| 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 |
| immunoblot and ultrastructural analysis of antigens extracted from dichelobacter nodosus with potassium thiocyanate. | the antigens extracted from dichelobacter nodosus with potassium thiocyanate were analyzed by western blotting with sera from footrot-free sheep and from sheep infected with d. nodosus to identify components specific for infection. several components with molecular mass < 33 kd were associated with infection, particularly bands of 32.5 kd, 30.5 kd, and 28 kd. components with molecular mass > 56 kd may be responsible for false-positive reactions observed when sera of footrot-free sheep react with ... | 1996 | 8844574 |
| assessment of gelatin gel and elastase tests for detection of protease activity of dichelobacter nodosus isolates from ovine footrot. | protease tests (the gelatin gel protease thermostability test, the elastase test or both) were performed on 4296 isolates of dichelobacter nodosus derived from 452 outbreaks of ovine footrot occurring in new south wales. both tests showed a high level of repeatability. in the gelatin gel test, culture broths were heated for 16 min at 66.8 degrees c. heated broths containing thermostable protease digested gelatin (positive gelatin gel test) while those broths containing thermolabile protease fail ... | 1996 | 8870192 |
| comparison of gene probe and conventional methods for the differentiation of ovine footrot isolates of dichelobacter nodosus. | in a collaborative study that involved four australian veterinary diagnostic laboratories a gene probe test based on the recombinant plasmids pjir318, pjir314b, and pjir313, which contain genomic vap or vrl regions, was compared with conventional tests used for the differential diagnosis of ovine footrot. a total of 771 clinical dichelobacter nodosus isolates were tested and designated as belonging to one of several gene probe categories. the results showed that 87% of the virulent isolates belo ... | 1996 | 8914257 |
| 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 |
| identification, purification, and characterization of the type 4 fimbriae of pasteurella multocida. | the presence of fimbriae on pasteurella multocida has been reported, but there have been no prior studies aimed at conclusively characterizing these structures. we now report on the identification and characterization of type 4 fimbriae on serogroup a, b, and d strains of p. multocida. under microaerophilic conditions p. multocida showed an increased expression of the fimbriae, which were observed to form bundles. fimbriae purified by high-performance reverse-phase liquid chromatography constitu ... | 1997 | 8975936 |
| effect of adjuvants on antibody responses of sheep immunised with recombinant pili from dichelobacter nodosus. | to compare the effects of two oil emulsion adjuvants (incomplete freunds adjuvant and a proprietary oil adjuvant), deae-dextran, l-tyrosine particles and quil a on the humoral immune responses of sheep immunised with recombinant pili of dichelobacter nodosus (strain a). | 1996 | 9006863 |
| physical and genetic map of the chromosome of dichelobacter nodosus strain a198. | a physical map of the chromosome of dichelobacter nodosus strain a198 was constructed using the restriction endonucleases eagi and stui. mapping data indicated the presence of a single, circular chromosome of 1.54 mb. the three rrna operons and the virulence related locus (vrl) were precisely positioned at the junctions of eagi and stui fragments, and their transcriptional orientations were also determined. other d. nodosus genes were assigned to specific eagi and stui fragments. analysis of the ... | 1997 | 9031642 |
| analysis of sequences flanking the vap regions of dichelobacter nodosus: evidence for multiple integration events, a killer system, and a new genetic element. | dichelobacter nodosus is the causative agent of ovine footrot. the vap regions of the d. nodosus genome may have arisen by the integration of a genetic element and may have a role in virulence. the virulent d. nodosus strain a198 has multiple copies of the vap regions. in the present study, sequences to the left and right of vap regions 1, 2 and 3 of strain a198 were analysed by southern blotting and dna sequencing. the results suggest that vap regions 1 and 2 rose by independent integration eve ... | 1997 | 9043132 |
| antigens for serological diagnosis of ovine footrot. | an antigen extracted from dichelobacter nodosus with potassium thiocyanate (kscn) is currently used in enzyme-linked immunosorbent assay (elisa) for serological diagnosis of ovine footrot, but the test lacks specificity in mature sheep. other antigens were therefore evaluated for use in this test. structural components of the cell envelope of d. nodosus including outer membrane, cytoplasmic membrane, lipopolysaccharide and pilus and extracellular proteases were purified from cultured d. nodosus ... | 1997 | 9100327 |
| improved laboratory diagnosis of ovine footrot: an update. | ovine footrot is a complex clinical disease syndrome primarily resulting from infection by the anaerobic bacterium dichelobacter nodosus. in order to aid clinical diagnosis, various laboratory tests based on the detection and measurements of phenotypic properties of d. nodosus have been developed for genus-specific detection as well as virulence determination. however, these tests are generally time-consuming, and tend to be variable with external factors that affect the growth and metabolism of ... | 1997 | 9125362 |
| 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 |
| high-level genetic diversity in the vapd chromosomal region of helicobacter pylori. | helicobacter pylori isolates from different patients are characterized by diversity in the nucleotide sequences of individual genes, variation in genome size, and variation in gene order. genetic diversity is particularly striking in vacuolating cytotoxin (vaca) alleles. in this study, five open reading frames (orfs) were identified within a 4.2-kb region downstream from vaca in h. pylori 60190. one of these orfs was closely related to the virulence-associated protein d (vapd) gene of dichelobac ... | 1997 | 9139899 |
