Publications

functional expression of heterologous type 4 fimbriae in pseudomonas aeruginosa.	type 4 fimbriae are surface organelles produced by a wide range of bacterial pathogens. in pseudomonas aeruginosa they are associated with a form of surface translocation known as twitching motility and have also been implicated as the receptor for a number of fimbrial-specific bacteriophages. the infrastructural machinery required for type 4 fimbrial biogenesis appears to be conserved as heterologous subunits from other species can be expressed in p. aeruginosa. all of these studies have, until ...	1996	8917091
manipulation of the helper t cell response to influence antigenic competition occurring with a multivalent vaccine.	the reduction in antibody observed following inoculation with multiple heterologous dichelobacter nodosus pili antigens is thought to be due to competition between antigen-specific b cells for a limited amount of t cell help. we demonstrate here that this competition is not further influenced by the expansion of cross-reactive antibody secreting cells at the expense of serogroup specific antibody secreting cells. the t cell determinants of pili recognized by sheep and balb/c mice have been defin ...	1996	8934658
organization of ribosomal rna genes from the footrot pathogen dichelobacter nodosus.	southern hybridization analysis revealed that there were three rrn loci within the genome of dichelobacter nodosus, the causative organism of ovine footrot. these loci (rrna, rrnb and rrnc) were isolated on recombinant lambda clones, and comprised 16s, 23s and 5s rrna genes closely linked in that order. sequence and primer extension analysis revealed the presence of putative genes encoding trna(ile) and trna(ala) within the 16s-23s spacer region, as well as a number of potential regulatory featu ...	1996	8936315
the molecular genetics of type-4 fimbriae in pseudomonas aeruginosa--a review.	type-4 fimbriae (or pili) are filaments found at the poles of a wide range of bacterial pathogens, including neisseria gonorrhoeae, moraxella bovis, dichelobacter nodosus and pseudomonas aeruginosa. they are composed of a small subunit which is highly conserved among different species and appear to mediate adhesion and translocation across epithelial surfaces via a phenomenon termed "twitching motility'. these fimbriae are key host colonisation factors and important protective antigens. we have ...	1996	8955641
virulence regions and virulence factors of the ovine footrot pathogen, dichelobacter nodosus.	ovine footrot is a debilitating and highly infectious disease that is primarily caused by the gram-negative, anaerobic bacterium dichelobacter nodosus. the major antigens implicated in virulence are the type iv fimbriae and extracellular proteases. the fimbriae show sequence and structural similarity to other type iv fimbriae, this similarity extends to genes that are involved in fimbrial biogenesis. several acidic and basic extracellular serine proteases are produced by both virulent and benign ...	1996	8961550
a role for bacteriophages in the evolution and transfer of bacterial virulence determinants.	a virulence-associated region in the genome of dichelobacter nodosus has been shown to contain an integrase gene which is highly related to the integrases of shigella flexneri phage sf6 and coliphages p4 and phi r73, together with open reading frames (vapb, c and d) related to genes borne on plasmids in neisseria gonorrhoeae, escherichia coli, actinobacillus actinomycetemcomitans and treponema denticola. similar to p4 and phi r73, the vap region is bracketed by putative bacteriophage att sites a ...	1995	8709840
molecular basis for the virulence of dichelobacter nodosus.		1995	8800839
relationship between clinical manifestations of footrot and specific dna products of dichelobacter nodosus amplified through pcr.	a total of 141 dichelobacter nodosus isolates from 46 merino sheep farms with various clinical forms of footrot was examined by the gelatin gel test and the polymerase chain reaction (pcr) using virulent (vf2 and vr2) and benign (bf and br) specific primers. isolates from sheep with virulent and high intermediate footrot usually produced relatively thermostable proteases, but a decreasing proportion of the isolates from sheep with medium and low intermediate or benign footrot had thermostable pr ...	1995	8525095
