Clindamycin demonstrates clinical effectiveness for bacteremic M1UK Streptococcus pyogenes pneumonia: A case report and in vitro evidence of notable antitoxin effects on M1UK

International Journal of Infectious Diseases 2026 Open access

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Authors: Masayoshi Ezaki, Tien Manh Nguyen, Hitoshi Kawasuji, Kentaro Nagaoka, Yusuke Takegoshi, Kaho Ikeda, Junichi Kanatani, Kazunori Oishi, Yoshitomo Morinaga, Yoshihiro Yamamoto
DOI: 10.1016/j.ijid.2026.108742
Cited by: 1
References: 14

Abstract

We report a case of bacteremic M1 UK Streptococcus pyogenes pneumonia in an immunocompetent patient, which improved with adjunctive clindamycin therapy. In vitro, clindamycin consistently suppressed expression of streptococcal pyrogenic exotoxin A ( speA ) in M1 UK strains but not in the M1 global strain, whereas levofloxacin showed no suppressive effect. These findings support a potential antitoxin role of clindamycin in M1 UK infections.

Fields of Study & Subjects

Streptococcal Infections and Treatments Pneumonia and Respiratory Infections Neonatal and Maternal Infections

Publication details

Journal / source
International Journal of Infectious Diseases
Publisher
Elsevier BV
Volume
168
Pages
108742–108742
Publication date
27 April 2026
Language
EN