| plasmid maintenance functions of the large virulence plasmid of shigella flexneri. | the large virulence plasmid pmysh6000 of shigella flexneri contains a replicon and a plasmid maintenance stability determinant (stb) on adjacent sali fragments. the presence of a repfiia replicon on the sali c fragment was confirmed, and the complete sequence of the adjacent sali o fragment was determined. it shows homology to part of the transfer (tra) operon of the f plasmid. stb stabilizes a partition-defective p1 miniplasmid in escherichia coli. a 1.1-kb region containing a homolog of the f ... | 1997 | 9171415 |
| ulcerative pododermatitis in free-ranging african elephant (loxodonta africana) in the kruger national park. | the occurrence of severe lameness in adult african elephant bulls in a shrub mopane (colophospermum mopane) ecosystem was investigated. large ulcers in the soles of at least one front foot were seen in each of the recorded cases. microscopically, the lesion can be described as a severe, chronic-active, ulcerative, bacterial pododermatitis (complicated by hypersensitivity/septic vasculitis). a variety of bacteria were isolated from these lesions as well as from regional lymph nodes. streptococcus ... | 1997 | 9204500 |
| post-translational modifications of meningococcal pili. identification of common substituents: glycans and alpha-glycerophosphate--a review. | neisseria meningitidis elaborate filamentous adhesins, pili or fimbriae, which belong to the type-4 structural group of pili also found on other bacterial pathogens such as neisseria gonorrhoeae, pseudomonas aeruginosa, moraxella bovis and dichelobacter nodosus. meningococcal pili readily undergo structural variations which arise as a result of inter- and intra-genomic recombinational events. structural variations often result in variations in bacterial adhesion mediated by pili. studies on stru ... | 1997 | 9224884 |
| complementation analysis of the dichelobacter nodosus fimn, fimo, and fimp genes in pseudomonas aeruginosa and transcriptional analysis of the fimnop gene region. | the causative agent of ovine footrot, the gram-negative anaerobe dichelobacter nodosus, produces polar type iv fimbriae, which are the major protective antigens. the d. nodosus genes fimn, fimo, and fimp are homologs of the pseudomonas aeruginosa fimbrial assembly genes, pilb, pilc, and pild, respectively. both the pild and fimp genes encode prepilin peptidases that are responsible for cleavage of the leader sequence from the immature fimbrial subunit. to investigate the functional similarity of ... | 1998 | 9423871 |
| serological classification and virulence determination of dichelobacter nodosus isolated from alberta and british columbia sheep. | ovine footrot is a contagious disease of sheep that occurs in temperature climates. it is caused by the strict anaerobe, dichelobacter nodosus. benign and virulent organisms are differentiated according to serotype and protease production. this study was conducted to identify the presence of virulent serotypes of d. nodosus in sheep flocks in alberta and british columbia. dichelobacter nodosus was detected in lame sheep from 11 of 15 (73%) flocks in alberta and in 4 of 5 (80%) british columbia f ... | 1998 | 9442937 |
| aetiology of ovine footrot in spain. | four hundred and sixty strains of obligate anaerobes were isolated from 216 cases of ovine foot rot distributed throughout spain. the predominant species was dichelobacter nodosus, which was isolated in 168 cases (77.8 per cent). a higher proportion of the strains of d nodosus than of the other strains had elastolytic activity, 118 of the 168 strains degrading elastin. species belonging to the genus prevotella were isolated from 96 cases (44.4 per cent). serotyping of the d nodosus strains showe ... | 1998 | 9481841 |
| severity and persistence of footrot in merino sheep experimentally infected with a protease thermostable strain of dichelobacter nodosus at five sites. | to test the hypothesis that ovine footrot associated with a thermostable protease strain of dichelobacter nodosus undergoes self cure or is sustained as an annually recurring disease, depending on the environment. | 1998 | 9578765 |
| purification and characterization of a putative fimbrial protein/receptor of porphyromonas gingivalis. | porphyromonas gingivalis has been implicated as a major aetiological agent in certain forms of periodontal disease, p. gingivalis is a gram-negative, asaccharolytic bacterium that obtains energy from the fermentation of amino acids derived from the hydrolysis of host protein. virulence factors of this bacterium include the capsule, fimbrial adhesins, cytotoxins and extracellular hydrolytic enzymes. a 43 kda fimbrillin from p. gingivalis has been isolated and characterized. however, there is evid ... | 1998 | 9612983 |
| biodegradable implants for the delivery of veterinary vaccines: design, manufacture and antibody responses in sheep. | biodegradable implants made from cholesterol and lecithin (c:l) were used to deliver a recombinant antigen (recombinant dichelobacter nodosus pili) and adjuvant (quil a) to sheep. implants (5.5- x 1.8-mm) were placed subcutaneously and compared to a conventional vaccination regime (2 injections, 4 weeks apart) for antibody responses and tissue compatibility. release profiles of antigen and adjuvant were also studied in vitro and in vivo. the presence of quil a in vaccine implants had a marked ef ... | 1998 | 9685925 |
| the gene for toxic shock toxin is carried by a family of mobile pathogenicity islands in staphylococcus aureus. | tst, the gene for toxic shock syndrome toxin-1 (tsst-1), is part of a 15.2 kb genetic element in staphylococcus aureus that is absent in tsst-1-negative strains. the prototype, in rn4282, is flanked by a 17 nucleotide direct repeat and contains genes for a second possible superantigen toxin, a dichelobacter nodosus vape homologue and a putative integrase. it is readily transferred to a reca recipient, and it always inserts into a unique chromosomal copy of the 17 nucleotide sequence in the same ... | 1998 | 9720870 |
| identification and characterisation of serogroup m among nepalese isolates of dichelobacter nodosus, the transmitting agent of footrot in small ruminants. | one thousand and sixty three isolates of dichelobacter nodosus cultured between 1992 and 1996 from cases of footrot in sheep and goats of migratory flocks of nepal were characterised by agglutination test using prototype antisera of the australian classification system. of those, sixty six isolates could not be classified into any of the nine serogroups (a-i). this study was therefore undertaken to characterise these isolates. it was established that they were agglutinated by antiserum against s ... | 1998 | 9791869 |
