title: The prevalence and epidemiology of plasmid-mediated penicillin and tetracycline resistance among Neisseria gonorrhoeae isolates in Guangzhou, China, 2002-2012.
abstract: BACKGROUND
  Gonococcal antimicrobial resistance is a global problem. Different resistance plasmids have emerged and spread among the isolates of Neisseria gonorrhoeae worldwide and in China. We conducted this study to monitor the plasmid-mediated penicillin and tetracycline resistance among N. gonorrhoeae isolates in Guangzhou from 2002 to 2012.
  
  
  METHODS
  Consecutive isolates of N. gonorrhoeae were collected from outpatients with gonorrhea attending the STD clinic in Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention. Penicillinase-producing N. gonorrhoeae (PPNG) isolates were analyzed by the paper acidometric method. Plasmid-mediated resistance to tetracycline in N. gonorrhoeae (TRNG) isolates was screened by the agar plate dilution method. Plasmid types were determined for TRNG and PPNG isolates using polymerase chain reaction (PCR). Minimum inhibitory concentrations (MICs) to penicillin and tetracycline were detected by the agar plate dilution.
  
  
  RESULTS
  Of 1378 consecutive N. gonorrhoeae isolates, 429 PPNG and 639 TRNG isolates were identified. The prevalence of PPNG, TRNG, and PPNG/TRNG increased from 18.3 to 47.1 % (χ (2) = 31.57, p < 0.001), from 29.4 to 52.1 % (χ (2) = 16.28, p < 0.001) and from 10.0 to 26.2 % (χ (2) = 10.46, p < 0.001) between 2002 and 2012, respectively. Genotyping of plasmids among PPNGs showed that the majority (93.7 %) of the isolates were the Asian type plasmids, while the African type plasmid emerged in 2008 and rapidly increased to 14.0 % in 2012 (χ (2) = 25.03, p < 0.001). For TRNGs, all 639 isolates carried the Dutch type plasmid. MICs of penicillin G and tetracycline persisted at high levels and the MIC90s were 32-fold higher than the resistant cutoff point over 11 years. The prevalence rates of penicillin- and tetracycline-resistant N. gonorrhoeae varied from 90.9 to 91.1 % and from 88.3 to 89.3 % during 2002 to 2012, respectively.
  
  
  CONCLUSIONS
  Resistance to penicillin and tetracycline among N. gonorrhoeae isolates remained at high levels in Guangzhou. The Asian type PPNG continued to spread and Dutch type TRNG was still the dominant strain. The African type PPNG has emerged and is spreading rapidly.
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. zhhpf@hotmail.com.
authors.forename: Heping
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. xingzhongwu@aliyun.com.
authors.forename: Xingzhong
authors.initials: X
authors.lastname: Wu
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. jinmeih2013@163.com.
authors.forename: Jinmei
authors.initials: J
authors.lastname: Huang
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. qinxiaolin200810@163.com.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Qin
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. 2207490328@qq.com.
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. 1450560649@qq.com.
authors.forename: Weiying
authors.initials: W
authors.lastname: Zeng
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. 459095418@qq.com.
authors.forename: Yinyuan
authors.initials: Y
authors.lastname: Lan
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. 330706670@qq.com.
authors.forename: Jiangli
authors.initials: J
authors.lastname: Ou
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. iamtangsanmei_2006@126.com.
authors.forename: Sanmei
authors.initials: S
authors.lastname: Tang
authors.affiliation: Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention, Guangzhou, 510091, China. meditate28@qq.com.
authors.forename: Mingheng
authors.initials: M
authors.lastname: Fang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006069:Gonorrhea / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D010400:Penicillin G; D010405:Penicillinase / Q000235:genetics / Q000378:metabolism; D010406:Penicillins / Q000494:pharmacology*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D013753:Tetracycline Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins; D010405:Penicillinase; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1; D010400:Penicillin G