RAPD profile and antibiotic susceptibility of Xylella fastidiosa, causal agent of citrus variegated chlorosis

Aims: The aim of this study was to evaluate the diversity of Xylella fastid iosa isolated from citrus trees affected by Citrus Variegated Chlorosis (CV C). Methods and Results: The antibiotic susceptibility by agar disc diffusion a nd minimum inhibitory concentration (MIC) methods was observed for all drug evaluated, except for penicillin-G. Genetic diversity by RAPD analysis rev ealed three major groups (citrus, coffee and grapevine), being the citrus g roup more similar with the coffee group than with the grapevine group. Conclusions, Significance and Impact of the Study: This study highlights th e possibility to use these antibiotics susceptibility as markers in the dev elopment of a cloning vector and penicillin-G could be used as a selective marker for the isolation of X. fastidiosa from citrus plants.