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At least 541 records · Page 30Linked to original sources
PubMed2004

Decreased susceptibility to tiamulin and valnemulin among Czech isolates of Brachyspira hyodysenteriae.

The agar dilution method was used to investigate the sensitivity to pleuromutilins of 100 isolates of Brachyspira hyodysenteriae isolated from 63 pig farms between 1997 and 2001. In the period under investigation, MICs to both tiamulin and valnemulin increased, with differences between the periods 1997-98 and 1999-2001 being statistically significant (P < 0.001 for tiamulin and P < 0.0001 for valnemulin). Between 1997 and 2001, the MIC50 and MIC90 of tiamulin increased from 0.062 and 0.25 microg ml, respectively, to 1.0 and 4.0 microg ml. Valnemulin MIC50 and MIC90 were < or = 0.031 microg ml in 1997 and by 2001 were respectively, 2.0 and 8.0 microg ml. The increase in MICs of tiamulin and valnemulin demonstrated in this study reflect the intensity of pleuromutilin use in the treatment of swine dysentery in the Czech Republic.

Animals↗
PubMed2004

Prevalence, risk factors and molecular epidemiology of Brachyspira pilosicoli in humans on the island of Bali, Indonesia.

The purpose of this study was to investigate the prevalence and epidemiology of the anaerobic intestinal spirochaete Brachyspira pilosicoli amongst Indonesians living in rural and urban settings on the island of Bali. Faecal samples (n = 992) were collected on two occasions, 4 months apart, from people living in four traditional farming villages, one peri-urban location and one urban area. Samples were cultured anaerobically on selective agar and intestinal spirochaete isolates were confirmed to be B. pilosicoli by using a species-specific PCR. Forty-eight of the 121 isolates obtained were typed by using PFGE. A questionnaire was administered to participants and analysed in order to identify potential risk factors for colonization. Overall prevalence of carriage on the two visits was 11.8 and 12.6 %, respectively. Prevalence at different locations varied from 3.3 to 23.4 %, with the highest prevalence occurring in the peri-urban location. Considerable strain diversity was found, with the 48 isolates being divided into 44 PFGE types. There was no significant association between colonization and ownership of animals, contact with animals, farming, age or gender. On the first visit, colonization was significantly more common in people who used well water compared to those who used tap water. On the second visit, colonization was significantly more common in people with wet faeces than in those with normal faeces.

Adolescent↗
PubMed2004

Analysis of genetic variation in Brachyspira aalborgi and related spirochaetes determined by partial sequencing of the 16S rRNA and NADH oxidase genes.

The purpose of this study was to investigate genetic variation in the anaerobic intestinal spirochaete Brachyspira aalborgi by partial sequencing of the 16S rRNA and NADH oxidase genes. The spirochaete is poorly cultivable; hence, only six isolates were available for analysis. Additional sequences were amplified from DNA extracted from fixed colorectal biopsies from 26 patients with histological evidence of intestinal spirochaetosis, and from the faeces of six non-human primates (NHP). Multiple biopsies from sites along the large intestine were tested from three of the 26 patients. Sequences from two biopsies were closely related to those of the spirochaete Brachyspira pilosicoli. Eight B. aalborgi-like 16S rDNA sequences were generated from the biopsies from the other 24 patients, and four from the NHP faeces. The B. aalborgi 16S rDNA sequences were divided into three clusters, 1, 2 and 4, with individual sequence similarities to the type strain ranging from 97.49 to 100 %. All human isolates of B. aalborgi were located in cluster 1, as was the sequence of the so-called 'Brachyspira ibaraki'. All four 16S rDNA sequences from the NHP faeces and the two NHP isolates of B. aalborgi were located in cluster 4, which was distinct. Cluster 4 may represent a novel Brachyspira species. Evidence for multiple strains of B. aalborgi or other Brachyspira species was found in biopsies from two patients. In the three individuals from whom multiple biopsies were amplified, the sequences at each intestinal site were the same, indicating the presence of one dominant strain.