| molecular analysis of dichelobacter nodosus isolated from footrot in sheep in malaysia. | pulsed field gel electrophoresis analysis of genomic dna was used to investigate genetic diversity among dichelobacter nodosus from footrot in sheep in malaysia. twelve dichelobacter nodosus strains isolated from lesion materials from infected sheep were confirmed as dichelobacter nodosus by polymerase chain reaction technique using the species-specific dichelobacter nodosus 16s rna sequence ac and c as primers. pulsed field gel electrophoresis banding profiles using restriction enzymes apai (5' ... | 1998 | 9791871 |
| electroporation-mediated transformation of the ovine footrot pathogen dichelobacter nodosus. | studies on the potential virulence genes of the ovine footrot pathogen dichelobacter nodosus have been hindered by the lack of a genetic system for this organism. in an attempt to accomplish the transformation of d. nodosus cells, we constructed a plasmid that contained part of a native d. nodosus plasmid and carried a tetracycline resistance gene that was located between the d. nodosus rrna promoter and terminator. this plasmid was used to transform several d. nodosus strains to tetracycline re ... | 1998 | 9868785 |
| isolation of spirochaetes from an incident of severe virulent ovine footrot. | | 1998 | 9921625 |
| analysis of the type 1 pilin gene cluster fim in salmonella: its distinct evolutionary histories in the 5' and 3' regions. | the type 1 pilin encoded by fim is present in both escherichia coli and salmonella natural isolates, but several lines of evidence indicate that similarities at the fim locus may be an example of independent acquisition rather than common ancestry. for example, the fim gene cluster is found at different chromosomal locations and with distinct gene orders in these closely related species. in this work we examined the fim gene cluster of salmonella, the genes of which show high nucleotide sequence ... | 1999 | 9973358 |
| identification and grouping of dichelobacter nodosus, using pcr and sequence analysis. | dichelobacter nodosus is the causative agent of ovine foot rot, a disease that is a constant economic burden for many western sheep ranches. vaccination is one method of treating foot rot. a higher and more specific immune response is observed when monovalent vaccines are used to treat foot rot, as compared to multivalent vaccines, which incorporate all 10 major new zealand d. nodosus serogroups. there is no single assay for specifically identifying and grouping d. nodosus for the purpose of inc ... | 1999 | 10024434 |
| complete nucleotide sequence of the 27-kilobase virulence related locus (vrl) of dichelobacter nodosus: evidence for extrachromosomal origin. | the vrl locus is preferentially associated with virulent isolates of the ovine footrot pathogen, dichelobacter nodosus. the complete nucleotide sequence of this 27.1-kb region has now been determined. the data reveal that the locus has a g+c content much higher than the rest of the d. nodosus chromosome and contains 22 open reading frames (orfs) encoding products including a putative adenine-specific methylase, two potential deah atp-dependent helicases, and two products with sequence similarity ... | 1999 | 10024571 |
| update on footrot in south-west germany. | 82 dichelobacter nodosus strains isolated from 9 footrot affected sheep flocks in south west germany were serotyped and tested for virulence. serovar b was present in all flocks, representing 64.4% of all isolated d. nodosus field strains. other serovares found were type a, c, e, g and h. virulent strains were identified in 5 flocks, while intermediate strains were isolated from all 9 flocks. all serological untypeable strains proved to be avirulent. based on these epidemiological findings the u ... | 1999 | 10085580 |
| a bacteriophage encoding a pathogenicity island, a type-iv pilus and a phage receptor in cholera bacteria. | the virulence properties of many pathogenic bacteria are due to proteins encoded by large gene clusters called pathogenicity islands, which are found in a variety of human pathogens including escherichia coli, salmonella, shigella, yersinia, helicobacter pylori, vibrio cholerae, and animal and plant pathogens such as dichelobacter nodosus and pseudomonas syringae. although the presence of pathogenicity islands is a prerequisite for many bacterial diseases, little is known about their origins or ... | 1999 | 10360577 |
| effectiveness of small workshops for improving farmers' knowledge about ovine footrot. | to determine sheep farmers' attitudes to and beliefs about ovine footrot, and to improve their knowledge about the diagnosis, control and eradication of this disease. | 1999 | 10376104 |
| eikenella corrodens phase variation involves a posttranslational event in pilus formation. | the human pathogen eikenella corrodens synthesizes type iv pili and exhibits a phase variation involving the irreversible transition from piliated to nonpiliated variants. on solid medium, piliated variants form small (s-phase), corroding colonies whereas nonpiliated variants form large (l-phase), noncorroding colonies. we are studying the molecular basis of this phase variation in the clinical isolate e. corrodens va1. a genomic fragment encoding the major type iv pilin was cloned from the s-ph ... | 1999 | 10400570 |
| transmission of virulent footrot between sheep and goats. | to determine the infectivity of ovine and caprine strains of dichelobacter nodosus for both sheep and goats. | 1999 | 10451731 |
| pcr-rflp of outer membrane proteins gene of dichelobacter nodosus: a new tool in the epidemiology of footrot. | currently only phenotypic epidemiological markers, serogrouping and virulence testing of dichelobacter nodosus, are available for investigating footrot outbreaks in small ruminants. these methods have limitations in tracing the source of infection. in this study, a genotypic marker, pcr-rflp of outer membrane protein gene, was used to characterize d. nodosus. the technique was evaluated in a controlled experiment involving two strains of bacteria. pcr-rflp was found to be highly specific in diff ... | 1999 | 10459657 |
