| polymerase chain reaction for detection of leptospira spp. in clinical samples. | a sensitive assay for leptospira spp., the causative agent of leptospirosis, was developed on the basis of the polymerase chain reaction (pcr). a 331-bp sequence from the leptospira interrogans serovar canicola rrs (16s) gene was amplified, and the pcr products were analyzed by dna-dna hybridization by using a 289-bp fragment internal to the amplified dna. specific pcr products also were obtained with dna from the closely related nonpathogenic leptospira biflexa but not with dna from other spiro ... | 1992 | 1400983 |
| cloning and dna sequence analysis of a serpulina (treponema) hyodysenteriae gene encoding a periplasmic flagellar sheath protein. | a serpulina (treponema) hyodysenteriae expression library was constructed in vector lambda zap and screened with a polyclonal antiserum raised against s. hyodysenteriae periplasmic flagella. a single immunoreactive plaque was chosen for further analysis. the recombinant phage from this plaque contained a gene encoding the 44-kda protein that is on the outer layer (or sheath) of the periplasmic flagella. dna sequence analysis showed that the gene encodes a protein of 320 amino acids. the protein ... | 1992 | 1612759 |
| phylogenetic analysis of the spirochetes. | the 16s rrna sequences were determined for species of spirochaeta, treponema, borrelia, leptospira, leptonema, and serpula, using a modified sanger method of direct rna sequencing. analysis of aligned 16s rrna sequences indicated that the spirochetes form a coherent taxon composed of six major clusters or groups. the first group, termed the treponemes, was divided into two subgroups. the first treponeme subgroup consisted of treponema pallidum, treponema phagedenis, treponema denticola, a thermo ... | 1991 | 1917844 |
| n-terminal amino acid sequences and amino acid compositions of the spirochaeta aurantia flagellar filament polypeptides. | the amino-terminal sequences and amino acid compositions of the three major and two minor polypeptides constituting the filaments of spirochaeta aurantia periplasmic flagella were determined. the amino-terminal sequence of the major 37.5-kda outer layer polypeptide is identical to the sequence downstream of the proposed signal peptide of the protein encoded by the s. aurantia flaa gene. however, the amino acid composition of the 37.5-kda polypeptide is not in agreement with that inferred from th ... | 1991 | 1991729 |
| demonstration of rare protein in the outer membrane of treponema pallidum subsp. pallidum by freeze-fracture analysis. | the surface of treponema pallidum subsp. pallidum (t. pallidum), the etiologic agent of syphilis, appears antigenically inert and lacks detectable protein, as judged by immunocytochemical and biochemical techniques commonly used to identify the outer membrane (om) constituents of gram-negative bacteria. we examined t. pallidum by freeze-fracture electron microscopy to visualize the architecture of its om. treponema phagedenis biotype reiter (t. phagedenis reiter), a nonpathogenic host-associated ... | 1989 | 2670902 |
| cloning and sequence analysis of flaa, a gene encoding a spirochaeta aurantia flagellar filament surface antigen. | spirochaeta aurantia dna that coded for an antigenic determinant of the flagellin associated with the filament surface of the periplasmic flagella was isolated. when expressed in escherichia coli, the antigenic polypeptide had an apparent molecular weight of 37,000. sequence analysis of the antigen-encoding dna revealed the presence of an open reading frame that determined a polypeptide with a predicted molecular weight of 31,241. this polypeptide showed a region of identity with the n-amino-ter ... | 1989 | 2921247 |
| isolation of the outer membrane and characterization of the major outer membrane protein from spirochaeta aurantia. | the outer membrane of spirochaeta aurantia was isolated after cells were extracted with sodium lauryl sarcosinate and was subsequently purified by differential centrifugation and kbr isopycnic gradient centrifugation. the purified outer membrane was obtained in the form of carotenoid-containing vesicles. four protein species with apparent molecular weights of 26,000 (26k), 36.5k, 41k, and 48.5k were readily observed as components of the vesicles. the 36.5k protein was the major polypeptide and c ... | 1987 | 3025168 |
| complementation of a trpe deletion in escherichia coli by spirochaeta aurantia dna encoding anthranilate synthetase component i activity. | a 2.7-kilobase sau3a fragment of spirochaeta aurantia dna cloned in pbr322 complemented a trpe deletion in escherichia coli. deletion analysis and tn5 mutagenesis of the resulting plasmid pbg100 defined a 2-kilobase-pair region that was required for both the complementation and the synthesis of 59,000- and 47,000-molecular-weight polypeptides (59k and 47k polypeptides) in maxicells. both the 59k and the 47k polypeptides appear to be encoded by a single gene. a maxicell analysis of pbg100::tn5 mu ... | 1987 | 3038849 |
| biochemical and cytological analysis of the complex periplasmic flagella from spirochaeta aurantia. | the periplasmic flagella of spirochaeta aurantia were isolated and were found to be ultrastructurally and biochemically complex. generally, flagellar filaments were 18 to 20 nm in diameter and appeared to consist of an 11 to 13-nm-wide inner region and an outer layer. the hook-basal body region consisted of two closely apposed disks connected to a hook by a rod. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified flagella together with a western blot analysis of a motility muta ... | 1988 | 3410822 |
