other than to p ...	2007	17449626
a serologic assessment of exposure to viral pathogens and leptospira in an urban raccoon (procyon lotor) population inhabiting a large zoological park.	in urban environments, raccoons (procyon lotor) may act as reservoirs for an array of pathogenic organisms, presenting spillover risks for human, domestic animal, and captive (zoo) animal populations. over 5 yr, 159 raccoons from a high-density raccoon population in st. louis, missouri (usa), were surveyed for exposure to canine distemper virus (cdv), canine adenovirus 1 (cav-1); feline parvovirus (fpv; =feline panleukopenia), and several serovars of leptospira interrogans. exposure to each of t ...	2007	17469271
efficacy of fluoroquinolones against leptospira interrogans in a hamster model.	ciprofloxacin, gatifloxacin, and levofloxacin were evaluated for their abilities to prevent mortality in hamsters infected with a lethal inoculum of leptospira interrogans serovar portlandvere. each agent produced a statistically significant survival advantage compared to no treatment and demonstrated survival similar to that seen with doxycycline therapy.	2007	17470646
vapc-1 of nontypeable haemophilus influenzae is a ribonuclease.	nontypeable haemophilus influenzae (nthi) organisms are obligate parasites of the human upper respiratory tract that can exist as commensals or pathogens. toxin-antitoxin (ta) loci are highly conserved gene pairs that encode both a toxin and antitoxin moiety. seven ta gene families have been identified to date, and nthi carries two alleles of the vapbc family. here, we have characterized the function of one of the nthi alleles, vapbc-1. the gene pair is transcribed as an operon in two nthi clini ...	2007	17496075
a genomic island of the pathogen leptospira interrogans serovar lai can excise from its chromosome.	an examination of the two leptospira interrogans genomes sequenced so far reveals few genetic differences, including an extra dna region, 54 kb in length, in l. interrogans serovar lai. this locus contains 103 predicted coding sequences that are absent from the genome of l. interrogans serovar copenhageni, of which only 20% had significant blastp hits in genbank. by analyzing the l. interrogans serovar lai genome by pulsed-field gel electrophoresis, we also found that this 54-kb dna fragment exi ...	2007	17118975
leptospirosis in farmed deer in new zealand : a review.	current knowledge of leptospirosis in farmed deer in new zealand is reviewed. over the past 25 years, leptospirosis has been reported to occur in individual cases as well as in herd outbreaks in farmed deer and in human cases linked to farmed deer. serological studies and evidence from bacterial culture suggest infection is widespread. mixing of young stock from several sources appears to be a significant risk factor for outbreaks. the culture of leptospira interrogans serovars hardjobovis, pomo ...	2007	17534410
use of an enzyme-linked immunosorbent assay in bulk milk to estimate the prevalence of neospora caninum on dairy farms in prince edward island, canada.	this study evaluated the use of bulk milk as a diagnostic tool for estimation of herd-level neospora caninum exposure in atlantic canada; it was used to estimate the prevalence of dairy farms with a within-herd n. caninum-seroprevalence > or = 15% in prince edward island (pei). the variation over time of n. caninum antibodies in bulk milk is also reported. skimmed bulk milk and individual serum samples were analyzed for n. caninum antibodies by using an enzyme-linked immunosorbent assay (elisa). ...	2007	17542367
leptospirosis in urban wild boars, berlin, germany.	we found antibodies to leptospires in 25 (18%) of 141 wild boars from berlin (95% confidence interval 12-25). seropositivity was associated with chronic interstitial nephritis (odds ratio 10.5; p=0.01), and leptospires were detected in kidney tissues. wild boars represent a potential source for human leptospirosis in urban environments.	2007	17553254
classical complement activation and acquired immune response pathways are not essential for retinal degeneration in the rd1 mouse.	misregulation of the innate immune response and other immune-related processes have been suggested to play a critical role in the pathogenesis of a number of different neurodegenerative diseases, including age related macular degeneration. in an animal model for photoreceptor degeneration, several genes of the innate and acquired immune system were found to be differentially regulated in the retina during the degenerative process. in addition to this differential regulation of individual genes, ...	2007	17069800
human infection with schineria iarvae.		2007	17561570
classical complement activation and acquired immune response pathways are not essential for retinal degeneration in the rd1 mouse.	misregulation of the innate immune response and other immune-related processes have been suggested to play a critical role in the pathogenesis of a number of different neurodegenerative diseases, including age related macular degeneration. in an animal model for photoreceptor degeneration, several genes of the innate and acquired immune system were found to be differentially regulated in the retina during the degenerative process. in addition to this differential regulation of individual genes, ...	2007	17069800
characterization of the outer membrane proteome of leptospira interrogans expressed during acute lethal infection.	pathogenic leptospira species adapt to a wide range of environmental conditions during disease transmission and infection. while the proteome of in vitro cultivated leptospira has been characterized in several studies to date, relatively little is known of the proteome as expressed by leptospira during disease processes. isolates of leptospira obtained from patients suffering the severe pulmonary form of leptospirosis cause acute lethal infection in guinea pigs and chronic asymptomatic infection ...	2007	17101664
genetic diversity among major endemic strains of leptospira interrogans in china.	leptospirosis is a world-widely distributed zoonosis. humans become infected via exposure to pathogenic leptospira spp. from contaminated water or soil. the availability of genomic sequences of leptospira interrogans serovar lai and serovar copenhageni opened up opportunities to identify genetic diversity among different pathogenic strains of l. interrogans representing various kinds of serotypes (serogroups and serovars).	2007	17603913
clinicopathologic features and outcome predictors of leptospira interrogans australis serogroup infection in dogs: a retrospective study of 20 cases (2001-2004).	we retrospectively evaluated the clinicopathologic findings and outcome predictors in dogs with leptospira interrogans australis serogroup infections.	2007	17338143