Adolescent↗
PubMed2004

Identification of three clusters of canine intestinal spirochaetes by biochemical and 16S rDNA sequence analysis.

It has been suggested that canine intestinal spirochaetes consist of Brachyspira pilosicoli and a group of strains that has been provisionally designated 'Brachyspira canis'. The purpose of the present study was to compare 22 spirochaete isolates that were obtained from intestinal specimens of dogs in Sweden (n = 12), Norway (n = 4), the United States (n = 3), Australia (n = 2) and Germany (n = 1) with type and reference strains, as well as field isolates, of Brachyspira species by five biochemical tests and determination of almost-complete 16S rDNA sequences. In an evolutionary tree derived from 16S rDNA sequences, the canine isolates grouped into three clusters. One cluster included the type strain of porcine B. pilosicoli, whereas a second larger cluster, which was monophyletic, contained a canine strain that was identified previously as 'B. canis'. The third cluster consisted of three canine isolates of Scandinavian origin, which grouped together with the type strain of the species Brachyspira alvinipulli (pathogenic to chicken). These three genotypes, which were identified on the basis of 16S rDNA sequences, corresponded to four phenotypic groups based on biochemical testing. Two biochemical tests, hippurate hydrolysis and alpha-galactosidase production, were sufficient for rapid identification of each canine cluster.

Animals↗
PubMed2004

Brachyspira hyodysenteriae and other strongly beta-haemolytic and indole-positive spirochaetes isolated from mallards (Anas platyrhynchos).

The aims of the current study were to collect intestinal spirochaetes (genus Brachyspira) from farmed and wild mallards (Anas platyrhynchos) and to identify and classify those isolates that phenotypically resembled Brachyspira hyodysenteriae, an enteric pathogen of pigs. The isolation rate of Brachyspira spp. was high from both farmed (93 %) and wild mallards (78 %). In wild mallards, it appeared that Brachyspira spp. were more likely to be found in migratory birds (multivariate analysis: RR = 1.8, 95 % CI 1.1-3.1) than in mallards sampled in a public park. Pure cultures of putative B. hyodysenteriae were obtained from 22 birds. All five isolates from farmed mallards and ten randomly selected isolates with this phenotype were used for further studies. All isolates from farmed mallards and two of the isolates from wild mallards were PCR-positive for the tlyA gene of B. hyodysenteriae. Two isolates from farmed mallards were selected for pulsed field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD) analysis. These isolates clustered with the type and reference strains of B. hyodysenteriae. 16S rDNA sequence analysis performed on 11 of the strains showed that they were all closely related to each other and to the B. hyodysenteriae-Brachyspira intermedia cluster. Three of the mallard isolates had 16S rDNA sequences that were identical to those of B. hyodysenteriae strains R1 and NIV-1 previously isolated from common rheas (Rhea americana). To conclude, the isolates from farmed mallards and two isolates from wild mallards were classified as B. hyodysenteriae based on the fact that they could not be differentiated by any of the applied methods from type, reference and field strains of B. hyodysenteriae. The remaining isolates could not be assigned irrefutably to any of the presently recognized Brachyspira species. These results point to a broader host spectrum of B. hyodysenteriae than is generally recognized, and to the presence in mallards of strongly beta-haemolytic and indole-producing spirochaetes that possess many, but not all, of the currently recognized characteristics of B. hyodysenteriae.

Animals↗
PubMed2004

Immunomagnetic separation of the intestinal spirochaetes Brachyspira pilosicoli and Brachyspira hyodysenteriae from porcine faeces.

Porcine intestinal spirochaetes are fastidious anaerobic organisms and, as a consequence, it has been necessary to develop various protocols to enhance their isolation from or detection in faeces. Immunomagnetic separation (IMS) is a method developed recently to improve separation of target cells from mixed cell suspensions. The purpose of the present study was to compare the relative sensitivity of IMS for isolation of Brachyspira pilosicoli and Brachyspira hyodysenteriae with current routine diagnostic methods (culture on selective media and PCR) for detection of these micro-organisms in pig faeces. Neither direct nor indirect IMS methods enhanced the sensitivity of detection of either organism when performed with the recommended washings during sample processing. Performance of the IMS procedure without washing gave sensitivity at levels similar to direct culture onto selective medium. Further development of IMS techniques is required to improve isolation rates of Brachyspira species from faecal samples.