| chemotactic transducer proteins of escherichia coli exhibit homology with methyl-accepting proteins from distantly related bacteria. | transducers are transmembrane, methyl-accepting proteins central to the chemotactic systems of the enteric bacteria escherichia coli and salmonella typhimurium. methyl-accepting proteins have been reported in a number of species in addition to these enteric bacteria. those species include bacillus subtilis and spirochaeta aurantia, representatives of groups that diverged from ancestral enteric bacteria and from each other very early in bacterial evolution. an antiserum that reacts with all trans ... | 1985 | 3924893 |
| chemoattractants elicit methylation of specific polypeptides in spirochaeta aurantia. | on the basis of this investigation, chemotaxis in spirochaeta aurantia correlates with methylation of specific polypeptides which are presumed to be analogous to the methyl-accepting chemotaxis proteins (mcps) in bacteria such as escherichia coli. the polypeptides exhibited apparent molecular weights in the range of 55,000 to 65,000. generally, two major presumptive mcp bands and three minor bands were observed on sodium dodecyl sulfate-polyacrylamide gels. upon addition of d-glucose to s. auran ... | 1983 | 6413498 |
| enhancement of chemotaxis in spirochaeta aurantia grown under conditions of nutrient limitation. | spirochaeta aurantia m1 cells were grown in a chemostat under conditions of energy and carbon source limitation. the chemotactic responses of the chemostat-grown cells were compared with those of s. aurantia cells grown in batch culture in the presence of excess energy and carbon source. chemotactic responses were measured by determining the number of cells that entered a capillary tube containing a solution of attractant. s. aurantia cells grown in the chemostat under energy and carbon source l ... | 1984 | 6735977 |
| uptake of d-xylose and d-glucose by spirochaeta aurantia. | uptake of d-[14c]glucose and d-[14c]xylose by spirochaeta aurantia was demonstrated to be osmotic shock sensitive and to require a high-energy phosphorylated compound rather than a proton motive force. these features are similar to those of binding protein-mediated transport systems in other gram-negative bacteria. | 1984 | 6735985 |
| chemotaxis of spirochaeta aurantia: involvement of membrane potential in chemosensory signal transduction. | the effects of valinomycin and nigericin on sugar chemotaxis in spirochaeta aurantia were investigated by using a quantitative capillary assay, and the fluorescent cation, 3,3'-dipropyl-2,2'-thiodicarbocyanine iodide was used as a probe to study effects of chemoattractants on membrane potential. addition of a chemoattractant, d-xylose, to cells in either potassium or sodium phosphate buffer resulted in a transient membrane depolarization. in the presence of valinomycin, the membrane potential of ... | 1981 | 7309678 |
| chemotaxis in borrelia burgdorferi. | borrelia burgdorferi is a motile spirochete which has been identified as the causative microorganism in lyme disease. the physiological functions which govern the motility of this organism have not been elucidated. in this study, we found that motility of b. burgdorferi required an environment similar to interstitial fluid (e.g., ph 7.6 and 0.15 m nacl). several methods were used to detect and measure chemotaxis of b. burgdorferi. a number of chemical compounds and mixtures were surveyed for the ... | 1998 | 9440510 |
| starvation-induced changes in motility, chemotaxis, and flagellation of rhizobium meliloti | the changes in motility, chemotactic responsiveness, and flagellation of rhizobium meliloti rmb7201, l5-30, and jj1c10 were analyzed after transfer of the bacteria to buffer with no available c, n, or phosphate. cells of these three strains remained viable for weeks after transfer to starvation buffer (sb) but lost all motility within just 8 to 72 h after transfer to sb. the rates of motility loss differed by severalfold among the strains. each strain showed a transient, two- to sixfold increase ... | 1998 | 9572940 |
| a new class of caulobacter crescentus flagellar genes. | eight caulobacter crescentus flagellar genes, flma, flmb, flmc, flmd, flme, flmf, flmg, and flmh, have been cloned and characterized. these eight genes are clustered in pairs (flmab, flmcd, flmef, and flmgh) that appear to be structurally organized as operons. homology comparisons suggest that the proteins encoded by the flm genes may be involved in posttranslational modification of flagellins or proteins that interact with flagellin monomers prior to their assembly into a flagellar filament. ex ... | 1998 | 9748431 |
| the borrelia burgdorferi 37-kilodalton immunoblot band (p37) used in serodiagnosis of early lyme disease is the flaa gene product. | the 37-kda protein (p37) of borrelia burgdorferi is an antigen that elicits an early immunoglobulin m (igm) antibody response in lyme disease patients. the p37 gene was cloned from a b. burgdorferi genomic library by screening with antibody from a lyme disease patient who had developed a prominent humoral response to the p37 antigen. dna sequence analysis of this clone revealed the identity of p37 to be flaa, an outer sheath protein of the periplasmic flagella. recombinant p37 expression was acc ... | 1999 | 9986810 |
| esterases in serum-containing growth media counteract chloramphenicol acetyltransferase activity in vitro. | the spirochete borrelia burgdorferi was unexpectedly found to be as susceptible to diacetyl chloramphenicol, the product of the enzyme chloramphenicol acetyltransferase, as it was to chloramphenicol itself. the susceptibilities of escherichia coli and bacillus subtilis, as well as that of b. burgdorferi, to diacetyl chloramphenicol were then assayed in different media. all three species were susceptible to diacetyl chloramphenicol when growth media were supplemented with rabbit serum or, to a le ... | 1999 | 10049283 |