bartonella quintana lipopolysaccharide is a natural antagonist of toll-like receptor 4.	bartonella quintana is a gram-negative microorganism that causes trench fever and chronic bacteremia. b. quintana lipopolysaccharide (lps) was unable to induce the production of proinflammatory cytokines in human monocytes. interestingly, b. quintana lps is a potent antagonist of toll-like receptor 4 (tlr4), as it inhibited both mrna transcription and the release of tumor necrosis factor alpha, interleukin 1beta (il-1beta), and il-6 by escherichia coli lps in human monocytes, at ratios ranging f ...	2007	17606598
does human proximity affect antibody prevalence in marine-foraging river otters (lontra canadensis)?	the investigation of diseases of free-ranging river otters (lontra canadensis) is a primary conservation priority for this species; however, very little is known about diseases of river otters that forage in marine environments. to identify and better understand pathogens that could be important to marine-foraging river otters, other wildlife species, domestic animals, and humans and to determine if proximity to human population could be a factor in disease exposure, serum samples from 55 free-r ...	2007	17347401
increased prevalence of borrelia burgdorferi infections in bernese mountain dogs: a possible breed predisposition.	glomerulonephritis in dogs has been associated with b. burgdorferi infections. in bernese mountain dogs with glomerulonephritis antibodies against b. burgdorferi have been found in most dogs, raising the question if the breed is predisposed to infections with b. burgdorferi. the aim of this study was to determine the prevalence of antibodies against b. burgdorferi sensu lato in a well defined population of bernese mountain dogs and to compare this prevalence with data from dogs of other breeds.	2007	17626630
the terminal portion of leptospiral immunoglobulin-like protein liga confers protective immunity against lethal infection in the hamster model of leptospirosis.	subunit vaccines are a potential intervention strategy against leptospirosis, which is a major public health problem in developing countries and a veterinary disease in livestock and companion animals worldwide. leptospiral immunoglobulin-like (lig) proteins are a family of surface-exposed determinants that have ig-like repeat domains found in virulence factors such as intimin and invasin. we expressed fragments of the repeat domain regions of liga and ligb from leptospira interrogans serovar co ...	2007	17629368
purification, crystallization and preliminary crystallographic studies on 2-dehydro-3-deoxygalactarate aldolase from leptospira interrogans.	2-dehydro-3-deoxygalactarate (ddg) aldolase is a member of the class ii aldolase family and plays an important role in the pyruvate-metabolism pathway, catalyzing the reversible aldol cleavage of ddg to pyruvate and tartronic semialdehyde. as it is a potential novel antibiotic target, it is necessary to elucidate the catalytic mechanism of ddg aldolase. to determine the crystal structure, crystals of ddg aldolase from leptospira interrogans were obtained by the hanging-drop vapour-diffusion meth ...	2006	17142914
characterization of chew genes of leptospira interrogans and their effects in escherichia coli.	the motility and chemotaxis systems are critical for the virulence of leptospires. in this study, the phylogenetic profiles method was used to predict the interaction of chemotaxis proteins. it was shown that chew1 links to chea1, chey, cheb and chew2; chew3 links to chea2, mcp (la2426), cheb3 and ched1; and chew2 links only to chew1. the similarity analysis demonstrated that chew2 of leptospira interrogans strain lai had poor homology with chew of escherichia coli in the region of residues 30-5 ...	2006	16474898
in silico and microarray-based genomic approaches to identifying potential vaccine candidates against leptospira interrogans.	currently available vaccines against leptospirosis are of low efficacy, have an unacceptable side-effect profile, do not induce long-term protection, and provide no cross-protection against the different serovars of pathogenic leptospira. the current major focus in leptospirosis research is to discover conserved protective antigens that may elicit longer-term protection against a broad range of leptospira. there is a need to screen vaccine candidate genes in the genome of leptospira interrogans.	2006	17109759
modeling of phosphomethyl pyrimidine kinase from leptospira interrogans serovar lai strain 56601.	many microorganisms, as well as plants and fungi, synthesize thiamin, but vertebrates do not produce it. phosphomethyl pyrimidine kinase is an enzyme involved in an intermediary step of thiamin biosynthesis from purine molecules. this enzyme is absent in humans. thus, it is a potential chemotherapeutic target for antileptospiral treatment. structure of this enzyme from leptospira interrogans serovar lai strain 56601 has not yet been elucidated. we used the structural template of phosphomethyl py ...	2006	17597880
bacterial programmed cell death and multicellular behavior in bacteria.	traditionally, programmed cell death (pcd) is associated with eukaryotic multicellular organisms. however, recently, pcd systems have also been observed in bacteria. here we review recent research on two kinds of genetic programs that promote bacterial cell death. the first is mediated by mazef, a toxin-antitoxin module found in the chromosomes of many kinds of bacteria, and mainly studied in escherichia coli. the second program is found in bacillus subtilis, in which the skf and sdp operons med ...	2006	17069462
crystallization and preliminary x-ray diffraction studies of ferredoxin reductase from leptospira interrogans.	ferredoxin-nadp+ reductase (fnr) is an fad-containing enzyme that catalyzes electron transfer between nadp(h) and ferredoxin. here, results are reported of the recombinant expression, purification and crystallization of fnr from leptospira interrogans, a parasitic bacterium of animals and humans. the l. interrogans fnr crystals belong to a primitive monoclinic space group and diffract to 2.4 angstroms resolution at a synchrotron source.	2006	16820688
proinflammatory and immunomodulatory cytokine mrna time course profiles in hamsters infected with a virulent variant of leptospira interrogans.	in order to quantify in vivo the mrnas of cytokines which play important roles in leptospirosis, we have developed quantitative real-time pcr assays for interleukin-2 (il-2), il-4, il-10, il-12p40, tumor necrosis factor alpha (tnf-alpha), gamma interferon (ifn-gamma), transforming growth factor beta, and two housekeeping genes (encoding beta-actin and hypoxanthine phosphoribosyltransferase). we used a lethal hamster model reflecting severe leptospirosis in humans. the lightcycler system was used ...	2006	16790792
