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D J Hampson - One of the best experts on this subject based on the ideXlab platform.
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brachyspira catarrhinii sp nov an anaerobic intestinal spirochaete isolated from vervet monkeys may have been misidentified as brachyspira aalborgi in previous studies
Anaerobe, 2019Co-Authors: Nyree D. Phillips, D J HampsonAbstract:Abstract To date nine species of anaerobic intestinal Spirochaetes have been validly assigned to the genus Brachyspira. These include both pathogenic and non-pathogenic species. In the current study a genomic analysis of a novel spirochaete isolate was undertaken to determine whether it is a distinct species that previously has been misidentified as Brachyspira aalborgi. The genome of spirochaete strain Z12 isolated from the faeces of a vervet monkey was sequenced and compared to the genomes of the type strains of the nine assigned Brachyspira species. Genome to Genome Distance (GGD) values and Average Nucleotide Identity (ANI) values were determined. Single nucleotide polymorphisms (SNP) were used to create a phylogenetic tree to assess relatedness. The 16S rRNA gene sequences of the strains were aligned and the similarity amongst the Brachyspira species was recorded. Multilocus sequence typing (MLST) using five loci was conducted on Z12 and results compared with those for other Brachyspira isolates. Assembly of the Z12 sequences revealed a 2,629,108 bp genome with an average G + C content of 31.3%. The GGD, ANI, 16S rRNA gene sequence comparisons and the MLST results all indicated that Z12 represents a distinct species within the genus Brachyspira, with its nearest neighbour being B. aalborgi. Spirochaete strain Z12T was assigned as the type strain of a new species, Brachyspira catarrhinii sp. nov. The diagnostic PCR currently in use to detect B. aalborgi cross-reacts with Z12, but RFLP analysis of PCR product can be used to distinguish the two species. Previous reports of non-human primates being colonised by B. aalborgi based on PCR results may have been incorrect. The development of an improved diagnostic method will allow future studies on the distribution and possible clinical significance of these two anaerobic spirochaete species.
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development of a modified selective medium to enhance the recovery rate of brachyspira hyodysenteriae and other porcine intestinal Spirochaetes from faeces
Letters in Applied Microbiology, 2012Co-Authors: Kittitat Lugsomya, D J Hampson, Padet Tummaruk, Nuvee PrapasarakulAbstract:Aims: The aim of this study was to develop a modified selective medium to improve the recovery rate of Brachyspira hyodysenteriae and other clinically significant intestinal Spirochaetes from porcine faeces. Methods and Results: The susceptibility of five Brachyspira spp. type strains and five Thai field isolates of B. hyodysenteriae to the antimicrobials halquinol and flavomycin was determined by in vitro susceptibility tests in the agar dilution method, and optimal incorporation rates were confirmed by broth dilution. All the Spirochaetes were susceptible to halquinol at ≤1μgml -1, while 16μgml -1 of flavomycin (F) allowed their growth, and therefore, only the latter was selected for further use. F and different combinations of colistin (C), spectinomycin (S) and rifampacin (R) were incorporated into pre-enrichment broths and/or agar plates, and growth of the Spirochaetes from seeded faeces was determined. Two solid media were selected for further testing using faeces from 90 finishing pigs on 10 farms. A previously recommended method of pre-enrichment did not increase the recovery rate. The use of blood agar modified medium (BAM) containing F (16μgml -1), S (400μgml -1), R (30μgml -1) and colistin (C, 100Uml -1) (assigning as BAM-CSRF) reduced the growth of contaminating intestinal microbiota and resulted in a significantly higher rate of spirochaete recovery than the previous recommended medium. Conclusion: BAM-CSRF is a useful new selective medium for the isolation of B. hyodysenteriae and other intestinal Spirochaetes from pig faeces. Significance and Impact of the Study: The new selective medium for isolating B. hyodysenteriae and other Brachyspira spp. from pig faeces will improve their recovery and subsequent disease diagnosis.