| tn5-induced and spontaneous switching of sinorhizobium meliloti to faster-swarming behavior. | tn5 mutants of sinorhizobium meliloti rmb7201 which swarmed 1.5 to 2. 5 times faster than the parental strain in semisolid agar, moist sand, and viscous liquid were identified. these faster-swarming (fs) mutants outgrew the wild type 30- to 40-fold within 2 days in mixed swarm colonies. the fs mutants survived and grew as well as or better than the wild type under all of the circumstances tested, except in a soil matrix subjected to air drying. exopolysaccharide (eps) synthesis was reduced in ea ... | 1999 | 10049888 |
| overexpression of methanococcus voltae flagellin subunits in escherichia coli and pseudomonas aeruginosa: a source of archaeal preflagellin. | methanococcus voltae is a flagellated member of the archaea. four highly similar flagellin genes have previously been cloned and sequenced, and the presence of leader peptides has been demonstrated. while the flagellins of m. voltae are predicted from their gene sequences to be approximately 22 to 25 kda, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) analysis of purified flagella revealed flagellin subunits with apparent molecular masses of 31 and 33 kda. here we describe ... | 1999 | 10400569 |
| spirochaeta aurantia has diacetyl chloramphenicol esterase activity. | the free-living spirochete spirochaeta aurantia was nearly as susceptible to diacetyl chloramphenicol, the product of chloramphenicol acetyltransferase, as it was to chloramphenicol itself. this unexpected susceptibility to diacetyl chloramphenicol was wholly or partly the consequence of intrinsic carboxylesterase activity, as indicated by high-performance liquid chromatography, thin-layer chromatography, and microbiological assays. the esterase converted the diacetate to chloramphenicol, thus i ... | 2000 | 10714999 |
| motility and chemotaxis of filamentous cells of escherichia coli. | filamentous cells of escherichia coli can be produced by treatment with the antibiotic cephalexin, which blocks cell division but allows cell growth. to explore the effect of cell size on chemotactic activity, we studied the motility and chemotaxis of filamentous cells. the filaments, up to 50 times the length of normal e. coli organisms, were motile and had flagella along their entire lengths. despite their increased size, the motility and chemotaxis of filaments were very similar to those prop ... | 2000 | 10894745 |
| effects of organic antagonists of ca(2+), na(+), and k(+) on chemotaxis and motility of escherichia coli. | various ca(2+) antagonists used in animal research, many of them known to be ca(2+) channel blockers, inhibited escherichia coli chemotaxis (measured as entry of cells into a capillary containing attractant). the most effective of these, acting in the nanomolar range, was omega-conotoxin gvia. the next most effective were gallopamil and verapamil. at concentrations around 100-fold higher than that needed for inhibition of chemotaxis, each of these antagonists inhibited motility (measured as entr ... | 2000 | 10940028 |
| evolutionary conservation of methyl-accepting chemotaxis protein location in bacteria and archaea. | the methyl-accepting chemotaxis proteins (mcps) are concentrated at the cell poles in an evolutionarily diverse panel of bacteria and an archeon. in elongated cells, the mcps are located both at the poles and at regions along the length of the cells. together, these results suggest that mcp location is evolutionarily conserved. | 2000 | 11053396 |
| the spirochete flaa periplasmic flagellar sheath protein impacts flagellar helicity. | spirochete periplasmic flagella (pfs), including those from brachyspira (serpulina), spirochaeta, treponema, and leptospira spp., have a unique structure. in most spirochete species, the periplasmic flagellar filaments consist of a core of at least three proteins (flab1, flab2, and flab3) and a sheath protein (flaa). each of these proteins is encoded by a separate gene. using brachyspira hyodysenteriae as a model system for analyzing pf function by allelic exchange mutagenesis, we analyzed purif ... | 2000 | 11073915 |
| evidence for horizontal gene transfer in evolution of elongation factor tu in enterococci. | the elongation factor tu, encoded by tuf genes, is a gtp binding protein that plays a central role in protein synthesis. one to three tuf genes per genome are present, depending on the bacterial species. most low-g+c-content gram-positive bacteria carry only one tuf gene. we have designed degenerate pcr primers derived from consensus sequences of the tuf gene to amplify partial tuf sequences from 17 enterococcal species and other phylogenetically related species. the amplified dna fragments were ... | 2000 | 11092850 |
| amino acid residues in luxr critical for its mechanism of transcriptional activation during quorum sensing in vibrio fischeri. | pcr-based site-directed mutagenesis has been used to generate 38 alanine-substitution mutations in the c-terminal 41 amino acid residues of luxr. this region plays a critical role in the mechanism of luxr-dependent transcriptional activation of the vibrio fischeri lux operon during quorum sensing. the ability of the variant forms of luxr to activate transcription of the lux operon was examined by using in vivo assays in recombinant escherichia coli. eight recombinant strains produced luciferase ... | 2001 | 11114940 |