molecular epidemiology of leptospirosis in the amazon.		2006	16933961
determining risk for severe leptospirosis by molecular analysis of environmental surface waters for pathogenic leptospira.	although previous data indicate that the overall incidence of human leptospirosis in the peruvian amazon is similar in urban and rural sites, severe leptospirosis has been observed only in the urban context. as a potential explanation for this epidemiological observation, we tested the hypothesis that concentrations of more virulent leptospira would be higher in urban than in rural environmental surface waters.	2006	16933963
autogenous and nonautogenous control of response in a genetic network.	feedback-based control methods determine the behavior of cellular systems, an example being autogenous control, the regulation of production of a protein by itself. this control strategy was theoretically shown to be superior to an equivalent but nonautogenously regulated system when based on a repressor. although some of its advantages were later confirmed with isolated synthetic circuits, the superiority of autogenous control in natural networks remains untested. here, we use the sos dna repai ...	2006	16908855
genome reduction in leptospira borgpetersenii reflects limited transmission potential.	leptospirosis is one of the most common zoonotic diseases in the world, resulting in high morbidity and mortality in humans and affecting global livestock production. most infections are caused by either leptospira borgpetersenii or leptospira interrogans, bacteria that vary in their distribution in nature and rely on different modes of transmission. we report the complete genomic sequences of two strains of l. borgpetersenii serovar hardjo that have distinct phenotypes and virulence. these two ...	2006	16973745
an outbreak of leptospirosis in seals (phoca vitulina) in captivity.	an outbreak of leptospirosis in seals (phoca vitulina) in captivity is described. in a zoo in the netherlands 5 adult seals died within 12 days. at necropsy all animals showed signs of acute septicaemia, consistent with acute leptospirosis. serological examination of one animal was positive for antibodies against leptospira interrogans serovar icterohaemorrhagiae and the serologically closely related serovar copenhageni. polymerase chain reaction was positive in one other animal. 8 nutria (myoca ...	2006	16605159
neospora caninum and leptospira serovar serostatus in dairy cattle in ontario.	no significant association existed between neospora caninum titer and serostatus to leptospira serovar hardjo, icterohaemorrhagiae, or pomona in cattle on 78 dairy herds in ontario. leptospira titer increased with parity. amongst herds not vaccinated against leptospira, the proportions of herds with > or = 1 animal seropositive to serovar hardjo, icterohaemorrhagiae, or pomona were 45%, 42%, and 58%, respectively.	2006	16734373
[study on the immunogenicity of major leptospiral genus-specific protein antigens and the distribution of antigens in different serogroups of leptospira interrogans].	the determination of antigenicity and immunogenicity of leptospira interrogans genus-specific outer envelope proteins (oeps) will offer evidence for developing universal leptospiral genetic engineering vaccine and detection kit.	2006	17415989
characterization of the chey genes from leptospira interrogans and their effects on the behavior of escherichia coli.	the motility and chemotaxis system are critical for the virulence of pathogenic leptospire, which enable them to penetrate host tissue barriers during infection. the completed genome sequence of a representative virulent serovar type strain (lai) of leptospira interrogans serogroups icterohaemorrhagiae (l. interrogans strain lai) suggested that there were multiple copies of putative chemotaxis homologues located at its large chromosome. in order to verify the function of these proteins, the puta ...	2006	16701553
high precision multi-genome scale reannotation of enzyme function by eficaz.	the functional annotation of most genes in newly sequenced genomes is inferred from similarity to previously characterized sequences, an annotation strategy that often leads to erroneous assignments. we have performed a reannotation of 245 genomes using an updated version of eficaz, a highly precise method for enzyme function prediction.	2006	17166279
improvement in motion efficiency of the spirochete brachyspira pilosicoli in viscous environments.	spirochetes are unique among swimming bacteria in terms of their lack of external flagella. they actively move in viscous environments, and, surprisingly, the swimming speed of the spirochete leptospira interrogans has been reported to increase with viscosity in methylcellulose solutions. many researchers consider that the presence of a loose, quasi-rigid network formed by linear polymer molecules is related to this strange phenomenon. one of the authors has proposed a theory that expresses this ...	2006	16415052
iron limitation and expression of immunoreactive outer membrane proteins in leptospira interrogans serovar icterohaemorrhagiae strain lai.		2006	17185872
evaluation of recombinant leptospira interrogans serovar canicola outer membrane proteins as diagnostic antigen.		2006	17185875
leptospirosis in the tropics and in travelers.	leptospirosis, caused by spirochetes of the genus leptospira, has increasingly been recognized to affect travelers and residents in tropical settings. a zoonotic disease, leptospirosis is transmitted to humans through environmental surface waters contaminated by the urine of chronically infected mammals. outcome of infection varies, ranging from acute febrile illness (including self-resolving undifferentiated fever) to aseptic meningitis to a fulminant syndrome of jaundice, oliguric renal failur ...	2006	16448601
immunoreactive outer membrane proteins of leptospira interrogans serovar canicola strain hond utrecht iv.	leptospirosis is a severe and complex zoonotic disease prevalent in many countries including india. current leptospiral research is focussed on the identification of the outer membrane proteins (omps) of the organism that could be used in developing diagnostic assays for leptospirosis.	2006	17213526
multilocus sequence typing method for identification and genotypic classification of pathogenic leptospira species.	leptospira are the parasitic bacterial organisms associated with a broad range of mammalian hosts and are responsible for severe cases of human leptospirosis. the epidemiology of leptospirosis is complex and dynamic. multiple serovars have been identified, each adapted to one or more animal hosts. adaptation is a dynamic process that changes the spatial and temporal distribution of serovars and clinical manifestations in different hosts. serotyping based on repertoire of surface antigens is an a ...	2006	17121682
