Previous Article | Next Article ![]()
Journal of Clinical Microbiology, June 2001, p. 2283-2286, Vol. 39, No. 6
Institute for Animal Science and Health,
Lelystad, The Netherlands,1 and
Veterinary Laboratories Agency (Weybridge), New Haw, United
Kingdom2
Received 28 August 2000/Returned for modification 30 November
2000/Accepted 26 March 2001
A collection of Campylobacter fetus strains,
including both C. fetus subsp. fetus and
C. fetus subsp. venerealis, were
phenotypically identified to the subspecies level and
genotypically typed by PCR and amplified fragment length polymorphism
(AFLP) analysis. Phenotypic subspecies determination methods were
unreliable. Genotyping of the strains by PCR and AFLP showed a clear
discrimination between the two subspecies.
Campylobacter fetus can
cause disease in both animals and humans. This species is divided into
C. fetus subspecies fetus and C. fetus
subspecies venerealis on the basis of biochemical
differences (16). C. fetus subsp.
venerealis appears to have a restricted host species
specificity and may cause fertility problems in cows. C. fetus subsp. fetus, on the other hand, is commonly
recovered from the intestinal tract of a number of animal species and
may cause abortion and infertility in sheep and cattle. It can also cause serious systemic disease in humans (13). Testing for
bovine C. fetus infection and subtyping of isolates are
statutory requirements for the import and export of bovine semen and
embryos (1). Subspecies differentiation of C. fetus is generally done on the basis of growth in the presence of
1% glycine (12). However, glycine tolerance can be
mediated by phages (2), and differences in the glycine
tolerance of a C. fetus strain have been described (7). Other tests, such as selenite reduction and
cefoperazone resistance, are considered only indicative (9,
15). Therefore, the phenotypic assays, on which the
discrimination between these two subspecies is based, are considered to
be poorly robust.
Genotyping techniques have been successfully developed for the genus
Campylobacter (17). Recently, the use of
amplified fragment length polymorphism (AFLP) analysis for genotyping
C. jejuni and C. coli has been described
(5, 6). The discriminatory power of this technology is
comparable to that of pulsed-field gel electrophoresis
(3). The aim of this study was to determine the value of
AFLP typing, biochemical typing, and typing by PCR (8) for
subtyping C. fetus.
Bacteriology.
Sixty-nine bacterial strains from three
geographical regions were grown at 37°C under microaerobic conditions
(6% O2, 7% CO2, 7%
H2, 80% N2). For
discrimination between C. fetus subsp. fetus and
C. fetus subsp. venerealis, growth in the
presence of 1% (wt/vol) glycine was determined. Forty-seven of the
strains were typed as C. fetus subsp. fetus, and
22 were typed as C. fetus subsp. venerealis
(Table 1). However, for eight
strains, the results of the glycine test were not consistently
reproducible and were difficult to interpret. Difficulties associated
with phenotypic tests for differentiating between C. fetus
subsp. venerealis and C. fetus subsp.
fetus are well recognized (9, 10). As the biochemical tests are unpredictable, alternative methods of subspecies differentiation have been investigated.
0095-1137/01/$04.00+0 DOI: 10.1128/JCM.39.6.2283-2286.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Comparative Study Using Amplified Fragment Length Polymorphism
Fingerprinting, PCR Genotyping, and Phenotyping To Differentiate
Campylobacter fetus Strains Isolated from
Animals
and
![]()
ABSTRACT
Top
Abstract
Text
References
![]()
TEXT
Top
Abstract
Text
References
TABLE 1.