Animals↗
PubMed2004

Biochemical properties of membrane-associated proteases of Brachyspira pilosicoli isolated from humans with intestinal disorders.

A membrane-associated, subtilisin-like, serine protease activity was found in both pathogenic and non-pathogenic strains of Brachyspira species in a previous study, but the biochemical properties of the enzyme were not investigated. The purpose of the present study was to characterize further the biochemical properties, including substrate specificity, of the membrane-associated protease of Brachyspira pilosicoli isolated from humans with intestinal disorders. Protease activity of detergent-enriched membrane protein extracts of B. pilosicoli was assessed using fluorescent dye-labelled synthetic peptides as substrates and determination of electrophoretic mobility of cleavage products in agarose gels. Each activity was further confirmed with class-specific protease inhibitors and thermal denaturation. The presence of a hydrophilic membrane-associated thermolabile serine endopeptidase with specificity for Leu was confirmed. Two additional hydrophilic membrane-associated thermostable proteolytic activities were identified, one with a putative Ala specificity, and one a carboxypeptidase. Taken together, these data suggest that, in addition to a previously described membrane-associated subtilisin-like serine protease, the membrane of B. pilosicoli contains proteins with at least two other proteolytic activities.

Brachyspira↗
PubMed2006

Immunological alterations during the clinical and recovery phases of experimental swine dysentery.

The aim of this study was to examine changes in the systemic immune response during the incubation period and following the onset of clinical swine dysentery, including the recovery period. Ten healthy conventional pigs were inoculated with Brachyspira hyodysenteriae. Blood was sampled at pre-inoculation, at days 4 and 14 post-inoculation, during the first 4 days with clinical signs of dysentery and at days 1, 3, 7, 11 and 15 of the recovery period. Eight pigs developed haemorrhagic diarrhoea. Flow-cytometric analyses of lymphocyte subpopulations showed that all animals, including the two that remained healthy, had an increase in CD8alpha+ CD4- cells and gammadelta T cells at days 4 and 14 post-inoculation. In addition, an increase in CD4+ CD8alpha+ cells and CD8alpha+ CD8beta+ cells was observed at days 4 and 14 post-inoculation in animals that developed dysentery. During clinical signs of dysentery, the acute-phase protein serum amyloid A was increased. There was a two- to threefold increase in both neutrophils and monocytes during signs of dysentery and at the beginning of the recovery period. The numbers of CD8alpha+ CD8beta- CD4-, CD45RA- lymphocytes also increased during the dysentery period. Circulating CD21+ cells and CD21+ CD45RA- cells decreased at the end of the incubation period, during signs of dysentery and at the beginning of the recovery period. The dysentery-affected animals developed antibodies to B. hyodysenteriae-specific antigens (approximately 16 kDa and approximately 30 kDa) from the first day of recovery, and gammadelta T cells showed an increase during the recovery period. In comparison with pre-inoculation, increased numbers of monocytes, neutrophils, CD8alpha+ CD8beta- CD4- lymphocytes and CD45RA- lymphocytes were observed during clinical dysentery. Increased numbers of neutrophils, gammadelta T cells and specific antibodies were seen during the recovery period.

Animals↗
PubMed2004

Identification and cloning of the gene encoding BmpC: an outer-membrane lipoprotein associated with Brachyspira pilosicoli membrane vesicles.

