Diversity of DNA sequences among restriction endonucleases producing Selenomonas ruminantium isolates detected by enterobacteriial repetitive intergenic consensus based polymerase chain reaction (ERIC-PCR)

Enterobacterial repetitive intergenic consensus-based polymerase chain reac tion (ERIC-PCR) was found useful for discrimination of rumen selenomonads. Simultaneous use of ERICIR and ERIC2 primers yielded strain-specific bandin g patterns. The patterns were compared using Dice similarity coefficients a nd a DNA relatedness dendrogram based on the unweighted pair group method u sing arithmetic averages (UPGMA) was constructed. Five clusters and four si ngle strains were identified at a similarity level of 50%. Very weak groupi ng was observed for lactilytica and ruminantium subspecies of Selenomonas r uminantium, indicating that lactate utilization has probably no taxonomic v alue. Restriction and modification phenotypes are weakly reflected in the d endrogram probably as the result of horizontal genetic transfer of genes en coding these phenotypic traits. While diverse in ERIC-PCR analysis, strains shown little variation in restriction fragment length polymorphism of ampl ified 16S-rRNA genes. All but one strain produced nearly identical profile indicating that majority of DNA diversity observed is due to epigenetic fac tors and not due to evolutionary divergence. (C) 2000 Academic Press.