| identification of a virulence-associated protein homolog gene and isra1 in a plasmid of riemerella anatipestifer. | riemerella anatipestifer is the causative agent of polyserositis of ducks and geese. we have previously reported that a 3.9-kb plasmid, pcfc1, carries protein genes (vapd1 and vapd2) that are similar to virulence-associated genes of other bacteria. in the present study, we report the complete sequence of a second plasmid of 5.6 kb, pcfc2. pcfc2 has a 28% g-c content and three large open reading frames (orfs). one of the orfs (designated asvapd1) encodes a polypeptide that shares 53.9, 53.9, 48.3 ... | 1999 | 10481080 |
| the site-specific integration of genetic elements may modulate thermostable protease production, a virulence factor in dichelobacter nodosus, the causative agent of ovine footrot. | the gram-negative anaerobe dichelobacter nodosus is the causative agent of footrot in sheep. the authors have previously characterized two genetic elements, the inta (vap) and intb elements, which integrate into the genome of d. nodosus. in the virulent strain a198 there are two copies of the inta element. one copy is integrated into the 3' end of the trna-sergcu gene, close to the aspartokinase (aska) gene, and the second copy is integrated into the 3' end of the trna-sergga gene, next to the p ... | 1999 | 10537206 |
| cloning, overexpression, and mutagenesis of the sporobolomyces salmonicolor aku4429 gene encoding a new aldehyde reductase, which catalyzes the stereoselective reduction of ethyl 4-chloro-3-oxobutanoate to ethyl (s)-4-chloro-3-hydroxybutanoate. | we cloned and sequenced the gene encoding an nadph-dependent aldehyde reductase (arii) in sporobolomyces salmonicolor aku4429, which reduces ethyl 4-chloro-3-oxobutanoate (4-cobe) to ethyl (s)-4-chloro-3-hydroxybutanoate. the arii gene is 1,032 bp long, is interrupted by four introns, and encodes a 37,315-da polypeptide. the deduced amino acid sequence exhibited significant levels of similarity to the amino acid sequences of members of the mammalian 3beta-hydroxysteroid dehydrogenase-plant dihyd ... | 1999 | 10583966 |
| genetic characterisation of protective vaccine responses in sheep using multi-valent dichelobacter nodosus vaccines. | protective vaccine responses to nine distinct serogroups of dichelobacter nodosus (serogroups a-i) can be readily measured by serogroup-specific k-agglutinating antibody titres. on the basis of a large quantitative genetic experiment (1200 progeny from 129 sire groups), it was shown that variation in antibody responses following vaccination with a multi-valent pilus antigen d. nodosus vaccine (serogroups a-i) is, in part, under genetic control and thus heritable. based on the genetic relationshi ... | 1999 | 10614512 |
| severe ovine foot disease. | | 1999 | 10619613 |
| extensive diversity in new zealand dichelobacter nodosus strains from infected sheep and goats. | footrot is a contagious bacterial disease of ruminants spread by the gram-negative, anaerobic organism, dichelobacter nodosus. it is endemic in new zealand and throughout sheep and goat farming regions of the world. using the polymerase chain reaction (pcr) to amplify fragments of the fimbrial gene (fima), d. nodosus was detected in 14 hoof scrapings, sampled from six farming regions within new zealand. dna sequencing revealed 15 strains covering eight serogroups on the new zealand farms. the pr ... | 2000 | 10665539 |
| type iv pilus genes pila and pilc of pseudomonas stutzeri are required for natural genetic transformation, and pila can be replaced by corresponding genes from nontransformable species. | pseudomonas stutzeri lives in terrestrial and aquatic habitats and is capable of natural genetic transformation. after transposon mutagenesis, transformation-deficient mutants were isolated from a p. stutzeri jm300 strain. in one of them a gene which coded for a protein with 75% amino acid sequence identity to pilc of pseudomonas aeruginosa, an accessory protein for type iv pilus biogenesis, was inactivated. the presence of type iv pili was demonstrated by susceptibility to the type iv pilus-dep ... | 2000 | 10735861 |
| identification and characterization of a native dichelobacter nodosus plasmid, pdn1. | the gram-negative anaerobe dichelobacter nodosus is the primary causative agent of ovine footrot, a mixed bacterial infection of the hoof. we report here the characterization of a novel native plasmid, pdn1, from d. nodosus. sequence analysis has revealed that pdn1 has a high degree of similarity to broad-host-range plasmids belonging, or related, to escherichia coli incompatibility group q. however, in contrast to these plasmids, pdn1 encodes no antibiotic resistance determinants, lacks genes e ... | 2000 | 10783302 |
| occurrence of different strains of dichelobacter nodosus in new clinical lesions in sheep exposed to footrot associated with multi-strain infections. | to investigate the occurrence of s1, u1 and t strains of dichelobacter nodosus in new clinical lesions in sheep exposed to footrot associated with multi-strain infections. | 2000 | 10840576 |
| novel fimbrial subunit genes of dichelobacter nodosus: recombination in vivo or in vitro? | polymerase chain reaction (pcr) was used to amplify the variable region of the fimbrial subunit encoding gene (fima) of dichelobacter nodosus from sheep and goats infected with footrot. two amplimers (designated x and y) generated single-strand conformation polymorphism (sscp) patterns different to those of previously identified serogroups and serotypes. dna sequencing revealed that these two fragments were novel. the upstream of x (nt 1-183) was identical to serotype m1 while its downstream (nt ... | 2000 | 10946146 |
| 3'overhangs influence pcr-sscp patterns. | | 2000 | 11084854 |
| fimw is a negative regulator affecting type 1 fimbrial expression in salmonella enterica serovar typhimurium. | type 1 fimbriae are proteinaceous surface appendages that carry adhesins specific for mannosylated glycoproteins. these fimbriae are found on most members of the family enterobacteriaceae and are known to facilitate binding to a variety of eukaryotic cells, including those found on the mucosal surfaces of the alimentary tract. we have shown that the regulation of type 1 fimbrial expression in salmonella enterica serovar typhimurium is controlled, in part, by the products of four genes found with ... | 2001 | 11133935 |
