Characterization and CRISPR-based genotyping of clinical -positive .

BACKGROUND

is a causative agent of gastroenteritis. Most of the clinical isolates carry either and/or genes which are considered as the major virulence genes of this pathogen. In this study, the clinical isolates of carrying gene (= 73) obtained from 1886 to 2012 from various countries were investigated for the urease production, haemolytic activity, and biofilm formation. In addition, the potential of clustered regularly interspaced short palindromic repeats (CRISPR)-based genotyping among these isolates was investigated.

RESULTS

In this study, no significant differences were observed in the urease production between 1 and 2 isolates ( = 0.063) and between the 1 and 2 isolates ( = 0.788). The isolates carrying only the gene showed variation in their haemolytic activity. The ratio of urease production and haemolytic activity between the 1 and 2 isolates and biofilm formation of isolates were not significantly different. Sixteen of thirty-four tested isolates (47.0%) of were positive for CRISPR detection. The discriminatory power index (DI) of CRISPR-virulence typing was higher than the DI obtained by CRISPR typing alone.

CONCLUSION

The and genes were not involved in urease production in the , and variation of haemolytic activity detected in carrying only the gene might be correlated to the sequence variation within 1 and 2 genes. Additionally, biofilm production of was not associated with harboring of virulence genes. For genotyping, CRISPR sequences combined with virulence genes can be used as genetic markers to differentiate strains.