BACTERIOCIN TYPING OF BURKHOLDERIA (PSEUDOMONAS) SOLANACEARUM RACE-1 OF THE FRENCH-WEST-INDIES AND CORRELATION WITH GENOMIC VARIATION OF THE PATHOGEN

Burkholderia solanacearum race 1 isolates indigenous to the French Wes t Indies were characterized by bacteriocin typing and two genomic fing erprinting methods: pulsed-field gel electrophoresis of genomic DNA di gested by rare-cutting restriction endonucleases (RC-PFGE) and PCR wit h primers corresponding to repetitive extragenic palindromic (REP), en terobacterial repetitive intergenic consensus (ERIC), and BOX elements (collectively known as rep-PCR). The survey comprised 24 reference st rains and 65 isolates obtained from a field trial in Guadeloupe in 199 3. Comparison of the data identified RC-PFGE as the most discriminator y method, delineating 17 pulsed-field gel profile types. rep-PCR and b acteriocin typing identified nine rep-PCR profile types and nine bacte riocin groups. Independent determination of similarity coefficients an d clustering of RC-PFGE and rep-PCR data identified six groups common to both sets of data that correlated to biovar and bacteriocin groups. Further study of bacteriocin production in planta gave results consis tent with in vitro bacteriocin typing. It was observed that spontaneou s bacteriocin-resistant mutants exhibited a cross-resistance to other bacteriocins as identified by the typing scheme and that such mutants possessed a selective advantage for growth over isogenic nonmutants in the presence of a bacteriocin. The results are significant in the sea rch for biological control of disease by nonpathogenic mutants of the wild-type organism.