| vaccination against ovine footrot using a live bacterial vector to deliver basic protease antigen. | a strain of corynebacterium pseudotuberculosis, designated toxminus, that has been rationally attenuated by deletion of the phospholipase d gene, is being developed as a live vaccine vector for the delivery of veterinary vaccine antigens. in the present study a recombinant form of the basic protease gene of the ovine footrot causative bacterium, dichelobacter nodosus, was introduced into the vector strain using the high copy number plasmid pep2. this strain secreted the basic protease protein. v ... | 2001 | 11164307 |
| pilus elisa and an anamnestic test for the diagnosis of virulent ovine footrot and its application in a disease control program in nepal. | the immunological memory (anamnestic) responses in sheep recovered from virulent footrot (vfr) can be aroused by subcutaneous injection of outer membrane protein (omp) antigens of dichelobacter nodosus. the magnitude of this response is directly correlated to the highest antibody response attained during infection and memory lasts at least a year after recovery from vfr. however, some older animals show non-specific responses to omp antigens. in this study an evaluation of d. nodosus pilus antig ... | 2001 | 11230927 |
| pseudomonas stutzeri has two closely related pila genes (type iv pilus structural protein) with opposite influences on natural genetic transformation. | pseudomonas stutzeri has type iv pili for which the pila gene (here termed pilai) provides the structural protein and which are required for dna uptake and natural genetic transformation. downstream of pilai we identified a gene, termed pilaii, coding for a deduced protein with a size similar to that of pilai with 55% amino acid sequence identity and with a typical leader peptide including a leader peptidase cleavage site. fusions to lacz revealed that pilaii is expressed only about 10% compared ... | 2001 | 11244078 |
| dichelobacter nodosus serotype m fimbrial subunit gene: implications for serological classification. | dichelobacter nodosus fimbrial subunit gene (fima) from a serotype m strain (m-spahl) was investigated in this study. a primer set targeting the relatively conserved fima regions and based on the published sequence from nepalese serogroup m isolates (nepalese m), failed to amplify the fima of m-spahl. however, when the downstream primer was substituted with a primer that is specific for other serogroups of d. nodosus, the fima was successfully amplified. cloning followed by dna sequencing, revea ... | 2001 | 11267795 |
| rapid and accurate typing of dichelobacter nodosus using pcr amplification and reverse dot-blot hybridisation. | here we describe an approach to genotyping d. nodosus, based on variation in the fimbrial subunit gene (fima), which uses polymerase chain reaction (pcr) amplification and hybridisation to immobilised oligonucleotides (pcr/oligotyping). the variable region of d. nodosus fima, amplified and labelled with digoxigenin (dig) in a single multiplex pcr amplification, was hybridised to a panel of group- and type-specific poly-dt tailed oligonucleotides that were immobilised on a nylon membrane strip. a ... | 2001 | 11295335 |
| comparison of erythromycin and oxytetracycline for the treatment of ovine footrot. | a microbiological study of 25 cases of ovine footrot was performed. cultures belonging to dichelobacter nodosus were isolated in 48% of the sampled animals. the sensitivity of the 99 strict anaerobic bacterial isolates to 5 antibiotics (penicillin g, amoxycillin, spiramycin, erythromycin and oxytetracycline) was studied. the percentage of resistant cultures was in all cases higher than 30%. the efficacy of erythromycin and oxytetracycline in the treatment of ovine footrot was studied. to conduct ... | 2001 | 11402641 |
| the type iv fimbrial subunit gene (fima) of dichelobacter nodosus is essential for virulence, protease secretion, and natural competence. | dichelobacter nodosus is the essential causative agent of footrot in sheep. the major d. nodosus-encoded virulence factors that have been implicated in the disease are type iv fimbriae and extracellular proteases. to examine the role of the fimbriae in virulence, allelic exchange was used to insertionally inactivate the fima gene, which encodes the fimbrial subunit protein, from the virulent type g d. nodosus strain vcs1703a. detailed analysis of two independently derived fima mutants revealed t ... | 2001 | 11443078 |
| eradication of ovine footrot by repeated daily footbathing in a solution of zinc sulphate with surfactant. | to investigate the effect on ovine footrot of repeated daily footbathing in a solution of zinc sulphate with surfactant. | 2001 | 11491224 |
| evaluation of equine immunoglobulin specific for rhodococcus equi virulence-associated proteins a and c for use in protecting foals against rhodococcus equi-induced pneumonia. | to determine whether purified equine immunoglobulin specific for rhodococcus equi virulence-associated proteins a and c (vapa and vapc) can confer passive protection against r. equi-induced pneumonia in foals. | 2001 | 11497456 |
| fimz is a molecular link between sticking and swimming in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium produces two types of filamentous appendages on its surface. fimbriae mediate adherence to tissues and cells via receptor-specific interactions, and flagella are the organelles of motility. these appendages play a role in colonization and dissemination, respectively, from infected surfaces and may be important components of bacterial survival. increased expression of fimz in serovar typhimurium resulted in bacteria which were hyperfimbriated but were nonmo ... | 2002 | 11807085 |
| fimz binds the salmonella typhimurium fima promoter region and may regulate its own expression with fimy. | the fimz protein, an activator of fima production in salmonella typhimurium, acts in conjunction with fimy to facilitate the expression of type 1 fimbriae. the predicted amino acid sequence of fimz suggests that this protein may be a dna-binding protein related to bvga, a sensory regulator of virulence gene expression in bordetella pertussis. purification of fimz following overexpression of the protein by a strong inducible promoter and gel mobility shift assays confirm that fimz is a 25-kda pol ... | 2002 | 11911183 |
