title: Prevalence, resistance patterns, and characterization of integrons of Shigella flexneri isolated from Jiangsu Province in China, 2001-2011.
abstract: OBJECTIVE
  To provide the epidemiology, resistance pattern, and characterization of integrons in Shigella flexneri isolated between 2001 and 2011 in Jiangsu Province.
  
  
  METHODS
  A total of 624 strains of S. flexneri were collected from both outpatients and inpatients in hospitals in Jiangsu Province from January 2001 to December 2011. The Kirby-Bauer disk diffusion method was used to perform the antimicrobial susceptibility test. Polymerase chain reaction (PCR) was used in the detection of integrons. Pulsed-field gel electrophoresis (PFGE) was applied in the homology studies.
  
  
  RESULTS
  Serotype 2a accounted for the largest proportion in S. flexneri, namely 26.4 %. Notably, an increasing trend was detected in the resistance to common antimicrobial agents during the period 2001-2011. In recent years, more than 80.0 % isolates of S. flexneri have proved to be resistant to ampicillin, nalidixic acid, and tetracycline. The positive rates of class 1, class 2, and the atypical class 1 integrons in S. flexneri are 69.3 %, 87.8 %, and 89.2 % respectively. Most integrons detected in our research carry genes encoding resistance to trimethoprim and streptomycin.
  
  
  CONCLUSIONS
  Antimicrobial resistance in S. flexneri has demonstrated a continuous rising trend in Jiangsu Province. A high prevalence of integrons and gene cassettes play an important role in the transmission of drug resistance in S. flexneri. Effective measures are urgently needed to control the spread of multi-drug-resistant S. flexneri, and more continuing active surveillance of antimicrobial resistance should be established worldwide, especially in developing countries.
authors.affiliation: Department of General Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Acute Infectious Disease Prevention and Control, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, 210029, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhuang
authors.affiliation: Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, China.
authors.forename: H
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, China.|Medical Technology Institute of Xuzhou Medical University, Xuzhou, 221004, China.
authors.forename: P
authors.initials: P
authors.lastname: Ma
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: T
authors.initials: T
authors.lastname: Xu
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China. sypan@njmu.edu.cn.
authors.forename: S
authors.initials: S
authors.lastname: Pan
authors.affiliation: Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, China. gb20031129@163.com.|Medical Technology Institute of Xuzhou Medical University, Xuzhou, 221004, China. gb20031129@163.com.
authors.forename: B
authors.initials: B
authors.lastname: Gu
mesh_terms: D000900:Anti-Bacterial Agents; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000032:analysis* / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004405:Dysentery, Bacillary / Q000453:epidemiology* / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D032023:Integrons / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D012763:Shigella flexneri / Q000187:drug effects* / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial