Differentiation of Streptococcus uberis and Streptococcus parauberis by restriction fragment length polymorphism analysis of the 16S ribosomal RNA gene and further studies on serological properties

The 16S rRNA gene of 36 previously characterized streptococci was amplified by polymerase chain reaction and subsequently digested with the restriction enzymes RsaI and AvaII. We found a restriction pattern characteristic for Streptococcus uberis for 34 isolates and a restriction profile characteristic for S, parauberis for two isolates respectively. The isolates were aditionally investigated for B-glucuronidase enzyme activity and for the occurrence of type-specific antigens. The latter was performed with antisera prepared against S. porcinus type reference strains of serogroup E. The beta-glucuronidase enzyme activity did not reliably differentiate into the species S. uberis and S. parauberis. In addition the beta-glucuronidase enzyme activity and previously observed properties such as CAMP-like reactivities, lectin agglutination reactions and the occurrence of group-specific antigens seemed to be not related to each other. One S. uberis cross-reacted with antisera produced against the S. porcinus group E-type II reference strain. None of the remaining strains showed cross reactivity with any of the sera tested. (C) 1998 Chapman & Hall Ltd.