lipl46 is a novel surface-exposed lipoprotein expressed during leptospiral dissemination in the mammalian host.	leptospirosis is a widespread zoonosis caused by invasive spirochaetes belonging to the genus leptospira. pathogenic leptospires disseminate via the bloodstream to colonize the renal tubules of reservoir hosts. little is known about leptospiral outer-membrane proteins expressed during the dissemination stage of infection. in this study, a novel surface-exposed lipoprotein is described; it has been designated lipl46 to distinguish it from a previously described 31 kda peripheral membrane protein, ...	2006	17159228
the reach of the genome signature in prokaryotes.	with the increased availability of sequenced genomes there have been several initiatives to infer evolutionary relationships by whole genome characteristics. one of these studies suggested good congruence between genome synteny, shared gene content, 16s ribosomal dna identity, codon usage and the genome signature in prokaryotes. here we rigorously test the phylogenetic signal of the genome signature, which consists of the genome-specific relative frequencies of dinucleotides, on 334 sequenced pr ...	2006	17040564
prevalence of brucella abortus antibodies in equines of a tropical region of mexico.	a cross-sectional study was conducted to determinate the seroprevalence rate of equine brucellosis in the state of tamaulipas, mexico. serum samples from 420 equines were analyzed with the rose bengal test at cell concentrations of 3% (rbt-3%) and 8% (rbt-8%), and positive results were confirmed with the rivanol test (rt). risk factors were determined with the prevalence ratio (pr) and the use of variables generated from a questionnaire administered to the animals' owners. serum from 1 stallion ...	2006	17042384
an inventory of yeast proteins associated with nucleolar and ribosomal components.	although baker's yeast is a primary model organism for research on eukaryotic ribosome assembly and nucleoli, the list of its proteins that are functionally associated with nucleoli or ribosomes is still incomplete. we trained a naïve bayesian classifier to predict novel proteins that are associated with yeast nucleoli or ribosomes based on parts lists of nucleoli in model organisms and large-scale protein interaction data sets. phylogenetic profiling and gene expression analysis were carried ou ...	2006	17067374
identification of pathogenic leptospira species by conventional or real-time pcr and sequencing of the dna gyrase subunit b encoding gene.	leptospira is the causative genus of the disease, leptospirosis. species identification of pathogenic leptospira in the past was generally performed by either dna-dna hybridisation or 16s rrna gene sequencing. both methods have inherent disadvantages such as the need for radio-labelled isotopes or significant homology between species. a conventional and real-time pcr amplification and sequencing method was developed for an alternate gene target: dna gyrase subunit b (gyrb). phylogenetic comparis ...	2006	17067399
transformation of anaplasma phagocytophilum.	tick-borne pathogens cause emerging zoonoses, and include fastidious organisms such as anaplasma phagocytophilum. because of their obligate intracellular nature, methods for mutagenesis and transformation have not been available.	2006	17076894
application of multilocus variable-number tandem-repeat analysis for molecular typing of the agent of leptospirosis.	leptospirosis is a worldwide-distributed zoonosis, endemic in tropical areas. epidemiologic investigations of leptospirosis still rely on tedious serological identification tests. recently, molecular typing systems based on variable-number tandem-repeat (vntr) analysis have been described and have been used to identify leptospira interrogans strains. although l. interrogans is the most common leptospira species encountered in human infections around the world, other pathogenic species, such as l ...	2006	17088367
dynamic state of dna topology is essential for genome condensation in bacteria.	in bacteria, dps is one of the critical proteins to build up a condensed nucleoid in response to the environmental stresses. in this study, we found that the expression of dps and the nucleoid condensation was not simply correlated in escherichia coli, and that fis, which is an e. coli (gamma-proteobacteria)-specific nucleoid protein, interfered with the dps-dependent nucleoid condensation. atomic force microscopy and northern blot analyses indicated that the inhibitory effect of fis was due to ...	2006	17093499
partial rpob gene sequencing for identification of leptospira species.	the usual target for sequence-based identification of leptospira species is the 16s rrna gene. however, because the 16s rrna gene is not polymorphic enough, it is necessary to sequence a 1500 bp segment of this gene for accurate identification. based on the alignment of previously determined rpob of three leptospira strains, we designed and tested a primer pair that enabled us to amplify and sequence a 600 bp segment of leptospira rpob. this segment was species-specific for the 16 species tested ...	2006	16978348
evaluation of a recombinant lipl41 antigen of leptospira interrogans serovar canicola in elisa for serodiagnosis of bovine leptospirosis.	the efficacy of a recombinant leptospiral lipoprotein lipl41 as an antigen for conducting enzyme-linked immunosorbent assay (elisa) for diagnosis of bovine leptospirosis was evaluated. using known positive and known negative cattle sera the recombinant antigen was found to be highly reactive in the concentration of 100 ng/well. using a total of 321 field cattle sera the sensitivity of elisa as compared to microscopic agglutination test (mat) was calculated to be 100% whereas the specificity was ...	2006	16979238
comparative and functional genomic analyses of iron transport and regulation in leptospira spp.	the spirochetes of the leptospira genus contain saprophytic and pathogenic members, the latter being responsible for leptospirosis. despite the recent sequencing of the genome of the pathogen l. interrogans, the slow growth of these bacteria, their virulence in humans, and a lack of genetic tools make it difficult to work with these pathogens. in contrast, the development of numerous genetic tools for the saprophyte l. biflexa enables its use as a model bacterium. leptospira spp. require iron fo ...	2006	16980464
