| amidoligases with atp-grasp, glutamine synthetase-like and acetyltransferase-like domains: synthesis of novel metabolites and peptide modifications of proteins. | recent studies have shown that the ubiquitin system had its origins in ancient cofactor/amino acid biosynthesis pathways. preliminary studies also indicated that conjugation systems for other peptide tags on proteins, such as pupylation, have evolutionary links to cofactor/amino acid biosynthesis pathways. following up on these observations, we systematically investigated the non-ribosomal amidoligases of the atp-grasp, glutamine synthetase-like and acetyltransferase folds by classifying the kno ... | 2009 | 20023723 |
| comprehensive comparative-genomic analysis of type 2 toxin-antitoxin systems and related mobile stress response systems in prokaryotes. | the prokaryotic toxin-antitoxin systems (tas, also referred to as ta loci) are widespread, mobile two-gene modules that can be viewed as selfish genetic elements because they evolved mechanisms to become addictive for replicons and cells in which they reside, but also possess "normal" cellular functions in various forms of stress response and management of prokaryotic population. several distinct tas of type 1, where the toxin is a protein and the antitoxin is an antisense rna, and numerous, unr ... | 2009 | 19493340 |
| interactions of h562 in the s5 helix with t618 and s621 in the pore helix are important determinants of herg1 potassium channel structure and function. | herg1 is a member of the cyclic nucleotide binding domain family of k(+) channels. alignment of cyclic nucleotide binding domain channels revealed an evolutionary conserved sequence hwx(a/g)c in the s5 domain. we reasoned that histidine 562 in herg1 could play an important structure-function role. to explore this role, we created in silica models of the herg1 pore domain based on the kvap crystal structure with rosetta-membrane modeling and molecular-dynamics simulations. simulations indicate th ... | 2009 | 19413965 |
| evaluation of surveillance case definition in the diagnosis of leptospirosis, using the microscopic agglutination test: a validation study. | leptospirosis is endemic in both urban and rural areas of sri lanka and there had been many out breaks in the recent past. this study was aimed at validating the leptospirosis surveillance case definition, using the microscopic agglutination test (mat). | 2009 | 19386085 |
| amino acid features of p1b-atpase heavy metal transporters enabling small numbers of organisms to cope with heavy metal pollution. | phytoremediation refers to the use of plants for extraction and detoxification of pollutants, providing a new and powerful weapon against a polluted environment. in some plants, such as thlaspi spp, heavy metal atpases are involved in overall metal ion homeostasis and hyperaccumulation. p1b-atpases pump a wide range of cations, especially heavy metals, across membranes against their electrochemical gradients. determination of the protein characteristics of p1b-atpases in hyperaccumulator plants ... | 2011 | 21573033 |
| multiple inter-kingdom horizontal gene transfers in the evolution of the phosphoenolpyruvate carboxylase gene family. | pepcase is a gene encoding phosphoenolpyruvate carboxylase that exists in bacteria, archaea and plants,playing an important role in plant metabolism and development. most plants have two or more pepcase genes belonging to two gene sub-families, while only one gene exists in other organisms. previous research categorized one plant pepcase gene as plant-type pepcase (ptpc) while the other as bacteria-type pepcase (btpc) because of its similarity with the pepcase gene found in bacteria. phylogeneti ... | 2012 | 23251445 |
| characterization of the genome, proteome, and structure of yersiniophage ϕr1-37. | the bacteriophage vb_yecm-ϕr1-37 (ϕr1-37) is a lytic yersiniophage that can propagate naturally in different yersinia species carrying the correct lipopolysaccharide receptor. this large-tailed phage has deoxyuridine (du) instead of thymidine in its dna. in this study, we determined the genomic sequence of phage ϕr1-37, mapped parts of the phage transcriptome, characterized the phage particle proteome, and characterized the virion structure by cryo-electron microscopy and image reconstruction. t ... | 2012 | 22973030 |
| leptospiral outer membrane protein microarray, a novel approach to identification of host ligand-binding proteins. | leptospirosis is a zoonosis with worldwide distribution caused by pathogenic spirochetes belonging to the genus leptospira. the leptospiral life cycle involves transmission via freshwater and colonization of the renal tubules of their reservoir hosts. infection requires adherence to cell surfaces and extracellular matrix components of host tissues. these host-pathogen interactions involve outer membrane proteins (omps) expressed on the bacterial surface. in this study, we developed an leptospira ... | 2012 | 22961849 |
| automatic assignment of prokaryotic genes to functional categories using literature profiling. | in the last years, there was an exponential increase in the number of publicly available genomes. once finished, most genome projects lack financial support to review annotations. a few of these gene annotations are based on a combination of bioinformatics evidence, however, in most cases, annotations are based solely on sequence similarity to a previously known gene, which was most probably annotated in the same way. as a result, a large number of predicted genes remain unassigned to any functi ... | 2012 | 23077617 |
| positive regulation of leptospira interrogans kdp expression by kdpe as demonstrated with a novel β-galactosidase reporter in leptospira biflexa. | leptospirosis is a potentially deadly zoonotic disease that afflicts humans and animals. leptospira interrogans, the predominant agent of leptospirosis, encounters diverse conditions as it proceeds through its life cycle, which includes stages inside and outside the host. unfortunately, the number of genetic tools available for examining the regulation of gene expression in l. interrogans is limited. consequently, little is known about the genetic circuits that control gene expression in leptosp ... | 2012 | 22685146 |
| multiple activities of ligb potentiate virulence of leptospira interrogans: inhibition of alternative and classical pathways of complement. | microbial pathogens acquire the immediate imperative to avoid or counteract the formidable defense of innate immunity as soon as they overcome the initial physical barriers of the host. many have adopted the strategy of directly disrupting the complement system through the capture of its components, using proteins on the pathogen's surface. in leptospirosis, pathogenic leptospira spp. are resistant to complement-mediated killing, in contrast to the highly vulnerable non-pathogenic strains. patho ... | 2012 | 22911815 |
