Need for an Optimized Protocol for Screening Seafood and Aquatic Environment for Shigella sp

Abstract

Shigella sp are known to cause shigellosis, an acute enteric infection affecting over 164.7 million people accounting for 69 per cent mortality in children below 5 years of age globally (Kotloff et al., 1999; WHO, 2005) and 80 per cent of these cases are registered in Asia (Bardhan et al., 2010). India is endemic to Shigellosis (Taneja & Mewara, 2016) and the most common species reported is Shigella flexneri. Increase in seafood trade and consumption may potentiate the spread of this bacterium. Shigella is not a native flora of fish and Shigellosis outbreaks may occur by consumption of uncooked shrimp and tuna salad contaminated with Shigella sp (Novotny et al., 2004). The main mode of transmission in humans is through oral-faecal route through contamination of food and water by the infected people. Further, the infective dose of this bacterium is as low as ten cells and this makes Shigella a highly contagious pathogen (Du Pont et al., 1989). Few reports are available on the isolation, identification and molecular confirmation of Shigella sp from seafood (Reeve et al., 1989; David et al., 2009; Iwamoto et al., 2010; Sujatha et al., 2011; Sichewo et al., 2013; Obaidat & Salman, 2017) and there is difficulty in differentiating Shigella from E. coli. Hence, the present study was undertaken to assess the occurrence of Shigella sp in various seafood, ice and fishery environments and to determine the suitability of the standard method for identifying Shigella in seafood.