Campylobacter fetus strain information and
typing results
PCR subtyping. A subspecies-specific PCR was performed as previously described (8). Of the PCR primers, one primer set was directed to both C. fetus subspecies (±750 bp), whereas another primer set only amplified a C. fetus subsp. venerealis-specific band (142 bp). All strains showed the C. fetus-specific band. In general the results are consistent with the phenotypic tests. However, 7 of the 54 C. fetus subsp. fetus strains identified by PCR were negative for growth on 1% glycine. In these cases the PCR results were supported by data from the AFLP, suggesting that strains were mistyped by the biochemical method. Interestingly, these seven strains were part of a group of nine strains from South Africa. These results may indicate some evolutionary distinction between C. fetus subsp. fetus strains from South Africa and those from other geographical regions. Unfortunately, appropriate clinical data were not available for these strains to determine whether this difference was host, disease, or epidemiology related. Conversely, 1 out of the 15 C. fetus subsp. venerealis strains (98/v445) identified by PCR was positive for growth on 1% glycine. For this strain, the biochemical typing and PCR results were inconsistent and the AFLP results did not correlate with the PCR. This strain was also tested in a routine immunofluorescence assay but did not react with C. fetus-specific antiserum. It appears that this strain shows aberrant behavior phenotypically as well as genotypically.
The molecular basis of this PCR test and the relevance of this DNA difference to disease presentation are currently unknown. Although the PCR subtyped only one C. fetus subsp. fetus strain as C. fetus subsp. venerealis, it should be clear that the consequences of such a mistyping may be serious for import and export of animals and the veterinary health status of a country. In the original study that described the PCR, two isolates typed as C. fetus subsp. venerealis were considered C. fetus subsp. fetus by a probabilistic identification score (8). Before this PCR assay can be recommended as a stand-alone test for statutory test purposes, more strains should be typed.AFLP subtyping.
AFLP typing was performed according to the
adapted PE Applied Biosystems protocol previously described
(5). The obtained AFLP pattern consisted of approximately
55 to 60 bands in all strains (Fig. 1).
Differentiation was initially based on the whole profile that clustered
all the C. fetus subsp. venerealis strains together and divided the C. fetus subsp. fetus
strains into several clusters. Using cluster analysis on only a small
region of the pattern (Fig. 1) improved the discrimination
between C. fetus subsp. venerealis strains and
the C. fetus subsp. fetus clusters. The patterns
showed extensive homology, which may therefore restrict the use of this
technique for typing individual strains. This was partly shown by
fingerprinting isolates obtained from two outbreaks. For
C. fetus subsp. venerealis, isolates from the
outbreaks were not clustered separately from unrelated strains,
whereas strains from a C. fetus subsp. fetus
outbreak could be separated, but only when the whole pattern was
analyzed (data not shown).
|
| |
ACKNOWLEDGMENTS |
|---|
We thank Alan Rigter, Ellard Kruijt, and Ank van Zijderveld from ID-Lelystad for technical assistance and M. Henton (South Africa), L. Guler (Turkey), E. G. Hartman and I. J. Visser (The Netherlands), and J. Shreeve (United Kingdom) for supplying strains.
We also thank the Ministry of Agriculture Fisheries and Foods, GB, for partly funding this study.
| |
FOOTNOTES |
|---|
* Corresponding author. Mailing address: Institute for Animal Science and Health, P.O. Box 65, 8200 AB Lelystad, The Netherlands. Phone: 31-320-238157. Fax: 31 320-238153. E-mail: j.a.wagenaar{at}id.wag-ur.nl.
Present address: Department of Clinical Veterinary Science,
Division of Animal Health and Husbandry, Bristol, United Kingdom.
| |
REFERENCES |
|---|
|
|
|---|
| 1. | Anonymous. 1996. OIE manual of standards for diagnostic tests and vaccines 3rd ed., p. 256-266. Office International des Epizooties, Paris, France. |
| 2. | Chang, W., and J. Ogg. 1971. Transduction and mutation to glycine tolerance in Vibrio fetus. Am. J. Vet. Res. 32:649-653[Medline]. |
| 3. |
De Boer, P.,
B. Duim,
A. Rigter,
J. van der Plas,
W. F. Jacobs-Reitsma, and J. A. Wagenaar.
2000.
Computer-assisted analysis and epidemiological value of genotyping methods for Campylobacter jejuni and Campylobacter coli.
J. Clin. Microbiol.
38:1940-1946 |
| 4. | Denes, A. S., C. L. Lutze-Wallace, M. L. Cormier, and M. M. Garcia. 1997. DNA fingerprinting of Campylobacter fetus using cloned constructs of ribosomal RNA and surface array protein genes. Vet. Microbiol. 54:185-193[CrossRef][Medline]. |
| 5. |
Duim, B.,
T. M. Wassenaar,
A. Rigter, and J. Wagenaar.
1999.