| lipoidal soft hybrid biocarriers of supramolecular construction for drug delivery. | lipid-based innovations have achieved new heights during the last few years as an essential component of drug development. the current challenge of drug delivery is liberation of drug agents at the right time in a safe and reproducible manner to a specific target site. a number of novel drug delivery systems has emerged encompassing various routes of administration, to achieve controlled and targeted drug delivery. microparticulate lipoidal vesicular system represents a unique technology platfor ... | 2012 | 22888455 |
| renal involvement in leptospirosis: the effect of glycolipoprotein on renal water absorption. | leptospirotic renal lesions frequently produce a polyuric form of acute kidney injury with a urinary concentration defect. our study investigated a possible effect of the glycolipoprotein, (glpc) extracted from l. interrogans, on vasopressin (vp) action in the guinea pig inner medullary collecting duct (imcd). | 2012 | 22701573 |
| multiple leptospiral sphingomyelinases (or are there?). | culture supernatants of leptospiral pathogens have long been known to haemolyse erythrocytes. this property is due, at least in part, to sphingomyelinase activity. indeed, genome sequencing reveals that pathogenic leptospira species are richly endowed with sphingomyelinase homologues: five genes have been annotated to encode sphingomyelinases in leptospira interrogans. such redundancy suggests that this class of genes is likely to benefit leptospiral pathogens in their interactions with the mamm ... | 2012 | 22422753 |
| leptospire genomic diversity revealed by microarray-based comparative genomic hybridization. | comparative genomic hybridization was used to compare genetic diversity of five strains of leptospira (leptospira interrogans serovars bratislava, canicola, and hebdomadis and leptospira kirschneri serovars cynopteri and grippotyphosa). the array was designed based on two available sequenced leptospira reference genomes, those of l. interrogans serovar copenhageni and l. interrogans serovar lai. a comparison of genetic contents showed that l. interrogans serovar bratislava was closest to the ref ... | 2012 | 22344655 |
| vesiculation from pseudomonas aeruginosa under sos. | bacterial infections can be aggravated by antibiotic treatment that induces sos response and vesiculation. this leads to a hypothesis concerning association of sos with vesiculation. to test it, we conducted multiple analyses of outer membrane vesicles (omvs) produced from the pseudomonas aeruginosa wild type in which sos is induced by ciprofloxacin and from the lexa noncleavable (lexan) strain in which sos is repressed. the levels of omv proteins, lipids, and cytotoxicity increased for both the ... | 2012 | 22448133 |
| mathematical modeling and comparison of protein size distribution in different plant, animal, fungal and microbial species reveals a negative correlation between protein size and protein number, thus providing insight into the evolution of proteomes. | the sizes of proteins are relevant to their biochemical structure and for their biological function. the statistical distribution of protein lengths across a diverse set of taxa can provide hints about the evolution of proteomes. | 2012 | 22296664 |
| predictors of the development of myocarditis or acute renal failure in patients with leptospirosis: an observational study. | leptospirosis has a varied clinical presentation with complications like myocarditis and acute renal failure. there are many predictors of severity and mortality including clinical and laboratory parameters. early detection and treatment can reduce complications. therefore recognizing the early predictors of the complications of leptospirosis is important in patient management. this study was aimed at determining the clinical and laboratory predictors of myocarditis or acute renal failure. | 2012 | 22243770 |
| interaction of leptospira elongation factor tu with plasminogen and complement factor h: a metabolic leptospiral protein with moonlighting activities. | the elongation factor tu (ef-tu), an abundant bacterial protein involved in protein synthesis, has been shown to display moonlighting activities. known to perform more than one function at different times or in different places, it is found in several subcellular locations in a single organism, and may serve as a virulence factor in a range of important human pathogens. here we demonstrate that leptospira ef-tu is surface-exposed and performs additional roles as a cell-surface receptor for host ... | 2013 | 24312361 |
| membrane na+-pyrophosphatases can transport protons at low sodium concentrations. | membrane-bound na(+)-pyrophosphatase (na(+)-ppase), working in parallel with the corresponding atp-energized pumps, catalyzes active na(+) transport in bacteria and archaea. each ~75-kda subunit of homodimeric na(+)-ppase forms an unusual funnel-like structure with a catalytic site in the cytoplasmic part and a hydrophilic gated channel in the membrane. here, we show that at subphysiological na(+) concentrations (<5 mm), the na(+)-ppases of chlorobium limicola, four other bacteria, and one archa ... | 2013 | 24158447 |
| functional genes to assess nitrogen cycling and aromatic hydrocarbon degradation: primers and processing matter. | targeting sequencing to genes involved in key environmental processes, i.e., ecofunctional genes, provides an opportunity to sample nature's gene guilds to greater depth and help link community structure to process-level outcomes. vastly different approaches have been implemented for sequence processing and, ultimately, for taxonomic placement of these gene reads. the overall quality of next generation sequence analysis of functional genes is dependent on multiple steps and assumptions of unknow ... | 2013 | 24062736 |
| chiral colloidal molecules and observation of the propeller effect. | chiral molecules play an important role in biological and chemical processes, but physical effects due to their symmetry-breaking are generally weak. several physical chiral separation schemes which could potentially be useful, including the propeller effect, have therefore not yet been demonstrated at the molecular scale. however, it has been proposed that complex nonspherical colloidal particles could act as "colloidal molecules" in mesoscopic model systems to permit the visualization of molec ... | 2013 | 23883328 |
| prospective evaluation of three rapid diagnostic tests for diagnosis of human leptospirosis. | diagnosis of leptospirosis by the microscopic agglutination test (mat) or by culture is confined to specialized laboratories. although elisa techniques are more common, they still require laboratory facilities. rapid diagnostic tests (rdts) can be used for easy point-of-care diagnosis. this study aims to evaluate the diagnostic performance of the rdts leptotek dri dot, leptotek lateral flow, and leptocheck-wb, prospectively. | 2013 | 23875034 |
