Presence of variations in ribosomal protein L16 corresponding to susceptibility of enterococci to oligosaccharides (avilamycin and evernimicin)

Fragments (414 bp) of the gene encoding ribosomal protein L16 from Enterococcus faecium and Enterococcus faecalis that were resistant and susceptible to the oligosaccharide antibiotics avilamycin and evernimicin (SCH 27899) were sequenced and compared. The susceptible E. faecalis and E.faecium isolates had sequences that were similar to those of the type strains. All resistant E.faecalis isolates contained the same base pair variation [CGT (Arg-56) --> CAT (His-56)]. The same variation and two additional variations [ATC (Ile-52) --> ACC (Thr-52) and ATC (Ile-52) --> AGC (Ser-52)] were found in the resistant E.faecium isolates. This study indicated that resistance to the oligosaccharides in enterococci is associated with variations in the ribosomal protein L16.