Clonal lineages and antimicrobial resistance of nonencapsulated Streptococcus pneumoniae in the post-pneumococcal conjugate vaccine era in Japan

International Journal of Infectious Diseases

Noriko Urushibara¹  Meiji Soe Aung²  Mitsuyo Kawaguchiya²  Kenji Kudo²  Nobumichi Kobayashi²  Masahiko Ito³  Ayako Sumi³ 

[1] Corresponding author at: Department of Hygiene, Sapporo Medical University School of Medicine, S-1 W-17, Chuo-ku, Sapporo 060-8556, Japan;Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan;Sapporo Clinical Laboratory, Inc., Sapporo, Japan;

关键词: Nonencapsulated;    Streptococcus pneumoniae;    Antimicrobial susceptibility;    Multi-drug resistance;    Sequence type;    Pneumococcal surface protein K;   

DOI  :  

来源: DOAJ

【 摘 要 】

Objectives: The emergence and spread of nonencapsulated Streptococcus pneumoniae (NESp) is a public health concern in the post-pneumococcal conjugate vaccine era. We analyzed the prevalence, molecular characteristics, and antimicrobial resistance of NESp responsible for noninvasive infections in northern Japan. Methods: NESp isolates were identified using molecular and phenotypical methods among 4463 S. pneumoniae isolates from noninvasive infection cases during 4 study periods between January 2011 and January 2019. NESp isolates were analyzed for antimicrobial susceptibility, genotype, and virulence-associated genes. Results: Seventy-one NESp isolates were identified (1.6% of total clinical isolates) and assigned to the null capsule clade (NCC)1 (pspK+) (94.4%) or NCC2 (aliC+/aliD+) (5.6%). The dominant sequence types (STs) were ST7502 (23.9%), ST4845 (19.7%), ST16214 (11.3%), ST11379 (9.9%), and ST7786 (7.0%). These 5 dominant STs and all 7 novel STs were related to the sporadic NESp lineage ST1106 or PMEN clone Denmark14-ST230. High non-susceptibility rates of NESp were observed for trimethoprim-sulfamethoxazole, erythromycin, and tetracycline (>92.9%), and multidrug resistance was observed in 88.7% of the NESp isolates, including all ST7502, ST4845, and ST11379 isolates. Conclusions: The study revealed that the dominant clonal groups of NESp were associated with a high prevalence of non-susceptibility to antimicrobials in northern Japan.

【 授权许可】

Unknown