title: Surveillance of antimicrobial susceptibility patterns among Shigella species isolated in China during the 7-year period of 2005-2011.
abstract: BACKGROUND
  Shigella is a frequent cause of bacterial dysentery in the developing world. Treatment with antibiotics is recommended for shigellosis, but the options are limited due to globally emerging resistance. This study was conducted to determine the frequency and pattern of antimicrobial susceptibility of Shigella in China.
  
  
  METHODS
  We studied the antimicrobial resistance profiles of 308 Shigella spp. strains (260 S. flexneri, 40 S. sonnei, 5 S. boydii, and 3 S. dysenteriae) isolated from fecal samples of patients (age, from 3 months to 92 yr) presenting with diarrhea in different districts of Anhui, China. The antimicrobial resistance of strains was determined by the agar dilution method according to the CSLI guidelines.
  
  
  RESULTS
  The most common serogroup in the Shigella isolates was S. flexneri (n=260, 84.4%), followed by S. sonnei (n=40, 13.0%). The highest resistance rate was found for nalidixic acid (96.4%), followed by ampicillin (93.2%), tetracycline (90.9%), and trimethoprim/sulfamethoxazole (80.8%). Among the isolates tested, 280 (91.0%) were multidrug resistant (resistant to ≥2 agents). The most common resistance pattern was the combination of ampicillin, tetracycline, and trimethoprim/sulfamethoxazole (70.8%). Resistance to ampicillin and tetracycline were more common among S. flexneri than among S. sonnei isolates.
  
  
  CONCLUSIONS
  S. flexneri is predominant in Anhui, China, and its higher antimicrobial resistance rate compared with that of S. sonnei is a cause for concern. Continuous monitoring of resistance patterns is necessary to control the spread of resistance in Shigella. The recommendations for antimicrobial treatment must be updated regularly based on surveillance results.
authors.affiliation: Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
authors.forename: Haifei
authors.initials: H
authors.lastname: Yang
authors.forename: Guosheng
authors.initials: G
authors.lastname: Chen
authors.forename: Yulin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.forename: Lifen
authors.initials: L
authors.lastname: Hu
authors.forename: Ying
authors.initials: Y
authors.lastname: Ye
authors.forename: Jiabin
authors.initials: J
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000667:Ampicillin / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D002681:China; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D004405:Dysentery, Bacillary / Q000175:diagnosis* / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009268:Nalidixic Acid / Q000494:pharmacology; D012760:Shigella / Q000187:drug effects* / Q000302:isolation & purification; D012763:Shigella flexneri / Q000187:drug effects / Q000302:isolation & purification; D012764:Shigella sonnei / Q000187:drug effects / Q000302:isolation & purification; D013752:Tetracycline / Q000494:pharmacology; D013997:Time Factors; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents; D009268:Nalidixic Acid; D000667:Ampicillin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D013752:Tetracycline
keywords: Antimicrobial resistance; Antimicrobial susceptibility; Shigella