PCR-based detection of tyrosine decarboxylase (tdc) gene among different enterococcal strains tested. 1, E. faecalis KH 12; 2, E. faecium KH 24; 3, E. faecium DH 28; 4, E. faecium RH 31; 5, E. faecium RH 33; 6, E. faecium RH 38; 7, E. faecium DH 56; 8, E. faecium KH 58; 9, E. faecium DH 59; 10, E. faecium CH 60; 11, E. faecalis KH 62; 12, E. faecalis KH 67; 13, E. faecalis KH 70; 14, E. faecalis KH 72; 15, E. faecium RH 78; 16, E. faecium KH 79; 17, L. lactis subsp. cremoris NCDC 61 (negative control); 18, E. faecalis NCDC 114 (positive control); 19, E. faecalis NCDC 114 (positive control); 20, L. lactis subsp. cremoris NCDC 61 (negative control); 21, E. faecium KH 81; 22, E. faecalis KH 91; 23, E. faecalis KH 93; 24, E. faecalis KH 98; 25, E. faecium FH 99; 26, E. faecium FH 102; 27, E. faecium RH 106; 28, E. faecium KH 110; 29, E. faecalis KH 111; 30, E. faecium DH 115; 31, E. faecium KH 126 and 32, E. faecium FH 133.