Emergence and Evolution of High-Level Cephalosporin-Resistant Salmonella Goldcoast in Northern Taiwan

Ye Feng; Yi-Jung Chang; Szu-Hsuan Fang; Lin-Hui Su; Hsin-Chieh Li; Hsin-Ping Yang; Min-Jia Yu; Cheng-Hsun Chiu

doi:10.1093/ofid/ofz447

Emergence and Evolution of High-Level Cephalosporin-Resistant Salmonella Goldcoast in Northern Taiwan

Open Forum Infect Dis. 2019 Dec 17;6(12):ofz447. doi: 10.1093/ofid/ofz447. eCollection 2019 Dec.

Authors

Ye Feng^{1

2

3}, Yi-Jung Chang^{4

5}, Szu-Hsuan Fang⁵, Lin-Hui Su⁴, Hsin-Chieh Li⁴, Hsin-Ping Yang⁴, Min-Jia Yu⁴, Cheng-Hsun Chiu^{4

5}

Affiliations

¹ Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
² Institute for Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China.
³ Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China.
⁴ Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
⁵ Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.

Abstract

Background: Nontyphoidal Salmonella (NTS) is an important foodborne pathogen worldwide. We investigated a 2018 outbreak of highly antimicrobial-resistant Salmonella enterica serotype Goldcoast in northern Taiwan.

Methods: We collected 30 clinical isolates and 2 meat isolates from this outbreak in New Taipei and Taoyuan, Taiwan in 2018. The clinical manifestations and the treatment of the patients were reviewed. To trace the source, we examined NTS isolated from food samples collected from the markets in northern Taiwan. All of the isolates along with an additional human isolate from China were sequenced and compared with the sequences of Salmonella Goldcoast reported by other countries.

Results: The outbreak involved 14 pediatric patients (<5 years old) and 16 adults (36 to 83 years old). Nine patients with invasive or severe disease required carbapenem treatment. The MIC₉₀ of ceftriaxone and ciprofloxacin for the outbreak isolates was >256 μg/mL and 1 μg/mL, respectively, and a conjugative 278-kilobase plasmid harboring bla _CTX-M-55 and qnrS1 contributed towards the resistance. Whole-genome sequencing revealed a clonal relationship among the outbreak isolates and the 2 collected from the retail meats. The outbreak clone was phylogenetically close to that of Salmonella Goldcoast reported in the United Kingdom, Poland, and China, whereas similar resistance plasmids were found in China and Cambodia.

Conclusions: The clinical spectrum of the high-level cephalosporin-resistant Salmonella Goldcoast is similar to that of other NTS serotypes, but severe cases required carbapenem treatment. The study confirmed the emergence of a highly antimicrobial-resistant clone of Salmonella Goldcoast, highlighting the importance of surveillance for food safety.

Keywords: Salmonella Goldcoast; cephalosporin resistance; clone; conjugative plasmid; whole-genome sequencing.