effects of the severity and duration of lesions on the primary and anamnestic humoral responses of sheep to dichelobacter nodosus and observations of natural resistance to footrot.	in a flock of 137 sheep naturally infected with dichelobacter nodosus the severity of the lesions was the principal factor associated with the humoral response early in the period of spread of d. nodosus, underrun lesions having the greatest effect. however, after five to six weeks, the duration of underrun lesions rather than their severity or number primarily influenced the response. sheep first affected late in the period of spread had fewer affected feet, milder lesions and a lower humoral r ...	1995	8525101
a single amino-acid change between the antigenically different extracellular serine proteases v2 and b2 from dichelobacter nodosus.	dichelobacter nodosus (dn), the causative organism of ovine footrot, secrets three distinct types of extracellular serine proteases which have been implicated in virulence. southern analyses have shown that the proteases are encoded by three separate genes, and the genes encoding an acidic protease v5 and a basic protease have already been characterised from virulent dn strain 198. the gene encoding the third protease type, as represented by acidic protease v2, was isolated from an ecori-bamhi l ...	1995	8566792
a gene region in dichelobacter nodosus encoding a lipopolysaccharide epitope.	dichelobacter nodosus is a gram-negative anaerobic bacterium that is the causative organism of footrot in sheep. a d. nodosus locus responsible for a modification of the host lipopolysaccharide (lps) in escherichia coli was cloned and sequenced. genetic studies showed that the modification occurred within the inner-core region of the host lps, most likely to one or more of the heptose molecules. antibodies eluted from the modified lps reacted preferentially with the lipid-a-core region of d. nod ...	1995	7539688
identification of a gene encoding a bacteriophage-related integrase in a vap region of the dichelobacter nodosus genome.	dichelobacter nodosus is the principal causative agent of ovine footrot. nucleotide (nt) sequences from the d. nodosus genome have been isolated and a series of overlapping lambda clones defining vap (virulence-associated protein) regions 1, 2 and 3 have been reported [katz et al., j. bacteriol. 176 (1994) 2663-2669]. in the present study, the limits of the virulence-associated (va) dna around vap regions 1 and 3 were determined by dot-blot hybridization experiments using plasmid subclones to pr ...	1995	7557417
comparative characterization of release factor rf-3 genes of escherichia coli, salmonella typhimurium, and dichelobacter nodosus.	the termination of protein synthesis in bacteria requires two codon-specific release factors, rf-1 and rf-2. a gene for a third factor, rf-3, that stimulates the rf-1 and rf-2 activities has been isolated from the gram-negative bacteria escherichia coli and dichelobacter nodosus. in this work, we isolated the rf-3 gene from salmonella typhimurium and compared the three encoded rf-3 proteins by immunoblotting and intergeneric complementation and suppression. a murine polyclonal antibody against e ...	1995	7559341
identification of fimbrial assembly genes from dichelobacter nodosus: evidence that fimp encodes the type-iv prepilin peptidase.	dichelobacter nodosus (dn) is the causative agent of footrot, an economically significant disease of sheep. one of the factors believed to be involved in the virulence of this organism is its ability to produce type-iv fimbriae, which are the major protective antigens. to investigate the process of fimbrial biogenesis in dn, gene probes were constructed from pilus biogenesis genes of pseudomonas aeruginosa (pa) and used to isolate homologues from dn. a homologue, designated fimp, of the pa prepi ...	1995	7642131
observations on the indirect transmission of virulent ovine footrot in sheep yards and its spread in sheep on unimproved pasture.	virulent ovine footrot was transmitted accidentally to a group of 23 adult merino sheep (flock b) after holding for 1 hour in sheep yards, which earlier the same day had contained another flock (flock a) with < 1% prevalence of sheep with footrot lesions. sheep in flock b were rendered susceptible to virulent footrot by grazing 600 mm high unimproved pasture dominated by paspalum (paspalum dilatatum) and kangaroo grass (themeda australis) during warm, humid and wet weather. in addition to moistu ...	1995	7646377
