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Journal of Clinical Microbiology, January 1998, p. 261-265, Vol. 36, No. 1
Centre for Infectious Diseases and
Microbiology,
Received 17 June 1997/Returned for modification 12 August
1997/Accepted 15 September 1997
Histologic evidence of intestinal spirochetosis (IS) was found in
22 of 41 (53.7%) rectal biopsy specimens from homosexual men attending
a sexually transmitted diseases clinic. Serpulina pilosicoli was cultured from 11 of the IS-positive biopsy
specimens (50%) and from 2 specimens (10.5%) in which spirochetes
were not observed. The association between seeing spirochetes in biopsy specimens and isolating S. pilosicoli was statistically
significant, clearly indicating that this spirochete is the agent of
IS.
The term intestinal spirochetosis
(IS) was coined in 1967 for an infection of the large bowel in which
uncharacterized spirochetes were found attached by one end to the
colonic epithelium to form a dense "false brush border"
(11). Subsequently, there has been considerable controversy
over the pathologic and epidemiologic significance of this
colonization. Some investigators have reported symptoms such as rectal
bleeding and/or diarrhea in patients with IS (6, 7, 9, 20, 30,
42), and in some cases clinical improvement has occurred after
treatment with antibiotics which eliminated the spirochetes (7,
14, 29). Other investigators have been unable to relate the
presence of intestinal spirochetes to gastrointestinal symptoms
(3, 26, 31, 32).
Most studies of IS have involved histologic examination of biopsy
material, without concurrent bacterial culture (17, 21, 24, 31,
42); a smaller number of studies have involved only fecal culture
for spirochetes (3, 13, 18, 30, 33). One exception was a
study by Hovind-Hougen et al. (12) in which the newly
described spirochete Brachyspira aalborgi was isolated from
the feces of one of five patients showing histologic evidence of IS in
rectal biopsy specimens. Since then, when IS has been diagnosed on the
basis of histologic examination, it has usually been assumed that the
organism involved was B. aalborgi (10, 15, 26, 27,
29). This is despite the fact that in another study in which
spirochetes were seen in rectal biopsy specimens from five of eight
homosexual men, a different, incompletely characterized spirochete was
isolated (5).
Histologic studies have suggested that spirochetes are present in 2.5 to 9% of rectal biopsy specimens from unselected Europeans (11, 17, 20, 26), but are more common (9 of 14; 64%) in biopsy specimens from individuals in southern India (22) and are present in 30 to 39% of biopsy specimens from homosexual men in
western societies (16, 24). Studies involving selective culture for spirochetes have established that they can be isolated from
the feces of only 1.2 to 1.5% of unselected individuals in the United
Kingdom and Australia (18, 33), while they were isolated
from 12 of 27 (44%) samples from untreated human immunodeficiency virus (HIV)-positive homosexual males in Germany (14). Rates of colonization in adult Omani Arabs (3), Australian
Aboriginal children (18), and villagers of all ages in the
Highlands of Papua New Guinea (38) have also been high,
ranging from 11.4 to 32.6%. These highly variable colonization rates
may be influenced by a variety of factors, including immune function,
sexual practices, diet, sanitation, and community structure (4,
19, 33, 38).
Representative isolates from the studies described above were recently
analyzed by multilocus enzyme electrophoresis (MLEE). None of these
isolates was B. aalborgi; instead, all were shown to be
Serpulina pilosicoli (formerly "Anguillina
coli") (19, 36), the recently described agent of
porcine intestinal spirochetosis (37). Infection of pigs
with S. pilosicoli is widespread and is associated with poor
growth rates, colitis, and diarrhea. S. pilosicoli also
infects dogs and birds and again is associated with diarrhea (8,
23). Experimentally, infection of pigs with a human isolate of
S. pilosicoli caused colitis with crypt abscessation
(35). In experimentally infected chicks, human isolates have
caused watery diarrhea and reduced growth rates, and they also attached
by one end to the cecal epithelium (25, 34). These findings
strongly suggest that human strains of S. pilosicoli have
pathogenic potential.
