Publications

diagnosis of proliferative enteritis in frozen and formalin-fixed, paraffin-embedded tissues from a hamster, horse, deer and ostrich using a lawsonia intracellularis-specific multiplex pcr assay.	proliferative enteritis (pe) is an enteric disease that has been reported in a variety of animals. it is caused by an obligate intracellular bacterium identified in swine as lawsonia intracellularis. the organism can be detected ante-mortem in swine with pe using molecular diagnostic methods. the disease can be diagnosed post-mortem in all species by gross examination of tissues and special histologic staining procedures. in this study we extracted total dna from frozen or formalin-fixed, paraff ...	1997	9050170
oral administration of tylosin phosphate for treatment and prevention of proliferative enteropathy in pigs.	to evaluate the efficacy of orally administered tylosin phosphate for prevention and treatment proliferative enteropathy (pe) in pigs.	1997	9028475
proliferative enteropathy of rabbits: the intracellular campylobacter-like organism is closely related to lawsonia intracellularis.	the intracellular campylobacter-like organism associated with proliferative enteropathy of rabbits is closely related to lawsonia intracellularis, the primary pathogen in porcine intestinal adenomatosis. polymerase chain reaction primers based on the 16s rrna gene of l. intracellularis were used to amplify dna harvested from intestinal tissues of rabbits with severe proliferative intestinal lesions containing curved argentophilic intracellular bacteria. sequencing of a 180-nucleotide dna fragmen ...	1996	9001174
developed and resolving lesions in porcine proliferative enteropathy: possible pathogenetic mechanisms.	proliferative enteropathy, caused by lawsonia intracellularis, offers the opportunity to examine bacterial mechanisms that influence epithelial cell proliferation. ultrastructural features of developed and resolving lesions included the presence of enlarged intestinal crypts containing undifferentiated immature epithelial cells and an absence of goblet cells. numerous intracytoplasmic bacteria, identified as l. intracellularis, were consistently present within affected cells. in recovering intes ...	1996	8878750
detection of ileal symbiont intracellularis in porcine faecal samples by polymerase chain reaction.	ileal symbiont intracellularis (isi), the organism causing proliferative enteritis (pe) in pigs was detected in faeces by the application of polymerase chain reaction (pcr). the assay based on a 319 base pair dna fragment was used on faecal and mucosal samples derived from pigs either affected or unaffected with pe. as few as 10(3) isi could be detected in pig faeces spiked with isi. no amplification product was detected in the faeces of unaffected pigs but faeces of confirmed clinical cases wer ...	1995	8748553
proliferative enteropathy in a foal caused by lawsonia intracellularis-like bacterium.		1996	8744752
proliferative enteritis associated with lawsonia intracellularis (ileal symbiont intracellularis) in white-tailed deer.		1996	8744751
replication of australian porcine isolates of ileal symbiont intracellularis in tissue culture.	ileal symbiont intracellularis (isi) isolated from australian cases of pia and phe was replicated in the rat ileum enterocyte cell line iec 18. the number of isi within cells varied, as did the number of isi infected within the monolayer. at 24 h post infection a large number of cells were infected with approximately 100 isi per cell. at the termination of infection, fewer iec 18 cells were infected but isi had replicated to fill the cell cytoplasmic space. numerous foci of infected cells were v ...	1996	8734642
entry of the bacterium ileal symbiont intracellularis into cultured enterocytes and its subsequent release.	separate suspensions of two strains of ileal symbiont (is) intracellularis, an obligate intracellular bacterium and the causative agent of porcine proliferative enteropathy, were added to 40 or 80 per cent confluent monolayers of established cultures of rat (iec-18) or pig enterocytes (ipec-j2). peak numbers of intracellular organisms were detected within the enterocytes six days later, but no cytopathic effects were evident. after an initial close association with the cell membrane of the enter ...	1995	8588102
reproduction of porcine proliferative enteropathy with pure cultures of ileal symbiont intracellularis.	porcine proliferative enteropathy is consistently associated with the presence of intracellular curved bacteria in epithelial cells in affected portions of intestine. two strains of these intracellular bacteria were cultured in a cell culture system with rat enterocytes (iec-18) and passaged several times and used as oral inocula for 14 gnotobiotic and 8 conventional pigs. dna and immunological studies had identified these bacteria as belonging to a new taxon, ileal symbiont (is) intracellularis ...	1993	8406817
ileal symbiont intracellularis, an obligate intracellular bacterium of porcine intestines showing a relationship to desulfovibrio species.	a new genus and species of obligate intracellular-bacteria found in porcine intestines are described. growth on any bacteriological medium deprived of living cells has not been demonstrated. the organism has been grown intracellularly in cell culture. the 16s rrna gene sequence data, dna probe results, and microscopic observations provide evidence that these bacteria differ from those in other described genera and that they belong to the delta subdivision of the class proteobacteria. we have amp ...	1993	8347512
enhanced detection of intracellular organism of swine proliferative enteritis, ileal symbiont intracellularis, in feces by polymerase chain reaction.	a sensitive assay based on amplification of a 319-bp dna fragment of the intracellular bacterium of swine proliferative enteritis was developed for the detection of the organism in the feces of swine. a vernacular name, ileal symbiont intracellularis (is-intracellularis), has recently been published for the intracellular bacterium, which was formerly known as a campylobacter-like organism (c.j. gebhart, s.m. barnes, s. mcorist, g.f. lin, and g.h.k. larson, int. j. syst. bacteriol. 43:533-538, 19 ...	1993	8253956