| pyrophosphate-fueled na+ and h+ transport in prokaryotes. | in its early history, life appeared to depend on pyrophosphate rather than atp as the source of energy. ancient membrane pyrophosphatases that couple pyrophosphate hydrolysis to active h(+) transport across biological membranes (h(+)-pyrophosphatases) have long been known in prokaryotes, plants, and protists. recent studies have identified two evolutionarily related and widespread prokaryotic relics that can pump na(+) (na(+)-pyrophosphatase) or both na(+) and h(+) (na(+),h(+)-pyrophosphatase). ... | 2013 | 23699258 |
| a prime-boost strategy using the novel vaccine candidate, lema, protects hamsters against leptospirosis. | toward developing an effective vaccine capable of conferring heterologous protection, the putative lipoprotein lema, which presents an m3 epitope similar to that of listeria, was evaluated as a vaccine candidate in the hamster model of leptospirosis. lema is conserved (>70% pairwise identity) among the pathogenic leptospira spp., indicating its potential in stimulating a cross-protective immune response. using different vaccination strategies, including prime-boost, dna vaccine, and a subunit pr ... | 2013 | 23515012 |
| a gene transfer agent and a dynamic repertoire of secretion systems hold the keys to the explosive radiation of the emerging pathogen bartonella. | gene transfer agents (gtas) randomly transfer short fragments of a bacterial genome. a novel putative gta was recently discovered in the mouse-infecting bacterium bartonella grahamii. although gtas are widespread in phylogenetically diverse bacteria, their role in evolution is largely unknown. here, we present a comparative analysis of 16 bartonella genomes ranging from 1.4 to 2.6 mb in size, including six novel genomes from bartonella isolated from a cow, two moose, two dogs, and a kangaroo. a ... | 2013 | 23555299 |
| essential calcium-binding cluster of leptospira lipl32 protein for inflammatory responses through the toll-like receptor 2 pathway. | leptospirosis is the most widespread zoonosis caused by the pathogenic leptospira worldwide. lipl32, a 32-kda lipoprotein, is the most abundant protein on the outer membrane of leptospira and has an atypical poly(asp) motif ((161)dddddgdd(168)). the x-ray crystallographic structure of lipl32 revealed that the calcium-binding cluster of lipl32 includes several essential residues asp(132), thr(133), asp(164), asp(165), and tyr(178). the goals of this study were to determine possible roles of the c ... | 2013 | 23486465 |
| importance of uncharged polar residues and proline in the proximal two-thirds (pro107-ser128) of the highly conserved region of mouse ileal na+-dependent bile acid transporter, slc10a2, in transport activity and cellular expression. | slc10a2-mediated reabsorption of bile acids at the distal end of the ileum is the first step in enterohepatic circulation. because bile acids act not only as detergents but also as signaling molecules in lipid metabolism and energy production, slc10a2 is important as the key transporter for understanding the in vivo kinetics of bile acids. slc10a family members and the homologous genes of various species share a highly conserved region corresponding to gly104-pro142 of slc10a2. the functional im ... | 2013 | 23374508 |
| pathogenic and saprophytic leptospira species in water and soils from selected urban sites in peninsular malaysia. | leptospira species were studied in water and soils from selected urban sites in malaysia. a total of 151 water (n=121) and soil (n=30) samples were collected from 12 recreational lakes and wet markets. all samples were filtered and inoculated into semi-solid ellinghausen and mccullough modified by johnson and harris (emjh) media supplemented with additional 5-fluorouracil. the cultures were then incubated at 30°c and observed under a dark field microscope with intervals of 10 days. a pcr assay t ... | 2013 | 23363618 |
| cross-sectional study of leptospira seroprevalence in humans, rats, mice, and dogs in a main tropical sea-port city. | samples were collected from 128 symptomatic humans, 83 dogs, 49 mice, and 20 rats (rattus rattus: 16; rattus norvegicus: 4) in neighborhoods where human leptospirosis have been reported within the principal sea-port city of colombia. seroprevalences were assessed against 19 pathogenic, 1 intermediate pathogenic, and 1 saprophytic leptospira serogroups. pathogenic leptospira were confirmed using conventional leptospira-specific polymerase chain-reaction and pulsed-field gel electrophoresis analys ... | 2013 | 23149584 |
| liposomes as vaccine delivery systems: a review of the recent advances. | liposomes and liposome-derived nanovesicles such as archaeosomes and virosomes have become important carrier systems in vaccine development and the interest for liposome-based vaccines has markedly increased. a key advantage of liposomes, archaeosomes and virosomes in general, and liposome-based vaccine delivery systems in particular, is their versatility and plasticity. liposome composition and preparation can be chosen to achieve desired features such as selection of lipid, charge, size, size ... | 2014 | 25364509 |
| a filtration based technique for simultaneous sem and tem sample preparation for the rapid detection of pathogens. | diagnostic electron microscopy for infectious diseases has the advantage that "everything" in the specimen can be observed, without a priori knowledge of the likely identity of the microorganisms present in the sample. the classical specimen preparation method used employs a droplet of sample, which allows particles to adsorb to a support film, and is subsequently negative stained. this "grid on drop" procedure has a sensitivity range of approximately 106 viruses per ml if no enrichment procedur ... | 2014 | 25243370 |
| structures of bacterial homologues of sweet transporters in two distinct conformations. | sweets and their prokaryotic homologues are monosaccharide and disaccharide transporters that are present from archaea to plants and humans. sweets play crucial roles in cellular sugar efflux processes: that is, in phloem loading, pollen nutrition and nectar secretion. their bacterial homologues, which are called semisweets, are among the smallest known transporters. here we show that semisweet molecules, which consist of a triple-helix bundle, form symmetrical, parallel dimers, thereby generati ... | 2014 | 25186729 |
| seroprevalence of seven zoonotic pathogens in pregnant women from the caribbean. | studies examining the prevalence of zoonotic agents in the caribbean are very limited. the objective of this study was to examine the seroprevalence of seven zoonotic agents among individuals residing on 10 english-speaking caribbean countries. sera from healthy, pregnant women were collected from antigua-barbuda, belize, bermuda, dominica, grenada, jamaica, montserrat, st. kitts-nevis, st. lucia, and st. vincent-grenadines and tested for the presence of igg antibodies to dengue virus, hepatitis ... | 2014 | 24914001 |