The intestinal spirochaete Brachyspira pilosicoli causes colitis in a wide variety of host species. Little is known about the structure or protein constituents of the B. pilosicoli outer membrane (OM). To identify surface-exposed proteins in this species, membrane vesicles were isolated from B. pilosicoli strain 95-1000 cells by osmotic lysis in dH(2)O followed by isopycnic centrifugation in sucrose density gradients. The membrane vesicles were separated into a high-density fraction (HDMV; rho=1.18 g cm(-3)) and a low-density fraction (LDMV; rho=1.12 g cm(-3)). Both fractions were free of flagella and soluble protein contamination. LDMV contained predominantly OM markers (lipo-oligosaccharide and a 29 kDa B. pilosicoli OM protein) and was used as a source of antigens to produce mAbs. Five B. pilosicoli-specific mAbs reacting with proteins with molecular masses of 23, 24, 35, 61 and 79 kDa were characterized. The 23 kDa protein was only partially soluble in Triton X-114, whereas the 24 and 35 kDa proteins were enriched in the detergent phase, implying that they were integral membrane proteins or lipoproteins. All three proteins were localized to the B. pilosicoli OM by immunogold labelling using specific mAbs. The gene encoding the abundant, surface-exposed 23 kDa protein was identified by screening a B. pilosicoli 95-1000 genome library with the mAb and was expressed in Escherichia coli. Sequence analysis showed that it encoded a unique lipoprotein, designated BmpC. Recombinant BmpC partitioned predominantly in the OM fraction of E. coli strain SOLR. The mAb to BmpC was used to screen a collection of 13 genetically heterogeneous strains of B. pilosicoli isolated from five different host species. Interestingly, only strain 95-1000 was reactive with the mAb, indicating that either the surface-exposed epitope on BmpC is variable between strains or that the protein is restricted in its distribution within B. pilosicoli.

Amino Acid Sequence↗
PubMed2006

Lipoprotein computational prediction in spirochaetal genomes.

Lipoproteins are of great interest in understanding the molecular pathogenesis of spirochaetes. Because spirochaete lipobox sequences exhibit more plasticity than those of other bacteria, application of existing prediction algorithms to emerging sequence data has been problematic. In this paper a novel lipoprotein prediction algorithm is described, designated SpLip, constructed as a hybrid of a lipobox weight matrix approach supplemented by a set of lipoprotein signal peptide rules allowing for conservative amino acid substitutions. Both the weight matrix and the rules are based on a training set of 28 experimentally verified spirochaetal lipoproteins. The performance of the SpLip algorithm was compared to that of the hidden Markov model-based LipoP program and the rules-based algorithm Psort for all predicted protein-coding genes of Leptospira interrogans sv. Copenhageni, L. interrogans sv. Lai, Borrelia burgdorferi, Borrelia garinii, Treponema pallidum and Treponema denticola. Psort sensitivity (13-35 %) was considerably less than that of SpLip (93-100 %) or LipoP (50-84 %) due in part to the requirement of Psort for Ala or Gly at the -1 position, a rule based on E. coli lipoproteins. The percentage of false-positive lipoprotein predictions by the LipoP algorithm (8-30 %) was greater than that of SpLip (0-1 %) or Psort (4-27 %), due in part to the lack of rules in LipoP excluding unprecedented amino acids such as Lys and Arg in the -1 position. This analysis revealed a higher number of predicted spirochaetal lipoproteins than was previously known. The improved performance of the SpLip algorithm provides a more accurate prediction of the complete lipoprotein repertoire of spirochaetes. The hybrid approach of supplementing weight matrix scoring with rules based on knowledge of protein secretion biochemistry may be a general strategy for development of improved prediction algorithms.

Algorithms↗
PubMed2005

Superoxide reductase from the syphilis spirochete Treponema pallidum: crystallization and structure determination using soft X-rays.

