Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China.
Department of Infectious Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
J Antimicrob Chemother. 2019 Jan 1;74(1):29-37. doi: 10.1093/jac/dky412.
Development of resistance in Neisseria gonorrhoeae to ceftriaxone monotherapy or ceftriaxone plus azithromycin dual therapy is a global public health concern. The aim of this study was to analyse the trend in antimicrobial resistance in Hangzhou, China, over the period 2015-17.
In total, 379 clinical isolates were collected from seven hospitals and antimicrobial susceptibility was determined using the agar dilution method. Isolates showing resistance to ceftriaxone, azithromycin or cefixime were analysed for the presence of resistance determinants. STs were determined with the N. gonorrhoeae multiantigen sequence typing (NG-MAST) method and phylogenetic analysis and strain clustering was determined using porB and tbpB sequences.
Ceftriaxone resistance, decreased susceptibility to ceftriaxone and azithromycin resistance were observed in 3%, 17% and 21% of the isolates, respectively. This resulted in 5% of the isolates showing both decreased susceptibility to ceftriaxone and azithromycin resistance. Importantly, resistance levels to ceftriaxone and azithromycin increased over the study period, resulting in 5% ceftriaxone resistance, 27% decreased susceptibility to ceftriaxone and 35% azithromycin resistance in 2017 and 11% of the isolates showing both decreased susceptibility to ceftriaxone and azithromycin resistance. Phylogenetic and cluster analysis showed the emergence and expansion in 2017 of a clonally related cluster containing strains with high abundance of decreased susceptibility to ceftriaxone and/or cefixime, which was related to the presence of the mosaic penA allele X. Co-resistance to azithromycin was also observed in this cluster.
Our findings have major implications for the future reliability of ceftriaxone monotherapy and ceftriaxone plus azithromycin dual therapy in China.
淋病奈瑟菌对头孢曲松单药治疗或头孢曲松联合阿奇霉素联合治疗产生耐药性是全球公共卫生关注的问题。本研究旨在分析 2015-2017 年期间中国杭州地区抗菌药物耐药性的趋势。
共从 7 家医院采集了 379 株临床分离株，采用琼脂稀释法测定抗菌药物敏感性。对头孢曲松、阿奇霉素或头孢克肟耐药的分离株进行耐药决定因素分析。采用淋病奈瑟菌多位点序列分型（NG-MAST）方法和系统进化分析确定 ST 型，并通过 porB 和 tbpB 序列进行菌株聚类分析。
3%、17%和 21%的分离株分别出现了头孢曲松耐药、头孢曲松中介和阿奇霉素耐药，这导致 5%的分离株同时出现了头孢曲松中介和阿奇霉素耐药。重要的是，研究期间头孢曲松和阿奇霉素的耐药水平有所增加，导致 2017 年头孢曲松耐药率为 5%，头孢曲松中介率为 27%，阿奇霉素耐药率为 35%，11%的分离株同时出现了头孢曲松中介和阿奇霉素耐药。系统进化和聚类分析显示，2017 年出现了一个克隆相关的克隆群，该克隆群中含有大量头孢曲松和/或头孢克肟中介的菌株，这与 mosaic penA 等位基因 X 的存在有关。该克隆群中也观察到了对阿奇霉素的共同耐药性。
我们的研究结果对头孢曲松单药治疗和头孢曲松联合阿奇霉素联合治疗在中国未来的可靠性有重要影响。
