Penicillin-binding protein typing, antibiotic resistance gene identification and molecular phylogenetic analysis of meropenem-resistant Streptococcus pneumoniae serotype 19A-CC3111 strains in Japan.

Penicillin-binding protein typing, antibiotic resistance gene identification and molecular phylogenetic analysis of meropenem-resistant Streptococcus pneumoniae serotype 19A-CC3111 strains in Japan. Antimicrob Agents Chemother. 2019 Jun 24;: Authors: Nakano S, Fujisawa T, Ito Y, Chang B, Matsumura Y, Yamamoto M, Suga S, Ohnishi M, Nagao M Abstract Since the introduction of pneumococcal conjugate vaccines, the prevalence of non-meropenem-susceptible pneumococci has been increasing in Japan. In an earlier study, we demonstrated that the multidrug-resistant serotype 15A-ST63 in Japan has a specific pbp1a sequence (pbp1a--13) that could promote meropenem resistance. To trace the origin of pbp1a, we analyzed isolates of serotype 19A-CC3111, which is the most prevalent non-meropenem-susceptible clone in Japan. We analyzed a total of 119 serotype 19A-CC3111 strains recovered in Japan using whole-genome sequencing. Of the 119 isolates, 53 (44.5%) harbored pbp1a-13, indicating that the clone may be the primary reservoir of the pbp1a type, and the pbp1a region may be horizontally transferred between different serotype strains. The single acquisition of pbp1a-13 seemed to cause only penicillin resistance and not multidrug resistance; a combination of PBP recombination in the pbp2b and/or pbp2x region(s) with acquisition of pbp1a-13 caused multidrug resistance. Conserved amino acid motif analysis suggested that the pbp1a 370SXXK, pbp2b 448SXN an...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research