effects of temperature on gene expression patterns in leptospira interrogans serovar lai as assessed by whole-genome microarrays.	leptospirosis is an important zoonosis of worldwide distribution. humans become infected via exposure to pathogenic leptospira spp. from infected animals or contaminated water or soil. the availability of genome sequences for leptospira interrogans, serovars lai and copenhageni, has opened up opportunities to examine global transcription profiles using microarray technology. temperature is a key environmental factor known to affect leptospiral protein expression. leptospira spp. can grow in arti ...	2006	16988264
[leptospirosis].	leptospirosis is the most common zoonosis worldwide, although most cases occur in tropical countries. leptospira interrogans, a spirochete, is the causative agent. rats are the main reservoir. most patients present a mild clinical form of the disease, which consists of a self-limited febrile process, without jaundice. nevertheless, about 10% of patients suffer severe infections, with intense jaundice. typically the disease manifests in two phases: acute or leptospiremic and immune or leptospiuri ...	2006	16999233
identification of a novel, invasive, not-yet-cultivated treponema sp. in the large intestine of pigs by pcr amplification of the 16s rrna gene.	laser capture microdissection in combination with fluorescent in situ hybridization was used to identify an unknown species of spirochetes from the pig colonic mucosa. the 16s rrna gene was pcr amplified, and the closest related type strain was treponema bryantiit (90.1%). the spirochete, here named "candidatus treponema suis," was associated with colitis, including invasion of the surface epithelium as well as superficial parts of the mucosa.	2006	17005743
intrinsic and selected resistance to antibiotics binding the ribosome: analyses of brucella 23s rrn, l4, l22, ef-tu1, ef-tu2, efflux and phylogenetic implications.	brucella spp. are highly similar, having identical 16s rna. however, they have important phenotypic differences such as differential susceptibility to antibiotics binding the ribosome. neither the differential susceptibility nor its basis has been rigorously studied. differences found among other conserved ribosomal loci could further define the relationships among the classical brucella spp.	2006	17014718
identification of potential virulence determinants by himar1 transposition of infectious borrelia burgdorferi b31.	lyme disease borrelia organisms are highly invasive spirochetes that alternate between vertebrate and arthropod hosts and that establish chronic infections and elicit inflammatory reactions in mammals. although progress has been made in the targeted mutagenesis of individual genes in infectious borrelia burgdorferi, the roles of the vast majority of gene products in pathogenesis remain unresolved. in this study, we examined the feasibility of using transposon mutagenesis to identify infectivity- ...	2006	17015459
development of species-specific pcr primer sets for the detection of leptospira.	spirochetes of the genus leptospira infect animals and humans and are the causative agents for the emerging infectious disease leptospirosis. rapid and simple assays for the identification of individual leptospira species are currently not available. for identification of individual leptospira species, pcr primers that detect the ompl1 gene sequence for the majority of pathogenic leptospires were developed in this study. the primer pairs detect leptospira interrogans, leptospira borgpetersenii, ...	2006	17020546
species-specific identification of leptospiraceae by 16s rrna gene sequencing.	the genus leptospira is classified into 13 named species and 4 genomospecies based upon dna-dna reassociation studies. phenotypic tests are unable to distinguish between species of leptospira, and there is a need for a simplified molecular approach to the identification of leptospires. 16s rrna gene sequences are potentially useful for species identification of leptospira, but there are a large number of sequences of various lengths and quality in the public databases. 16s rrna gene sequences of ...	2006	17021075
an improved multiple-locus variable number of tandem repeats analysis for leptospira interrogans serovar australis: a comparison with fluorescent amplified fragment length polymorphism analysis and its use to redefine the molecular epidemiology of this serovar in queensland, australia.	in this study, an improved multiple-locus variable number of tandem repeats analysis (mlva) method based upon a previously published method is described. improvements to the method included redesigned primers and pcr conditions, combined with pooled capillary electrophoresis using multicolored dyes. allele sizes were converted into an allele string, and each unique allele string was assigned a numerical mlva type (mvt). the improved mlva method was then applied to 96 previously characterized lep ...	2006	17030915
[modified emjh medium for cultivation of leptospira interrogans serogroup ballum].	strains within the ballum serogroup of spirochete leptospira show fastidious growth with more exigent nutritional requirements than those of other leptospira pathogenic strains. the influence of 37 nutritional compounds on the growth of leptospira interrogans serogroup ballum was investigated employing the synthetic emjh medium as the base for the study. microbial growth was estimated spectrophotometrically and direct counts were performed with a petroff-hausser counting chamber. virulence stabi ...	2006	17037250
tasa-tasb, a new putative toxin-antitoxin (ta) system from bacillus thuringiensis pgi1 plasmid is a widely distributed composite maze-doc ta system.	post-segregational killing systems are present in a large variety of microorganisms. when found on plasmids, they are described as addiction systems that act to maintain the plasmid during the partitioning of the cell. the plasmid to be maintained through the generations harbours a group of two genes, one coding for a stable toxin and the other coding for an unstable antitoxin that inhibits the effects of the toxin. if, during cell division, the plasmid is lost, the toxin and antitoxin proteins ...	2006	17038198
detection of brucella canis and leptospira interrogans in canine semen by multiplex nested pcr.	brucella canis and leptospira interrogans are pathogenic bacteria that cause brucellosis and leptospirosis in dogs around the world. both diseases can be diagnosed serologically, but the direct detection of these organisms in canine semen is needed when it is used for artificial reproduction. we have been attempting the artificial reproduction of guide dogs for greater breeding efficiency and for this purpose have developed a multiplex nested pcr technique for the detection of b. canis and l. in ...	2006	16820720
