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 blaCTX-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.

No abstract

Background: The epidemiology of nontyphoidal Salmonella (NTS) resistant to ciprofloxacin or ceftriaxone and its impact on patients' clinical course are rarely reported. Methods: Children with culture-proven salmonellosis treated in a medical center in northern Taiwan in 2017 were enrolled. To trace the source of Salmonella, Salmonella isolated from food samples were collected from markets. Antimicrobial susceptibility and serotypes were determined. Results: Among the 453 isolates, 122 (26.9%) were highly antimicrobial-resistant, as defined by resistance to ciprofloxacin or ceftriaxone or both. The most prevalent highly resistant serotype was S. Anatum (66, 54.1%). Salmonella was detected in 94.1%, 66.7%, and 8.6% of examined pork, chicken, and vegetables examined, respectively. S. Anatum (6, 21.4%) and S. Derby (6, 21.4%) were the major serotypes isolated. Majority of the S. Anatum (5, 83.3%) were highly antimicrobial-resistant. More patients infected by highly resistant Salmonella required carbapenem treatment (OR Z 23.5, 95% confidence interval [CI] 2.8e192.7, P < 0.001). Patients with ceftriaxone-resistant NTS infections had a significantly longer hospital stay than others

Memorial Hospital (CGMH) is a main referral hospital for cities in northern Taiwan, including Taipei, New Taipei, and Taoyuan. The population in this region is approximately seven million. The Clinical Microbiology Laboratory has launched a program to monitor the serovars of NTS causing human infections since 2012. All Salmonella isolates from patients were collected and serotyped. Antimicrobial susceptibility testing was performed using the disc diffusion method specified in the Clinical and Laboratory Standards Institute (CLSI) guidelines (1). S. Anatum is a relatively uncommonly recorded serovar for human infections.