OBJECTIVES: To investigate the nature of the amino acid motifs found in penicillin-binding protein (PBP) 2x of penicillin-resistant Streptococcus pneumoniae isolates across the province of Quebec (Canada), and to obtain preliminary information regarding the prevalence of these alterations. METHODS: The pbp2x genomic region encompassing codons 178-703, which includes the entire region of the transpeptidase domain, was sequenced and compared for 52 clinical isolates comprising 20 penicillin-susceptible (PSSP), 20 penicillin-intermediate (PISP) and 12 penicillin-resistant (PRSP) pneumococci. RESULTS: The degree of diversity within PBP2x correlated with increased resistance to beta-lactam antibiotics. There were an average of 5.0 +/- 1.8 mutations in PSSP, 37.9 +/- 4.4 in PISP, and 63.0 +/- 2.0 in PRSP isolates when compared with the control penicillin-susceptible strain R6. At least six distinct amino acid profiles were identified among PISP strains isolated in Quebec. In contrast, all PRSP isolates shared a similar pattern of altered amino acids compared with the sequence from susceptible strains. CONCLUSIONS: These data will be useful in future studies to monitor the genetic changes associated with the emergence and spread of beta-lactam resistance in Quebec.
OBJECTIVES: To investigate the nature of the amino acid motifs found in penicillin-binding protein (PBP) 2x of penicillin-resistant Streptococcus pneumoniae isolates across the province of Quebec (Canada), and to obtain preliminary information regarding the prevalence of these alterations. METHODS: The pbp2x genomic region encompassing codons 178-703, which includes the entire region of the transpeptidase domain, was sequenced and compared for 52 clinical isolates comprising 20 penicillin-susceptible (PSSP), 20 penicillin-intermediate (PISP) and 12 penicillin-resistant (PRSP) pneumococci. RESULTS: The degree of diversity within PBP2x correlated with increased resistance to beta-lactam antibiotics. There were an average of 5.0 +/- 1.8 mutations in PSSP, 37.9 +/- 4.4 in PISP, and 63.0 +/- 2.0 in PRSP isolates when compared with the control penicillin-susceptible strain R6. At least six distinct amino acid profiles were identified among PISP strains isolated in Quebec. In contrast, all PRSP isolates shared a similar pattern of altered amino acids compared with the sequence from susceptible strains. CONCLUSIONS: These data will be useful in future studies to monitor the genetic changes associated with the emergence and spread of beta-lactam resistance in Quebec.
Authors: Rendani I Manenzhe; Felix S Dube; Meredith Wright; Katie Lennard; Stephanie Mounaud; Stephanie W Lo; Heather J Zar; William C Nierman; Mark P Nicol; Clinton Moodley Journal: Front Public Health Date: 2020-09-22
Authors: Claire Chewapreecha; Pekka Marttinen; Nicholas J Croucher; Susannah J Salter; Simon R Harris; Alison E Mather; William P Hanage; David Goldblatt; Francois H Nosten; Claudia Turner; Paul Turner; Stephen D Bentley; Julian Parkhill Journal: PLoS Genet Date: 2014-08-07 Impact factor: 5.917