design: All isolates were sequenced using Illumina technologies (HiSeq 2500 or MiSeq). Isolate genomes were sequenced using an Illumina MiSeq and multilocus sequence typing (MLST) was performed as described (26). Resistance mechanisms related to clinically relevant antibiotic classes, including ampicillin, amoxicillin-clavulanate, and the cephalosporins, were investigated. Genes were identified by a BLAST search of genome assemblies using NCBI reference sequences for H. influenzae blaROB-1 (NC_019178), and the PubMLST full-length sequences for ftsI (HAEM1263) and blaTEM-1 (HAEM0118) genes (27). Amino-acid mutations in ftsI were identified by aligning the translated sequence to allele 1 from PubMLST using BioPython (28). Genome assemblies were submitted to PubMLST.