nucleotide and deduced protein sequence of the extracellular, serine basic protease gene (bprb) from dichelobacter nodosus strain 305: comparison with the basic protease gene (bprv) from virulent strain 198.	in earlier studies, it appeared that benign strains of the gram-negative, obligate anaerobe, dichelobacter nodosus, were devoid of the extracellular, serine basic protease (pi approximately 9.5) of virulent strains. however, southern and pcr analysis have shown a homologous gene (bprb) in the representative benign strain 305. the deduced amino acid sequence of the prepro- and mature protease regions of bprb confirmed this homology and showed 97% sequence identity with the bprv precursor from vir ...	1995	7663404
a multiple site-specific dna-inversion model for the control of omp1 phase and antigenic variation in dichelobacter nodosus.	the molecular cloning and sequence analysis of four structurally variant linked genes (omp1a,b,c,d) that encode the major outer membrane protein of dichelobacter nodosus strain vcs1001 are described. the isolation of rearranged copies of omp1a and omp1b, and the identification in the 5' regions of all four genes of short cross-over-site sequences that were similar to the din family of cross-over-site sequences, suggested that site-specific dna inversion was involved in omp1 rearrangement. eviden ...	1995	7476204
delineation of the virulence-related locus (vrl) of dichelobacter nodosus.	dichelobacter nodosus is the primary pathogen implicated in ovine footrot. in this paper we have delineated a 27 kb locus, termed the virulence-related locus (vrl), that was essentially specific for virulent d. nodosus isolates. the precise ends of this locus were mapped and the sequences of the junction regions from the virulent strain a198 were compared to corresponding sequences from the benign isolate c305. the left end of the vrl locus was located in a sequence similar to that of the small ...	1995	7496519
grading the lesions of ovine footrot.	sixteen methods of grading the lesions of ovine footrot were assessed on the basis of the effect of the lesions on the humoral immune response of the host to a causative bacterium, dichelobacter nodosus. methods that allowed for qualitative and quantitative differences in lesion scores between sheep were the best predictors of host response, and methods that assessed the lesions in each of the eight digits were more efficient than methods that did not grade the digits within feet. weighting the ...	1995	7709056
a polymerase chain reaction assay for improved determination of virulence of dichelobacter nodosus, the specific causative pathogen for ovine footrot.	three sets of oligonucleotide primers (vf1 and vr1, vf2 and vr2, bf and br) were derived from a d. nodosus virulent-specific clone pv470-13 (2146 bp) and a benign-specific clone pb645-335 (737 bp), respectively. using the virulent-specific primers vf1 and vr1 in a polymerase chain reaction (pcr) enabled amplification of a dna fragment of 460 bp in 25/27 virulent, 9/25 high intermediate, 9/24 low intermediate and 2/20 benign isolates of d. nodosus. on the other hand, using the second set of the v ...	1995	7740758
expression and secretion of heterologous proteases by corynebacterium glutamicum.	genes encoding the basic protease of dichelobacter nodosus (bprv) and the subtilisin of bacillus subtilis (apre) were cloned and expressed in corynebacterium glutamicum. in each case, enzymatically active protein was detected in the supernatants of liquid cultures. while the secretion of subtilisin was directed by its own signal peptide, the natural signal peptide of the bprv basic protease did not facilitate secretion. a hybrid apre-bprv gene in which the promoter and signal peptide coding sequ ...	1995	7747974
application of elisa to the serological diagnosis of virulent ovine footrot.	the sensitivity and specificity of an elisa that detects antibody in the serum of sheep against dichelobacter nodosus was investigated. the sensitivity of the assay was determined in two trials in which sheep free of virulent footrot were exposed to a virulent strain of d. nodosus. in the first trial up to 96.6% of sheep that developed severe foot lesions were seropositive 2 weeks later. the proportion of seropositive sheep depended on the interval between exposure to d. nodosus and collection o ...	1994	7801518