Superoxide reductase is a 14 kDa metalloprotein containing a catalytic non-haem iron centre [Fe(His)4Cys]. It is involved in defence mechanisms against oxygen toxicity, scavenging superoxide radicals from the cell. The oxidized form of Treponema pallidum superoxide reductase was crystallized in the presence of polyethylene glycol and magnesium chloride. Two crystal forms were obtained depending on the oxidizing agents used after purification: crystals grown in the presence of K3Fe(CN)6 belonged to space group P2(1) (unit-cell parameters a = 60.3, b = 59.9, c = 64.8 A, beta = 106.9 degrees) and diffracted beyond 1.60 A resolution, while crystals grown in the presence of Na2IrCl6 belonged to space group C2 (a = 119.4, b = 60.1, c = 65.6 A, beta = 104.9 degrees) and diffracted beyond 1.55 A. A highly redundant X-ray diffraction data set from the C2 crystal form collected on a copper rotating-anode generator (lambda = 1.542 A) clearly defined the positions of the four Fe atoms present in the asymmetric unit by SAD methods. A MAD experiment at the iron absorption edge confirmed the positions of the previously determined iron sites and provided better phases for model building and refinement. Molecular replacement using the P2(1) data set was successful using a preliminary trace as a search model. A similar arrangement of the four protein molecules could be observed.

Crystallization↗
PubMed1980

Electron microscopy of the spherical body of oral spirochetes in vitro. Further studies.

The surface and inner structure of the spherical bodies (SB) produced by the human oral treponeme strain G7201, similar to Treponema macrodentium, were studied by electron microscopy. Ultrathin sectioning and scanning techniques demonstrated that in the presence of a high concentration of sucrose, the outer envelope of one or both terminal ends of this oral spirochete changed into a swollen structure, the SB. Spirochetal cells adhered firmly to the surface of the resultant body. The membrane of the SB, i.e. the outer envelope, enclosed the coiled protoplasmic cylinder and five axial fibrils which were located between the envelope and th cylinder. Large expanded protoplasmic cylinders were observed, surrounded by a partially disrupted double membrane in some SBs. A number of frizzly fibrous structures, which differed from axial fibrils in number and shape, were also observed within these SBs. Except for abnormal or partially broken cylinders, the protoplasmic cylinders tended to be located close to the inner surface of the SB membrane, resulting in a central vacant space with occasional axial fibrils. These findings suggest that the oral spirochete produces an SB by terminal expansion of the outer envelope in the presence of high concentrations of sucrose. The outer envelope of the SB, which consists of two electron-dense layers, has the property of binding spirochetal cells to its outer layer and the protoplasmic cylinder and axial fibrils to the inner layer. Some protoplasmic cylinders were also observed to be swollen in the presence of high sucrose concentrations.

Microscopy, Electron↗
PubMed2003

Morphological properties of a human intestinal spirochete first isolated from a patient with diarrhea in Japan.

A human intestinal spirochete isolated from a rectal biopsy specimen was morphologically characterized. The isolate was comma-shaped, 3-6 microm in length, 0.2 micro m in diameter and had tapered ends. The surface layer, external to the outer envelope, was amorphous. Four string-like periplasmic flagella with a diameter of 20 nm were presented at each end of the SDS-treated cells. Thin sections of the bacterial cell revealed a high-density cytoplasmic membrane and flagella in the periplasmic space between the cytoplasmic membrane and the outer envelope. Three segments of equal length were observed in some of the cells, while other cells were bi-segmented and more frequently observed.

Biopsy↗
PubMed1984

Thirteen British cases of erythema chronicum migrans, a spirochaetal disease.

Thirteen British cases of erythema chronicum migrans are reported. An antibody to the Lyme disease spirochaete was found in three of five recent cases, but Lyme disease was not seen. The distribution and life cycle of the tick Ixodes ricinus is described and related to the occurrence of erythema chronicum migrans in Great Britain.

England↗
PubMed1985

Tick-borne spirochetes as a cause of facial palsy.

Twenty consecutive patients visiting an otolaryngological department in Sweden with a facial palsy were investigated for serological signs of tick-borne spirochete infection. Four patients showed serological evidence of and had a medical history compatible with a tick-borne spirochetosis. Spinal fluid analyses were performed in 3 of these patients and showed elevated specific antispirochetal antibody titres and an increase in mononuclear cells. The importance of a correct diagnosis and of antibiotic therapy in patients with spirochete-induced facial palsy is emphasized.

Adolescent↗