Antimicrobial Susceptibility Patterns Of Shigella Species In Southern Taiwan, 2001-2007

Background: Antibiotic resistance of Shigella spp. has increased recently and varies with geographic distribution. The empirical antibiotic therapy in each region would need to be updated accordingly. Methods: Anti-microbial susceptibilities of Shigella isolates collected in a central laboratory in southern Taiwan were examined by the disc diffusion method. Epidemiologically related cases were classified as cases of an outbreak event. Only one isolate for each episodic case or outbreak event was included for analysis. Results: From 2001 to 2007, 47 Shigella isolates including 25 S. flexneri, 2 S. boydii and 20 S. sonnei were analyzed. All were susceptible to ciprofloxacin and with varied resistance to other antibiotics: 6.4% to cefotaxime, 51.1% to ampicillin, 63.8% to trimethoprim -sulfamethoxazole, and 38.3% to chloramphenicol. Resistance to cefotaxime emerged since 2006, whereas resistance trends to other antibiotics were unchanged significantly in the past 7 years. Conclusion: Continued monitoring of Shigella isolates to detect the emergence of resistance is essential, especially resistance to the 3rd generation cephalosporin.