| genomic islands of dichelobacter nodosus. | | 2002 | 12012869 |
| characterization and expression of a novel porphyromonas gingivalis outer membrane protein, omp28. | we report the characterization of a porphyromonas gingivalis gene, designated omp28, encoding a protein that we have previously purified and characterized as a 28-kda outer membrane protein. the deduced amino acid sequence of the omp28 open reading frame displayed an outer membrane leader sequence and lipoprotein attachment site but did not exhibit any significant overall sequence identity with protein sequences in the databases. a small stretch of amino acids (19 residues) exhibits 50% sequence ... | 2002 | 12030966 |
| diagnosis of footrot in goats: application of elisa tests for response to antigens of dichelobacter nodosus. | goats are an important natural host for footrot and are infected with dichelobacter nodosus that have virulence characteristics similar to those of sheep strains. however, the humoral response of goats to d. nodosus antigens and the possibility of a serological diagnosis of footrot in goats have not been studied. with the aim of evaluating a diagnostic elisa test, we investigated the primary immune response of goats to experimental and natural infection, the memory response in recovered animals, ... | 2002 | 12052334 |
| eradication of virulent footrot from sheep and goats in an endemic area of nepal and an evaluation of specific vaccination. | programmes based on the identification and treatment of cases and the culling of animals refractory to treatment had failed to eradicate virulent footrot from two districts in the western region of nepal. from 1993 to 1996 vaccination against two endemic virulent strains of dichelobacter nodosus was tested for its potential to contribute to the eradication of footrot from the region. only sheep and goats which had been free of signs of footrot at three inspections at monthly intervals before the ... | 2002 | 12243270 |
| serogroup specific single and multiplex pcr with pre-enrichment culture and immuno-magnetic bead capture for identifying strains of d. nodosus in sheep with footrot prior to vaccination. | the identification of dichelobacter nodosus present in a flock is a prerequisite to specific (autogenous) vaccination. current methods of identification of the serogroup present in a population requires that the organisms be isolated, identified visually in mixed culture on streak plates, subcultured to purify and subjected to antigenic analysis. this process takes at least 3 to 4 weeks. this study describes the development of a simple and rapid serogroup specific pcr test for d. nodosus. a comm ... | 2002 | 12270270 |
| transformation-mediated serogroup conversion of dichelobacter nodosus. | dichelobacter nodosus is the essential causative agent of footrot in sheep. the type iv fimbriae of d. nodosus are required for virulence, are highly immunogenic and immunoprotective, and can be divided into 10 major serogroups. fimbrial variation has been postulated to have arisen because of genetic recombination within the fimbrial gene region perhaps as a means of evading the immune response invoked by infection. to show that antigenic variation in these fimbriae could occur after natural tra ... | 2003 | 12488080 |
| aetiology of ovine footrot in the portuguese region of alto alentejo. | in this work, we found it appropriate to carry out a study directed towards isolating and identifying the entailed microorganisms which trigger off footrot in sheep, placing special emphasis on the serotipification of the different dichelobacter nodosus species. with this goal in mind four flocks from the portuguese region of 'alto alentejo' were selected, all of them had one common feature: their main health problem was ovine footrot. we also set out to determine the elastolitic capacity of iso ... | 2003 | 12667188 |
| ovine periodontitis as a potential model for periodontal studies. cross-sectional analysis of clinical, microbiological, and serum immunological parameters. | : to investigate infection and host immunity patterns in sheep with naturally occurring "broken-mouth" periodontitis. | 2003 | 12702113 |
| clinical and radiographic findings in six cattle with cervical diskospondylitis. | | 2003 | 12790169 |
| contagious ovine digital dermatitis. | | 2003 | 12790246 |
| genome sequences of two closely related vibrio parahaemolyticus phages, vp16t and vp16c. | two bacteriophages of an environmental isolate of vibrio parahaemolyticus were isolated and sequenced. the vp16t and vp16c phages were separated from a mixed lysate based on plaque morphology and exhibit 73 to 88% sequence identity over about 80% of their genomes. only about 25% of their predicted open reading frames are similar to genes with known functions in the genbank database. both phages have cos sites and open reading frames encoding proteins closely related to coliphage lambda's termina ... | 2003 | 14563879 |
| failure to eradicate ovine footrot associated with dichelobacter nodosus strain a198 by repeated daily footbathing in zinc sulphate with surfactant. | to investigate the effect of repeated daily footbathing in zinc sulphate on virulent ovine footrot associated with s1, u1 and u5 zymogram types of dichelobacter nodosus, including the highly virulent s1 strain a198. | 2003 | 15084013 |
| eradication of footrot of lesser clinical severity (intermediate footrot). | to determine if intermediate footrot (ifr) can be eradicated from a flock of sheep by inspection and culling of cases during a non-transmission period and if prior antibiotic treatment or vaccination increases the likelihood of eradication. | 2003 | 15086111 |
| a 10-year comparison of endogenous endophthalmitis outcomes: an east asian experience with klebsiella pneumoniae infection. | to evaluate the infection sources and causative organisms in cases of endogenous endophthalmitis and review the outcomes for patients with klebsiella pneumoniae infection during a 10-year period. | 2004 | 15187660 |