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exposure to norepinephrine enhances brachyspira pilosicoli growth attraction to mucin and attachment to caco 2 cells
Microbiology, 2011Co-Authors: Ram Naresh, D J HampsonAbstract:Brachyspira pilosicoli is an anaerobic intestinal spirochaete that colonizes the large intestine of a variety of species of birds and mammals, including human beings. Colonization may result in a mild colitis and diarrhoea in a condition known as 'intestinal spirochaetosis'. The catecholamine norepinephrine (NE), which is known to influence the behaviour of many bacterial species, may be present in the colon. The purpose of the current study was to determine whether exposure of B. pilosicoli to NE would influence its in vitro behaviour in assays that may reflect in vivo colonization potential. B. pilosicoli strain 95/1000 was used in all the assays. Addition of NE at a concentration of 0.05 mM to B. pilosicoli growing in anaerobic broth significantly increased spirochaete numbers after 4 days incubation. The effect of higher concentrations of NE was not significant. Exposure to 0.05 mM NE, but not to higher concentrations, also resulted in significantly more spirochaete cells entering capillary tubes containing 4% porcine gastric mucin than occurred with untreated cultures. When NE was added to chemotaxis buffer in capillary tubes, significantly more Spirochaetes were attracted to the buffer containing NE at 0.1, 0.5 and 1.0 mM than to buffer containing 0.05 mM NE, or when no NE was added. Exposure of B. pilosicoli cultures to 0.05 mM NE prior to incubation with Caco-2 monolayers resulted in more attachment to the monolayer than occurred with non-exposed cultures. These results show that at higher concentrations, NE acts as a chemoattractant for B. pilosicoli, and at 0.05 mM it increases the spirochaete's growth rate, attraction to mucin and rate of attachment to cultured enterocytes. These activities are likely to enhance the ability of B. pilosicoli to colonize, and may be induced by conditions that increase NE concentrations in the intestinal tract, such as the stresses associated with crowding.
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comparison of prevalence and risk factors for faecal carriage of the intestinal Spirochaetes brachyspira aalborgi and brachyspira pilosicoli in four australian populations
Epidemiology and Infection, 2006Co-Authors: C J Brooke, Thomas V Riley, D J HampsonAbstract:This study examined the prevalence of the intestinal Spirochaetes Brachyspira aalborgi and Brachyspira pilosicoli in different Western Australian (WA) populations. Faecal samples included 287 from rural patients with gastrointestinal symptoms, comprising 142 from non-Aboriginal and 145 from Aboriginal people; 227 from recent healthy migrants to WA from developing countries; and 90 from healthy non-Aboriginal individuals living in Perth, WA. DNA was extracted from faeces, and subjected to PCR assays for both species. B. pilosicoli-positive individuals were confined to the rural Aboriginal (14·5%) and migrant (15·0%) groups. B. aalborgi was detected at a lower but similar prevalence in all four groups: rural non-Aboriginals, 5·6%; rural Aboriginals, 6·9%; migrants, 7·9%; controls, 5·6%. In migrants and Aborigines, the presence of B. pilosicoli and B. aalborgi was associated (P<0·001), suggesting that colonization by B. pilosicoli may be facilitated by colonization with B. aalborgi. Amongst the Aboriginal patients, logistic regression identified both spirochaete species as being associated with chronic diarrhoea, failure to thrive and being underweight. Both species may have pathogenic potential, but B. aalborgi appears more host-adapted than the opportunistic B. pilosicoli.
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a cross sectional study to investigate the occurrence and distribution of intestinal Spirochaetes brachyspira spp in three flocks of laying hens
Veterinary Microbiology, 2005Co-Authors: Nyree D. Phillips, D J HampsonAbstract:A cross-sectional study was conducted on a commercial egg-producing farm with a history of wet litter. A total of 600 fresh caecal faecal samples were obtained from under cages of laying hens in three sheds each containing flocks of ∼5400 hens. Samples were cultured for intestinal Spirochaetes, and growth on the primary isolation plate was observed under a phase contrast microscope and subjected to PCRs specific for the intestinal Spirochaetes Brachyspira intermedia and Brachyspira pilosicoli. Spirochaete isolates obtained in pure culture were assessed for their ability to cause haemolysis on blood agar and to produce indole, and were typed using pulsed field gel electrophoresis (PFGE). A 1250 base pair portion of the 16S rRNA gene of three B. intermedia and five unidentified isolates was sequenced, and the sequences compared with those of other Brachyspira species. Overall, 121 (20.2%) of the faecal samples contained Spirochaetes as determined by growth on the plate and microscopy. Using PCR on the primary growth from these positive samples, 43 (7.2% overall) were shown to contain B. intermedia, 8 (1.3%) to contain B. pilosicoli, and 70 (11.7%) were PCR negative. Only 24 isolates of B. intermedia and five isolates of unknown species were obtained in pure culture. Comparative analysis of the 16S rRNA gene sequence identified the non-B. intermedia isolates as belonging to the proposed species "Brachyspira pulli". PFGE analysis of the B. intermedia strains identified them as having four major banding patterns. Individual patterns were found in hens from different flocks, suggesting cross-transmission of strains between flocks. No environmental sources of infection were identified. The youngest flock had a significantly lower level of colonisation with B. intermedia than the flock of intermediate age (P = 0.004), suggesting that following initial infection of individual young hens on this farm there was amplification and transmission of infection amongst members of the flock.
