Evaluation of numerical analysis of PFGE-DNA profiles for differentiating Campylobacter fetus subspecies by comparison with phenotypic, PCR and 16S rDNA sequencing methods.
OBJECTIVE
To assess the efficacy of numerical analysis of PFGE-DNA profiles for identification and differentiation of Campylobacter fetus subspecies.


RESULTS
31 Camp. fetus strains were examined by phenotypic, PCR- and PFGE-based methods, and the 16S rDNA sequences of 18 strains compared. Numerical analysis of PFGE-DNA profiles divided strains into two clusters at the 86% similarity level. One cluster contained 19 strains clearly identified as Camp. fetus subsp. venerealis. The other cluster comprised 12 strains, of which 10 were unambiguously identified as Camp. fetus subsp. fetus. The remaining two strains were identified as Camp. fetus subsp. venerealis by either phenotypic or PCR methods, but not both. At higher similarity levels, clusters containing isolates from each of two countries were identified, suggesting that certain clones predominate in certain geographical regions.


CONCLUSIONS
Numerical analysis of PFGE-DNA profiles is an effective method for differentiating Camp. fetus subspecies.


CONCLUSIONS
Critical comparison of PFGE, PCR, 16S rDNA sequencing and phenotypic methods for differentiation of Camp. fetus subspecies was attained. Novel phenotypic markers for distinguishing subspecies were identified. Evidence for dominant clones of each subspecies in certain countries was provided.
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Danish Veterinary Laboratory, Bülowsvej 27, DK-1790, Copenhagen V, Denmark. sto@svs.dk
Harrington
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CS
D000818:Animals; D015373:Bacterial Typing Techniques; D002169:Campylobacter Infections / Q000382:microbiology*; D002168:Campylobacter fetus / Q000145:classification* / Q000235:genetics; D002417:Cattle; D004269:DNA, Bacterial / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D020459:Genes, rRNA; D006801:Humans; D009716:Numerical Analysis, Computer-Assisted; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011336:Probability; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012756:Sheep
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S