double immunogold labelling demonstrating expression of recombinant genes for production of an anti-fertility vaccine.	the multiple antibody technique for double immunogold labelling for the simultaneous localization of two antigens with negative staining was utilized to demonstrate the expression of recombinant genes in bacteria, with the primary antibodies being raised in different host species. for the production of a vaccine for immunological control of fertility, a multi-functional plasmid vector was introduced into the bacterium pseudomonas aeruginosa containing the dichelobacter nodosus fimbrial subunit g ...	1994	7881895
protective antibody titres and antigenic competition in multivalent dichelobacter nodosus fimbrial vaccines using characterised rdna antigens.	the relationship between k-agglutination antibody titres and protection against experimental challenge with dichelobacter nodosus, the effect of increasing the number of d. nodosus fimbrial antigens, and the importance of the nature of additional antigens in multivalent vaccines on antibody response and protection against experimental challenge with d. nodosus were examined in merino sheep. a total of 204 merino sheep were allocated to one of 12 groups, and vaccinated with preparations containin ...	1994	7909183
antigenic competition in a multivalent foot rot vaccine.	the antigenic competition that occurs when pilus antigens of different serogroups are combined in multivalent vaccines for foot rot has been investigated using recombinant pilus antigens. our prototype vaccine contains pili from nine serogroups of dichelobacter nodosus which are expressed in pseudomonas aeruginosa. sheep inoculated with this multivalent vaccine were not as well protected against foot rot as those given the monovalent vaccine. levels of agglutinating and total antibody specific f ...	1994	7912871
expression in escherichia coli of the extracellular basic protease from dichelobacter nodosus.	dichelobacter nodosus, a gram-negative obligate anaerobe and the causative agent of ovine footrot, secretes a number of extracellular proteases, one of which is highly basic in nature. the gene (bprv) encoding this basic protease, from virulent strain 198, has been cloned and sequenced. clone pbr3kb contained the complete bprv gene which constitutively expressed an active protease using its own promoter, when cloned in escherichia coli. however, levels of protease expression were low and unstabl ...	1994	7921259
development of gene probes of dichelobacter nodosus for differentiating strains causing virulent, intermediate or benign ovine footrot.	seven dichelobacter nodosus genomic dna clones including six specific for virulent and one for benign strains were identified. a collection of 96 footrot isolates, which in turn comprised 27 virulent isolates showing elastase activity at 7 days, 25 high intermediate isolates with elastase activity at 14 days, 24 low intermediate isolates with elastase activity at 21-28 days and 20 benign isolates with no elastase activity at up to 28 days, were used to assess these clones. of the six virulent sp ...	1994	7953579
characterization of the serine protease and serine protease inhibitor from the tissue-penetrating nematode anisakis simplex.	a serine protease and a serine protease inhibitor were purified from infective larvae of the parasitic nematode anisakis simplex. the serine protease was found to be trypsin-like and preferentially cleaved substrates with the basic amino acid arginine at the p1 position (z-gly-pro-arg-amc (where z is benzyloxycarbonyl), km = 0.019 mm, and z-phe-pro-arg-amc, km = 0.013 mm) at rates similar to those determined for trypsin (0.002 mm and 0.006 mm, respectively). however, the presence of a bulky hydr ...	1994	7961683
experimental evaluation of a commercial footrot vaccine against native canadian strains of dichelobacter nodosus.	two serotypes of the anaerobic bacterium dichelobacter nodosus were used to experimentally infect young sheep resulting in infectious pododermatitis or footrot characteristic of the natural disease in sheep. the specific serotypes of d. nodosus were reisolated from the feet and identified using immunofluorescent microscopy of hoof scrapings. prior immunization of sheep with a commercially available bacterin containing whole cell preparations of ten strains of d. nodosus resulted in serum igg rea ...	1994	8004537
