Shi Qiucheng, Ye Yihua, Lan Peng, Han Xinhong, Quan Jingjing, Zhou Mingming, Yu Yunsong, Jiang Yan
Department of Clinical Laboratory, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, China.
Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Front Microbiol. 2021 Nov 22;12:764787. doi: 10.3389/fmicb.2021.764787. eCollection 2021.
The non-Typhi (NTS) infection is critical to children's health, and the ceftriaxone is the important empirical treatment choice. With the increase resistance rate of ceftriaxone in , the molecular epidemiology and resistance mechanism of ceftriaxone-resistant needs to be studied. From July 2019 to July 2020, a total of 205 NTS isolates were collected, 195 of which (95.1%) were cultured from stool, but 10 isolates were isolated from an extraintestinal site. Serogroup B accounted for the vast majority (137/205) among the isolates. Fifty-three isolates were resistant to ceftriaxone, and 50 were isolated from children younger than 4years of age. The resistance rates for ceftriaxone, ciprofloxacin, and levofloxacin were significantly higher in younger children than the older children. The resistance genes in the ceftriaxone-susceptible isolates were detected by PCR, and ceftriaxone-resistant were selected for further whole-genome sequencing. Whole-genome analysis showed that serotype Typhimurium and its monophasic variant was the most prevalent in ceftriaxone-resistant isolates (37/53), which comprised ST34 (33/53), ST19 (2/53), and ST99 (2/53), and they were close related in the phylogenetic tree. However, the other isolates were diverse, which included one Enteritidis (ST11), one Indiana (ST17), one Derby (ST40), four Kentucky (ST198), two Goldcoast (ST2529, ST358), one Muenster (ST321), one Virchow (ST359), one Rissen (ST469), one Kedougou (ST1543), two Uganda (ST684), and one Kottbus (ST8839). Moreover, CTX-M-55 ESBLs production (33/53) was found to be mainly responsible for ceftriaxone resistance, followed by (12/53), (4/53), (2/53), (1/53), (1/53), and (1/53). IS, IS, IS , IS, and IS were connected to antimicrobial resistance genes transfer. In conclusion, the dissemination of ESBL-producing isolates resulted in an increased prevalence of ceftriaxone resistance in young children. The high rate of multidrug resistance should be given additional attention.
非伤寒沙门氏菌（NTS）感染对儿童健康至关重要，头孢曲松是重要的经验性治疗选择。随着头孢曲松耐药率的上升，耐头孢曲松NTS的分子流行病学和耐药机制需要进行研究。2019年7月至2020年7月，共收集了205株NTS分离株，其中195株（95.1%）从粪便中培养获得，但有10株从肠外部位分离得到。分离株中B血清群占绝大多数（137/205）。53株对头孢曲松耐药，其中50株从4岁以下儿童中分离得到。头孢曲松、环丙沙星和左氧氟沙星在年幼儿童中的耐药率显著高于年长儿童。通过PCR检测头孢曲松敏感分离株中的耐药基因，并选择耐头孢曲松NTS进行进一步全基因组测序。全基因组分析表明，鼠伤寒血清型及其单相变体在耐头孢曲松分离株中最为常见（37/53），包括ST34（33/53）、ST19（2/53）和ST99（2/53），它们在系统发育树中密切相关。然而，其他分离株则多种多样，包括一株肠炎沙门氏菌（ST11）、一株印第安纳沙门氏菌（ST17）、一株德比沙门氏菌（ST40）、四株肯塔基沙门氏菌（ST198）、两株黄金海岸沙门氏菌（ST2529、ST358）、一株明斯特沙门氏菌（ST321）、一株菲尔肖沙门氏菌（ST359）、一株里森沙门氏菌（ST469）、一株凯杜古沙门氏菌（ST1543）、两株乌干达沙门氏菌（ST684）和一株科特布斯沙门氏菌（ST8839）。此外，发现CTX-M-55型超广谱β-内酰胺酶（ESBLs）产生（33/53）是头孢曲松耐药的主要原因，其次是blaSHV（12/53）、blaTEM（4/53）、blaOXA-1（2/53）、blaCTX-M-1（1/53）、blaCTX-M-2（1/53）和blaCTX-M-27（1/53）。IS26、IS1、IS5、IS903和IS10与抗菌耐药基因转移有关。总之，产ESBLs NTS分离株的传播导致年幼儿童中头孢曲松耐药率上升。应格外关注其高多重耐药率。