spatial hierarchical variances and age covariances for seroprevalence to leptospira interrogans serovar hardjo, bohv-1 and bvdv for cattle in the state of paraíba, brazil.	we estimated spatial hierarchal variances and age-group covariances for seroprevalence to leptospira interrogans serovar hardjo (leptoh), bovine viral-diarrhea virus (bvdv) and bovine herpesvirus type 1 (bohv-1) among 2343 cattle from 72 properties sampled in the state of paraíba, brazil in 2000. from each property, eight animals in each of the four age categories were evaluated. the age categories studied were: pre-weaned (0-6 months), young (7-18 months), replacement (19-30 months) and mature ...	2006	16828906
rooting the tree of life by transition analyses.	despite great advances in clarifying the family tree of life, it is still not agreed where its root is or what properties the most ancient cells possessed--the most difficult problems in phylogeny. protein paralogue trees can theoretically place the root, but are contradictory because of tree-reconstruction artefacts or poor resolution; ribosome-related and dna-handling enzymes suggested one between neomura (eukaryotes plus archaebacteria) and eubacteria, whereas metabolic enzymes often place it ...	2006	16834776
leptospirosis in squirrels imported from united states to japan.	we diagnosed leptospirosis in 2 patients exposed to southern flying squirrels imported from the united states to japan. patients worked with exotic animals in their company. leptospira isolates from 1 patient and 5 of 10 squirrels at the company were genetically and serologically identical and were identified as leptospira kirschneri.	2006	16836840
hemin-dependent modulation of the lipid a structure of porphyromonas gingivalis lipopolysaccharide.	porphyromonas gingivalis is a periopathogen strongly associated with the development of adult-type periodontitis. both the virulence characteristics of periopathogens and host-related factors are believed to contribute to periodontitis. p. gingivalis lipopolysaccharide (lps) displays a significant amount of lipid a structural heterogeneity, containing both penta- and tetra-acylated lipid a structures. however, little is known concerning how the lipid a structural content of p. gingivalis is regu ...	2006	16861633
peptide deformylase is a potential target for anti-helicobacter pylori drugs: reverse docking, enzymatic assay, and x-ray crystallography validation.	colonization of human stomach by the bacterium helicobacter pylori is a major causative factor for gastrointestinal illnesses and gastric cancer. however, the discovery of anti-h. pylori agents is a difficult task due to lack of mature protein targets. therefore, identifying new molecular targets for developing new drugs against h. pylori is obviously necessary. in this study, the in-house potential drug target database (pdtd, http://www.dddc.ac.cn/tarfisdock/) was searched by the reverse dockin ...	2006	16882991
serotype 1-specific monoclonal antibody-based antigen capture immunoassay for detection of circulating nonstructural protein ns1: implications for early diagnosis and serotyping of dengue virus infections.	rapid diagnosis and serotyping of dengue virus (dv) infections are important for timely clinical management and epidemiological control in areas where multiple flaviviruses are endemic. however, the speed and accuracy of diagnosis must be balanced against test cost and availability, especially in developing countries. we developed a specific antigen capture enzyme-linked immunosorbent assay (elisa) for early detection and serotyping of dv serotype 1 (dv1) by using well-characterized monoclonal a ...	2006	16891505
treatment of presumptive idiopathic immune-mediated anemia in a holstein heifer, using blood transfusions and corticotherapy.	an idiopathic immune-mediated anemia was diagnosed in a 1-year-old holstein heifer. the diagnostic procedures, blood transfusions, use of an immunosuppressive dosage of dexamethasone, and favorable outcome are described, and idiopathic immune-mediated anemia in mammals is briefly reviewed.	2006	16898112
[presence of igm antibodies for leptospira interrogans in wild animals from tocantins state, 2002].	four hundred and twenty-seven serum samples of wild animals were tested against 18 serovars of leptospira interrogans. of 286 samples of cebus apella, 46 (16.1%) were positive for the serovars pomona, brasiliensis, mini, swajizak, grippotyphosa, sarmin, fluminense, autumnalis, hebdomadis, guaratuba, javanica and icterohaemorrhagiae. of 82 samples of alouatta caraya, 2 (2.4%) were positive for the serovars mangus and fluminense. of 31 samples of nasua nasua, 4 (12.9%) were positive for the serova ...	2006	16906258
crystal structure of neurotropism-associated variable surface protein 1 (vsp1) of borrelia turicatae.	vsp surface lipoproteins are serotype-defining antigens of relapsing fever spirochetes that undergo multiphasic antigenic variation to allow bacterial persistence in spite of an immune response. two isogenic serotypes of borrelia turicatae strain oz1 differ in their vsp sequences and in disease manifestations in infected mice: vsp1 is associated with the selection of a neurological niche, while vsp2 is associated with blood and skin infection. we report here crystal structures of the vsp1 dimer ...	2006	16740958
a constitutively expressed, truncated umudc operon regulates the reca-dependent dna damage induction of a gene in acinetobacter baylyi strain adp1.	in response to environmentally caused dna damage, sos genes are up-regulated due to reca-mediated relief of lexa repression. in escherichia coli, the sos umudc operon is required for dna damage checkpoint functions and for replicating damaged dna in the error-prone process called sos mutagenesis. in the model soil bacterium acinetobacter baylyi strain adp1, however, the content, regulation, and function of the umudc operon are unusual. the umuc gene is incomplete, and a remnant of an isehe3-like ...	2006	16751513
competitive metagenomic dna hybridization identifies host-specific microbial genetic markers in cow fecal samples.	several pcr methods have recently been developed to identify fecal contamination in surface waters. in all cases, researchers have relied on one gene or one microorganism for selection of host-specific markers. here we describe the application of a genome fragment enrichment (gfe) method to identify host-specific genetic markers from fecal microbial community dna. as a proof of concept, bovine fecal dna was challenged against a porcine fecal dna background to select for bovine-specific dna seque ...	2006	16751515
simple sequence proteins in prokaryotic proteomes.	the structural and functional features associated with simple sequence proteins (ssps) are non-globularity, disease states, signaling and post-translational modification. ssps are also an important source of genetic and possibly phenotypic variation. analysis of 249 prokaryotic proteomes offers a new opportunity to examine the genomic properties of ssps.	2006	16762057