sequencing and expression of the aroa gene from dichelobacter nodosus.	the aroa locus of the gram- pathogen dichelobacter nodosus, which encodes 5-enolpyruvylshikimate 3-phosphate (epsp) synthase, has been sequenced and expressed in escherichia coli. the gene is located on a 1.48-kb drai-hindiii fragment located directly upstream and in opposite transcriptional orientation to the gene encoding the fimbrial structural subunit. the deduced open reading frame is 1329 nucleotides in length, which encodes a protein of 443 amino acids (aa) with a calculated m(r) of 47,41 ...	1994	8045432
the laboratory culture of dichelobacter nodosus in a footrot eradication program.	as part of a program to eradicate virulent footrot from western australia, 2745 isolates of dichelobacter nodosus were isolated from 5263 specimens from 1883 submissions. the virulence of each isolate was assessed using protease thermostability and isoenzyme zymogram. we describe changes to the materials and methods required to handle these specimens and to reduce the interval between submission and report to 8 days.	1994	8048905
genetic organization of the duplicated vap region of the dichelobacter nodosus genome.	the recombinant plasmid pjir318 contains a fragment of the dichelobacter nodosus genome which is associated with virulence. sequence analysis of the pjir318 insert has shown that it contains four vap (virulence-associated protein) genes which are homologous to open reading frames found on the escherichia coli f plasmid and the neisseria gonorrhoeae cryptic plasmid (m. e. katz, r. a. strugnell, and j. i. rood, infect. and immun. 60:4586-4592, 1992). the plasmid pjir318 hybridizes to three regions ...	1994	8169216
characterization of a basic serine proteinase (pi approximately 9.5) secreted by virulent strains of dichelobacter nodosus and identification of a distinct, but closely related, proteinase secreted by benign strains.	an extracellular serine proteinase with a pi approximately 9.5 (referred to as 'basic proteinase') was purified to homogeneity, from strains of dichelobacter nodosus that cause virulent foot-rot, by gel filtration of concentrated culture supernatant on sephadex g-100 and chromatography on sulphopropyl-sephadex c-25 at ph 8.6 d. nodosus strains that cause benign foot-rot do not secrete a corresponding basic proteinase with a pi of approximately 9.5. benign strains secrete a closely related, but d ...	1994	8172614
purification of the extracellular acidic proteases of dichelobacter nodosus.	dichelobacter nodosus, a gram negative obligate anaerobe and causative organism of ovine footrot, secretes a family of extracellular acidic serine proteases with pi's in the range of 5.2 to 5.6, and a basic serine protease with a pi of approximately 9.5. four acidic proteases (v1, v2, v3 and v5) from virulent and five acidic proteases (b1 to b5) from benign strains of d. nodosus were purified by chromatography on sephadex g-100 and deae-sepharose cl-6b. proteases v2, v5 and b5 were found to yiel ...	1994	7696988
properties of the extracellular acidic proteases of dichelobacter nodosus. stability and specificity of peptide bond cleavage.	dichelobacter nodosus, a gram negative obligate anaerobe and causative organism of ovine footrot, secretes a family of extracellular acidic serine proteases with pi's in the range of 5.2 to 5.6, and a basic serine protease with a pi of approximately 9.5. the acidic proteases show optimum activity at ph 8 and require a divalent metal ion (eg. ca) to maintain structural integrity. in the presence of edta or conditions that cause protein unfolding, the proteases undergo rapid and complete autolysis ...	1994	7696989
a retrospective study of clinical and laboratory characteristics of ovine footrot.	the infection of the feet of sheep by the anaerobic bacterium dichelobacter nodosus results in a spectrum of diseases ranging from virulent through intermediate to benign footrot. by examining the clinical characteristics of various forms of footrot from 22 properties in victoria, australia in association with the results of several laboratory tests including the gene probe-based dot blot hybridisation, it was shown that virulent footrot could not be differentiated from intermediate footrot usin ...	1994	9133062
