EVALUATION OF THE APPLICABILITY OF AMPLIFIED RDNA-RESTRICTION ANALYSIS (ARDRA) TO IDENTIFICATION OF SPECIES OF THE GENUS CORYNEBACTERIUM

The 16S rRNA genes (rDNA) of 50 strains belonging to 26 different cory neform bacterial species and genomospecies and of the type strain of R hodococcus equi were enzymatically amplified. Amplified rDNA restricti on analysis (ARDRA) with the enzymes AluI, CfoI and RsaI was carried o ut. The combination of the ARDRA patterns obtained after restriction w ith these three different enzymes enabled the differentiation between the following species: Corynebacterium accolens (number of strains = 2 ), C. afermentans subsp. afermentans (2), C. afermentans subsp. lipoph ilum (2), C. amycolatum (3), CDC coryneform group ANF-1-like (1), CDC coryneform group ANF-3-like (1), C. cystitidis (1), C. diphtheriae (4) , C. jeikeium (3), C. macginleyi (2), C. minutissimum (1), C. pilosum (1), C. pseudotuberculosis (2), C. renale (2), C. striatum (2), C. ure alyticum (3), C. xerosis (1), CDC coryneform groups B-1 (2); B-3 (2), F-1, genomospecies 1 and 2 (6) G, genomospecies 1 (1) and G, genomospe cies 2 (2). The following strains or species could not be differentiat ed from each other: C. pseudodiphtheriticum (2) from C. propinquum (fo rmer CDC coryneform group ANF-3) (2), CDC coryneform group F-1, genomo species 1 (4) from genomospecies 2 (2) and C. jeikeium genomospecies A (1) from genomospecies C (2). ARDRA may represent a possible alternat ive for identification of coryneforms, since this technique enabled th e identification of most coryneforms tested and since DNA extraction ( i.e. cell lysis by boiling), amplification, restriction and electropho resis can be carried out within 8 hours. This might allow quick identi fication of C. diphtheriae and other possible pathogens of the genus C orynebacterium.