To date systemic disease associated with S. pilosicoli has
not been reported in animals, but S. pilosicoli has recently
been isolated from the bloodstreams of critically ill human patients, some of whom had a history of intestinal disease (39). In
humans, spirochetes have occasionally been seen in colonic or rectal
epithelial cells, goblet cells, macrophages, and Schwann cells in both
immunocompetent and immunocompromised patients (1, 10, 15,
27). In some cases severe inflammatory reactions have been
recorded, including crypt abscessation and epithelial ulceration and
necrosis (15). In all these cases it was assumed that the
spirochetes were B. aalborgi. The purpose of the present
study was to isolate and identify spirochetes from rectal biopsy
specimens taken from a group of high-risk individuals with histologic
evidence of IS. This would then answer the question of whether
spirochetes that can be seen in biopsy specimens from patients with IS
are B. aalborgi or the more recently described spirochete
S. pilosicoli.
The subjects of the study were a group of 40 homosexual men attending a
sexual health clinic in Sydney, Australia. Approximately half the men
were HIV antibody positive, but none was suffering from AIDS. Most
reported having minor nonspecific gastrointestinal symptoms. Informed
consent was obtained for participation in the study. For one individual
a second biopsy specimen was taken 6 months after the first biopsy
specimen was obtained. Proctoscopy was performed with disposable
sigmoidoscopes. Rectal biopsy specimens were taken 10 to 15 cm from the
anal verge by using flexible colonoscopy biopsy forceps as described
previously (16). Half of the biopsy specimen was placed in
neutral buffered formalin for histologic examination, and the other
half was streaked directly onto selective Trypticase soy agar (BBL,
Becton Dickinson Microbiology Systems, Cockeysville, Md.) supplemented
with 5% defibrinated horse blood and 400 µg of spectinomycin
(Sigma-Aldrich Pty Ltd., Castle Hill, Australia) per ml
(33). Plates were incubated at 37°C in an environment of
85% N2-10% H2-5% CO2 and were
examined daily for up to 14 days for the presence of spirochetes.
Suspected spirochete colonies were examined by dark-field microscopy to
determine cell morphology. Isolated spirochetes were maintained on
antibiotic-free Columbia agar plates (Columbia Agar base; Oxoid Unipath
Ltd., Basingstoke, United Kingdom) containing 5% defibrinated horse blood.
Isolates were subjected to a S. pilosicoli-specific PCR
designed to amplify a 1.33-kb portion of the S. pilosicoli
16S rRNA gene (28). Whole cells were harvested from plates
in phosphate-buffered saline, washed, and then boiled for 10 min prior
to amplification. The product was detected by ethidium bromide staining
following electrophoresis in 1.5% agarose. For nine isolates,
including the two isolates recovered from biopsy specimens collected
from the same individual 6 months apart, the electrophoretic mobilities of 15 constitutive enzymes were determined by MLEE. The same
electrophoretic running conditions, buffers, and enzyme assays reported
previously were used (19). The allele profiles generated
were grouped into electrophoretic types (ETs) and were compared with
the ETs generated for 70 human fecal strains of S. pilosicoli which we had examined previously (19, 39).
Genetic distances between ETs were calculated as the proportion of
fixed loci at which dissimilar alleles occurred. A phenogram
illustrating genetic distances between ETs was constructed as described
previously (19).
Formalin-fixed biopsy tissues were dehydrated through alcohol, paraffin
embedded, cut to a thickness of 5 µm, stained with hematoxylin and
eosin, and examined by light microscopy. A total of 22 of the 41 biopsy
specimens (53.7%) exhibited a blue-stained haze of spirochetes on the
surface of the epithelium, but there was no evidence of spirochete
penetration or inflammation. The positive samples were examined further
by transmission electron microscopy. These biopsy specimens were washed
and postfixed in 2% osmium tetroxide (buffered in 0.1 M cacodylate)
for 4 h. Samples were dehydrated through alcohol and prepared for
embedding by absorption in a 1:1 mixture of acetone and low-viscosity
epoxy resin. The tissue was embedded in 100% low-viscosity epoxy resin and polymerized at 70°C for a minimum of 8 h. Semithin (0.5 µm) and ultrathin (70 to 90 nm) sections were cut from the biopsy specimen by ultramicrotomy. These were stained with 2% uranyl acetate
containing 50% ethanol for 15 min and then washed and restained with
lead citrate for 4 min. The preparations were examined with a Phillips
CM10 transmission electron microscope.
A 20-µm-thick layer of spirochetes was observed attached end on to
the mucosal layer of the rectal epithelial cells of the 22 positive
biopsy specimens. These spirochetes were situated between and parallel
to the microvilli, with little obvious loss of microvilli (Fig.
