Serotype and drug resistance of isolated Shigella strains in Taiyuan in 2006

Objective The study was conducted to investigate the main serotypes and drug resistance to commonly used antibiotics of isolated Shigella strains in Taiyuan. Methods Serotyping, biochemical identification and drug susceptibility tests were performed for the Shigella strains isolated from diarrhea patients. Results There were 40 positive strains isolated from 129 diarrhea samples, including 33 strains of Shigella flexneri, accounting for 82.5% of all isolates; 7 strains of Shigella sonnei, accounting for 17.5%. 21 strains of Shigella flexneri type 4c were found, accounting for 63.6% of all shigella flexneri strains. The Shigella flexneri strains had 100% resistance to nalidixic acid, and 97% resistance to ampicillin and tetracycline. By contrast, they had 97% sensitivity to cefotaxime and gentamicin. The Shigella sonnei strains had 100% resistance to nalixidic acid, tetracycline and co-trimoxazole, 100% sensitivity to amoxicillin, cefotaxime and ciprofloxacin. Conclusion The predominant Shigella strain was Shigella flexneri type 4c in Taiyuan in 2006. Different serotypes of Shigella presented varying degrees of resistance to commonly used antibiotics.