Aim: Chromobacterium are saprophytes that cause highly fatal opportunistic infections. Identification and strain differentiation were performed to identify the strain variability among the environmental samples. We have evaluated the suitability of individual and combined methods to detect the strain variations of the samples collected in different seasons.
Methods and results: Amplified ribosomal DNA restriction analysis (ARDRA) and random amplified polymorphic DNA (RAPD) profiles were obtained using four different restriction enzyme digestions (AluI, HaeIII, MspI and RsaI) and five random primers. A matrix of dice similarity coefficients was calculated and used to compare these restriction patterns. ARDRA showed rapid differentiation of strains based on 16S rDNA, but the combined RAPD and ARDRA gave a more reliable differentiation than when either of them was analysed individually.
Conclusion: A high level of genetic diversity was observed, which indicates that the Kolli Hills' C. violaceum isolates would fall into at least three new clusters.
Significance and impact of the study: Results showed a noteworthy bacterial variation and genetic diversity of C. violaceum in the unexplored, virgin forest area.
© 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.