disease resistance in merino sheep. iii. genetic variation in resistance to footrot following challenge and subsequent vaccination with an homologous rdna pilus vaccine under both induced and natural conditions.	summary: eight traits representing clinical indicators of resistance to footrot were examined in 1562 merino sheep, representing the progeny from 162 sires in four major bloodlines. over a 4-year period, sheep were exposed to virulent isolates of dicbelobacter nodosus under both an experimental challenge in which footrot was induced, and a separate natural challenge involving a different isolate of d. nodosus. five footrot traits and three healing traits were each recorded on seven occasions fol ...	1994	21395787
recombinant vaccines against ovine footrot.	for the past 20 years footrot vaccines have evolved from simple bacterins to highly specific recombinant dna (rdna) fimbrial vaccines. the development of these vaccines has left a trail of discoveries, challenges and solutions; these processes continue as we move closer to understanding the requirements of a footrot vaccine. the initial whole cell vaccines were unsuccessful due to the short duration of immunity and incorporation of limited serotypes. a multistrain vaccine eliminated the problem ...	1993	7505770
detection of dichelobacter nodosus using species-specific oligonucleotides as pcr primers.	dichelobacter nodosus is an essential causative agent of ovine footrot, a disease of major economic significance. four oligonucleotides complementary to variable regions of the 16s rrna of d. nodosus were identified, synthesized and tested for their specificity and sensitivity as probes for the detection of d. nodosus. in hybridization reactions using total rna as the target nucleic acid, three probes were found to be both sensitive and species-specific. when these probes were used as primers in ...	1993	7689774
a gelatin test to detect activity and stability of proteases produced by dichelobacter (bacteroides) nodosus.	previously reported tests to distinguish thermostable and thermolabile proteases of dichelobacter nodosus used hide powder azure as a test substrate. this paper describes an alternative test for protease stability using gelatin, an inexpensive and convenient substrate. the test required less equipment and time than the hide powder tests, and simplified the testing of multiple samples. proteases from 2965 isolates of d. nodosus from samples collected as part of a footrot eradication scheme were t ...	1993	8236773
cloning, sequence and expression of the gene (aprv5) encoding extracellular serine acidic protease v5 from dichelobacter nodosus.	the acidic protease v5-encoding gene (aprv5) from gram- dichelobacter nodosus virulent strain 198 was isolated from a cosmid bank by activity screening and sequenced. the 2371-bp nucleotide (nt) sequence contained an open reading frame coding for a protein precursor of 595 amino acid (aa) residues composed of a signal peptide, a pro-region, a mature active protease of 347 aa and a c-terminal extension region of 120 aa. the deduced aa sequence of the pre-pro-mature protease regions showed about 6 ...	1993	8299956
amino acid sequence of extracellular acidic protease v5 of dichelobacter nodosus, the causative organism of ovine footrot.	dichelobacter nodosus, a gram-negative obligate anaerobe and the causative organism of ovine footrot, secretes a family of extracellular serine proteases with pi's in the range of 5.2 to 5.6 and a serine basic protease with a pi of approximately 9.5. the primary structure of acidic protease v5 (pi approximately 5.2) from d. nodosus virulent strain 198 was determined by direct amino acid sequencing. this protease consists of a single polypeptide chain of 347 amino acids, contains two disulfide bo ...	1993	8330022
use of a gram- signal peptide for protein secretion by gram+ hosts: basic protease of dichelobacter nodosus is produced and secreted by bacillus subtilis.	the bprv gene, encoding the extracellular basic protease of the gram- anaerobic bacterium dichelobacter nodosus, was expressed and the protein secreted in bacillus subtilis using the novel cloning/expression vector pnc3 [wu et al., gene 106 (1991) 103-107]. the pre- and pro-peptides were processed correctly in this heterologous system, and the 127-amino acid c-terminal extension region was also removed. the recombinant gene product was indistinguishable biochemically or immunochemically from the ...	1993	8370546