| molecular detection and characterization of dichelobacter nodosus in ovine footrot in india. | dichelobacter nodosus was detected in three clinical cases of ovine footrot in kashmir, india. the detection was done by pcr in three clinical specimens directly, without isolating the organism, using species-specific 16s rdna primers. positive results were indicated by amplification of a 783 bp product. all the three samples were subjected to serogrouping by multiplex pcr using group (a-i) specific primers. all the three samples revealed the presence of serogroup b of d. nodosus by yielding a s ... | 2004 | 15294315 |
| minimum inhibitory concentrations for 25 selected antimicrobial agents against dichelobacter nodosus and fusobacterium strains isolated from footrot in sheep of portugal and spain. | the agar dilution method was used to determine the inhibitory activity of 25 antimicrobial agents against 69 strains of dichelobacter nodosus and 108 strains of the genus fusobacterium, all of which were isolated from 90 clinical cases of ovine footrot between october 1998 and november 2000. in the case of the micro-organisms belonging to the genus fusobacterium, the six beta-lactams studied (benzyl penicillin, ampicillin, cloxacillin, cefadroxil, cefuroxime and cephalexine) proved to be, in gen ... | 2004 | 15330985 |
| comparative study of biochemical methods for the identification of dichelobacter nodosus. | the aim of this study was to compare four identification procedures to detect dichelobacter nodosus and develop a rapid, simple and effective method to identify d. nodosus strains isolated from cases of ovine footrot. the four methods used were: (a) the classic guidelines set down by holdeman et al. (1977) and summanen et al. (1993) which are based on gas liquid chromatography (glc) and different biochemical tests, this method was considered as landmark; (b) baron and citron's flowchart for the ... | 2004 | 15379442 |
| effectiveness of different adjuvants in stimulating dichelobacter nodosus antibody in sheep vaccinated against ovine footrot. | this research consists of an evaluation of the effectiveness of different substances administered as adjuvants in the stimulation of humoral immune response induced by the vaccine composed of strains a1, a2 and c of dichelobacter nodosus. to do this, a total of 120 merino sheep were vaccinated and revaccinated. these sheep were selected from a farm located in the region of extremadura (spain), and they were divided into 12 groups of 10 animals each. an additional group with 10 sheep was used as ... | 2004 | 15379443 |
| identification of a dichelobacter nodosus ferric uptake regulator and determination of its regulatory targets. | the expression of iron regulated genes in bacteria is typically controlled by the ferric uptake regulator (fur) protein, a global transcriptional repressor that regulates functions as diverse as iron acquisition, oxidative stress, and virulence. we have identified a fur homologue in dichelobacter nodosus, the causative agent of ovine footrot, and shown that it complements an escherichia coli fur mutant. homology modeling of the d. nodosus fur protein with the recently solved crystal structure of ... | 2005 | 15601721 |
| comparative study of three surgical treatments for two forms of the clinical presentation of bovine pododermatitis. | in this study, 1013 animals showing signs of clinical pododermatitis were examined and divided into five unevenly numbered groups. affected animals in groups i and ii showed only signs of vegetative interdigital pododermatitis. the lesions were surgically removed and either protected with bandages (in group i) or cauterized with incandescent iron (group ii). the animals in groups iii, iv, and v, showed signs of necrotic pododermatitis. these were treated with different protocols after the necrot ... | 2004 | 15604479 |
| current approaches to the management of ovine footrot. | ovine footrot remains the most important cause of lameness in sheep flocks in the uk, despite the existence of proven methods for the control of the disease. recent research suggests that sheep farmers may be unaware of these methods and may allocate greater resources to treatment of footrot rather than to its prevention. foot paring, topical treatments, vaccination and parenteral antibiotic therapy all have a role in treating sheep with advanced footrot infections, but prevention of severe infe ... | 2005 | 15683762 |
| interaction of klebsiella oxytoca and burkholderia cepacia in dual-species batch cultures and biofilms as a function of growth rate and substrate concentration. | dual-species microbial interactions have been extensively reported for batch and continuous culture environments. however, little research has been performed on dual-species interaction in a biofilm. this research examined the effects of growth rate and substrate concentration on dual-species population densities in batch and biofilm reactors. in addition, the feasibility of using batch reactor kinetics to describe dual-species biofilm interactions was explored. the scope of the research was dir ... | 2005 | 15688257 |
| plasmid-borne florfenicol resistance in pasteurella multocida. | a florfenicol-resistant pasteurella multocida isolate from a calf was investigated for the genetic basis of florfenicol resistance and the location of the resistance gene. | 2005 | 15814600 |
| the detection and characterisation of dichelobacter nodosus from cases of ovine footrot in england and wales. | footrot, caused by the strictly anaerobic bacterium dichelobacter nodosus, is the most common cause of lameness in sheep in great britain but problems exist in association with its diagnosis and control. the fastidious nature of d. nodosus means that complex media and several weeks are required for characterisation. an alternative method to simplify and enhance the detection of d. nodosus in clinical samples is therefore highly desirable. in terms of control, anecdotal evidence from the farming ... | 2005 | 15917134 |
| the use of an autogenous dichelobacter nodosus vaccine to eliminate clinical signs of virulent footrot in a sheep flock in bhutan. | an outbreak of virulent footrot was investigated in a flock of 605 merino cross-bred sheep in bhutan. conventional control methods in the preceding eight years had reduced its prevalence from 36-79% in different components of the flock to about 15% overall. only one serogroup (b) of dichelobacter nodosus was identified among 40 isolates cultured from affected sheep. a vaccine prepared from this strain was used in a pilot trial to compare the response of 14 treated and 14 untreated sheep. all aff ... | 2006 | 16019243 |