David J. Hampson - One of the best experts on this subject based on the ideXlab platform.
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Anaerobic Spirochaetes and animals
Microbiology Australia, 2015Co-Authors: David J. Hampson, Nyree D. PhillipsAbstract:Anaerobic Spirochaetes colonise the large intestine of many avian and mammalian host species. The most well known pathogenic species is the strongly haemolytic Brachyspira hyodysenteriae that was first isolated from pigs with swine dysentery (SD) in the early 1970s. Classical SD is a severe mucohaemorrhagic colitis that occurs in growingpigs and is endemic in most pig-rearing areas of the world. The spirochaete acts in concert with other components of the colonic microbiota to disrupt the integrity of the colonic epithelium and induce inflammation. In recent years two new strongly haemolytic species, the proposed ‘Brachyspira suanatina’ and ‘Brachyspira hampsonii’, both with reservoirs in migratory water birds, have been described as new and emerging agents of SD in the northern hemisphere. Weakly haemolytic species also have been described, some of which have pathogenic potential. In particular Brachyspira pilosicoli causes a mild colitis and diarrhoea in many species, including human beings, whilst Brachyspira intermedia is a common pathogen in adult poultry. Infection with B. intermedia and/orB. pilosicoli can causewet litter, faecal staining of eggshells and delays in reaching peak egg production. Options for control of these widespread and economically significant anaerobic infections are limited.
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Development of a multiplex qPCR for detection and quantitation of pathogenic intestinal Spirochaetes in the faeces of pigs and chickens.
Veterinary microbiology, 2008Co-Authors: Yong Song, David J. HampsonAbstract:Anaerobic intestinal Spirochaetes of the genus Brachyspira include several important pathogenic species, particularly those infecting pigs and chickens. In this study a multiplex-quantitative polymerase chain reaction (M-qPCR) assay was developed based on amplification of a 198 base pair portion of the NADH oxidase gene, using TaqMan probes for detecting and quantifying the three main pathogenic species, B. hyodysenteriae, B. pilosicoli and B. intermedia. The specificity of the assay was validated using 130 spirochaete strains belonging to members of the seven officially named and two provisionally named Brachyspira species. The detection limit for all three targeted species was 1-10 viable cells and 10 fg DNA per reaction. Further detection limit testing was conducted on porcine and chicken faecal specimens that were spiked with spirochaete cells before DNA extraction. The assay could detect 10(2) to 10(3)cells per 0.2g of sample, giving an improved detection threshold compared to standard PCRs. The M-qPCR was further developed by incorporating a novel internal control (IC) that employed host cells as template DNA. This adaptation allowed monitoring of the quality of the extracted DNA and ensured that there was no inhibition of the PCR reaction. Use of the IC further improved the detection limits of the assay and increased confidence in being able to detect low numbers of pathogens in faecal samples. Taken together, the results indicate that the new M-qPCR assay is a valuable tool for detecting and quantifying low numbers of pathogenic intestinal Spirochaetes in the faeces of pigs and chickens, and potentially other species.
