在鉴定出一种新的整合和接合元件的耐氟喹诺酮B群分离株中，III/ST19和Ib/ST10谱系占主导且具有高度多重耐药性。
Predominance of III/ST19 and Ib/ST10 Lineages With High Multidrug Resistance in Fluoroquinolone-Resistant Group B Isolates in Which a New Integrative and Conjugative Element Was Identified.
作者信息
Gao Kankan, Gao Chunyan, Huang Lianfen, Guan Xiaoshan, Ji Wenjing, Chang Chien-Yi, McIver David J, Deng Qiulian, Zhong Huamin, Xie Yongqiang, Deng Lei, Gao Fei, Zeng Lanlan, Liu Haiying
机构信息
Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
Clinical Laboratory, Tangshan Municipal Women and Children's Hospital, Tangshan, China.
出版信息
Front Microbiol. 2021 Jan 25;11:609526. doi: 10.3389/fmicb.2020.609526. eCollection 2020.
Fluoroquinolone (FQ)-resistant Group B (GBS) has been reported with considerable cross-resistance, worsening the crisis of multidrug-resistant (MDR) GBS in clinical settings. However, national epidemiological data on FQ-resistant GBS in mainland China have not been well-characterized. This study aimed to determine the prevalence of FQ resistance among GBS from neonatal invasive infections and maternal colonization in northern and southern China, to investigate the serotyping, multilocus sequence typing, and antibiotic cross-resistance, and to characterize the mutations in and genes in quinolone resistance-determining region (QRDR). In order to provide a comprehensive view of the location and structure of resistance genes, whole-genome sequencing on III/ST19 MDR isolates were performed. Among 426 GBS, 138 (32.4%) were FQ resistant, with higher prevalence in northern China than in southern China in both neonates (57.8%, 37/64 vs. 21.7%, 39/180) and pregnant women (50.9%, 29/57 vs. 26.4%, 33/125). Serotypes were distributed as III (48.5%), Ib (39.9%), V (6.5%), and Ia (5.1%). Sequence types were mainly ST19 (53.6%) and ST10 (39.1%), followed by ST12 (1.4%), ST17 (1.4%), ST23 (1.4%), and 0.7% each of ST27, ST188, ST197, and ST597. ST19 isolates were more prevalent in southern China than in northern China in both neonates (64.1%, 25/39 vs. 27.0%, 10/37) and pregnant women (81.8%, 27/33 vs. 41.4%, 12/29), whereas ST10 isolates were more common in northern China than in southern China in both neonates (64.9%, 24/37 vs. 20.5%, 8/39) and pregnant women (58.6%, 17/29 vs. 15.2%, 5/33). Serotype III isolates were mainly ST19 (89.6%, 60/67), while Ib isolates were largely ST10 (94.5%, 52/55). Sequencing data revealed several mutations in QRDR, including Ser81Leu in (99.2%, 130/131), Ser79Phe or Tyr in (76.2%, 48/63), and a previously unreported Ile218Thr and Ile219Phe double mutation pattern (49.2%, 31/63) in . ST10 isolates were associated with Ser79Phe (84%, 21/25), while ST19 isolates were limited to Ser79Tyr (95.7%, 22/23). A new integrative and conjugative element (ICE) harboring and genes was identified in a III/ST19 isolate. This study investigates the molecular characteristics of FQ-resistant GBS in northern and southern China, emphasizing the need for continuous surveillance geographically and further research to characterize the mechanisms of ICE transfer.
据报道，耐氟喹诺酮（FQ）的B组链球菌（GBS）存在相当程度的交叉耐药性，这加剧了临床环境中耐多药（MDR）GBS的危机。然而，中国大陆耐FQ的GBS的全国流行病学数据尚未得到充分描述。本研究旨在确定中国北方和南方新生儿侵袭性感染及产妇定植的GBS中FQ耐药性的流行情况，调查血清型、多位点序列分型及抗生素交叉耐药性，并鉴定喹诺酮耐药决定区（QRDR）中gyrA和parC基因的突变。为全面了解耐药基因的位置和结构，对III/ST19 MDR分离株进行了全基因组测序。在426株GBS中，138株（32.4%）耐FQ，在中国北方的新生儿（57.8%，37/64对21.7%，39/180）和孕妇（50.9%，29/57对26.4%，33/125）中，北方的患病率均高于南方。血清型分布为III型（48.5%）、Ib型（39.9%）、V型（6.5%）和Ia型（5.1%）。序列型主要为ST19（53.6%）和ST10（39.1%），其次是ST12（1.4%）、ST17（1.4%）、ST23（1.4%），ST27、ST188、ST197和ST597各占0.7%。在新生儿（64.1%，25/39对27.0%，10/37）和孕妇（81.8%，27/33对41.4%，12/29）中，ST19分离株在南方比北方更普遍，而ST10分离株在北方比南方更常见。血清型III分离株主要为ST19（89.6%，60/67），而Ib分离株主要为ST10（94.5%，52/55）。测序数据显示QRDR中有多个突变，包括gyrA中的Ser81Leu（99.2%，130/131）、parC中的Ser79Phe或Tyr（76.2%，48/63），以及parC中先前未报道的Ile218Thr和Ile219Phe双突变模式（49.2%，31/63）。ST10分离株与Ser79Phe相关（84%，21/25），而ST19分离株仅限于Ser79Tyr（95.7%，22/23）。在一株III/ST19分离株中鉴定出一个携带gyrA和parC基因的新的整合和接合元件（ICE）。本研究调查了中国北方和南方耐FQ的GBS的分子特征，强调了在地理上持续监测以及进一步研究以表征ICE转移机制的必要性。
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