| subdomain ii of α-isopropylmalate synthase is essential for activity: inferring a mechanism of feedback inhibition. | the committed step of leucine biosynthesis, converting acetyl-coa and α-ketoisovalerate into α-isopropylmalate, is catalyzed by α-isopropylmalate synthase (ipms), an allosteric enzyme subjected to feedback inhibition by the end product l-leucine. we characterized the short form ipms from leptospira biflexa (lbipms2), which exhibits a catalytic activity comparable with that of the long form ipms (lbipms1) and has a similar n-terminal domain followed by subdomain i and subdomain ii but lacks the w ... | 2014 | 25128527 |
| early diagnosis of leptospirosis. | a 25-years old man from zagreb, croatia, was admitted to the university hospital for infectious diseases four days after the onset of symptoms such as fever, intense pain in the calves and anuria. the patient owned a rabbit and, before the onset of the disease, repaired some rubber pipes damaged by rodents. at admission, he had a severe clinical picture with fever, hypotension, jaundice, immobility, and pain in leg muscles. treatment with ceftriaxone was initiated in combination with volume rest ... | 2014 | 25002958 |
| destruction of the hepatocyte junction by intercellular invasion of leptospira causes jaundice in a hamster model of weil's disease. | weil's disease, the most severe form of leptospirosis, is characterized by jaundice, haemorrhage and renal failure. the mechanisms of jaundice caused by pathogenic leptospira remain unclear. we therefore aimed to elucidate the mechanisms by integrating histopathological changes with serum biochemical abnormalities during the development of jaundice in a hamster model of weil's disease. in this work, we obtained three-dimensional images of infected hamster livers using scanning electron microscop ... | 2014 | 24945433 |
| multiplex nucleic acid amplification test for diagnosis of dengue fever, malaria, and leptospirosis. | dengue, leptospirosis, and malaria are among the most common etiologies of systemic undifferentiated febrile illness (ufi) among travelers to the developing world, and these pathogens all have the potential to cause life-threatening illness in returned travelers. the current study describes the development of an internally controlled multiplex nucleic acid amplification test for the detection of dengue virus (denv) and leptospira and plasmodium species, with a specific callout for plasmodium fal ... | 2014 | 24671788 |
| microfluidics expanding the frontiers of microbial ecology. | microfluidics has significantly contributed to the expansion of the frontiers of microbial ecology over the past decade by allowing researchers to observe the behaviors of microbes in highly controlled microenvironments, across scales from a single cell to mixed communities. spatially and temporally varying distributions of organisms and chemical cues that mimic natural microbial habitats can now be established by exploiting physics at the micrometer scale and by incorporating structures with sp ... | 2014 | 24773019 |
| interpretation of microscopic agglutination test for leptospirosis diagnosis and seroprevalence. | determination of antibody titer by microscopic agglutination test (mat) has been used as a tool for leptospirosis diagnosis. four fold or greater rise in antibody titers between acute and convalescent sera suggests recent leptospira infection. in addition, results obtained by mat have been used to predict infecting serovars. however, cross reactivity among various leptospira serovars have been reported when patient sera were tested with a battery of leptospira serovars. this study demonstrates c ... | 2014 | 25183074 |
| production and characterization of a polyclonal antibody of anti-rlipl21-igg against leptospira for early detection of acute leptospirosis. | leptospirosis is one of the zoonotic diseases in animals and humans throughout the world. lipl21 is one of the important surface-exposed lipoproteins in leptospires and the most effective cross protective immunogenic antigen. it is widely considered as a diagnostic marker for leptospirosis. in this study, we evaluated the serodiagnostic potential of lipl21 protein of leptospira interrogans serovar pomona. we have successfully amplified, cloned, and expressed lipl21 in e. coli and evaluated its s ... | 2014 | 24860824 |
| serodiagnosis of equine leptospirosis by enzyme-linked immunosorbent assay using four recombinant protein markers. | leptospirosis, caused by leptospira spp., is one of the most common zoonotic diseases in the world. we tested four recombinant proteins of leptospira interrogans, namely, rlipl21, rloa22, rlipl32, and rligacon4-8, to evaluate their potential for use as antigens for the diagnosis of equine leptospirosis. we employed equine sera (n = 130) that were microscopic agglutination test (mat) negative and sera (n = 176) that were mat positive for the 5 serovars that most commonly cause equine leptospirosi ... | 2014 | 24451330 |
| high-temperature protein g is an essential virulence factor of leptospira interrogans. | leptospira interrogans is a global zoonotic pathogen and is the causative agent of leptospirosis, an endemic disease of humans and animals worldwide. there is limited understanding of leptospiral pathogenesis; therefore, further elucidation of the mechanisms involved would aid in vaccine development and the prevention of infection. htpg (high-temperature protein g) is the bacterial homolog to the highly conserved molecular chaperone hsp90 and is important in the stress responses of many bacteria ... | 2014 | 24366253 |
| regional differences of leptospirosis in sri lanka: observations from a flood-associated outbreak in 2011. | leptospirosis is known to be an important cause of weather disaster-related infectious disease epidemics. in 2011, an outbreak of leptospirosis occurred in the relatively dry district of anuradhapura, sri lanka where diagnosis was resisted by local practitioners because leptospirosis was not known in the area and the clinical presentation was considered atypical. to identify the causative leptospira associated with this outbreak, we carried out a cross-sectional study. consecutive clinically sus ... | 2014 | 24454971 |
| role of sph2 gene regulation in hemolytic and sphingomyelinase activities produced by leptospira interrogans. | pathogenic members of the genus leptospira are the causative agents of leptospirosis, a neglected disease of public and veterinary health concern. leptospirosis is a systemic disease that in its severest forms leads to renal insufficiency, hepatic dysfunction, and pulmonary failure. many strains of leptospira produce hemolytic and sphingomyelinase activities, and a number of candidate leptospiral hemolysins have been identified based on sequence similarity to well-characterized bacterial hemolys ... | 2015 | 26274394 |
| evaluation of two immunodiagnostic tests for early rapid diagnosis of leptospirosis in sri lanka: a preliminary study. | leptospirosis is often treated based on clinical diagnosis. there is a need for rapid laboratory diagnosis for this condition. the aim of this study was to compare the diagnostic accuracy of two rapid igm based immunodiagnostic assays with the microscopic agglutination test (mat), in acute leptospirosis infection. | 2015 | 26259957 |