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Prevalence, disease associations and risk factors for colonization with intestinal Spirochaetes (Brachyspira spp.) in flocks of laying hens in north-eastern Italy
Avian pathology : journal of the W.V.P.A, 2008Co-Authors: Luca Bano, David J. Hampson, G. Merialdi, Paolo Bonilauri, G. Dall'anese, Katia Capello, D. Comin, G. Cattoli, V. Sanguinetti, Fabrizio AgnolettiAbstract:The present study investigated the occurrence of anaerobic intestinal Spirochaetes of the genus Brachyspira in laying hen flocks in Treviso province, north-eastern Italy, with respect to prevalence, spirochaete species present, disease associations and risk factors for colonization. A total of 450 faecal samples from 45 sheds on 29 laying hen farms were cultured for intestinal Spirochaetes. Nineteen sheds on 12 farms contained chickens with symptoms consistent with avian intestinal spirochaetosis, including reduced egg production, wet litter and/or pasty vents. Spirochaetes were isolated from 157 (34.8%) samples from 21 (72.4%) farms, and from 32 (71.1%) sheds. From these positive samples, 189 spirochaetal isolates were speciated using three polymerase chain reaction assays and a restriction fragment polymorphism analysis of 16S rDNA polymerase chain reaction products. Overall, 52 (27.5%) isolates were identified as pathogenic Brachyspira intermedia, 26 (13.8%) as pathogenic Brachyspira pilosicoli, 93 (49.7%) as non-pathogenic (Brachyspira innocens/Brachyspira murdochii), and 18 (9.6%) were unidentified. Faeces from 14 sheds (31%) on 10 farms (34.5%) contained B. intermedia and/or B. pilosicoli, and disease consistent with avian intestinal spirochaetosis was observed in nine of these sheds on seven farms. There was a significant association (P=0.042) between the presence of Spirochaetes and using deep pits rather than conveyor belts for manure disposal. Sheds housing chickens >40 weeks of age were significantly more likely to contain Spirochaetes (P=0.048) and pathogenic species (P=007) than sheds housing younger chickens. A significant association (P=0.02) was found between infection with pathogenic Spirochaetes and reduced egg production.
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Evaluation of blood culture systems for detection of the intestinal spirochaete Brachyspira (Serpulina) pilosicoli in human blood.
Journal of medical microbiology, 2000Co-Authors: C. Josephine Brooke, Thomas V Riley, K. Rini Margawani, Alayne K. Pearson, Ian D. Robertson, David J. HampsonAbstract:The anaerobic intestinal spirochaete Brachyspira (Serpulina) pilosicoli has been isolated from the bloodstream of French patients by manual blood culture systems. The purpose of this study was to determine whether the automated and manual blood culture systems used in Australia are suitable for growth and detection of this organism. Strains of B. pilosicoli were added to human blood to give concentrations ranging from 1×104 to 1×101 Spirochaetes/ml and 10-ml volumes were inoculated into the media. Three strains of B. pilosicoli grew slowly in all manual Hemoline and BBL Septi-Chek formulations tested. Subcultures taken between 2 and 10 days after inoculation yielded growth only after incubation for a further 5–8 days. Growth and automated detection were achieved in the BACTEC system with Anaerobic/F medium with or without Fastidious Organism Supplement. Minimum time to signal for nine strains varied between 5.6 and 14.9 days, with a minimum concentration of 101 Spirochaetes/ml of blood being detected. None of nine strains gave a positive signal in the BacT/Alert system when FAN Anaerobic culture bottles were used; however, four strains were detected by subculture taken at 7 or 14 days after inoculation. When Anaerobic medium was used in the BacT/Alert system, two of three strains gave a signal and the other strain grew and was detected by subculture. Spirochaetaemias caused by B. pilosicoli may be unrecognised because detection time by the signal or subculture exceeds 5 days.
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Prevalence and disease association of intestinal Spirochaetes in chickens in eastern Australia.
Avian pathology : journal of the W.V.P.A, 1999Co-Authors: C.p. Stephens, David J. HampsonAbstract:Faecal samples (n = 1786) from chickens in broiler breeder (n = 28), layer (n = 22) or broiler (n = 19) flocks in the eastern states of Australia were cultured for intestinal Spirochaetes. Overall, birds in 42.9% of broiler breeder and 68.2% of layer flocks were colonized with Spirochaetes, but no birds in broiler flocks were infected. Colonization rates in infected flocks ranged from 10 to 100% of birds sampled. Faeces from colonized flocks were on average 14% wetter than those from non-colonized flocks. There was a highly significant association between colonization with Spirochaetes and the occurrence of wet litter and/or reduced production. A subset of 57 spirochaete isolates from birds in 16 flocks were identified to the species level using a panel of polymerase chain reaction tests. Isolates from nine (56%) of these flocks were Spirochaetes that are known to be pathogens of poultry: Serpulina pilosicoli was isolated from birds from five flocks, birds from two flocks were infected with Serpulina intermedia, and in two other flocks both species were identified. Isolates from the other seven flocks belonged to other Serpulina species, which are currently of unknown pathogenicity. This study indicates that infections with intestinal Spirochaetes are a common but currently under-diagnosed cause of wet litter and/or reduced egg production in broiler breeder and layer flocks in Australia.