1). At the point of attachment between
the ends of the spirochetes and the mucosal cell membrane was seen a
depression or pocket, forming a small electron-lucent pit, and some
exhibited an electron-dense cap at this point (Fig.
2). The epithelial cell membranes
remained intact, with the spirochetes confined to the cell surface.
Spirochetes were isolated from 11 of the 22 (50%) biopsy specimens
showing histologic evidence of IS and from 2 of the 19 specimens
(10.5%) not showing histologic evidence of colonization. The
association between histologic evidence of spirochete colonization and
isolation was examined by a chi-squared test and was shown to be
significant ( Two different weakly
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Copyright © 1998, American Society for Microbiology. All rights reserved.
Isolation of Serpulina pilosicoli from
Rectal Biopsy Specimens Showing Evidence of Intestinal
Spirochetosis
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FIG. 1.
Transmission electron microscopic view of sectioned
rectal biopsy specimen showing a "false brush border" of intestinal
spirochetes attached by one end to the mucosa, with minimal disruption
of the microvilli. Bar, 3 µm.

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FIG. 2.
Transmission electron micrograph of sectioned rectal
biopsy tissue showing spirochetes on the mucosal layer of rectal
epithelial cells, invaginated into the terminal web of the cells. Bar,
0.5 µm.
2 = 7.34; P < 0.01).
-hemolytic colony types were observed on blood
agar plates, and both were visible only after 6 days of incubation. The
first colony type was <1 mm in diameter, convex, grey, and
translucent, and the other was 1 to 1.5 mm in diameter, crenated,
mucoid, grey, and translucent. Bacteria from the two colony types were
indistinguishable by both light and electron microscopy; they were 6 to
10 µm long, with a tapered end, and had four to six periplasmic
flagella at each cell end (Fig. 3). All
gave positive DNA amplifications in the S. pilosicoli-specific PCR, and the 9 that were subjected to MLEE
analysis all grouped with well-characterized fecal isolates of S. pilosicoli (Fig. 4). Each of the
nine isolates belonged to a different ET. One, in ET 62, was relatively
distantly related to the others. Pairs of isolates in ETs 16 and 17 and
ETs 28 and 29 differed by only a single allele. The two isolates
cultured from the same individual 6 months apart were different, being
located in ETs 28 and 32, respectively.

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FIG. 3.
Transmission electron micrograph of a transversely
sectioned spirochete showing five periplasmic flagella. Bar, 0.1 µm.

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FIG. 4.
Phenogram illustrating relationships of nine isolates of
S. pilosicoli cultured from rectal biopsy specimens,
indicated by bold lines, and 70 fecal isolates from previous studies
located in another 53 ETs.
This study has shown a clear and significant relationship between the
presence of intestinal spirochetes attached as a "false brush
border" in histologic sections from the rectum
a condition consistent with previous reports of IS
and isolation of S. pilosicoli from the biopsy specimens. It is therefore highly
likely that in other studies in which IS has been diagnosed on the
basis of histologic examination alone, these spirochetes also were
S. pilosicoli. In no case was B. aalborgi
isolated in this study, even though the medium used supports its
growth, and plates were incubated for 2 weeks, as described when the
organism was originally isolated (12). Since that original
report, no other isolations of this organism have been made. Unlike
S. pilosicoli, B. aalborgi recently failed to
colonize experimentally infected chicks (41). Clearly, over
the years, the significance of B. aalborgi appears to have been greatly overestimated.
The high prevalence of rectal biopsy specimens showing evidence of IS (53.7%) among the group of individuals examined in the present study was similar to that in previous reports of studies with homosexual males with or without HIV infection (5, 14, 16). The relatively low rate of isolation of S. pilosicoli from the biopsy specimens showing evidence of IS (50%) was interesting and suggests that studies based on culture alone, including fecal culture, may underestimate the true prevalence of infection. In the two cases in which S. pilosicoli was isolated from biopsy specimens without histologic evidence of IS, these organisms may have been present in the intestinal lumen, having originated from the mucosa in more proximal colonic sites.