| cold-adapted beta-galactosidase from the antarctic psychrophile pseudoalteromonas haloplanktis. | the beta-galactosidase from the antarctic gram-negative bacterium pseudoalteromonas haloplanktis tae 79 was purified to homogeneity. the nucleotide sequence and the nh(2)-terminal amino acid sequence of the purified enzyme indicate that the beta-galactosidase subunit is composed of 1,038 amino acids with a calculated m(r) of 118,068. this beta-galactosidase shares structural properties with escherichia coli beta-galactosidase (comparable subunit mass, 51% amino sequence identity, conservation of ... | 2001 | 11282601 |
| more than one way to sense chemicals. | | 2001 | 11466269 |
| natural rifampin resistance in treponema spp. correlates with presence of n531 in rpob rif cluster i. | | 2001 | 11702716 |
| construction and characterization of a chea mutant of treponema denticola. | the treponema denticola chea gene, encoding the central kinase of the general chemotaxis pathway, was analyzed for its role in chemotaxis and tissue penetration. the chea gene was interrupted by insertion of an ermf-ermam gene cassette. reverse transcription-pcr confirmed that the other downstream chemotaxis genes within the same operon (chew, chex, and chey) were still expressed in the chea mutant strain. lack of chea resulted in decreased swarming on soft-agar swarm plates and failure to respo ... | 2002 | 12003957 |
| conserved amplification of chemotactic responses through chemoreceptor interactions. | many bacteria concentrate their chemoreceptors at the cell poles. chemoreceptor location is important in escherichia coli, since chemosensory responses are sensitive to receptor proximity. it is not known, however, whether chemotaxis in other bacteria is similarly regulated. to investigate the importance of receptor-receptor interactions in other bacterial species, we synthesized saccharide-bearing multivalent ligands that are designed to cluster relevant chemoreceptors. as has been shown with e ... | 2002 | 12193613 |
| successful predation of filamentous bacteria by a nanoflagellate challenges current models of flagellate bacterivory. | current models suggest that (i) filamentous bacteria are protected against predation by nanoflagellates, (ii) prey size is positively correlated with prey-predator contact probability, and (iii) contact probability is mainly responsible for size-selective predation by interception-feeding flagellates. we used five strains of filamentous bacteria and one bacterivorous nanoflagellate, ochromonas sp. strain ds, to test these assumptions. the five strains, including one spirochete and four betaprote ... | 2004 | 14711660 |
| description of treponema azotonutricium sp. nov. and treponema primitia sp. nov., the first spirochetes isolated from termite guts. | long after their original discovery, termite gut spirochetes were recently isolated in pure culture for the first time. they revealed metabolic capabilities hitherto unknown in the spirochaetes division of the bacteria, i.e., h(2) plus co(2) acetogenesis (j. r. leadbetter, t. m. schmidt, j. r. graber, and j. a. breznak, science 283:686-689, 1999) and dinitrogen fixation (t. g. lilburn, k. s. kim, n. e. ostrom, k. r. byzek, j. r. leadbetter, and j. a. breznak, science 292:2495-2498, 2001). howeve ... | 2004 | 15006748 |
| flagellin from listeria monocytogenes is glycosylated with beta-o-linked n-acetylglucosamine. | glycan staining of purified flagellin from listeria monocytogenes serotypes 1/2a, 1/2b, 1/2c, and 4b suggested that the flagellin protein from this organism is glycosylated. mass spectrometry analysis demonstrated that the flagellin protein of l. monocytogenes is posttranslationally modified with o-linked n-acetylglucosamine (glcnac) at up to six sites/monomer. the sites of glycosylation are all located in the central, surface-exposed region of the protein monomer. immunoblotting with a monoclon ... | 2004 | 15466023 |
| chex is a phosphorylated chey phosphatase essential for borrelia burgdorferi chemotaxis. | motility and chemotaxis are believed to be important in the pathogenesis of lyme disease caused by the spirochete borrelia burgdorferi. controlling the phosphorylation state of chey, a response regulator protein, is essential for regulating bacterial chemotaxis and motility. rapid dephosphorylation of phosphorylated chey (chey-p) is crucial for cells to respond to environmental changes. chey-p dephosphorylation is accomplished by one or more phosphatases in different species, including chez, che ... | 2005 | 16291669 |
| identification of specific chemoattractants and genetic complementation of a borrelia burgdorferi chemotaxis mutant: flow cytometry-based capillary tube chemotaxis assay. | measuring the chemotactic response of borrelia burgdorferi, the bacterial species that causes lyme disease, is relatively more difficult than measuring that of other bacteria. because these spirochetes have long generation times, enumerating cells that swim up a capillary tube containing an attractant by using colony counts is impractical. furthermore, direct counts with a petroff-hausser chamber is problematic, as this method has a low throughput and necessitates a high cell density; the latter ... | 2007 | 17172459 |
| identification of specific chemoattractants and genetic complementation of a borrelia burgdorferi chemotaxis mutant: flow cytometry-based capillary tube chemotaxis assay. | measuring the chemotactic response of borrelia burgdorferi, the bacterial species that causes lyme disease, is relatively more difficult than measuring that of other bacteria. because these spirochetes have long generation times, enumerating cells that swim up a capillary tube containing an attractant by using colony counts is impractical. furthermore, direct counts with a petroff-hausser chamber is problematic, as this method has a low throughput and necessitates a high cell density; the latter ... | 2007 | 17172459 |
