Chinese PLA Center for Disease Control and Prevention, 20th Dongda Street, Beijing, 100071, Fengtai District, China.
Xingcheng Special Service Recuperation Center of PLA Strategic Support Force, 210th Xinghai South Road, Xingcheng, 125100, China.
BMC Infect Dis. 2020 Jul 15;20(1):511. doi: 10.1186/s12879-020-05203-3.
Salmonella enterica subsp. enterica serovar Typhimurium infections continue to be a significant public health threat worldwide. The aim of this study was to investigate antibiotic resistance among 147 S. Typhimurium isolates collected from patients in Henan, China from 2006 to 2015.
147 S. Typhimurium isolates were collected from March 2006 to November 2015 in Henan Province, China. Antimicrobial susceptibility testing was performed, and the resistant genes of ciprofloxacin, cephalosporins (ceftriaxone and cefoxitin) and azithromycin were detected and sequenced. Clonal relationships were assessed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE).
Of the 147 isolates, 91.1% were multidrug resistant (MDR), with 4.1% being resistant to all antibiotic classes tested. Of concern, 13 MDR isolates were co-resistant to the first-line treatments cephalosporins and ciprofloxacin, while three were also resistant to azithromycin. Seven PFGE patterns were identified among the 13 isolates. All of the isolates could be assigned to one of four main groups, with a similarity value of 89%. MLST assigned the 147 isolates into five STs, including two dominant STs (ST19 and ST34). Of the 43 ciprofloxacin-resistant isolates, 39 carried double gyrA mutations (Ser83Phe, Asp87Asn/Tyr/Gly) and a single parC (Ser80Arg) mutation, including 1 isolate with four mutations (gyrA: Ser83Phe, Asp87Gly; parC: Ser80Arg; parE: Ser458Pro). In addition, 12 isolates not only carried mutations in gyrA and parC but also had at least one plasmid-mediated quinolone resistance (PMQR) gene. Among the 32 cephalosporin-resistant isolates, the most common extended-spectrum β-lactamase (ESBL) gene was bla, followed by bla, bla, and bla. Moreover, the mphA gene was identified in 5 of the 15 azithromycin-resistant isolates. Four MDR isolates contained ESBL and PMQR genes, and one of them also carried mphA in addition.
The high level of antibiotic resistance observed in S. Typhimurium poses a great danger to public health, so continuous surveillance of changes in antibiotic resistance is necessary.
肠道沙门氏菌亚种肠炎血清型鼠伤寒感染仍然是全世界的一个重大公共卫生威胁。本研究的目的是调查 2006 年至 2015 年从中国河南省患者中分离的 147 株鼠伤寒沙门氏菌的抗生素耐药情况。
2006 年 3 月至 2015 年 11 月，从中国河南省采集了 147 株鼠伤寒沙门氏菌。进行了抗生素敏感性测试，并对环丙沙星、头孢菌素（头孢曲松和头孢西丁）和阿奇霉素的耐药基因进行了检测和测序。通过多位点序列分型（MLST）和脉冲场凝胶电泳（PFGE）评估克隆关系。
在 147 株分离株中，91.1%为多药耐药（MDR），4.1%对所有测试的抗生素类别均有耐药性。值得关注的是，13 株 MDR 分离株对一线治疗药物头孢菌素和环丙沙星同时具有耐药性，而 3 株分离株还对阿奇霉素具有耐药性。在 13 株分离株中发现了 7 种 PFGE 模式。所有分离株均可以归入四个主要组中的一个，相似度为 89%。MLST 将 147 株分离株分为五个 ST，包括两个主要 ST（ST19 和 ST34）。在 43 株环丙沙星耐药分离株中，39 株携带双重gyrA 突变（Ser83Phe，Asp87Asn/Tyr/Gly）和单个 parC 突变（Ser80Arg），包括 1 株具有四个突变（gyrA：Ser83Phe，Asp87Gly；parC：Ser80Arg；parE：Ser458Pro）。此外，12 株分离株不仅携带 gyrA 和 parC 突变，而且还至少携带一个质粒介导的喹诺酮耐药（PMQR）基因。在 32 株头孢菌素耐药分离株中，最常见的超广谱β-内酰胺酶（ESBL）基因是 bla，其次是 bla，bla，和 bla。此外，在 15 株阿奇霉素耐药分离株中鉴定出 mphA 基因。4 株 MDR 分离株含有 ESBL 和 PMQR 基因，其中 1 株除了含有 mphA 基因外，还含有 blaCTX-M-15 基因。
鼠伤寒沙门氏菌中观察到的高水平抗生素耐药性对公共卫生构成了巨大威胁，因此有必要持续监测抗生素耐药性的变化。