S. pilosicoli is a known pathogen of animals, and its capacity to cause disease in humans now requires further assessment. In the current study no attempt was made to associate histologic evidence of IS and disease. All the subjects described here reported only mild nonspecific gastrointestinal disorders. Rectal spirochetosis has been reported in patients with proctitis (5, 7, 42), but this was not present in any of the current subjects, and indeed, no evidence of inflammation was found at the histologic level. Because samples were taken only from the rectum, it was not known whether colonization extended beyond this site. This is significant, since diarrheal disease in pigs is associated with extensive colonization of the cecum and colon (37). Similarly, in humans it seems likely that extensive colonization at other sites is more likely than rectal colonization to be problematic, but it is not known how frequently rectal colonization and colonic colonization coexist. Lindboe et al. (20) reported finding spirochetes more commonly in the rectum (2.5%) than at other large intestinal sites (1.2 to 1.9%) in patients undergoing biopsy, while Lo et al. (21) reported finding spirochetes in the proximal colon but not the distal colon or rectum of one of their patients. When spirochetes are isolated from the feces, their major site of colonization in the intestine remains unknown. This may help explain some of the difficulties in linking the presence of S. pilosicoli in the feces or in rectal biopsy specimens to the presence or absence of specific intestinal symptoms.
The large genetic diversity found among the strains isolated here was consistent with previous findings for strains recovered from humans and animals (2, 19). The isolation of different strains of S. pilosicoli from biopsy specimens from the same patient taken 6 months apart was also consistent with findings for some individuals in an Australian Aboriginal community (18, 19) and in villages in the Highlands of Papua New Guinea (38, 40). Nevertheless, in the former study some other subjects were found to be colonized with the same strain of S. pilosicoli over a 12-month period, while in the latter studies the average duration of colonization was calculated to be approximately 4 months. It is also possible that individuals can be colonized concurrently with different strains of the spirochete, and this could have important implications for the development of protective immunity and for antimicrobial drug therapy if one or more resistant strains were also present. This possibility requires further investigation, for example, by undertaking strain typing with multiple isolates obtained from a range of sites sampled along the length of the large intestine.
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ACKNOWLEDGMENTS |
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We thank Ross Boadle, Department of Anatomical Pathology, ICPMR, for the use of the electron microscope and Adrian Lee, School of Microbiology and Immunology, University of New South Wales, for assistance with interpreting the electron micrographs.
The original study on sexually transmitted diseases and bowel conditions in homosexual men attending a sexual health clinic was funded by the Sydney Hospital Foundation for Medical Research, with grants awarded to Carmella L. H. Law.
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FOOTNOTES |
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* Corresponding author. Mailing address: Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia. Phone: 61 08 9360 2287. Fax: 61 08 9310 4144. E-mail: hampson{at}numbat.murdoch.edu.au.
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REFERENCES |
|---|
|
|
|---|
| 1. | Antonakopoulos, G., J. Newman, and M. Wilkinson. 1982. Intestinal spirochaetosis: an electron microscopic study of an unusual case. Histopathology 6:477-488[Medline]. |
| 2. | Atyeo, R. F., S. L. Oxberry, and D. J. Hampson. 1996. Pulsed-field gel electrophoresis for sub-specific differentiation of Serpulina pilosicoli (formerly "Anguillina coli"). FEMS Microbiol. Lett. 141:77-81[Medline]. |