High-resolution genotyping of Campylobacter strains isolated from poultry and humans with amplified fragment length polymorphism fingerprinting.
Appl. Environ. Microbiol.
65:2369-2375 |
| 6. |
Duim, B.,
C. W. Ang,
A. van Belkum,
A. Rigter,
W. J. van Leeuwen,
H. P. Endtz, and J. A. Wagenaar.
2000.
Amplified fragment length polymorphism analysis of Campylobacter jejuni strains isolated from chickens and from patients with gastroenteritis or Guillain-Barré or Miller Fisher syndrome.
Appl. Environ. Microbiol.
66:3917-3923 |
| 7. | Harvey, S. M., and J. R. Greenwood. 1983. Relationships among catalase-positive campylobacters determined by deoxyribonucleic acid-deoxyribonucleic acid hybridization. Int. J. Syst. Bacteriol. 33:275-284. |
| 8. | Hum, S., K. Quinn, J. Brunner, and S. L. On. 1997. Evaluation of a PCR assay for identification and differentiation of Campylobacter fetus subspecies. Aust. Vet. J. 75:827-831[Medline]. |
| 9. | On, S. L. W. 1996. Identification methods for campylobacters, helicobacters, and related organisms. Clin. Microbiol. Rev. 9:405-422[Abstract]. |
| 10. | On, S. L. W., and C. Harrington. 2001. Evaluation of numerical analysis of PFGE-DNA profiles for differentiating of Campylobacter fetus subspecies by comparison with phenotypic, PCR, and 16S rDNA sequencing methods. J. Appl. Microbiol. 90:285-293[CrossRef][Medline]. |
| 11. |
Salama, S. M.,
M. M. Garcia, and D. E. Taylor.
1992.
Differentiation of the subspecies of Campylobacter fetus by genomic sizing.
Int. J. Syst. Bacteriol.
42:446-450 |
| 12. | Smibert, R. M. 1984. Genus Campylobacter Sebald and Véron 1963, 907AL, p. 111-118. In N. R. Krieg, and J. G. Holt (ed.), Bergey's manual of systematic bacteriology, vol. 1. Williams & Wilkins, Baltimore, Md. |
| 13. | Thompson, S. A., and M. J. Blaser. 2000. Pathogenesis of Campylobacter fetus infections, p. 321-347. In I. Nachamkin, and M. J. Blaser (ed.), Campylobacter, 2nd ed. American Society for Microbiology, Washington, D.C. |
| 14. |
Vandamme, P.,
E. Falsen,
R. Rossau,
B. Hoste,
P. Segers,
R. Tytgat, and J. de Ley.
1991.
Revision of Campylobacter, Helicobacter, and Wolinella taxonomy: emendation of generic descriptions and proposal of Arcobacter gen. nov.
Int. J. Syst. Bacteriol.
41:88-103 |
| 15. | Vandamme, P. 2000. Taxonomy of the family Campylobacteriaceae, p. 3-26. In I. Nachamkin, and M. J. Blaser (ed.), Campylobacter, 2nd ed. American Society for Microbiology, Washington, D.C. |
| 16. |
Véron, M., and R. Chatelain.
1973.
Taxonomic study of the genus Campylobacter Sebald and Véron and designation of the neotype strain for the type species. Campylobacter fetus (Smith and Taylor) Sebald and Véron.
Int. J. Syst. Bacteriol.
23:122-134 |
| 17. |
Wassenaar, T. M., and D. G. Newell.
2000.
Genotyping of Campylobacter spp.
Appl. Environ. Microbiol.
66:1-9 |
| 18. |
Wesley, I. V.,
R. D. Wesley,
M. Cardella,
F. E. Dewhirst, and B. J. Paster.
1991.
Oligodeoxynucleotide probes for Campylobacter fetus and Campylobacter hyointestinalis based on 16S rRNA sequences.
J. Clin. Microbiol.
29:1812-1817 |
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»