| the voltage-gated na+ channel navbp co-localizes with methyl-accepting chemotaxis protein at cell poles of alkaliphilic bacillus pseudofirmus of4. | na(v)bp, found in alkaliphilic bacillus pseudofirmus of4, is a member of the bacterial voltage-gated na(+) channel superfamily. the alkaliphile requires na(v)bp for normal chemotaxis responses and for optimal ph homeostasis during a shift to alkaline conditions at suboptimally low na(+) concentrations. we hypothesized that interaction of na(v)bp with one or more other proteins in vivo, specifically methyl-accepting chemotaxis proteins (mcps), is involved in activation of the channel under the ph ... | 2007 | 18048917 |
| motility and chemotaxis in alkaliphilic bacillus species. | alkaliphilic bacillus species grow at ph values up to approximately 11. motile alkaliphilic bacillus use electrochemical gradients of na(+) (sodium-motive force) to power ion-coupled, flagella-mediated motility as opposed to the electrochemical gradients of h(+) (proton-motive force) used by most neutralophilic bacteria. membrane-embedded stators of bacterial flagella contain ion channels through which either h(+) or na(+) flow to energize flagellar rotation. stators of the major h(+)-coupled ty ... | 2009 | 19895217 |
| comparative genomic analyses of the bacterial phosphotransferase system. | we report analyses of 202 fully sequenced genomes for homologues of known protein constituents of the bacterial phosphoenolpyruvate-dependent phosphotransferase system (pts). these included 174 bacterial, 19 archaeal, and 9 eukaryotic genomes. homologues of pts proteins were not identified in archaea or eukaryotes, showing that the horizontal transfer of genes encoding pts proteins has not occurred between the three domains of life. of the 174 bacterial genomes (136 bacterial species) analyzed, ... | 2005 | 16339738 |
| direct measurement of helical cell motion of the spirochete leptospira. | leptospira are spirochete bacteria distinguished by a short-pitch coiled body and intracellular flagella. leptospira cells swim in liquid with an asymmetric morphology of the cell body; the anterior end has a long-pitch spiral shape (s-end) and the posterior end is hook-shaped (h-end). although the s-end and the coiled cell body called the protoplasmic cylinder are thought to be responsible for propulsion together, most observations on the motion mechanism have remained qualitative. in this stud ... | 2014 | 24411236 |
| polarity in action: asymmetric protein localization in bacteria. | | 2001 | 11344132 |
| spatiotemporal distribution of marine magnetotactic bacteria in a seasonally stratified coastal salt pond. | the occurrence and distribution of magnetotactic bacteria (mb) were studied as a function of the physical and chemical conditions in meromictic salt pond, falmouth, mass., throughout summer 2002. three dominant mb morphotypes were observed to occur within the chemocline. small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. the distributions of these groups displayed s ... | 2004 | 15466570 |
| complete genome sequence of the termite hindgut bacterium spirochaeta coccoides type strain (spn1(t)), reclassification in the genus sphaerochaeta as sphaerochaeta coccoides comb. nov. and emendations of the family spirochaetaceae and the genus sphaerochaeta. | spirochaeta coccoides dröge et al. 2006 is a member of the genus spirochaeta ehrenberg 1835, one of the oldest named genera within the bacteria. s. coccoides is an obligately anaerobic, gram-negative, non-motile, spherical bacterium that was isolated from the hindgut contents of the termite neotermes castaneus. the species is of interest because it may play an important role in the digestion of breakdown products from cellulose and hemicellulose in the termite gut. here we provide a taxonomic re ... | 2012 | 22768363 |
| porphyromonas gingivalis outer membrane vesicles mediate coaggregation and piggybacking of treponema denticola and lachnoanaerobaculum saburreum. | porphyromonas gingivalis sheds outer membrane vesicles that contain several virulence factors, including adhesins. in this study, we investigated the ability of p. gingivalis outer membrane vesicles to mediate the coaggregation and piggybacking of treponema denticola and lachnoanaerobaculum saburreum. marked coaggregation between t. denticola and l. saburreum occurred in the presence of p. gingivalis outer membrane vesicles. sucrose was an effective chemoattractant for the motile species t. dent ... | 2013 | 23365576 |
| depth-dependent geochemical and microbiological gradients in fe(iii) deposits resulting from coal mine-derived acid mine drainage. | we evaluated the depth-dependent geochemistry and microbiology of sediments that have developed via the microbially-mediated oxidation of fe(ii) dissolved in acid mine drainage (amd), giving rise to a 8-10 cm deep "iron mound" that is composed primarily of fe(iii) (hydr)oxide phases. chemical analyses of iron mound sediments indicated a zone of maximal fe(iii) reducing bacterial activity at a depth of approximately 2.5 cm despite the availability of dissolved o2 at this depth. subsequently, fe(i ... | 2014 | 24860562 |
| the involvement of transport proteins in transcriptional and metabolic regulation. | transport proteins have sometimes gained secondary regulatory functions that influence gene expression and metabolism. these functions allow communication with the external world via mechanistically distinctive signal transduction pathways. in this brief review we focus on three transport systems in escherichia coli that control and coordinate carbon, exogenous hexose-phosphate and phosphorous metabolism. the transport proteins that play central roles in these processes are: first, the phosphoen ... | 2014 | 24513656 |