| comparative genomic analyses of transport proteins encoded within the genomes of leptospira species. | select species of the bacterial genus leptospira are causative agents of leptospirosis, an emerging global zoonosis affecting nearly one million people worldwide annually. we examined two leptospira pathogens, leptospira interrogans serovar lai str. 56601 and leptospira borgpetersenii serovar hardjo-bovis str. l550, as well as the free-living leptospiral saprophyte, leptospira biflexa serovar patoc str. 'patoc 1 (ames)'. the transport proteins of these leptospires were identified and compared us ... | 2015 | 26247102 |
| neutrophil extracellular traps are involved in the innate immune response to infection with leptospira. | netosis is a process by which neutrophils extrude their dna together with bactericidal proteins that trap and/or kill pathogens. in the present study, we evaluated the ability of leptospira spp. to induce netosis using human ex vivo and murine in vivo models. microscopy and fluorometric studies showed that incubation of human neutrophils with leptospira interrogans serovar copenhageni strain fiocruz l1-130 (lic) resulted in the release of dna extracellular traps (nets). the bacteria number, path ... | 2015 | 26161745 |
| diagnosis of leptospirosis: comparison between microscopic agglutination test, igm-elisa and igm rapid immunochromatography test. | leptospirosis is diagnosed on clinical grounds, and confirmed by microscopic agglutination test (mat). igm-elisa (serion-virion) and immunochromatography test (leptocheck-wb) are two immunodiagnostic assays for leptospirosis. their sensitivity, specificity and applicability in sri lanka have not been systematically evaluated. | 2015 | 26086800 |
| highly active and specific tyrosine ammonia-lyases from diverse origins enable enhanced production of aromatic compounds in bacteria and saccharomyces cerevisiae. | phenylalanine and tyrosine ammonia-lyases form cinnamic acid and p-coumaric acid, which are precursors of a wide range of aromatic compounds of biotechnological interest. lack of highly active and specific tyrosine ammonia-lyases has previously been a limitation in metabolic engineering approaches. we therefore identified 22 sequences in silico using synteny information and aiming for sequence divergence. we performed a comparative in vivo study, expressing the genes intracellularly in bacteria ... | 2015 | 25911487 |
| molecular characterisation and disease severity of leptospirosis in sri lanka. | leptospirosis is a re-emerging zoonotic disease all over the world, important in tropical and subtropical areas. a majority of leptospirosis infected patients present as subclinical or mild disease while 5-10% may develop severe infection requiring hospitalisation and critical care. it is possible that several factors, such as the infecting serovar, level of leptospiraemia, host genetic factors and host immune response, may be important in predisposition towards severe disease. different leptosp ... | 2015 | 26061234 |
| prevalence of bacterial febrile illnesses in children in kilosa district, tanzania. | bacterial etiologies of non-malaria febrile illnesses have significantly become important due to high mortality and morbidity, particularly in children. despite their importance, there are few reports on the epidemiology of these diseases in tanzania, and the true burden of such illnesses remains unknown. this study aimed to identify the prevalence of leptospirosis, brucellosis, typhoid fever and urinary tract infections and their rate of co-infections with malaria. | 2015 | 25955522 |
| a multilocus variable number tandem repeat analysis assay provides high discrimination for genotyping leptospira santarosai strains. | considering the prevalence of leptospira santarosai infections in the americas and the scarce information about the species, we aimed to apply a multilocus variable number tandem repeat (vntr) analysis (mlva) for the molecular typing of l. santarosai isolates from various sources. amplification of three vntr loci selected from l. santarosai genome sequences resulted in a wide range of sizes for the amplified products amongst the 21 l. santarosai strains analysed. this suggested a variation in ta ... | 2015 | 25721051 |
| has madagascar lost its exceptional leptospirosis free-like status? | leptospirosis is a widespread but underreported cause of morbidity and mortality. it has rarely been reported in either humans or animals in madagascar. | 2015 | 25874381 |
| structural basis for the facilitative diffusion mechanism by semisweet transporter. | sweet family proteins mediate sugar transport across biological membranes and play crucial roles in plants and animals. the sweets and their bacterial homologues, the semisweets, are related to the pq-loop family, which is characterized by highly conserved proline and glutamine residues (pq-loop motif). although the structures of the bacterial semisweets were recently reported, the conformational transition and the significance of the conserved motif in the transport cycle have remained elusive. ... | 2015 | 25598322 |
| a comprehensive review of the lipid cubic phase or in meso method for crystallizing membrane and soluble proteins and complexes. | the lipid cubic phase or in meso method is a robust approach for crystallizing membrane proteins for structure determination. the uptake of the method is such that it is experiencing what can only be described as explosive growth. this timely, comprehensive and up-to-date review introduces the reader to the practice of in meso crystallogenesis, to the associated challenges and to their solutions. a model of how crystallization comes about mechanistically is presented for a more rational approach ... | 2015 | 25615961 |
| utility of modified faine's criteria in diagnosis of leptospirosis. | leptospirosis is a globally emerging zoonotic disease and an important public health threat in developing countries. diagnosis of leptospirosis is mainly based on clinical presentations in resource poor countries. world health organization (who) has introduced "faine's criteria" for diagnosis of leptospirosis. this study was conducted to evaluate the usefulness of modified faine's criteria (with amendment) 2012 to detect leptospirosis in resource poor settings. | 2016 | 27554098 |
| micronutrients and leptospirosis: a review of the current evidence. | leptospirosis is one of the most widespread zoonoses and represents a major threat to human health. due to the high burden of disease, limitations in diagnostics, and limited coverage and availability of effective human and veterinary vaccines, leptospirosis remains an important neglected zoonotic disease. improved surveillance and identification of modifiable risk factors for leptospirosis are urgently needed to inform preventive interventions and reduce the risk and severity of leptospira infe ... | 2016 | 27387046 |
