title: Primary antibiotic resistance of Helicobacter pylori isolated from Beijing children.
abstract: BACKGROUND
  The antimicrobials resistance of Helicobacter pylori (H. pylori) was able to sharply decline the eradication rate of H. pylori both in adults and children, but there are limited studies about the primary antibiotic resistance and the related gene mutations, specifically in China.
  
  
  METHODS
  The primary resistance to 9 antibiotics of 73 H. pylori strains isolated from gastric biopsies of children recruited at Beijing Children's Hospital was assessed, and the mutations in 23S rRNA gene of 65 macrolide-resistant strains and in gyrA and gyrB of 12 quinolone-resistant strains were investigated.
  
  
  RESULTS
  The resistance rate to clarithromycin, azithromycin, metronidazole, levofloxacin, moxifloxacin, and rifampicin was 84.9%, 87.7%, 61.6%, 13.7%, 15.1%, and 6.8%, respectively. No resistance to amoxicillin, gentamicin, and tetracycline was observed. Dual, triple, and quadruple antibacterial resistant percentage was 46.6% (34/73), 15.1% (11/73), and 2.7% (2/73), respectively. The gene mutation rate of A2142C, A2142G, and A2143G in 23S rRNA gene was 1.5% (1/65), 6.2% (4/65), and 84.6% (55/65), respectively. The detection rate of mutations of Asn87, Asp91, and Met191 in GyrA was 41.7% (5/12), 25% (3/12), and 25% (3/12), respectively.
  
  
  CONCLUSIONS
  The high prevalence of primary antibiotic resistance was out of expectation in H. pylori strains isolated from the children in Beijing. Antibiotic susceptibility should be made clear before the antibiotic was used in the anti-H. pylori therapy in this population. The A2143G was the most populated mutation in macrolide-resistant strains, and Asn87 and Asp91 of GyrA were the most common mutation points in quinolone resistance strains.
authors.affiliation: National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Liu
authors.forename: Xiwei
authors.initials: X
authors.lastname: Xu
authors.forename: Lihua
authors.initials: L
authors.lastname: He
authors.forename: Zhaolu
authors.initials: Z
authors.lastname: Ding
authors.forename: Yixin
authors.initials: Y
authors.lastname: Gu
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Zhang
authors.forename: Liya
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002681:China; D024881:Drug Resistance, Bacterial; D005260:Female; D005798:Genes, Bacterial; D016481:Helicobacter Infections / Q000188:drug therapy; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D059645:Mutation Rate; D012338:RNA, Ribosomal, 23S / Q000737:chemistry / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D012338:RNA, Ribosomal, 23S