| use of nonelectrolytes reveals the channel size and oligomeric constitution of the borrelia burgdorferi p66 porin. | in the lyme disease spirochete borrelia burgdorferi, the outer membrane protein p66 is capable of pore formation with an atypical high single-channel conductance of 11 ns in 1 m kcl, which suggested that it could have a larger diameter than 'normal' gram-negative bacterial porins. we studied the diameter of the p66 channel by analyzing its single-channel conductance in black lipid bilayers in the presence of different nonelectrolytes with known hydrodynamic radii. we calculated the filling of th ... | 2013 | 24223145 |
| flagellin glycosylation in paenibacillus alvei ccm 2051t. | flagellin glycosylation impacts, in several documented cases, the functionality of bacterial flagella. the basis of flagellin glycosylation has been studied for various gram-negative bacteria, but less is known about flagellin glycans of gram-positive bacteria including paenibacillus alvei, a secondary invader of honeybee colonies diseased with european foulbrood. paenibacillus alvei ccm 2051(t) swarms vigorously on solidified culture medium, with swarming relying on functional flagella as evide ... | 2016 | 26405108 |
| flagellin glycosylation in paenibacillus alvei ccm 2051t. | flagellin glycosylation impacts, in several documented cases, the functionality of bacterial flagella. the basis of flagellin glycosylation has been studied for various gram-negative bacteria, but less is known about flagellin glycans of gram-positive bacteria including paenibacillus alvei, a secondary invader of honeybee colonies diseased with european foulbrood. paenibacillus alvei ccm 2051(t) swarms vigorously on solidified culture medium, with swarming relying on functional flagella as evide ... | 2016 | 26405108 |
| chemotactic behavior of pathogenic and nonpathogenic leptospira species. | we have developed a capillary tube assay in combination with real-time pcr to quantitate the number of chemoattracted leptospira cells. we identified tween 80, glucose, sucrose, and pyruvate as attractants for leptospira cells; amino acids and vitamin b(12) were found to be nonchemotactic or weakly chemotactic. this assay has the general applicability to further our understanding of leptospiral chemotaxis. | 2012 | 23001652 |
| comparative transcriptomics across the prokaryotic tree of life. | whole-transcriptome sequencing studies from recent years revealed an unexpected complexity in transcriptomes of bacteria and archaea, including abundant non-coding rnas, cis-antisense transcription and regulatory untranslated regions (utrs). understanding the functional relevance of the plethora of non-coding rnas in a given organism is challenging, especially since some of these rnas were attributed to 'transcriptional noise'. to allow the search for conserved transcriptomic elements we produce ... | 2016 | 27154273 |
| chemoreceptors and flagellar motors are subterminally located in close proximity at the two cell poles in spirochetes. | green fluorescent protein (gfp) fusions, immunofluorescence microscopy, and cryo-electron tomography revealed that the chemoreceptors of the lyme disease spirochete borrelia burgdorferi form long, thin arrays near both cell poles. these arrays are in close proximity to the flagellar motors. this information provides a basis for further understanding motility, chemotaxis, and protein localization in spirochetes. | 2011 | 21441520 |
| leptospira: a spirochaete with a hybrid outer membrane. | summary leptospira is a genus of spirochaetes that includes organisms with a variety of lifestyles ranging from aquatic saprophytes to invasive pathogens. adaptation to a wide variety of environmental conditions has required leptospires to acquire a large genome and a complex outer membrane with features that are unique among bacteria. the most abundant surface-exposed outer membrane proteins are lipoproteins that are integrated into the lipid bilayer by amino-terminal fatty acids. in contrast t ... | 2010 | 20598085 |
| the elastic basis for the shape of borrelia burgdorferi. | the mechanisms that determine bacterial shape are in many ways poorly understood. a prime example is the lyme disease spirochete, borrelia burgdorferi (b. burgdorferi), which mechanically couples its motility organelles, helical flagella, to its rod-shaped cell body, producing a striking flat-wave morphology. a mathematical model is developed here that accounts for the elastic coupling of the flagella to the cell cylinder and shows that the flat-wave morphology is in fact a natural consequence o ... | 2009 | 19486665 |
| transcriptional organization of the region encoding the synthesis of the flagellar filament in pseudomonas fluorescens. | pseudomonas fluorescens f113 is motile by means of type b flagella. analysis of the region encoding the synthesis of the flagellar filament has shown a transcriptional organization different from that of type a flagella. additionally to the promoters driving flic, flid, and fleq expression, we have found promoters upstream of the flag gene and the flist operon. these promoters were functional in vivo. both promoters have been mapped and appear to be dependent on the vegetative sigma factor and i ... | 2008 | 18375555 |
