Analysis of a consensus fragment in ERIC-PCR fingerprinting of Enterobacter sakazakii

Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR was employed to generate ERIC-PCR fingerprints of 23 strains of E. sakazakii. A consensus fragment was observed in all 23 strains and was purified, cloned and sequenced from type strain ATCC29544. A comparison of the nucleotide acid with other sequences available in the GenBank revealed 98% of identity with E. sakazakii ATCC BAA-894 and 71%-75% identity with oligopeptidase gene or protease II gene of some species from the Enterobacteriaceae family. The consensus fragment from ATCC29544 was used to synthesize probes using DIG-labeling by PCR for dot hybridization. The consensus fragment was found to be highly conserved. Diversity analysis based on the consensus fragment sequencing showed a high heterogeneity between E. sakazakii strains and other related strains. In addition, 24 E. sakazakii strains could be distributed into two groups, while E. sakazakii ATCC51329 formed a separate branch. Genetic diversity and potential taxonomic complexity were evident within the E. sakazakii strains.