The Recent Trends of Shigellosis: A JIPMER Perspective

The multi-drug resistant Shigella has posed a therapeutic challenge in most parts of the world. In the last few years, there has been a tremendous change in the anti-microbial susceptibility profile of this organism.

This present study was carried out to determine the current anti-microbial susceptibility pattern of the members of the genus, Shigella in our region.

Two thausand six hundred fifty eight stool samples from patients with diarrhoea were received between 2008 and 2010. The disc diffusion testing was performed by the Kirby-Bauer method and the minimum inhibitory concentrations (MICs) of ciprofloxacin and ceftriaxone were obtained by the agar dilution method and the E-test. The double disk synergy test was used to confirm the status of the extended beta-lactamase producers.

74 (2.78%) Shigella spp were isolated, out of which S.flexneri was 90.54%, S.dysenteriae was 2.70%, S.boydii was 1.35% and S.sonnei was 5.40%. 43 (58.108%) strains were isolated from children of 0 to ≤5 years, 13(17.56%) were isolated from children who were >5 years but ≤ 15 years of age and the rest of the 18 (24.32%) were isolated from adult patients. 79% of the strains were resistant to ampicillin, followed by 51% which were resistant to nalidixic acid, followed by 50% which were resistant to ciprofloxacin (the MIC of ciprofloxacin was 16μg/ml), and 39.4% which were resistant to furoxone and chloramphenicol respectively. 2 (3%) strains of S.flexneri were found to be resistant to ceftriaxone, which had MICs of > 256µg/ml. The ceftriaxone resistant S. flexneri isolates were confirmed to be extended spectrum beta-lactamase producers by the double disk synergy test.

The continuous assessment of the anti-microbial susceptibility patterns and the periodic reporting in this context is important.