“…These approaches fall into two categories : those based on the detection of species-specific sequences that are not present in the chromosome of all staphylococci (Akatova et al, 1992 ;Chesneau et al, 1993a ;Martineau et al, 1996 ;Vandenesch et al, 1995) and those based on the detection of sequence variations in ubiquitous elements such as rRNA and tRNA operons (Bialkowska-Hobrzanska et al, 1990 ;Chesneau et al, 1992 ;De Buyser et al, 1989Forsman et al, 1997 ;Gaszewska-Mastalarz et al, 1998 ;Hesselbarth & Schwarz, 1995 ;Irlinger et al, 1997 ;Kluytmans et al, 1998 ;Maes et al, 1997 ;Mendoza et al, 1998 ;Pennington et al, 1991 ;Thomson-Carter et al, 1989 ;Webster et al, 1994 ;Welsh & McClelland, 1992) or chaperonin-encoding genes (Goh et al, 1997). The second of these categories of methods may be useful for classifying staphylococci if appropriate databases exist and are updated continuously as data for new taxa become available.…”