Etiology of shigellosis in Henan province,2008

Objective To understand the etiological characteristics of Shigella,its serotype,drug resistance and toxic gene carriage in Henan province,and provide evidence for rational antibiotic use and epidemiological research.MethodsThe morphological-biochemical identification,serotyping and toxic gene detection were conducted for the Shigella strains isolated from patients in diarrhea surveillance sites in Henan province in 2008.Results A total of 272 Shigella strains were detected,including 250 S.flexneri strains and 22 S.sonnei strains.The drug susceptibility test for 100 Shigella strains by K-B method showed severe resistance to 14 antibiotics;the resistant rate was 99.1% to ampicillin,99.1% to nalidixic acid,100% to tetracycline and 85.7% to chlormycetin,and the resistant rate was 21.6%/20.6% to cefalotin/cefotaxime,40.2% to ciprofloxacin,66.7% to trimethoprim+sulfamethoxazole and 15.7% to tobramycin.In 120 Shigella strains,82.50% carried 4 toxic genes-set2,ipaH,ial,set1B,which would lead to diarrhea and related symptoms.Conclusion S.flexneri and S.sonnei stains were detected in Henan in 2008.Drug susceptibility test and PCR indicated that most strains were resistant to commonly used antibiotics and carried toxic genes.Close attention should be paid to the drug resistance of Shigella.