| first isolates of leptospira spp., from rodents captured in angola. | rodents play an important role in the transmission of pathogenic leptospira spp. however, in angola, neither the natural reservoirs of these spirochetes nor leptospirosis diagnosis has been considered. regarding this gap, we captured rodents in luanda and huambo provinces to identify circulating leptospira spp. rodent kidney tissue was cultured and dna amplified and sequenced. culture isolates were evaluated for pathogenic status and typing with rabbit antisera; polymerase chain reaction (pcr) a ... | 2016 | 26928840 |
| transcriptome sequencing reveals wide expression reprogramming of basal and unknown genes in leptospira biflexa biofilms. | the genus leptospira is composed of pathogenic and saprophytic spirochetes. pathogenic leptospira is the etiological agent of leptospirosis, a globally spread neglected disease. a key ecological feature of some pathogenic species is their ability to survive both within and outside the host. for most leptospires, the ability to persist outside the host is associated with biofilm formation, a most important bacterial strategy to face and overcome hostile environmental conditions. the architecture ... | 2016 | 27303713 |
| leptospira mayottensis sp. nov., a pathogenic species of the genus leptospira isolated from humans. | a group of strains representing species of the genus leptospira, isolated from patients with leptospirosis in mayotte (indian ocean), were previously found to be considerably divergent from other known species of the genus leptospira. this was inferred from sequence analysis of rrs (16s rrna) and other genetic loci and suggests that they belong to a novel species. two strains from each serogroup currently identified within this novel species were studied. spirochaete, aerobic, motile, helix-shap ... | 2014 | 25249563 |
| dna prime-protein boost based vaccination with a conserved region of leptospiral immunoglobulin-like a and b proteins enhances protection against leptospirosis. | leptospirosis is a zoonotic disease caused by pathogenic spirochetes of the leptospira genus. vaccination with bacterins has severe limitations. here, we evaluated the n-terminal region of the leptospiral immunoglobulin-like b protein (ligbrep) as a vaccine candidate against leptospirosis using immunisation strategies based on dna prime-protein boost, dna vaccine, and subunit vaccine. upon challenge with a virulent strain ofleptospira interrogans, the prime-boost and dna vaccine approaches induc ... | 2015 | 26676320 |
| complement evasion by pathogenic leptospira. | leptospirosis is a neglected infectious disease caused by spirochetes from the genus leptospira. pathogenic microorganisms, notably those which reach the blood circulation such as leptospira, have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial ... | 2016 | 28066433 |
| characterization of leptospiral chemoreceptors using a microscopic agar drop assay. | bacterial chemotaxis is induced by sensing chemical stimuli via chemoreceptors embedded in the cytoplasmic membrane, enabling the cells to migrate toward nutrients or away from toxins. the chemoreceptors of escherichia coli and salmonella spp. have been well studied and are functionally classified on the basis of detectable substrates. the spirochete leptospira possesses more than ten chemoreceptors and shows attractive or repellent responses against some sugars, amino acids, and fatty acids. ho ... | 2016 | 27109059 |
| comparison of leptospira interrogans and leptospira biflexa genomes: analysis of potential leptospiral-host interactions. | leptospirosis, a potentially life-threatening disease, remains the most widespread zoonosis caused by pathogenic species of leptospira. the pathogenic spirochaete, leptospira interrogans, is characterized by its ability to permeate human host tissues rapidly and colonize multiple organs in the host. in spite of the efforts taken to comprehend the pathophysiology of the pathogen and the heterogeneity posed by l. interrogans, the current knowledge on the mechanism of pathogenesis is modest. in an ... | 2017 | 28294222 |
| crystallization of fcpa from leptospira, a novel flagellar protein that is essential for pathogenesis. | the protein fcpa is a unique component of the flagellar filament of spirochete bacteria belonging to the genus leptospira. although it plays an essential role in translational motility and pathogenicity, no structures of fcpa homologues are currently available in the pdb. its three-dimensional structure will unveil the novel motility mechanisms that render pathogenic leptospira particularly efficient at invading and disseminating within their hosts, causing leptospirosis in humans and animals. f ... | 2017 | 28291747 |
| leptospira interrogans lsa23 protein recruits plasminogen, factor h and c4bp from normal human serum and mediates c3b and c4b degradation. | it has been reported that pathogenic leptospira are resistant to normal human serum (nhs) due to their ability to evade the complement immune system by interacting with factor h (fh) and c4b-binding protein (c4bp) regulators. moreover, plasmin generation on the leptospiral surface diminishes c3b and igg deposition, decreasing opsonophagocytosis by immune competent cells. we have previously reported that lsa23 (lic11360) is a multipurpose protein capable of binding purified extracellular matrix m ... | 2016 | 26614523 |
| use of pcr to identify leptospira in kidneys of big brown bats (eptesicus fuscus) in kansas and nebraska, usa. | bats have been implicated as potential carriers of leptospira as a result of surveys, mostly in australia and south america. we measured the prevalence of pathogenic leptospires in kidneys of bats from kansas and nebraska. from 7 august 2012 to 21 august 2012, we extracted dna from kidneys of 98 big brown bats (eptesicus fuscus) submitted and found negative for rabies. the dna was processed in a two-step, seminested pcr assay with a dual-labeled taqman probe specific for pathogenic leptospires. ... | 2014 | 24807182 |
| in vivo cell aggregations of a recent swine biofilm-forming isolate of leptospira interrogans strain from argentina. | leptospirosis is a zoonosis of ubiquitous distribution caused by spirochetes. leptospires exist either as saprophytic water-associated organisms or as animal pathogens that can survive in water. previous works have demonstrated that both saprophytic and pathogenic leptospires are able to produce functional biofilms, which consist of a community of bacteria embedded in an extracellular matrix attached to a surface. this structure is believed to provide protection from environmental aggressiveness ... | 2012 | 23102459 |
| cloning and characterization of the type i baeyer-villiger monooxygenase from leptospira biflexa. | baeyer-villiger monooxygenases are recognized by their ability and high selectivity as oxidative biocatalysts for the generation of esters or lactones using ketones as starting materials. these enzymes represent valuable tools for biooxidative syntheses since they can catalyze reactions that otherwise involve strong oxidative reagents. in this work, we present a novel enzyme, the type i baeyer-villiger monooxygenase from leptospira biflexa. this protein is phylogenetically distant from other wel ... | 2017 | 28452041 |
