Molecular Characterization and Correlation with β-lactam Resistance of Streptococcus pneumonia Isolates in Hangzhou, China

Penicillin-binding proteins (PBPs) are the target of beta-lactam antibiotics (the major treatment for Streptococcus pneumoniae infections), and mutations in PBPs are considered as a primary mechanism for the development of beta-lactam resistance in S. pneumoniae. This study was conducted to investigate the mutations in the PBPs of clinical S. pneumoniae isolates in Hangzhou, China, in correlation with beta-lactam resistance. Results showed that 19F was the predominant serotype (7/27) and 14 of the S. pneumoniae isolates were resistant to both penicillin G and cephalosporin. Genotyping results suggested that beta-lactam-resistant isolates primarily exhibited single-site mutations in both the STMK and SRNVP motifs of pbp1 alpha in combination with double-site mutations in the STMK motif of pbp2x, which might be the primary mechanisms underlying the beta-lactam resistance of the isolates in this study.