genome-wide transcriptional analysis of temperature shift in l. interrogans serovar lai strain 56601.	leptospira interrogans is an important mammalian pathogen. transmission from an environmental source requires adaptation to a range of new environmental conditions in the organs and tissues of the infected host. several studies have shown that a shift in culture temperature from 28 degrees c to 37 degrees c, similar to that encountered during infection of a host from an environmental source, is associated with differential synthesis of several proteins of the outer membrane, periplasm and cytopl ...	2006	16762078
prrc-anticodon nuclease: functional organization of a prototypical bacterial restriction rnase.	the trna(lys) anticodon nuclease prrc is associated in latent form with the type ic dna restriction endonuclease ecoprri and activated by a phage t4-encoded inhibitor of ecoprri. the activation also requires the hydrolysis of gtp and presence of dttp and is inhibited by atp. the n-proximal ntpase domain of prrc has been implicated in relaying the activating signal to a c-proximal anticodon nuclease site by interacting with the requisite nucleotide cofactors [amitsur et al. (2003) mol. microbiol. ...	2006	16790566
diagnosis of gastric syphilis by direct immunofluorescence staining and real-time pcr testing.	we report on a case of gastric syphilis in a patient with chronic dyspepsia. the diagnosis was established by serology and the demonstration of spirochetes in diffusely inflammed gastric mucosa by staining with a fluorescent monoclonal antibody specific for pathogenic treponemes and by the detection of specific treponemal dna sequences by a real-time pcr.	2006	16954299
a newly identified leptospiral adhesin mediates attachment to laminin.	pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. several pathogens, including spirochetes, have been shown to express surface proteins that interact with the extracellular matrix (ecm). this adhesin-mediated binding process seems to be a crucial step in the colonization of host tissues. this study examined the interaction of putative leptospiral outer membrane proteins with laminin, collagen type i, collagen type iv, cellular fibro ...	2006	16954400
the scc spirochetal coiled-coil protein forms helix-like filaments and binds to nucleic acids generating nucleoprotein structures.	the analysis of the genome of leptospira spp., a group of bacteria of the phylum of spirochetes with several unique evolutionary and morphological features, has allowed the identification of a gene encoding a coiled-coil protein, called scc, which is completely unrelated to any other eukaryotic or prokaryotic protein. since coiled-coil proteins are often key elements of the cytoskeleton, we analyzed the protein scc, which is a 24-kda protein composed of a n-terminal coiled-coil domain, a proline ...	2006	16385037
lipoprotein computational prediction in spirochaetal genomes.	lipoproteins are of great interest in understanding the molecular pathogenesis of spirochaetes. because spirochaete lipobox sequences exhibit more plasticity than those of other bacteria, application of existing prediction algorithms to emerging sequence data has been problematic. in this paper a novel lipoprotein prediction algorithm is described, designated splip, constructed as a hybrid of a lipobox weight matrix approach supplemented by a set of lipoprotein signal peptide rules allowing for ...	2006	16385121
an outbreak of leptospirosis among israeli troops near the jordan river.	an outbreak of leptospirosis that involved 7 of a team of 27 israeli troops occurred following a military exercise in northern israel near the jordan river. the organism implicated in the outbreak was leptospira interrogans serovar hardjo. the clinical course was uncomplicated and all patients fully recovered. there were no cases of asymptomatic infection. military personnel should be recognized as having an occupational risk for contracting leptospirosis, especially when military activity takes ...	2006	16407357
bioinformatic analysis of an unusual gene-enzyme relationship in the arginine biosynthetic pathway among marine gamma proteobacteria: implications concerning the formation of n-acetylated intermediates in prokaryotes.	the n-acetylation of l-glutamate is regarded as a universal metabolic strategy to commit glutamate towards arginine biosynthesis. until recently, this reaction was thought to be catalyzed by either of two enzymes: (i) the classical n-acetylglutamate synthase (nags, gene arga) first characterized in escherichia coli and pseudomonas aeruginosa several decades ago and also present in vertebrates, or (ii) the bifunctional version of ornithine acetyltransferase (oat, gene argj) present in bacteria, a ...	2006	16409639
function and evolution of plasmid-borne genes for pyrimidine biosynthesis in borrelia spp.	the thyx gene for thymidylate synthase of the lyme borreliosis (lb) agent borrelia burgdorferi is located in a 54-kb linear plasmid. in the present study, we identified an orthologous thymidylate synthase gene in the relapsing fever (rf) agent borrelia hermsii, located it in a 180-kb linear plasmid, and demonstrated its expression. the functions of the b. hermsii and b. burgdorferi thyx gene products were evaluated both in vivo, by complementation of a thymidylate synthase-deficient escherichia ...	2006	16428394
toll-like receptor 4 protects against lethal leptospira interrogans serovar icterohaemorrhagiae infection and contributes to in vivo control of leptospiral burden.	the roles of innate immune responses in protection from or pathogenesis of severe leptospirosis remain unclear. we examined the role of toll-like receptors (tlrs) in mouse infection and macrophage responses to leptospira. c3h/hej mice (tlr4 deficient) and c3h/hej-scid mice, but not c3h/ouj mice (tlr4 intact), died after intraperitoneal infection with leptospira interrogans serovar icterohaemorrhagiae. death in both c3h/hej mouse strains was associated with jaundice and pulmonary hemorrhage, simi ...	2006	16428731
expression cloning and periplasmic orientation of the francisella novicida lipid a 4'-phosphatase lpxf.	francisella tularensis and related intracellular pathogens synthesize lipid a molecules that differ from their escherichia coli counterparts. although a functional orthologue of lpxk, the gene encoding the lipid a 4'-kinase, is present in francisella, no 4'-phosphate moiety is attached to francisella lipid a. we now demonstrate that a membrane-bound phosphatase present in francisella novicida u112 selectively removes the 4'-phosphate residue from tetra- and pentaacylated lipid a molecules. a clo ...	2006	16467300