| identification of a new borrelia species among small mammals in areas of northern spain where lyme disease is endemic. | the role of small mammals as reservoir hosts for borrelia burgdorferi was investigated in several areas where lyme disease is endemic in northern spain. a low rate of infestation by ixodes ricinus nymphs was found in the small mammal populations studied that correlated with the near-absence of b. burgdorferi sensu lato in 184 animals tested and with the lack of transmission of b. burgdorferi sensu lato to i. ricinus larvae that fed on them. in contrast, questing ticks collected at the same time ... | 2005 | 15746336 |
| asymmetrical flagellar rotation in borrelia burgdorferi nonchemotactic mutants. | the lyme disease spirochete borrelia burgdorferi has bundles of periplasmic flagella subpolarly located at each cell end. these bundles rotate in opposite directions during translational motility. when not translating, they rotate in the same direction, and the cells flex. here, we present evidence that asymmetrical rotation of the bundles during translation does not depend upon the chemotaxis signal transduction system. the histidine kinase chea is known to be an essential component in the sign ... | 2002 | 11983908 |
| energy taxis is the dominant behavior in azospirillum brasilense. | energy taxis encompasses aerotaxis, phototaxis, redox taxis, taxis to alternative electron acceptors, and chemotaxis to oxidizable substrates. the signal for this type of behavior is originated within the electron transport system. energy taxis was demonstrated, as a part of an overall behavior, in several microbial species, but it did not appear as the dominant determinant in any of them. in this study, we show that most behavioral responses proceed through this mechanism in the alpha-proteobac ... | 2000 | 11029423 |
| flagellins, but not endoflagellar sheath proteins, of treponema pallidum and of pathogen-related oral spirochetes are glycosylated. | glycosylation of the flagellar core proteins (flabs) was detected in treponema pallidum nichols and in the type or reference strains of seven oral treponema species. in several nonmotile strains of oral treponemes, the flabs were undetectable by both antibody and glycan staining. in contrast, a spontaneous low-motility variant of t. vincenti poundi-related strain ritza, omz 305a, lacked the flagellar sheath protein (flaa) and the two glycan-staining flab bands of the wild type, but antibody labe ... | 1998 | 9826350 |
| structure and expression of the flaa periplasmic flagellar protein of borrelia burgdorferi. | the spirochete which causes lyme disease, borrelia burgdorferi, has many features common to other spirochete species. outermost is a membrane sheath, and within this sheath are the cell cylinder and periplasmic flagella (pfs). the pfs are subterminally attached to the cell cylinder and overlap in the center of the cell. most descriptions of the b. burgdorferi flagellar filaments indicate that these organelles consist of only one flagellin protein (flab). in contrast, the pfs from other spirochet ... | 1998 | 9573194 |
| isolation and characterization of the outer membrane of borrelia hermsii. | the outer membrane of borrelia hermsii has been shown by freeze-fracture analysis to contain a low density of membrane-spanning outer membrane proteins which have not yet been isolated or identified. in this study, we report the purification of outer membrane vesicles (omv) from b. hermsii hs-1 and the subsequent identification of their constituent outer membrane proteins. the b. hermsii outer membranes were released by vigorous vortexing of whole organisms in low-ph, hypotonic citrate buffer an ... | 1998 | 9488399 |
| relationship between proton motive force and motility in spirochaeta aurantia. | the effects of various metabolic inhibitors on the motility of spirochaeta aurantia were investigated. after 15 min in sodium arsenate buffer, 90% of cells remained motile even though adenosine triphosphate levels dropped from 5.6 to 0.1 nmol/mg (dry weight) of cells. after 70 min in sodium arsenate, 5% of cells were motile. addition of phenazine methosulfate plus ascorbate at this time resulted in motility of 95% of cells, but adenosine triphosphate levels remained at 0.1 nmol/mg of cell dry we ... | 1980 | 7410320 |
| involvement of periplasmic fibrils in motility of spirochetes. | nonmotile (mot-) strains of spirochaeta aurantia and spirochaeta halophila were isolated with a procedure involving mutagenesis of motile wild-type cells. electron microscopy showed that a mot- mutant strain of s. halophia possessed incomplete periplasmic fibrils, inasmuch as most or all of the filamentous portion of the periplasmic fibrils was absent. some of the cells of this mot-, fibril-defective mutant strain lacked the filamentous portion of the periplasmic fibrils and formed proximal hook ... | 1980 | 7354002 |
| distribution of superoxide dismutase, catalase, and peroxidase activities among treponema pallidum and other spirochetes. | representative members of spirochaetales were surveyed for their content of superoxide dismutase (sod), catalase, and peroxidase activities. only leptospira exhibited peroxidase activity. obligately anaerobic cultivable treponema and spirochaeta possessed no sod or peroxidative capabilities. upon polyacrylamide gel electrophoresis, spirochaeta aurantia, borrelia hermsi, and five leptospira biflexa serovars showed sod activity associated with one electrophoretic band which was inhibited by h2o2, ... | 1981 | 7024127 |
| a voltage clamp inhibits chemotaxis of spirochaeta aurantia. | anaerobic conditions were employed to study the relationship between membrane potential and chemotaxis in spirochaeta aurantia. when cells were grown anaerobically and suspended in anaerobic potassium phosphate buffer (ph 5.5), membranes did not appear to be polarized. nevertheless, motility was supported by a transmembrane ph gradient, and the anaerobic cells exhibited d-xylose taxis. introduction of trace amounts of air into anaerobic cell suspensions resulted in a transient membrane polarizat ... | 1983 | 6822479 |
