The Drug Resistance Analysis And Epidemiology Characetristics Of Shigella

ObjectiveTo vestigat the distribution and resistance of122clinical isolates of Shigella spp in32hospitals in Anhui Province,Sept.2011to guide clinical medication.To the investigate distribution of integron and gene cassettes embedded in122clinicalShigella isolates and analyze the multi-drug resistance of the integron positive Shigellaisolates.To the investigate epidemic characteristics and flora distribution of bacillary dysentery of Hefeiarea between2004and2011.Materials and MethodsThe122clinical isolates of Shigella spp. were collected in Sept.2011from32hospitals ofAnhui province. All isolates were cultured according to national guide to clinical laboratoryprocedures and were identified with the Microscan Walkaway-96System and serologicalidentification.Antimicrobial susceptibility testing was performed by agar dilution method. E. coli ATCC25922and ATCC35218were stored at the Anhui Center for Surveillance of BacterialResistance (Hefei, Anhui, China).PCR were carried out to detected IntI gene and gene cassettes in all Shigella isolates.Retrospective analyze the Shigella-detecting results of outpatient’s stool and the data of age,gender and other related information ResultsIn122clinical Shigella isolates,118isolates (96.7%) were S.flexneri,4isolates (3.3%) wereS.sonnei, no S.dysenteriae and S.boydii.The resistance rates of122isolates to piperacillin/tazobactam, cefmetazole and latamoxefwere lower than othercephalosporins. All isolates were susceptible to imipenem. And theresistance rates were highest to ampicillin and tetracycline.The resistance rates tociprofloxacin is28.69%, levofloxacin17.21%and, gatifloxacin13.11%.Most Shigella isolates were found to harbor one or two classes of integrons:91isolatespossessed a class1integron including11typical class1integron and60atypical class1integron,67isolates possessed a class2integron.The gene cassettes of typical class1integrons dfrA17-aadA5and dfrA12-orfF-aadA2were detected in22isolates. IntI2wasamplified in67Shigella isolates and all contained constant gene cassette arrays ofdfrA1-sat1-aadA1. After statistical analysising, the positive rate of class1integrons,atypicalclass1integron and class2integron was statistically significant wiht multi-drug resistant.There were248confirmed bacillary dysentery patients among10366suspicious outpatients.The detection rate was2.42%. The sex ratio approached one to one and the average age was25.24years old. Patients from0to40years old accounted for81.04%of all confirmed patients.Totally，there were114strains of S. flexneri,129strains of S. sonnei,4strains of S. boydii and1strain of S. dysenteriae.ConclusionsThe main serotypes of Shigella isolates in Anhui province2011were S flexneri, Shigellaisolates showed high resistance to several antimicrobials and multidrug resistance is fairlyserious. Cefoxitin, cefepime, ceftazidim, piperacillin/tazobactam, imipenem and levofloxacincan be used in treating patients infected with Shigella as empirical therapy in our region. Theexistence of integrons plays an important role in drug resistance. Young adults are vulnerable to acute bacillary dysentery, and the gender difference is minimal. S. sonnei has surpassed S.flexneri in incidence rate and become the most common cause of bacillary dysentery.