Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from Hefei (2014–2015): genetic characteristics of antimicrobial resistance

Abstract

BackgroundAntimicrobial resistance (AMR) and genetic determinants of resistance of N. gonorrhoeae isolates from Hefei, China, were characterized adding a breadth of information to the molecular epidemiology of gonococcal resistance in China.Methods126 N. gonorrhoeae isolates from a hospital clinic in Hefei, were collected between January, 2014, and November, 2015. The minimum inhibitory concentration (MIC) of N. gonorrhoeae isolates for seven antimicrobials were determined by the agar dilution method. Isolates were tested for mutations in penA and mtrR genes and 23S rRNA, and also genotyped using N. gonorrhoeae multi-antigen sequence typing (NG-MAST).ResultsAll N. gonorrhoeae isolates were resistant to ciprofloxacin; 81.7% (103/126) to tetracycline and 73.8% (93/126) to penicillin. 39.7% (50/126) of isolates were penicillinase producing N. gonorrhoeae (PPNG), 31.7% (40/126) were tetracycline resistant N. gonorrhoeae (TRNG) and 28.6% (36/126) were resistant to azithromycin. While not fully resistant to extended spectrum cephalosporins (ESCs), a total of 14 isolates (11.1%) displayed decreased susceptibility to ceftriaxone (MIC ≥ 0.125 mg/L, n = 10), cefixime (MIC ≥ 0. 25 mg/L, n = 1) or to both ESCs (n = 3). penA mosaic alleles XXXV were found in all isolates that harbored decreased susceptibility to cefixime, except for one. Four mutations were found in mtrR genes and mutations A2143G and C2599T were identified in 23S rRNA. No isolates were resistant to spectinomycin. Gonococcal isolates were distributed into diverse NG-MAST sequence types (STs); 86 separate STs were identified.Conclusions N. gonorrhoeae isolates from Hefei during 2014–2015, displayed high levels of resistance to antimicrobials that had been recommended previously for treatment of gonorrhea, e.g., penicillin, tetracycline and ciprofloxacin. The prevalence of resistance to azithromycin was also high (28.6%). No isolates were found to be fully resistant to spectinomycin, ceftriaxone or cefixime; however, 11.1% isolates, overall, had decreased susceptibility to ESCs.

Increasing Resistance to Azithromycin in Neisseria gonorrhoeae in Eastern Chinese Cities: Resistance Mechanisms and Genetic Diversity among Isolates from Nanjing

“…3 ). In Nanjing (2008–2009), the prevalence of AZM-R N. gonorrhoeae was 6.8% (16/236) ( 33 ); in Hangzhou (2011–2012), resistance and high-level resistance to azithromycin were 21% (25/118) and 18% (21/118), respectively ( 22 ); in Guangzhou (2009–2013), resistance was 15.9% (77/485) ( 34 ); and in Hefei, resistance and high-level resistance to azithromycin were 28.6% (36/126) and 10% (13/126) in 2014 and 2015, respectively ( 35 ).…”

“…Our results indicate that the prevalence of AZM-R N. gonorrhoeae in Nanjing has risen >4-fold, from 6.8% to 32.3%, in the 7-year period between 2008 and 2009 ( 33 ) to 2013–2014, exceeding the national average by ∼1 3/4-fold in the latter period ( 36 ). During an earlier and overlapping period between 2009 and 2015, AZM-R almost doubled in three other eastern (and southeastern) Chinese cities, progressing from 16% in Guangzhou (2009–2013) ( 34 ) to 21% in Hangzhou (2011–2012) ( 22 ) to 29% in Hefei (2014–2015) ( 35 ) ( Fig. 3 ).…”

“…However, AZM resistance had not been monitored at the national level in China before 2013. Consequently, AZM resistance and molecular characterization of AZM-R N. gonorrhoeae in China had been limited ( 22 , 33 – 35 ). Between 2013 and 2016, the China Gonococcal Resistance Surveillance Programme (China-GRSP) determined that the prevalence of gonococcal AZM-R was 18.6% nationally (3,849 isolates tested from 7 sentinel sites located throughout China) ( 36 ).…”

The resistance of causative agents of sexually transmitted infections to azithromycin

“…В разных странах приняты рекомендации по лечению гонореи азитромицином в сочетании с антибиотиком цефалоспоринового ряда [8,12]. Однако в последнее время отмечен рост резистентности N. gonorrhoeae к азитромицину: в Китае, США, Австралии [5,6,8,9,12,13]. Не вызывает сомнений необходимость поиска новых методов лечения гонореи.…”

“…В Китае (Héféi) было проведено исследование резистентности N.gonorrhoeae к различным антибиотикам. По результатам исследований, проведенных с января 2014 по ноябрь 2015 г., во всех образцах отмечена резистентность к ципрофлоксацину, 81,7% -к тетрациклину, 73,8% -к пенициллину; в 39,7% образцов зарегистрирована продукция пенициллиназы, в 31,7% -резистентность к тетрациклину, в 28,6%к азитромицину [6]. В другом исследовании, проведенном в Китае (Нанкин), в 36,9% образцов, полученных от мужчин, страдавших гонорейным уретритом, отмечена резистентность к азитромицину [7].…”