| 3. | Barrett, S. P. 1991. Intestinal spirochaetes in a Gulf Arab population. Epidemiol. Infect. 104:261-266. |
| 4. | Barrett, S. P. 1997. Human intestinal spirochaetosis, p. 243-265. In D. J. Hampson, and T. B. Stanton (ed.), Intestinal spirochaetes in domestic animals and humans. CAB International, Wallingford, England. |
| 5. | Cooper, C., D. W. Cotton, M. J. Hudson, N. Kirkham, and F. E. Wilmott. 1986. Rectal spirochaetosis in homosexual men: characterisation of the organism and pathophysiology. Genitourin. Med. 62:47-52[Medline]. |
| 6. | Crucioli, V., and A. Busuttil. 1981. Human intestinal spirochaetosis. Scand. J. Gastroenterol. 16:177-179[Medline]. |
| 7. | Douglas, J. G., and V. Crucioli. 1981. Spirochaetosis: a remediable cause of diarrhoea and rectal bleeding? Br. Med. J. 283:1362. |
| 8. | Duhamel, G. E., B. D. Hunsaker, M. R. Mathieson, and R. A. Moxley. 1996. Intestinal spirochetosis and giardiasis in a beagle pup with diarrhea. Vet. Pathol. 33:360-362[Abstract]. |
| 9. | Gad, A., R. Willen, K. Furugard, B. Fors, and M. Hradsky. 1977. Intestinal spirochaetosis as a cause of longstanding diarrhoea. Uppsala J. Med. Sci. 82:49-54. |
| 10. | Guccion, J. G., D. A. Bentor, J. Zeller, B. Termanini, and N. Saini. 1995. Intestinal spirochetosis and acquired immunodeficiency syndrome: ultrastructural studies of two cases. Ultrastruct. Pathol. 19:15-22[Medline]. |
| 11. | Harland, W. A., and F. D. Lee. 1967. Intestinal spirochaetosis. Br. Med. J. 2:718-719. |
| 12. | Hovind-Hougen, K., A. Birch-Andersen, R. Hendrik-Nielsen, M. Orholm, J. O. Pedersen, P. S. Teglbaerg, and E. H. Thaysen. 1982. Intestinal spirochetosis: morphological characterization and cultivation of the spirochete Brachyspira aalborgi gen. nov., sp. nov. J. Clin. Microbiol. 6:1127-1136. |
| 13. | Jones, M. J., J. N. Miller, and W. L. George. 1986. Microbiological and biochemical characterization of spirochetes isolated from the feces of homosexual males. J. Clin. Microbiol. 6:1071-1074. |
| 14. | Kasbohrer, A., H. R. Gelderblom, K. Arasteh, W. Heise, G. Grosse, M. L'age, A. Schonberg, M. A. Koch, and G. Pauli. 1990. Intestinale spirochatose bei HIV-infektion. Dtsch. Med. Wochenschr. 115:1499-1506[Medline]. |
| 15. | Kosterman, J. R., M. Patel, E. Catalano, J. Camacho, J. Hoffpauir, and M. J. DiNubile. 1995. Invasive colitis and hepatitis due to previously uncharacterized spirochetes in patients with advanced human immunodeficiency virus infection. Clin. Infect. Dis. 21:1159-1165[Medline]. |
| 16. | Law, C. L. H., J. M. Grierson, and S. M. B. Stevens. 1994. Rectal spirochaetosis in homosexual men: the association with sexual practices, HIV infection and enteric flora. Gentourin. Med. 70:6-29. |
| 17. |
Lee, F. D.,
A. Kraszewski,
J. Gordon,
J. G. R. Howie,
D. McSeveney, and W. A. Harland.
1971.
Intestinal spirochaetosis.
Gut
12:126-133 |
| 18. | Lee, J. I., and D. J. Hampson. 1992. Intestinal spirochaetes colonising Aboriginals from communities in the remote north of Western Australia. Epidemiol. Infect. 109:133-141[Medline]. |
| 19. |
Lee, J. I., and D. J. Hampson.
1994.
Genetic characterisation of intestinal spirochaetes and their association with disease.
J. Med. Microbiol.
40:365-371 |
| 20. | Lindboe, C. F., N. E. Tostrup, R. Nersund, and G. Rekkavik. 1993. Human intestinal spirochaetosis in mid-Norway. APMIS 101:858-864[Medline]. |
| 21. |
Lo, T. C. N.,
R. C. Heading, and H. M. Gilmour.
1994.
Intestinal spirochaetosis.
Postgrad. Med. J.
70:134-137 |
| 22. |
Mathan, M. M., and V. I. Mathan.
1985.
Rectal mucosal morphologic abnormalities in normal subjects in southern India: a tropical colonopathy?
Gut
26:710-717 |
| 23. | McLaren, A. J., D. J. Trott, D. E. Swayne, S. L. Oxberry, and D. J. Hampson. 1997. Genetic and phenotypic characterization of intestinal spirochetes colonizing chickens and allocation of known pathogenic isolates to three distinct genetic groups. J. Clin. Microbiol. 35:412-417[Abstract]. |
| 24. |
McMillan, A., and F. D. Lee.
1981.
Sigmoidoscopic and microscopic appearance of the rectal mucosa in homosexual men.
