[Diagnosis of swine dysentery and spirochaetal diarrhea. 2. Effort of macrorestriction analysis for differentiation of intestinal Serpulina relative to determination by culture-biochemical markers following species classification].

Genotypic differentiation by means of macrorestriction fragment profile analysis using Mlul restriction enzyme was carried out differentiating 41 Serpulina field strains from swine (38), dog (2) and a rat as well as ten type and reference strains into 40 electrophoretic types. A dendrogram was created using the average linkage between groups method. At a level of 50% similarity the patterns could be divided into six groups that roughly corresponded to the results yielded by cultural and biochemical methods formerly (FELTRUP et al. 1999). Five of these clusters corresponded to the five known porcine Serpulina species, one cluster contained the S. pilosicoli isolates from dog and rat included in this study. Interestingly all nine investigated indole negative, strongly haemolytic isolates were clustered together in one group with the S. hyodysenteriae strains, so that incidence of indole negative variants of S. hyodysenteriae was confirmed. Because of being grouped together with two S. intermedia isolates, the suitability of B 256 as S. innocens type strain is--in accord to investigations carried out by PETTERSSON et al (1996)--called in question.