the probiotic bacterium lactobacillus casei induces activation of the gut mucosal immune system through innate immunity.	the mechanisms by which probiotic bacteria affect the immune system are unknown yet, but many of them are attributed to an increase in the innate or in the acquired immune response. to study the influence of the probiotic bacterium lactobacillus casei in the expression of receptors involved in the innate immune response, this bacterium was orally administered to balb/c mice. after, they were sacrificed; the small intestine and intestinal fluids were collected to measure secretory immunoglobulin ...	2006	16467329
brief report: leptospirosis after flooding of a university campus--hawaii, 2004.	on november 19, 2004, the hawaii department of health (hdoh) received a report that a university of hawaii professor aged 56 years had been hospitalized with suspected leptospirosis after cleaning his flooded laboratory. on october 31, heavy rains had caused an adjacent stream to overflow its banks and flood the campus. persons exposed to fresh water or mud contaminated by the urine of animals infected with the spirochete leptospira interrogans can have systemic illness if the leptospires enter ...	2006	16467778
seroprevalence of leptospirosis among high-risk population of andaman islands, india.	leptospirosis is a severe spirochetal zoonosis in the world. it is considered an occupational disease of persons engaged in agriculture, sewage works, forestry, and animal slaughtering. a study was conducted with an objective of assessing the seroprevalence of leptospirosis among the high-risk groups of andaman islands. a total of 611 sera samples from different high-risk populations were collected and tested by microscopic agglutination test (mat). genetic characterization of the isolate was do ...	2006	16474084
thrombocytopenia in the experimental leptospirosis of guinea pig is not related to disseminated intravascular coagulation.	thrombocytopenia is commonly observed in severe leptospirosis. however, previous studies on coagulation alterations during leptospirosis resulted in inconsistent conclusions. some findings showed that the prominent levels of thrombocytopenia observed in severe leptospirosis did not reflect the occurrence of disseminated intravascular coagulation (dic) syndrome, while the others reached the conclusion that the hemorrhages observed in leptospirosis were due to dic. the aim of this study is to eluc ...	2006	16451735
borrelia burgdorferi ftsz plays a role in cell division.	ftsz is essential for cell division in many microorganisms. in escherichia coli and bacillus subtilis, ftsz plays a role in ring formation at the leading edge of the cell division septum. an ftsz homologue is present in the borrelia burgdorferi genome (ftsz(bbu)). its gene product (ftsz(bbu)) is strongly homologous to other bacterial ftsz proteins, but its function has not been established. because loss-of-function mutants of ftsz(bbu) might be lethal, the tetr/teto system was adapted for regula ...	2006	16484209
immunoprotection of recombinant leptospiral immunoglobulin-like protein a against leptospira interrogans serovar pomona infection.	we previously reported the cloning and characterization of leptospiral immunoglobulin-like proteins liga and ligb of leptospira interrogans. liga and ligb are conserved at the amino-terminal region but are variable at the carboxyl-terminal region. here, we evaluate the potential of recombinant liga (rliga) as a vaccine candidate against infection by l. interrogans serovar pomona in a hamster model. rliga was truncated into conserved (rligacon) and variable (rligavar) regions and expressed in esc ...	2006	16495547
expression, crystallization and preliminary crystallographic analysis of sufe (xac2355) from xanthomonas axonopodis pv. citri.	xanthomonas axonopodis pv. citri (xac) sufe (xac2355) is a member of a family of bacterial proteins that are conserved in several pathogens and phytopathogens. the escherichia coli suf operon is involved in iron-sulfur cluster biosynthesis under iron-limitation and stress conditions. it has recently been demonstrated that sufe and sufs form a novel two-component cysteine desulfarase in which sufs catalyses the conversion of l-cysteine to l-alanine, forming a protein-bound persulfide intermediate ...	2006	16511319
comparison of culture and a novel 5' taq nuclease assay for direct detection of campylobacter fetus subsp. venerealis in clinical specimens from cattle.	a campylobacter fetus subsp. venerealis-specific 5' taq nuclease pcr assay using a 3' minor groove binder-dna probe (taqman mgb) was developed based on a subspecies-specific fragment of unknown identity (s. hum, k. quinn, j. brunner, and s. l. on, aust. vet. j. 75:827-831, 1997). the assay specifically detected four c. fetus subsp. venerealis strains with no observed cross-reaction with c. fetus subsp. fetus-related campylobacter species or other bovine venereal microflora. the 5' taq nuclease a ...	2006	16517880
prognostic factors associated with severe leptospirosis.	leptospirosis is an anthropozoonosis caused by leptospira interrogans. it occurs worldwide and is endemic in french polynesia. leptospirosis is associated with a large variety of clinical symptoms. most infections caused by leptospires are either sub-clinical or of very mild severity, but 5-10% of infections result in multiple organ damage, including kidney, liver and lung lesions. among 71 patients hospitalised in papeete for severe leptospirosis during a period of 2 years, the main risk-factor ...	2006	16524404
lfha, a novel factor h-binding protein of leptospira interrogans.	the early phase of leptospiral infection is characterized by the presence of live organisms in the blood. pathogenic leptospira interrogans is resistant to the alternative pathway of complement mediated-killing, while nonpathogenic members of the genus are not. consistent with that observation, only pathogenic leptospires bound factor h, a host fluid-phase regulator of the alternative complement pathway. ligand affinity blot analyses revealed that pathogenic l. interrogans produces at least two ...	2006	16622202
use of a multilocus variable-number tandem repeat analysis method for molecular subtyping and phylogenetic analysis of neisseria meningitidis isolates.	the multilocus variable-number tandem repeat (vntr) analysis (mlva) technique has been developed for fine typing of many bacterial species. the genomic sequences of neisseria meningitidis strains z2491, mc58 and fam18 have been available for searching potential vntr loci by computer software. in this study, we developed and evaluated a mlva method for molecular subtyping and phylogenetic analysis of n. meningitidis strains.	2006	16686962