Nyree D. Phillips - One of the best experts on this subject based on the ideXlab platform.
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brachyspira catarrhinii sp nov an anaerobic intestinal spirochaete isolated from vervet monkeys may have been misidentified as brachyspira aalborgi in previous studies
Anaerobe, 2019Co-Authors: Nyree D. Phillips, D J HampsonAbstract:Abstract To date nine species of anaerobic intestinal Spirochaetes have been validly assigned to the genus Brachyspira. These include both pathogenic and non-pathogenic species. In the current study a genomic analysis of a novel spirochaete isolate was undertaken to determine whether it is a distinct species that previously has been misidentified as Brachyspira aalborgi. The genome of spirochaete strain Z12 isolated from the faeces of a vervet monkey was sequenced and compared to the genomes of the type strains of the nine assigned Brachyspira species. Genome to Genome Distance (GGD) values and Average Nucleotide Identity (ANI) values were determined. Single nucleotide polymorphisms (SNP) were used to create a phylogenetic tree to assess relatedness. The 16S rRNA gene sequences of the strains were aligned and the similarity amongst the Brachyspira species was recorded. Multilocus sequence typing (MLST) using five loci was conducted on Z12 and results compared with those for other Brachyspira isolates. Assembly of the Z12 sequences revealed a 2,629,108 bp genome with an average G + C content of 31.3%. The GGD, ANI, 16S rRNA gene sequence comparisons and the MLST results all indicated that Z12 represents a distinct species within the genus Brachyspira, with its nearest neighbour being B. aalborgi. Spirochaete strain Z12T was assigned as the type strain of a new species, Brachyspira catarrhinii sp. nov. The diagnostic PCR currently in use to detect B. aalborgi cross-reacts with Z12, but RFLP analysis of PCR product can be used to distinguish the two species. Previous reports of non-human primates being colonised by B. aalborgi based on PCR results may have been incorrect. The development of an improved diagnostic method will allow future studies on the distribution and possible clinical significance of these two anaerobic spirochaete species.
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Anaerobic Spirochaetes and animals
Microbiology Australia, 2015Co-Authors: David J. Hampson, Nyree D. PhillipsAbstract:Anaerobic Spirochaetes colonise the large intestine of many avian and mammalian host species. The most well known pathogenic species is the strongly haemolytic Brachyspira hyodysenteriae that was first isolated from pigs with swine dysentery (SD) in the early 1970s. Classical SD is a severe mucohaemorrhagic colitis that occurs in growingpigs and is endemic in most pig-rearing areas of the world. The spirochaete acts in concert with other components of the colonic microbiota to disrupt the integrity of the colonic epithelium and induce inflammation. In recent years two new strongly haemolytic species, the proposed ‘Brachyspira suanatina’ and ‘Brachyspira hampsonii’, both with reservoirs in migratory water birds, have been described as new and emerging agents of SD in the northern hemisphere. Weakly haemolytic species also have been described, some of which have pathogenic potential. In particular Brachyspira pilosicoli causes a mild colitis and diarrhoea in many species, including human beings, whilst Brachyspira intermedia is a common pathogen in adult poultry. Infection with B. intermedia and/orB. pilosicoli can causewet litter, faecal staining of eggshells and delays in reaching peak egg production. Options for control of these widespread and economically significant anaerobic infections are limited.
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a cross sectional study to investigate the occurrence and distribution of intestinal Spirochaetes brachyspira spp in three flocks of laying hens
Veterinary Microbiology, 2005Co-Authors: Nyree D. Phillips, D J HampsonAbstract:A cross-sectional study was conducted on a commercial egg-producing farm with a history of wet litter. A total of 600 fresh caecal faecal samples were obtained from under cages of laying hens in three sheds each containing flocks of ∼5400 hens. Samples were cultured for intestinal Spirochaetes, and growth on the primary isolation plate was observed under a phase contrast microscope and subjected to PCRs specific for the intestinal Spirochaetes Brachyspira intermedia and Brachyspira pilosicoli. Spirochaete isolates obtained in pure culture were assessed for their ability to cause haemolysis on blood agar and to produce indole, and were typed using pulsed field gel electrophoresis (PFGE). A 1250 base pair portion of the 16S rRNA gene of three B. intermedia and five unidentified isolates was sequenced, and the sequences compared with those of other Brachyspira species. Overall, 121 (20.2%) of the faecal samples contained Spirochaetes as determined by growth on the plate and microscopy. Using PCR on the primary growth from these positive samples, 43 (7.2% overall) were shown to contain B. intermedia, 8 (1.3%) to contain B. pilosicoli, and 70 (11.7%) were PCR negative. Only 24 isolates of B. intermedia and five isolates of unknown species were obtained in pure culture. Comparative analysis of the 16S rRNA gene sequence identified the non-B. intermedia isolates as belonging to the proposed species "Brachyspira pulli". PFGE analysis of the B. intermedia strains identified them as having four major banding patterns. Individual patterns were found in hens from different flocks, suggesting cross-transmission of strains between flocks. No environmental sources of infection were identified. The youngest flock had a significantly lower level of colonisation with B. intermedia than the flock of intermediate age (P = 0.004), suggesting that following initial infection of individual young hens on this farm there was amplification and transmission of infection amongst members of the flock.
