Minimum Inhibitory Concentrations (MICs) for β-lactam Antibiotics Predicted by Penicillin Binding Protein Gene Types

The CDC Streptococcus Laboratory has created procedures for using whole-genome sequencing data to predict phenotypic susceptibility results for a range of antibiotics. For beta-lactam antibiotics, the procedure uses newly-defined Penicillin Binding Protein (PBP) types, which are based on transpeptidase-encoding regions of PBP proteins 1a, 2b, and 2x.  An isolate’s PBP type can predict a specific level of resistance to penicillin and other beta-lactam antibiotics. Below are minimum inhibitory concentrations (MIC) tables for reference.1, 2, 3, 4

Below are links to protein sequences (.faa files) that constitute PBP types. The downloadable files below can be run on multiple open source platforms, including EMBOSSexternal icon, Biostringsexternal icon (withing Bioconductor), and Clustal Omegaexternal icon. Updated June 2016


1Metcalf BJ, Gertz RE Jr, Gladstone RA, et al. Strain features and distributions in pneumococci from children with invasive disease before and after 13-valent conjugate vaccine implementation in the USAexternal icon. Clin Microbiol Infect. 2016;22(1):60 e9–60.

2Metcalf BJ, Chochua S, Gertz RE Jr, et al. Using whole genome sequencing to identify resistance determinants and predict antimicrobial resistance phenotypes for year 2015 invasive pneumococcal disease isolates recovered in the United States. Clin Microbiol Infect. 2016;22(12):1002.e1–1002.e8.

3CDC Strep Lab GAS bioinformatic pipelines for S. agalactiae, S. pyogenes, and S. pneumoniaeexternal icon.

4Li Y, Metcalf BJ, Chochua S, et al. Penicillin-binding protein transpeptidase signatures for tracking and predicting β-lactam resistance levels in Streptococcus pneumoniaeexternal icon. mBio. 2016;7(3):60 pii:e00756–16.

Page last reviewed: June 15, 2018