Gut
22:1035-1041 |
| 25. | Muniappa, N., G. E. Duhamel, M. R. Mathiesen, and T. W. Bargar. 1996. Light microscopic and ultrastructural changes in ceca of chicks inoculated with human and canine Serpulina pilosicoli. Vet. Pathol. 33:542-550[Abstract]. |
| 26. | Neilsen, H. R., J. O. Orholm, K. Pedersen, K. Hovind-Hougen, and E. H. Thaysen. 1983. Colorectal spirochaetosis: clinical significance of the infestation. Gastroenterology 85:62-67[Medline]. |
| 27. | Padmanabhan, V., J. Dahlstrom, L. Maxwell, G. Kaye, A. Clarke, and P. J. Barrett. 1996. Invasive intestinal spirochaetosis: a report of three cases. Pathology 28:283-296[Medline]. |
| 28. | Park, N. Y., C. Y. Chung, A. J. McLaren, R. F. Atyeo, and D. J. Hampson. 1995. Polymerase chain reaction for identification of human and porcine spirochaetes recovered from cases of intestinal spirochaetosis. FEMS Microbiol. Lett. 125:225-230[Medline]. |
| 29. | Rodgers, F. G., C. Rodgers, A. P. Shelton, and C. P. Hawkey. 1984. Proposed pathogenic mechanism for the diarrhoea associated with human intestinal spirochaetes. Am. J. Clin. Pathol. 86:679-682. |
| 30. | Sanna, A., G. Dettori, A. M. Agliano, G. Branca, R. Grillo, F. Leone, A. Rossi, and G. Parisi. 1984. Studies of treponemes isolated from human gastrointestinal tract. Ig. Mod. 81:959-973. |
| 31. | Surawicz, C. M., P. L. Roberts, A. Rompalo, T. C. Quinn, K. K. Holmes, and W. E. Stamm. 1987. Intestinal spirochetosis in homosexual men. Am. J. Med. 82:587-592[Medline]. |
| 32. | Takeuchi, A., H. R. Jervis, H. Nakazawa, and D. M. Robinson. 1974. Spiral-shaped organisms on the surface colonic epithelium of the monkey and man. Am. J. Clin. Nutr. 27:1287-1296[Abstract]. |
| 33. |
Tompkins, D. S.,
S. J. Foulkes,
P. G. R. Godwin, and A. P. West.
1986.
Isolation and characterisation of intestinal spirochaetes.
J. Clin. Pathol.
39:535-541 |
| 34. | Trott, D. J., A. J. McLaren, and D. J. Hampson. 1995. Pathogenicity of human and porcine intestinal spirochetes in one-day-old specific-pathogen-free chicks: an animal model of intestinal spirochetosis. Infect. Immun. 63:3705-3710[Abstract]. |
| 35. | Trott, D. J., C. R. Huxtable, and D. J. Hampson. 1996. Experimental infection of newly weaned pigs with human and porcine strains of Serpulina pilosicoli. Infect. Immun. 64:4648-4654[Abstract]. |
| 36. | Trott, D. J., T. B. Stanton, N. S. Jensen, and D. J. Hampson. 1996. Phenotypic characterisation of Serpulina pilosicoli, the agent of intestinal spirochetosis. FEMS Microbiol. Lett. 142:209-214[Medline]. |
| 37. |
Trott, D. J.,
T. B. Stanton,
N. S. Jensen,
G. E. Duhamel,
J. L. Johnson, and D. J. Hampson.
1996.
Serpulina pilosicoli sp. nov., the agent of porcine intestinal spirochetosis.
Int. J. System. Bacteriol.
46:206-215 |
| 38. | Trott, D. J., B. G. Combs, A. S. J. Mikosza, S. L. Oxberry, I. D. Robertson, M. Passey, J. Taime, R. Sehuko, M. P. Alpers, and D. J. Hampson. The prevalence of Serpulina pilosicoli in humans and domestic animals in the eastern highlands of Papua New Guinea. Epidemiol. Infect., in press. |
| 39. | Trott, D. J., N. S. Jensen, I. Saint Girons, S. L. Oxberry, T. B. Stanton, D. Lindquist, and D. J. Hampson. 1997. Identification and characterization of Serpulina pilosicoli isolates recovered from the blood of critically ill patients. J. Clin. Microbiol. 35:482-485[Abstract]. |
| 40. | Trott, D. J., A. S. J. Mikosza, B. G. Combs, S. L. Oxberry, and D. J. Hampson. Submitted for publication. |
| 41. | Trott, D. J., S. L. Oxberry, and D. J. Hampson. 1997. Evaluation of day-old SPF chicks for pathogenicity testing of intestinal spirochete species. In Abstracts of the NADC First International Virtual Conference on Infectious Diseases of Animals. I00003. |
| 42. | Willen, R., B. Carlen, J. Cronstedt, and H. Willen. 1985. Intestinal spirochaetosis of the colon diagnosed with colono-ileoscopy and multiple biopsies. Endoscopy 17:86-88[Medline]. |
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