relationship between ileal symbiont intracellularis and porcine proliferative enteritis.	the relationship between ileal symbiont (is) intracellularis, formerly known as a campylobacter-like organism, and porcine proliferative enteritis (pe) was studied by use of pigs with experimentally transmitted pe. twenty one pigs were experimentally inoculated with homogenized ileal mucosa from a pig that died with pe, and 7 were maintained as uninoculated controls. fecal samples were collected, and pigs were necropsied weekly postinoculation. light microscopy and electron microscopy were used ...	1993	8225599
synergism of ileal symbiont intracellularis and gut bacteria in the reproduction of porcine proliferative enteropathy.		1994	8203109
experimentally induced proliferative enteritis in hamsters: an ultrastructural study.	hamsters, three weeks old, were dosed orally with suspensions of intracellular bacteria grown in rat enterocyte tissue culture cells iec-18, which had been infected with suspensions of intracellular bacteria derived from the lesions of proliferative haemorrhagic enteropathy occurring naturally in two pigs. each bacterial strain, identified as ileal symbiont intracellularis, was passaged in the cell lines once, twice or five times, collected with the cells and used as inocula. ten of 16 hamsters ...	1994	8191009
enzyme-linked immunosorbent assay for measuring ileal symbiont intracellularis-specific immunoglobulin g response in sera of pigs.	proliferative enteritis (pe) is a common intestinal disease on pig farms. the disease is caused by ileal symbiont (is) intracellularis (campylobacter-like organisms) bacteria. an enzyme-linked immunosorbent assay (elisa) was developed to measure is intracellularis-specific immunoglobulin g (igg) response in the sera of pigs. the antigen used in the elisa was filtered, percoll gradient-purified is intracellularis extracted from the intestines of pigs affected with proliferative hemorrhagic entero ...	1994	7989553
polymerase chain reaction for diagnosis of porcine proliferative enteropathy.	a polymerase chain reaction (pcr) assay for detection of the intracellular bacteria, ileal symbiont intracellularis of porcine proliferative enteropathy is described. the test is based on specific dna primers and gave positive pcr product from samples of preserved intestinal mucosa and faeces from affected pigs. mucosa and faeces from normal pigs gave no positive pcr products. the identity of the pcr product was confirmed by dna-dna hybridization with a probe, pclo78, specific for is intracellul ...	1994	7975146
specific in situ hybridization of the intracellular organism of porcine proliferative enteropathy.	the identity of the intracellular bacteria found in the enterocytes of pigs with proliferative enteropathy was investigated using specific dna probes to various campylobacter species and to a novel organism, ileal symbiont intracellularis. the ilea from pigs (nos. 1-7) that were diagnosed by routine histopathology as having proliferative enteropathy were used. diagnosis was made on the basis of proliferation of the enterocytes on hematoxylin and eosin-stained sections and the presence of large n ...	1994	7941236
reproduction of proliferative enteritis in hamsters with a pure culture of porcine ileal symbiont intracellularis.	hamsters, three weeks old, were inoculated orally with suspensions of intracellular bacteria, grown in tissue culture cells, iec-18, rat enterocytes. cells had been infected with suspensions of intracellular bacteria derived from the lesions of proliferative haemorrhagic enteropathy occurring naturally in two pigs 916/91 and 1482/89. infected cell lines containing each separate strain, 916/91 and 1482/89, were passaged one, two or five times and pure cultures of intracellular bacteria, identifie ...	1994	7801512
antimicrobial susceptibility of ileal symbiont intracellularis isolated from pigs with proliferative enteropathy.	proliferative enteropathy is caused by the microaerophilic obligate intracellular bacterium ileal symbiont (is) intracellularis. treatment of this disease is problematic because of the lack of in vivo or in vitro data on the activities of antimicrobial agents. a new procedure for determining the susceptibility of is intracellularis was developed by using a tissue culture system which promotes the in vitro multiplication of this organism. nineteen antimicrobial agents were evaluated in triplicate ...	1995	7615747
characterization of lawsonia intracellularis gen. nov., sp. nov., the obligately intracellular bacterium of porcine proliferative enteropathy.	a novel obligately intracellular bacterium, ileal symbiont intracellularis, which was obtained from the intestines of pigs with proliferative enteropathy disease, was grown in pure cocultures with tissue cultures of rat cells. an examination of the 16s ribosomal dna gene sequence revealed that the isolates which we obtained are members of the delta subdivision of the proteobacteria and that the sequences of these organisms exhibit a level of similarly of 91% with the sequence of desulfovibrio de ...	1995	7547305
infection of cultured rat enterocytes by ileal symbiont intracellularis depends on host cell function and actin polymerisation.	the mechanisms of entry of ileal symbiont intracellularis into iec-18 rat enterocyte cells and subsequent bacterial proliferation were examined in centrifuge-assisted and static infections. live, oxygen or neomycin damaged, and formalin killed bacteria, each rapidly entered viable cells. live or damaged bacteria did not enter cells nor proliferate within cells after static infection of cells cooled to 5 degrees c. infection of cells was greatly reduced at 20 degrees or 32 degrees compared to inf ...	1995	7483247