use of elastase test, gelatin gel test and electrophoretic zymogram to determine virulence of dichelobacter nodosus isolated from ovine foot rot.	a comparative study using the elastase test, gelatin gel test and electrophoretic zymogram was conducted for virulence determination of 96 dichelobacter nodosus isolates from clinical cases of ovine foot rot. despite being time consuming, the elastase test provided a classification of d nodosus bacteria in general agreement with the severity of clinical characteristics. the gelatin gel test showed some correlation with the elastase test. while isolates showing elastase activity at 14 days or les ...	1993	8378606
benign footrot--an epidemiological investigation into the occurrence, effects on production, response to treatment and influence of environmental factors.	benign footrot was studied in 1 1/2-years-old merinos on 2 farms in central victoria from september 1987 to august 1990, inclusive. treatment groups of 100 sheep grazed together with the remaining untreated sheep. inspections were carried out every 3 weeks during the spring transmission period until the number of lesions greater than score 2 dropped below 3%. at each inspection, each sheep was weighed and lesion scores for each foot and digit were recorded, the treated group of sheep was treated ...	1993	8460991
the effects of antigenic competition on the efficacy of multivalent footrot vaccines.	a multivalent footrot vaccine has been developed, containing pilus antigens produced in recombinant pseudomonas aeruginosa and representing all nine serogroups of dichelobacter (bacteroides) nodosus commonly recognised in the field. the responses of sheep to the multivalent vaccine have been compared with those to monovalent vaccines representing only a single serogroup. antigenic competition between serogroups occurred in sheep immunised with the multivalent formation, but high levels of protec ...	1993	8098601
dichelobacter nodosus: differentiation of virulent and benign strains by gene probe based dot blot hybridisation.	gene probes specific for benign and virulent strains of dichelobacter nodosus were used in a dot blot hybridisation procedure involving 96 strains of d. nodosus isolated from cases of ovine footrot. the performance of the probes was compared with that of the elastase test. all 27 strains with elastase activity at 7 days and 12 of 25 strains with elastase activity at 14 days reacted with the virulent-specific probe. twenty-four strains with elastase activity between 21-28 days, and 20 strains wit ...	1993	8128604
humoral responses to a multivalent vaccine in age-matched lambs of different bodyweight and nutrition.	k-agglutination, pilus-enzyme-linked immunosorbent assay (elisa) and outer membrane protein-elisas were used to assess humoral responses after vaccination with a commercial, multivalent, ovine foot rot vaccine (dichelobacter nodosus whole cells) in three groups of nine-month-old lambs of markedly different bodyweight, nutritional history and dietary protein supply. mean bodyweights of lambs in low (l), medium (m) and high (h) bodyweight/nutrition groups were 22, 32 and 48 kg, respectively, at th ...	1992	1352408
molecular characterization of a genomic region associated with virulence in dichelobacter nodosus.	the major pathogen implicated in footrot, a highly contagious disease of sheep, is the strict anaerobe dichelobacter nodosus (formerly bacteroides nodosus). sequence analysis of a 2,262-bp segment of the d. nodosus genome which is more prevalent in virulent isolates than in other isolates showed the presence of four open reading frames which appeared to have consensus transcriptional and translational start signals. these virulence-associated genes have been designated vapabcd. two of the three ...	1992	1398971
amino acid and dna sequences of an extracellular basic protease of dichelobacter nodosus show that it is a member of the subtilisin family of proteases.	a dna fragment encoding an extracellular basic protease (pi approximately 9.5) from dichelobacter nodosus, a gram-negative obligate anaerobe and the causative agent of ovine footrot, has been cloned and expressed in escherichia coli and sequenced. e. coli harbouring a plasmid with a 3-kb dna fragment containing the d. nodosus basic-protease gene exhibited proteolytic activity when tested on skim-milk plates. the sequence of the native basic protease isolated from d. nodosus was also determined b ...	1992	1446666