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the wheat variety used in the diet of laying hens influences colonization with the intestinal spirochaete brachyspira intermedia
Avian Pathology, 2004Co-Authors: Nyree D. Phillips, J R Pluske, D J HampsonAbstract:This study investigated whether feeding different wheat varieties to laying hens could influence colonization with the intestinal spirochaete Brachyspira intermedia. Fifty ISA-Brown laying hens were divided into two groups. One group were fed a laying-hen diet formulated with wheat variety Westonia, and one were fed the diet incorporating variety Stilleto. Each group was divided into 15 hens experimentally infected with B. intermedia and 10 uninfected controls. The 30 infected hens were housed in individual cages in one room, and the controls were similarly housed in another room. Following administration of cultures of B. intermedia strain HB60 by crop-tube over 3 days, cloacal swabs were taken for spirochaete culture every 3 to 4 days. The water content of caecal faeces, and egg production and body weight were measured weekly. The hens were killed after 4 weeks, the caeca cultured for Spirochaetes and the viscosity of the ileal contents measured. A total of 48/120 (40%) of the excreta samples from infected hens fed Westonia contained B. intermedia, compared with 21/120 (17.5%) for Stiletto (P = 0.0002). The ileal viscosity of hens fed Westonia also was higher (P = 0.048), but viscosity was not clearly related to the non-starch polysaccharide (NSP) content of the wheats. Westonia had a slightly higher total NSP content than Stiletto, but the ratio of soluble to insoluble NSP was lower. Infected hens developed wetter excreta, but neither infection nor diet altered egg production. In conclusion, the wheat variety can influence colonization with B. intermedia, apparently through diet-related alterations in the intestinal microenvironment.
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a wheat based diet enhances colonization with the intestinal spirochaete brachyspira intermedia in experimentally infected laying hens
Avian Pathology, 2004Co-Authors: Nyree D. Phillips, J R Pluske, D J HampsonAbstract:This study investigated the influence of feeding diets based on cereals with different non-starch polysaccharide content on colonization with the intestinal spirochaete Brachyspira intermedia in experimentally infected laying hens. The diets were based on wheat, barley, or barley and sorghum, all with or without supplementation with exogenous dietary enzymes. Six groups of 12 individually caged laying hens were fed the respective diets for 2 weeks, and then challenged at 20 weeks of age by crop tube with 108 to 109 colony forming units of active motile Spirochaetes on five successive days. Eggs were collected daily. The birds were weighed weekly, and caecal faeces collected for assessment of water content. Every 3 to 4 days cloacal swabs were collected and subjected to culture and subsequent polymerase chain reaction for B. intermedia. The birds were killed at 27 weeks of age. Caecal contents were cultured for Spirochaetes, and the viscosity of the ileal and rectal contents assessed. Dietary soluble non-s...
Neil S Jensen - One of the best experts on this subject based on the ideXlab platform.
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Identification of the swine pathogen Serpulina hyodysenteriae in rheas (Rhea americana)
Veterinary Microbiology, 1996Co-Authors: Neil S Jensen, Thad B. Stanton, David E. SwayneAbstract:Abstract Recently intestinal spirochetes were isolated from rheas in Ohio and Iowa with a necrotizing typhlocolitis. These intestinal spirochetes, strains R1 and NIV-1, were characterized and compared with other intestinal spirochetes, including strains of S. hyodysenteriae . Both rhea spirochetes were indole positive, strongly β-hemolytic, grew under a 1% O 2 :99% N 2 atmosphere, and were morphologically similar to spirochetes in the genus Serpulina . Analysis of rRNA gene restriction patterns (ribotypes), and immunoblots of whole cell proteins, indicated both spirochetes were similar to Serpulina hyodysenteriae strains from swine. Comparisons of nearly complete sequences (> 1458 bases) of the 16S rRNA gene of the two rhea spirochetes with S. hyodysenteriae strains confirmed that rhea spirochetes R1 and NIV-1 were strains of S. hyodysenteriae . These results indicate that S. hyodysenteriae has a broader host range than previously recognized.