| protection of sheep against experimental footrot by vaccination with pili purified from bacteroides nodosus. | merino sheep vaccinated with either whole bacteroides nodosus organisms, a crude surface antigen preparation or highly purified pili (>99% homogeneity) in oil adjuvant, developed significant resistance to artificial footrot infection when compared with unvaccinated control sheep inoculated with saline-in-oil emulsion (freund;s incomplete adjuvant) alone. the pili-vaccinated sheep generally had higher k-agglutinating antibody titres than sheep vaccinated with whole b. nodosus. these results confi ... | 1982 | 16030827 |
| duration of resistance to experimental footrot infection in romney and merino sheep vaccinated with bacteroides nodosus oil adjuvant vaccine. | groups of 10-12 romney and merino wethers were challenged simultaneously with homologous experimental footrot infection after having received the second of 2 doses of bacteroides nodosus (strain 198) vaccine 0, 4, 8, 12, 16 and 20 weeks previously. inoculations were carried out 28 days apart and unvaccinated sheep of both breeds were challenged as controls. most romneys that had been vaccinated up to 16 weeks prior to challenge were resistant to footrot whereas 8 of 10 controls were susceptible. ... | 1982 | 16030853 |
| failure of orally administered zinc to prevent experimentally induced footrot in sheep. | two groups of adult merino sheep, initially grazed on pasture, were dosed daily with zinc sulphate (1 mg zn/kg lw) or zinc oxide (15 mg zn/kg lw) for six and seven weeks, respectively. on the 18th day, both groups were transferred to indoor pens together with unmedicated control sheep, and five days later the feet of all animals were infected artificially with a virulent strain of bacteroides nodosus. by the fourth week after challenge, 85% or more of the feet challenged had developed advanced f ... | 1983 | 16030954 |
| isolation of bacteroides nodosus from hoof lesions in a farmed red deer (cervus elaphus). | | 1983 | 16030972 |
| field trials with a killed, nine-strain, oil adjuvanted bacteroides nodosus footrot vaccine in sheep. | field trials were set up on five properties to determine the cure and protection rates of a killed, nine-strain, oil adjuvanted bacteriodes nodosus footrot vaccine, under natural conditions. foot infections were scored at the time of the first vaccination and at approximately four weeks and ten weeks later. cure rates were 34-47% for vaccinated sheep, and 18-47% for untreated sheep. using the australian licensing authorities calculation, the cure rates for the vaccine ranged from -40% to 44%. a ... | 1984 | 16031080 |
| a method to differentiate between virulent and benign isolated of bacteroides nodosus based on the thermal stability of their extracellular proteinases. | a rapid modification of the hide powder azure proteinase degrading test was devised to distinguish between benign and virulent strains of bucteroides nodosus grown as cultures on either liquid or solid media. the assay was based on the difference in stability, at 60 degrees c, of the enzymes released in the growth medium. the assay can be completed in four hours. results for ovine virulent strains and their culture variants were similar and were clearly distinguishable from those of the ovine be ... | 1985 | 16031095 |
| the use of melatonin as a vaccine agent. | molecules with immunomodulatory properties determine the magnitude and quality of immune responses specific for the coadministered antigen. melatonin is considered a biological-response modifier of the immune system with broad application in veterinary medicine. in seasonally-breeding animals, the indolamine is able to improve reproductive performance. with the purpose of expanding new advantageous roles for melatonin, we investigated the effect of subcutaneous slow-release melatonin implants in ... | 2005 | 16055232 |
| update on ovine footrot in new zealand: isolation, identification, and characterization of dichelobacter nodosus strains [corrected]. | dichelobacter nodosus, a gram-negative strict anaerobe, is the essential causative agent of ovine footrot. despite its worldwide presence, the disease has significant economic impact in those sheep-farming countries with a temperate climate and moderate to high rainfall, such as new zealand (nz) and australia. in this study, we aimed to isolate, identify, and characterize as many d. nodosus strains as possible from nz farms by using polymerase chain reaction (pcr)-based technology. understanding ... | 2005 | 16280202 |
| the occurrence of treponemes in contagious ovine digital dermatitis and the characterisation of associated dichelobacter nodosus. | contagious ovine digital dermatitis (codd) is a recently recorded, apparently new infection of the ovine hoof, which differs clinically from footrot caused by dichelobacter nodosus and which fails to respond well to accepted treatment practices for footrot. despite the welfare implications of such an infection, very little research has been performed on codd to date and the aetiology remains confused. suggestions have been made that there is a potential role for treponemes in the pathogenesis of ... | 2005 | 16280206 |
| recent footrot outbreak in debrezeit swine farm, central ethiopia. | an outbreak of footrot has occurred in debrezeit swine farm that is located 44 km south east of the capital. among 24 pigs, 75% showed lameness, hot, painful and swollen feet, hemorrhagic bruising of the coronary band, heel erosion, sole ulcers and separation of skin from hoof on hind limbs. bacteriological examination of the specimen from the affected limbs has shown the involvement of staphylococcus, streptococcus and dichelobacter nodosus. the overt clinical lameness and inability to stand or ... | 2005 | 16294005 |
| distribution and prevalence of footrot in bhutan. | the first cases of footrot in bhutan were reported in sheep in 1990 at the national sheep breeding centre (nsbc), which supplies breeding animals to village sheep flocks throughout bhutan. despite the presence of footrot at the centre the distribution of apparently disease-free sheep continued. cases of footrot were reported in village flocks soon after the disease was diagnosed at nsbc. a national survey was designed to establish the distribution and prevalence of footrot in bhutan. this detect ... | 2006 | 16490719 |