evaluation of a simple method for improving the precision of an elisa detecting antibody in serum.	a method of correcting od values to improve between-assay precision (pcf4 method) was evaluated using an elisa detecting anti-dichelobacter nodosus antibody in ovine serum. four control sera with pre-defined target od were included on each plate and used to calculate a correction factor. the mean between-plate cv for eight reference sera tested over a period of 6 months was reduced from 15.2% to 9.4% in a polyclonal conjugate assay (114 plates) and from 13.3% to 9.8% in a monoclonal conjugate as ...	1992	1564335
sequence of fimbrial subunit-encoding genes from virulent and benign isolates of dichelobacter (bacteroides) nodosus.	both virulent and benign isolates of the ovine pathogen dichelobacter (bacteroides) nodosus produce polar fimbriae which have been implicated in twitching motility. the fimbrial subunit-encoding genes from two virulent and two benign serogroup-b isolates of d. nodosus were cloned and sequenced. analysis of the deduced amino acid (aa) sequences of these subunits indicated the presence of substitutions that appeared to correlate with the virulence phenotype. however, these aa substitutions were lo ...	1991	1673665
shared antigenicity and immunogenicity of type 4 pilins expressed by pseudomonas aeruginosa, moraxella bovis, neisseria gonorrhoaea, dichelobacter nodosus, and vibrio cholerae.	immunoblotting with polyclonal rabbit antibodies raised against pilins expressed by pseudomonas aeruginosa, moraxella bovis, neisseria gonorrhoeae, dichelobacter nodosus, and vibrio cholerae was used to demonstrate that these polypeptides display conserved antigenic and, in most cases, immunogenic determinants. these determinants appear to be localized to the highly homologous amino-terminal domains (residues 1 to 25).	1991	1682267
identification of three gene regions associated with virulence in dichelobacter nodosus, the causative agent of ovine footrot.	dichelobacter nodosus (formerly bacteroides nodosus) is a gram-negative strict anaerobe and is the primary pathogen involved in ovine footrot. a comparative hybridization strategy was used to isolate recombinant clones which hybridized to dna from a virulent strain of d. nodosus but not with a benign isolate. three virulence-associated gene regions were identified and one of these regions was shown to be present in multiple copies in the d. nodosus genome. hybridization studies on 101 clinical i ...	1991	1748867
the type 4 pilin of moraxella nonliquefaciens exhibits unique similarities with the pilins of neisseria gonorrhoeae and dichelobacter (bacteroides) nodosus.	moraxella nonliquefaciens is a bacterium which is part of the normal flora of the human upper respiratory tract and is an occasional cause of disease. using a previously cloned type 4 pilin gene (tfpq) from moraxella bovis as a hybridization probe, we have cloned an 826 bp sau3 ai fragment which contains an m. nonliquefaciens type 4 pilin gene (tfpa) from strain nctc 7784. the pilin gene is expressed in escherichia coli. we have examined nctc 7784 and nine other m. nonliquefaciens strains by gen ...	1991	1770363
transfer of kingella indologenes (snell and lapage 1976) to the genus suttonella gen. nov. as suttonella indologenes comb. nov.; transfer of bacteroides nodosus (beveridge 1941) to the genus dichelobacter gen. nov. as dichelobacter nodosus comb. nov.; and assignment of the genera cardiobacterium, dichelobacter, and suttonella to cardiobacteriaceae fam. nov. in the gamma division of proteobacteria on the basis of 16s rrna sequence comparisons.	the 16s rrna sequences of kingella indologenes, cardiobacterium hominis, and bacteroides nodosus were determined by direct rna sequencing, using a modified sanger method. sequence comparisons indicated that these three species represent a novel family in the gamma division of proteobacteria. on the basis of these data, k. indologenes and b. nodosus cannot retain their current generic status as they are not closely related to other members of their assigned genera. therefore, we propose transfer ...	1990	2275858