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differentiation of intestinal Spirochaetes by multilocus enzyme electrophoresis analysis and 16s rrna sequence comparisons
Fems Microbiology Letters, 1996Co-Authors: Thad B. Stanton, Bruce J Paster, A. J. Mclaren, D J Hampson, Darren J. Trott, Neil S JensenAbstract:Multilocus enzyme electrophoresis (MEE) analysis and comparisons of nearly complete 16S rRNA gene sequences (1416 nucleotide positions) were used to evaluate phylogenetic relationships among Serpulina hyodysenteriae strain B78(T), S. innocens strain B256(T), Brachyspira aalborgi strain 513A(T), and eight uncharacterised strains of swine, avian, and human intestinal Spirochaetes. From MEE analysis, nine strains could be assigned to five groups containing other intestinal Spirochaetes (genetic distances between groups = 0.6-0.9). Chicken spirochaete strain C1 and B. aalborgi 513A(T) represented unique electrophoretic types and formed their own MEE groups. Despite MEE differences, the 11 strains had highly similar (96.3-99.9%) 16S rRNA sequences. These findings point out limitations of both MEE analysis and 16S rRNA sequence comparisons when used as solitary techniques for classifying intestinal Spirochaetes related to Brachyspira/Serpulina species.
Tom G. Schwan - One of the best experts on this subject based on the ideXlab platform.
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relapsing fever Spirochaetes produce a serine protease that provides resistance to oxidative stress and killing by neutrophils
Molecular Microbiology, 2006Co-Authors: Cyril Guyard, Patricia A. Rosa, James M Battisti, Sandra J Raffel, Merry E Schrumpf, Adeline R Whitney, Jonathan G Krum, Stephen F Porcella, Frank R Deleo, Tom G. SchwanAbstract:The Spirochaetes that cause tick-borne relapsing fever and Lyme disease are closely related human pathogens, yet they differ significantly in their ecology and pathogenicity. Genome sequencing of two species of relapsing fever Spirochaetes, Borrelia hermsii and Borrelia turicatae, identified a chromosomal open reading frame, designated bhpA, not present in the Lyme disease spirochaete Borrelia burgdorferi. The predicted amino acid sequence of bhpA was homologous with the HtrA serine proteases, which are involved with stress responses and virulence in other bacteria. B. hermsii produced an active serine protease that was recognized by BhpA antibodies and the recombinant BhpA protein-degraded beta-casein. bhpA was transcribed in vitro at all growth temperatures and transcription levels were slightly elevated at higher temperatures. These results correlated with the synthesis of BhpA during B. hermsii infection in mice. With the exception of Borrelia recurrentis, the bhpA gene, protein and enzymatic activity were found in all relapsing fever Spirochaetes, but not in Lyme disease or related Spirochaetes. Heterologous expression of bhpA in B. burgdorferi increased the spirochaete's resistance to both oxidative stress and killing by human neutrophils. Therefore, we propose that bhpA encodes a unique and functional serine protease in relapsing fever Spirochaetes. This periplasmic enzyme may prevent the accumulation of proteins damaged by the innate immune response and contribute to the ability of the relapsing fever Spirochaetes to achieve high cell densities in blood.
