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Page No. : 13-17

ABSTRACT

The emerging pathogens Escherichia albertii and Escherichia fergusonii have gradually gained public health importance with their increasing geographical range and spectrum of clinical manifestations in humans. Owing to the food-borne zoonotic potential of causing outbreaks of these two pathogens, elucidating the molecular epidemiology of these organisms become a necessity to develop appropriate intervention strategies. In this study, three PCR-based fingerprinting methods were compared to the gold standard of Pulsed Field Gel Electrophoresis in terms of typeability and discriminatory power. XbaI-based pulsotyping delineated 20 E. albertii and 39 E. fergusonii isolates with a discriminatory power of 0.9316 and 0.9744, respectively. Three E. albertii (15%) and five E. fergusonii (12.82%) isolates were considered untypable. Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR was able to type all the isolates with discriminatory power of 0.9947 and 1.0000 for E. albertii and E. fergusonii, respectively. On the other hand, (GTG)5 based rep-PCR was able to discriminate all isolates as separate entities, but lacked perfect typeability for E. albertii (95%). PCR-Random Amplified Polymorphic DNA (RAPD) was advantageous in terms of duration among the four with perfect typeability (100%) for both species, but failed to achieve perfect discriminatory power for E. fergusonii (0.9973). Repetitive elements-based PCR such as ERIC and GTG5, as well as PCR-RAPD using M13, serve as reliable alternatives to PFGE for understanding genetic diversity in a rapid and cost-effective manner.

Keywords: Escherichia albertii, Escherichia fergusonii, PFGE, ERIC-PCR, GTG5, PCR-RAPD