| a widely conserved bacterial cytoskeletal component influences unique helical shape and motility of the spirochete leptospira biflexa. | leptospires and other members of the evolutionarily ancient phylum of spirochaetes are bacteria often characterized by long, highly motile spiral- or wave-shaped cells. morphology and motility are critical factors in spirochete physiology, contributing to the ability of these bacteria to successfully colonize diverse environments. however, the mechanisms conferring the helical structure of leptospira spp. have yet to be fully elucidated. we have identified 5 l. biflexa bactofilin proteins, a rec ... | 2018 | 29363884 |
| serosurvey of leptospira spp. and toxoplasma gondii in rats captured from two zoos in southern brazil. | norway rats (rattus norvegicus) are zoonotic reservoirs for leptospira spp. and toxoplasma gondii, and influence diseases in urban areas. | 2018 | 29340468 |
| characterization of leptospira isolates from humans and the environment in uruguay. | laboratory diagnosis of human leptospirosis usually relies on indirect methods exploring specific immune response. isolation and identification of the involved strains are cumbersome, but can provide biological resources for pathogenic studies and relevant information for guiding prevention and control measures. the aim of the research we are hereby reporting was the characterization of leptospira isolates obtained from humans and the environment in uruguay. blood cultures were performed from ea ... | 2017 | 29267587 |
| construction of a library of random mutants in the spirochete leptospira biflexa using a mariner transposon. | in comparison to other bacterial species, genetics of leptospires are in their infancy. recently, we developed a system for random transposon mutagenesis in the saprophyte leptospira biflexa and then applied this approach to the pathogen l. interrogans. thousands of random mutants can be readily obtained in -l. -biflexa by random insertion of himar1 in the genome, thereby generating extensive libraries of mutants that could be screened for phenotypes affecting diverse aspects of the biology of t ... | 2012 | 22367871 |
| analysis of the chemotactic behaviour of leptospira using microscopic agar-drop assay. | chemotaxis allows bacterial cells to migrate towards or away from chemical compounds. in the present study, we developed a microscopic agar-drop assay (maa) to investigate the chemotactic behaviour of a coiled spirochete, leptospira biflexa. an agar drop containing a putative attractant or repellent was placed around the centre of a flow chamber and the behaviour of free-swimming cells was analysed under a microscope. maa showed that l. biflexa cells gradually accumulated around an agar drop tha ... | 2014 | 24894019 |
| bifurcation in the ultrafast dynamics of the photoactive yellow proteins from leptospira biflexa and halorhodospira halophila. | we explored the photoisomerization mechanisms in novel homologues of photoactive yellow protein (pyp) from leptospira biflexa (lbif) to identify conserved features and functional diversity in the primary photochemistry of this family of photoreceptors. in close agreement with the prototypical pyp from halorhodospira halophila (hhal), we observe excited-state absorbance near 375 nm and stimulated emission near 500 nm, with triphasic excited-state decay. while the excited-state decay for lbif pyp ... | 2016 | 27749038 |
| isolation of saprophytic leptospira spp. from a selected environmental water source of argentina. | ten leptospira spp. strains were isolated from water samples from nievas stream, olavarría, buenos aires province (argentina). the isolates showed the typical motility and morphology of the genus leptospira under dark field microscopy, developing in liquid emjh medium after eight days of incubation at 13°c and 30°c. all isolates were negative by the multiple locus variable number tandem repeat analysis (mlva). molecular identification by 16s rrna gene sequencing identified all isolates as nonpat ... | 2017 | 29198840 |
| redefining gold standard testing for diagnosing leptospirosis: further evidence from a well-characterized, flood-related outbreak in sri lanka. | a gap in the leptospirosis field remains the lack of well-characterized sample collections that allow for comparison of new methods to standard ones. in the context of a flood-related outbreak of leptospirosis evaluated in anuradhapura, sri lanka, a specimen bank was obtained with detailed metadata accompanied by gold standard diagnostic test results. blood samples collected on admission and 14 days later from suspected cases of leptospirosis were tested using microscopic agglutination test (mat ... | 2016 | 27402521 |
| comparative analyses of transport proteins encoded within the genomes of leptospira species. | select species of the bacterial genus leptospira are causative agents of leptospirosis, an emerging global zoonosis affecting nearly one million people worldwide annually. we examined two leptospira pathogens, leptospira interrogans serovar lai str. 56601 and leptospira borgpetersenii serovar hardjo-bovis str. l550, as well as the free-living leptospiral saprophyte, leptospira biflexa serovar patoc str. 'patoc 1 (ames)'. the transport proteins of these leptospires were identified and compared us ... | 2016 | 27296707 |
| characterization of lic11207, a novel leptospiral protein that is recognized by human convalescent sera and prevents apoptosis of polymorphonuclear leukocytes. | we report the study of a predicted outer-membrane leptospiral protein encoded by the gene lic11207. this protein is conserved in several pathogenic leptospiral strains but is absent in the saprophyte leptospira biflexa. this putative outer-membrane protein has a domain of unknown function (duf) 1565 found in several phylogenetically diverse bacteria and in the archaeon methanosarcina acetivorans. the gene was cloned and expressed in escherichia coli bl21 (si) strain using the expression vector p ... | 2013 | 23092690 |
| studies of the binding of ficolin-2 and ficolin-3 from the complement lectin pathway to leptospira biflexa, pasteurella pneumotropica and diarrheagenic escherichia coli. | ficolins recognize pathogen associated molecular patterns and activate the lectin pathway of complement system. however, our knowledge regarding pathogen recognition of human ficolins is still limited. we therefore set out to explore and investigate the possible interactions of the two main serum ficolins, ficolin-2 and ficolin-3 with different gram-negative bacteria. we used recombinant ficolin molecules and normal human serum, which were detected with anti-ficolin monoclonal antibodies. in add ... | 2015 | 26074063 |