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variable small protein vsp dependent and vsp independent pathways for glycosaminoglycan recognition by relapsing fever Spirochaetes
Molecular Microbiology, 2000Co-Authors: Loranne Magoun, Tom G. Schwan, Alan G. Barbour, Wolfram R Zuckert, Douglas Robbins, Nikhat Parveen, Kishore R Alugupalli, John M LeongAbstract:Tick-borne relapsing fever, caused by pathogenic Borrelia such as B. hermsii and B. turicatae, features recurrent episodes of bacteraemia, each of which is caused by a population of Spirochaetes that expresses a different variable major protein. Relapsing fever is also associated with the infection of a variety of tissues, such as the central nervous system. In this study, we show that glycosaminoglycans (GAGs) mediate the attachment of relapsing fever Spirochaetes to mammalian cells. B. hermsii strain DAH bound to immobilized heparin, and heparin and dermatan sulphate blocked bacterial binding to host cells. Bacterial binding was diminished by inhibition of host cell GAG synthesis or sulphation, or by the enzymatic removal of GAGs. GAGs mediated the attachment of relapsing fever Spirochaetes to potentially relevant target cells, such as endothelial and glial cells. B. hermsii was able to attach to GAGs independently of variable major proteins, because strains expressing the variable major proteins Vsp33, Vlp7 or no variable major protein at all each recognized GAGs. Nevertheless, we found that a variable major protein of B. turicatae directly promoted GAG binding by this relapsing fever spirochaete. B. turicatae strain Oz1 serotype B, which expresses the variable major protein VspB, bound to GAGs more efficiently than did B. turicatae Oz1 serotype A, which expresses VspA. Recombinant VspB, but not VspA, bound to heparin and dermatan sulphate. Previous studies have shown that strain Oz1 serotype B grows to higher concentrations in the blood than does Oz1 serotype A. Thus, relapsing fever Spirochaetes have the potential to express Vsp-dependent and Vsp-independent GAG-binding activities and, for one pair of highly related B. turicatae strains, differences in GAG binding correlate with differences in tissue tropism.
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temporal changes in outer surface proteins a and c of the lyme disease associated spirochete borrelia burgdorferi during the chain of infection in ticks and mice
Journal of Clinical Microbiology, 2000Co-Authors: Tom G. Schwan, Joseph PiesmanAbstract:The Lyme disease-associated spirochete, Borrelia burgdorferi, is maintained in enzootic cycles involving Ixodes ticks and small mammals. Previous studies demonstrated that B. burgdorferi expresses outer surface protein A (OspA) but not OspC when residing in the midgut of unfed ticks. However, after ticks feed on blood, some spirochetes stop making OspA and express OspC. Our current work examined the timing and frequency of OspA and OspC expression by B. burgdorferi in infected Ixodes scapularis nymphs as they fed on uninfected mice and in uninfected I. scapularis larvae and nymphs as they first acquired spirochetes from infected mice. Smears of midguts from previously infected ticks were prepared at 12- or 24-h intervals following attachment through repletion at 96 h, and spirochetes were stained for immunofluorescence for detection of antibodies to OspA and OspC. As shown previously, prior to feeding spirochetes in nymphs expressed OspA but not OspC. During nymphal feeding, however, the proportion of spirochetes expressing OspA decreased, while spirochetes expressing OspC became detectable. In fact, spirochetes rapidly began to express OspC, with the greatest proportion of spirochetes having this protein at 48 h of attachment and then with the proportion decreasing significantly by the time that the ticks had completed feeding. In vitro cultivation of the spirochete at different temperatures showed OspC to be most abundant when the spirochetes were grown at 37°C. Yet, the synthesis of this protein waned with continuous passage at this temperature. Immunofluorescence staining of spirochetes in smears of midguts from larvae and nymphs still attached or having completed feeding on infected mice demonstrated that OspA but not OspC was produced by these spirochetes recently acquired from mice. Therefore, the temporal synthesis of OspC by spirochetes only in feeding ticks that were infected prior to the blood meal suggests that this surface protein is involved in transmission from tick to mammal but not from mammal to tick.
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induction of an outer surface protein on borrelia burgdorferi during tick feeding
Proceedings of the National Academy of Sciences of the United States of America, 1995Co-Authors: Tom G. Schwan, Joseph Piesman, William T Golde, Marc C Dolan, Patricia A. RosaAbstract:Lyme disease spirochetes, Borrelia burgdorferi sensu lato, are maintained in zoonotic cycles involving ticks and small mammals. In unfed ticks, the spirochetes produce one outer surface protein, OspA, but not OspC. During infection in mammals, immunological data suggest that the spirochetes have changed their surface, now expressing OspC but little or no OspA. We find by in vitro growth experiments that this change is regulated in part by temperature; OspC is produced by spirochetes at 32-37 degrees C but not at 24 degrees C. Furthermore, spirochetes in the midgut of ticks that have fully engorged on mice now have OspC on their surface. Thus two environmental cues, an increase in temperature and tick feeding, trigger a major alteration of the spirochetal outer membrane. This rapid synthesis of OspC by spirochetes during tick feeding may play an essential role in the capacity of these bacteria to successfully infect mammalian hosts, including humans, when transmitted by ticks.