Distribution of the hyaluronate lyase encoding gene hylB and the insertion element is1548 in streptococci of serological group B isolated from animals and humans

The present study was performed to investigate streptococci of serological group B obtained from various sources and group B streptococcal reference strains for serotype, hyaluronate lyase enzyme activity, the occurrence of the hylB gene and the insertion sequence is 1548. All group B streptococci were identified by cultural, biochemical, and serological properties and by polymerase chain reaction amplification of species-specific parts of the 16S–23S r dna intergenic spacer region, the 16S r rna gene and the camp-factor ( cfb) gene. Of the 73 group B streptococci investigated, 59 strains displayed hyaluronate lyase enzyme activity. All hyaluronate-lyase-positive strains and three phenotypically hyaluronate-lyase-negative strains had a hylB gene with an amplicon size of 3.3 kb. Eleven of the 14 phenotypically hyaluronate-lyase-negative strains generated a hylB gene pcr product with a size of 4.6 kb, and 10 of these strains displayed a is 1548 amplicon with a size of 0.98 kb. The hyaluronate-lyase-negative isolates were mainly observed among group B streptococci of serotype III/Rib. All strains harbouring is 1548 had an additional copy of is 1548 located downstream of the C5a peptidase ( scpB) gene.