Clonal serotype 1c multidrug-resistant Shigella flexneri detected in multiple institutions by sentinel-site sequencing

• Published in: Frontiers in medicine Vol. 9; p. 964640
• Main Authors: Ko, Karrie K. K., Chu, Joash Jun Keat, Lim, Kar Mun, Yingtaweesittikul, Hatairat, Huang, Wenjie, Tan, Shireen Yan Ling, Goh, Kenneth Choon Meng, Tan, Si Huei, Ng, Tong Yong, Maiwald, Matthias, Chia, Jonathan Wei Zhong, Cao, Delphine Yanhong, Tan, Yen Ee, Sim, James Heng Chiak, Koh, Tse Hsien, Nagarajan, Niranjan, Suphavilai, Chayaporn
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 01.08.2022
• Subjects: Medicine; multidrug-resistant (MDR); outbreak; Shigella flexneri; surveillance; whole-genome sequence (WGS)
• ISSN: 2296-858X; 2296-858X
• DOI: 10.3389/fmed.2022.964640

Shigella flexneri is a major diarrhoeal pathogen, and the emergence of multidrug-resistant S. flexneri is of public health concern. We report the detection of a clonal cluster of multidrug-resistant serotype 1c (7a) S. flexneri in Singapore in April 2022. Long-read whole-genome sequence analysis found five S. flexneri isolates to be clonal and harboring the extended-spectrum β-lactamases bla CTX−M−15 and bla TEM−1 . The isolates were phenotypically resistant to ceftriaxone and had intermediate susceptibility to ciprofloxacin. The S. flexneri clonal cluster was first detected in a tertiary hospital diagnostic laboratory (sentinel-site), to which the S. flexneri isolates were sent from other hospitals for routine serogrouping. Long-read whole-genome sequence analysis was performed in the sentinel-site near real-time in view of the unusually high number of S. flexneri isolates received within a short time frame. This study demonstrates that near real-time sentinel-site sequence-based surveillance of convenience samples can detect possible clonal outbreak clusters and may provide alerts useful for public health mitigations at the earliest possible opportunity.