| enzymatic activities for interconversion of purines in spirochetes. | enzymatic activities that catalyze the interconversion of purines and purine derivatives were detected in cell extracts of spirochaeta aurantia, spirochaeta stenostrepta, treponema succinifaciens, and treponema denticola. phosphoribosyltransferase activities present in cell extracts of each of the four spirochete species functioned in the conversion of adenine, hypoxanthine, and guanine to amp, imp, and gmp, respectively. nucleotidase activities in the extracts mediated the formation of nucleosi ... | 1982 | 6292162 |
| inhibition of spirochaeta aurantia chemotaxis by neurotoxins. | the effects of neurotoxic compounds on the chemotactic response of spirochaeta aurantia were investigated. in the presence of neurotoxins that affect action potential generation and transmission in excitable eucaryotic cells, d-xylose taxis was inhibited by 69 to 93%. inhibition of chemotaxis was not due to decreased viability or motility. this study supports the hypothesis that the molecular basis for sensory signal transduction in s. aurantia involves ion fluxes across the cytoplasmic membrane ... | 1983 | 6136501 |
| motility and chemotaxis of spirochaeta aurantia: computer-assisted motion analysis. | a computer program has been designed to study behavior in populations of spirochaeta aurantia cells, and this program has been used to analyze changes in behavior in response to chemoattractants. three kinds of behavior were distinguished: smooth swimming, flexing, and reversals in direction of swimming after a short pause (120 ms). cell populations exposed to chemoattractants spent, on average, 66, 33, and 1% of the time in these modes, respectively. after the addition of a chemoattractant, beh ... | 1988 | 3350790 |
| chemotaxis mutants of spirochaeta aurantia. | five spirochaeta aurantia chemotaxis mutants were isolated. one mutant (the che-101 mutant) never reversed, one (the che-200 mutant) flexed predominantly, two (the che-300 and che-400-1 mutants) exhibited elevated reversal frequencies, and one (the che-400 mutant) exhibited chemotactically unstimulated behavior similar to that of the wild-type strain. the che-101 and che-400 mutants were essentially nonchemotactic, whereas the che-200, che-300, and che-400-1 mutants showed impaired chemotactic r ... | 1989 | 2914860 |
| antiserum to the 33,000-dalton periplasmic-flagellum protein of "treponema phagedenis" reacts with other treponemes and spirochaeta aurantia. | "treponema phagedenis" periplasmic flagella (pf) have two major protein bands at molecular weights of 33,000 and 39,800 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (r. j. limberger and n. w. charon, j. bacteriol. 166:105-112, 1986). by use of western blotting and a polyclonal antiserum directed toward the 33,000-molecular-weight pf protein, cell lysates of 12 species of spirochetes were surveyed for reactivity. eight species of treponema as well as spirochaeta aura ... | 1986 | 2430936 |
| nucleotide sequence and analysis of a gene encoding anthranilate synthase component i in spirochaeta aurantia. | a spirochaeta aurantia dna fragment containing the trpe gene and flanking chromosomal dna was cloned, and the sequence of the trpe structural gene plus 870 bp upstream and 1,257 bp downstream of trpe was determined. the s. aurantia trpe gene codes for a polypeptide of 482 amino acid residues with a predicted molecular weight of 53,629 that showed sequence similarity to trpe proteins from other organisms. the s. aurantia trpe polypeptide is not more closely related to the other published spiroche ... | 1991 | 1987149 |
| transcriptomics in the tropics: total rna-based profiling of costa rican bromeliad-associated communities. | rna-seq was used to examine the microbial, eukaryotic, and viral communities in water catchments ('tanks') formed by tropical bromeliads from costa rica. in total, transcripts with taxonomic affiliation to a wide array of bacteria, archaea, and eukaryotes, were observed, as well as rna-viruses that appeared related to the specific presence of eukaryotes. bacteria from 25 phyla appeared to comprise the majority of transcripts in one tank (wg24), compared to only 14 phyla in the other (wg25). conv ... | 2015 | 25755850 |
| transcriptomics in the tropics: total rna-based profiling of costa rican bromeliad-associated communities. | rna-seq was used to examine the microbial, eukaryotic, and viral communities in water catchments ('tanks') formed by tropical bromeliads from costa rica. in total, transcripts with taxonomic affiliation to a wide array of bacteria, archaea, and eukaryotes, were observed, as well as rna-viruses that appeared related to the specific presence of eukaryotes. bacteria from 25 phyla appeared to comprise the majority of transcripts in one tank (wg24), compared to only 14 phyla in the other (wg25). conv ... | 2015 | 25755850 |
| the leptospiral outer membrane. | the outer membrane (om) is the front line of leptospiral interactions with their environment and the mammalian host. unlike most invasive spirochetes, pathogenic leptospires must be able to survive in both free-living and host-adapted states. as organisms move from one set of environmental conditions to another, the om must cope with a series of conflicting challenges. for example, the om must be porous enough to allow nutrient uptake, yet robust enough to defend the cell against noxious substan ... | 2015 | 25388136 |
| bacterial chemotaxis toward environmental pollutants: role in bioremediation. | | 2002 | 12450797 |