A SINGLE EMM GENE-SPECIFIC OLIGONUCLEOTIDE PROBE DOES NOT RECOGNIZE ALL MEMBERS OF THE STREPTOCOCCUS-PYOGENES M-TYPE-1

Serological typing of the streptococcal M protein has recently been ch allenged by a number of unique molecular methodologies based on oligon ucleotide recognition of allelic variations within the M protein (emm) gene. In these methods, stringent hybridization of an oligonucleotide probe to a polymerase chain reaction amplified emm gene is used as co nfirmation of specific M type identity. A sample of 17 isolates from 7 previously defined distinct genotypes were tested using a single M1 o ligonucleotide probe. Isolates from only three of the genotypes hybrid ized with the probe. The results demonstrate that a single emm-specifi c oligonucleotide probe can not identify all members of M type 1, as d efined by conventional serotyping using polyclonal antisera.