Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Emergency Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Department of Laboratory Medicine, E-DA Hospital, Kaohsiung, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
J Microbiol Immunol Infect. 2019 Apr;52(2):289-296. doi: 10.1016/j.jmii.2018.08.007. Epub 2018 Aug 27.
BACKGROUND/PURPOSE: The increasing trend of ceftriaxone resistant non-typhoidal Salmonella (NTS) worldwide is of serious concern, however, data is lacked in southern Taiwan.
Salmonella isolates were collected at a regional hospital in Kaohsiung during 2004-2013. Ceftriaxone resistant NTS isolates were further characterized for beta-lactamases, typed by pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and their plasmids were analyzed by PCR replicon typing and plasmid mutilocus sequence typing.
Among 528 NTS isolates, the most common serogroup is serogroup B (44.9%), followed by serogroup D, and serogroup C. Eleven (2.1%) isolates were resistant to ceftriaxone and were distributed in three peak periods (2010, 2011, and 2013). PFGE and MLST revealed the ten serogroup B isolates were of two clones. Beta-lactamase genes were detected in 10 of the 11 isolates, including CMY-2 (5 isolates), TEM-1 (2), CTX-M-14 (1), and 2 isolates carried both TEM-1 and CMY-2. Plasmid incompatibility types were identified in 9 (81.8%) isolates; three were IncI1, three was IncHI2, one was IncFIB and two had both replicons of IncI1 and IncHI2. The only ESBL gene bla was found in an isolate with plasmid belonged to IncHI2, which has not been reported in NTS in Taiwan before. Most MLST types and plasmid MLST types of NTS isolates in this study are different from those in northern Taiwan.
Though clonal spread of ceftriaxone resistant NTS was suggested by PFGE and MLST, plasmid characterization and beta-lactamase detection revealed their plasmid types and beta-lactamase types were different.
背景/目的： 全球范围内头孢曲松耐药非伤寒沙门氏菌（NTS）的增长趋势令人严重关切，但台湾南部缺乏相关数据。
2004 年至 2013 年，在高雄的一家地区医院采集了沙门氏菌分离株。进一步对头孢曲松耐药 NTS 分离株进行了β-内酰胺酶的特征分析，通过脉冲场凝胶电泳（PFGE）、多位点序列分型（MLST）进行分型，并通过 PCR 复制子分型和质粒多位点序列分型分析其质粒。
在 528 株 NTS 分离株中，最常见的血清群是 B 群（44.9%），其次是 D 群和 C 群。11 株（2.1%）分离株对头孢曲松耐药，分布在三个高峰期（2010 年、2011 年和 2013 年）。PFGE 和 MLST 显示 10 株 B 群血清型分离株为两个克隆。在 11 株分离株中检测到 10 株β-内酰胺酶基因，包括 CMY-2（5 株）、TEM-1（2 株）、CTX-M-14（1 株）和 2 株同时携带 TEM-1 和 CMY-2。在 9 株（81.8%）分离株中鉴定出了质粒不相容类型；3 株为 IncI1，3 株为 IncHI2，1 株为 IncFIB，2 株同时具有 IncI1 和 IncHI2 两种复制子。唯一的 ESBL 基因 bla 存在于携带 IncHI2 质粒的分离株中，这在台湾以前的 NTS 中尚未报道过。本研究中 NTS 的大多数 MLST 类型和质粒 MLST 类型与台湾北部的不同。
尽管 PFGE 和 MLST 提示头孢曲松耐药 NTS 的克隆传播，但质粒特征和β-内酰胺酶检测显示其质粒类型和β-内酰胺酶类型不同。
