Mitsuyo Kawaguchiya1, Noriko Urushibara2, Meiji Soe Aung3, Kenji Kudo4, Masahiko Ito5, Ayako Sumi6, Nobumichi Kobayashi7. 1. Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: kawaguchiya@sapmed.ac.jp. 2. Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: noriko-u@sapmed.ac.jp. 3. Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: meijisoeaung@sapmed.ac.jp. 4. Sapporo Clinical Laboratory, Inc., Sapporo, Japan. Electronic address: saturin-saikin@saturin.co.jp. 5. Sapporo Clinical Laboratory, Inc., Sapporo, Japan. Electronic address: m-ito@saturin.co.jp. 6. Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: sumi@sapmed.ac.j. 7. Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: nkobayas@sapmed.ac.jp.
Abstract
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.
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.
Authors: Mary A Carr; Dennis Marcelo; K Michael Lovell; Angela H Benton; Nathan A Tullos; Erin W Norcross; Brandon Myers; Marcus K Robbins; Hayley Craddieth; Mary E Marquart Journal: Microorganisms Date: 2022-03-25