Prevalence and susceptibility of Shigella species to 11 antibiotics in a Kuwait Teaching Hospital

During the 5-year period 1990-1993 and 1996, 202 Shigella spp. were isolated from stool specimens of symptomatic patients of all age groups seen in our hospital. Over these periods the trend of the incidence of shigellosis showed that 18% of the total strains were isolated during the invasion year (1990) followed by an upsurge (24%) during the Gulf War period (1991) and a steady decline in the post-war period, 17% in 1992 and 14% in 1993. There was another wave of increased isolation rate (27%) during a period of relative calm in the country (1996) studied for comparison. The predominant Shigella species was S. flexneri which accounted for 46% of the 202 isolates, followed by S. sonnei (42%), S. dysenteriae (7%) and S. boydii (5%). Fifty-four percent of the 202 Shigella isolates were resistant to ampicillin, 56% to trimethoprim/sulfamethoxazole, 35% to chloramphenicol, 13% and 9% to cephalothin and amoxicillin/clavulanic acid respectively. All the isolates were fully susceptible to ciprofloxacin, the aminoglycosides and the second- and third-generation cephalosporins. Eighty-seven (43%) of the 202 isolates were resistant to two or more antibiotics. Of the 87 multiply resistant Shigella spp., 58 (67%) were S. flexneri while 19 (22%) were S. sonnei. Shigella resistance to the first-line antibiotics is a major problem that frequently limits the therapeutic options with orally available active antibiotic therapy.