[Antibiotic resistance rates of Shigella species isolated from stool cultures in the years 1999-2003].

In this study, species distribution, seasonal isolation rates and antibiotic susceptibilitiy patterns of 115 Shigella spp, isolated from 5396 stool samples in our microbiology laboratory between 1999 and 2003, were investigated. Of the isolates, 96 (83.5%) were S. sonnei, 15 (13%) were S. flexneri, 3 (2.6%) were S. dysenteriae and 1 (1.9%) was S. boydii. Maximum isolation rates were observed at summer and fall seasons, especially in August, September and November (24%, 40%, 17%, respectively). The resistance rates against trimetoprime-sulphametoxasole and ampicillin were 79.1% and 19.1%, respectively. The rate of co-resistance against these two drugs was 12.2 percent. No isolate was found to be resistant to ciprofloxacin. Only one S. sonnei isolate had extended spectrum beta-lactamase detected by double-disk synergy test. In conclusion, ciprofloxacin is the drug of choice for empirical treatment of shigellosis. However, to avoid the loss of this choice, ampicillin which still has an high effectivity rate, should be preferred for the treatment of shigellosis with the guidence of antibiogram results. On the other hand, emergence of ESBL production among Shigella spp. after Salmonella spp. should warn us about the unexpected results of inappropriate antibiotic therapy.