| functional thioredoxin reductase from pathogenic and free-living leptospira spp. | low molecular mass thiols and antioxidant enzymes have essential functions to detoxify reactive oxygen and nitrogen species maintaining cellular redox balance. the metabolic pathways for redox homeostasis in pathogenic (leptospira interrogans) and free-living (leptospira biflexa) leptospires species were not functionally characterized. we performed biochemical studies on recombinantly produced proteins to in depth analyze kinetic and structural properties of thioredoxin reductase (lintrxr) and t ... | 2016 | 27178006 |
| in vivo-expressed proteins of virulent leptospira interrogans serovar autumnalis n2 elicit strong igm responses of value in conclusive diagnosis. | leptospirosis is a serious zoonosis that is underdiagnosed because of limited access to laboratory facilities in southeast asia, central and south america, and oceania. timely diagnosis of locally distributed serovars of high virulence is crucial for successful care and outbreak management. using pooled patient sera, an expression gene library of a virulent leptospira interrogans serovar autumnalis strain n2 isolated in south india was screened. the identified genes were characterized, and the p ... | 2016 | 26607308 |
| clinical evaluation of rapid diagnostic test kit using the polysaccharide as a genus-specific diagnostic antigen for leptospirosis in korea, bulgaria, and argentina. | leptospirosis, a zoonotic disease that is caused by many serovars which are more than 200 in the world, is an emerging worldwide disease. accurate and rapid diagnostic tests for leptospirosis are a critical step to diagnose the disease. there are some commercial kits available for diagnosis of leptospirosis, but the obscurity of a species- or genus-specific antigen of pathogenic leptospira interrogans causes the reduced sensitivity and specificity. in this study, the polysaccharide derived from ... | 2016 | 26839470 |
| whole genome shotgun sequencing shows selection on leptospira regulatory proteins during in vitro culture attenuation. | leptospirosis is the most common zoonotic disease worldwide with an estimated 500,000 severe cases reported annually, and case fatality rates of 12-25%, due primarily to acute kidney and lung injuries. despite its prevalence, the molecular mechanisms underlying leptospirosis pathogenesis remain poorly understood. to identify virulence-related genes in leptospira interrogans, we delineated cumulative genome changes that occurred during serial in vitro passage of a highly virulent strain of l. int ... | 2016 | 26711524 |
| the scanning electron microscope in microbiology and diagnosis of infectious disease. | despite being an excellent tool for investigating ultrastructure, scanning electron microscopy (sem) is less frequently used than transmission electron microscopy for microbes such as viruses or bacteria. here we describe rapid methods that allow sem imaging of fully hydrated, unfixed microbes without using conventional sample preparation methods. we demonstrate improved ultrastructural preservation, with greatly reduced dehydration and shrinkage, for specimens including bacteria and viruses suc ... | 2016 | 27212232 |
| a diagnostic scoring model for leptospirosis in resource limited settings. | leptospirosis is a zoonotic infection with significant morbidity and mortality. the clinical presentation of leptospirosis is known to mimic the clinical profile of other prevalent tropical fevers. laboratory confirmation of leptospirosis is based on the reference standard microscopic agglutination test (mat), direct demonstration of the organism, and isolation by culture and dna detection by polymerase chain reaction (pcr) amplification. however these methods of confirmation are not widely avai ... | 2016 | 27333195 |
| phylogeny reconstruction with alignment-free method that corrects for horizontal gene transfer. | advances in sequencing have generated a large number of complete genomes. traditionally, phylogenetic analysis relies on alignments of orthologs, but defining orthologs and separating them from paralogs is a complex task that may not always be suited to the large datasets of the future. an alternative to traditional, alignment-based approaches are whole-genome, alignment-free methods. these methods are scalable and require minimal manual intervention. we developed slopetree, a new alignment-free ... | 2016 | 27336403 |
| pathogenic leptospira interrogans exoproteins are primarily involved in heterotrophic processes. | leptospirosis is a life-threatening and emerging zoonotic disease with a worldwide annual occurrence of more than 1 million cases. leptospirosis is caused by spirochetes belonging to the genus leptospira. the mechanisms of disease manifestation in the host remain elusive, and the roles of leptospiral exoproteins in these processes have yet to be determined. our aim in this study was to assess the composition and quantity of exoproteins of pathogenic leptospira interrogans and to construe how the ... | 2015 | 25987703 |
| a feedback-insensitive isopropylmalate synthase affects acylsugar composition in cultivated and wild tomato. | acylsugars are insecticidal specialized metabolites produced in the glandular trichomes of plants in the solanaceae family. in the tomato clade of the solanum genus, acylsugars consist of aliphatic acids of different chain lengths esterified to sucrose, or less frequently to glucose. through liquid chromatography-mass spectrometry screening of introgression lines, we previously identified a region of chromosome 8 in the solanum pennellii la0716 genome (il8-1/8-1-1) that causes the cultivated tom ... | 2015 | 25986128 |
| hemr is an ompr/phob-like response regulator from leptospira, which simultaneously effects transcriptional activation and repression of key haem metabolism genes. | several leptospira species cause leptospirosis, the most extended zoonosis worldwide. in bacteria, two-component systems constitute key signalling pathways, some of which are involved in pathogenesis. the physiological roles of two-component systems in leptospira are largely unknown, despite identifying several dozens within their genomes. biochemical confirmation of an operative phosphorelaying two-component system has been obtained so far only for the hklep/rrlep pair. it is known that hklep/r ... | 2014 | 25145397 |
| acquisition of negative complement regulators by the saprophyte leptospira biflexa expressing liga or ligb confers enhanced survival in human serum. | leptospiral immunoglobulin-like (lig) proteins are surface exposed molecules present in pathogenic but not in saprophytic leptospira species. we have previously shown that lig proteins interact with the soluble complement regulators factor h (fh), fh like-1 (fhl-1), fh related-1 (fhr-1) and c4b binding protein (c4bp). in this study, we used the saprophyte l. biflexa serovar patoc as a surrogate host to address the specific role of liga and ligb proteins in leptospiral complement evasion. l. bifl ... | 2016 | 26976804 |