PFGE-based dendrogram, resistance profile, replicon typing, isolate number, and strain serovars. The dendrogram is based on PFGE analyses using BioNumerics software. Antimicrobial resistance phenotypes (columns 2 to 16): black indicates resistance, and gray indicates intermediate or susceptible. Replicon typing results (columns 17 to 28): black indicates that the trait was detected, and gray indicates that the trait was not detected. The isolate number (column 36) and serovar (column 37) follow. Abbreviations for antimicrobial resistance phenotypes are as follows: amoxicillin-clavulanic acid (AMOX/CA), ampicillin (AMPC), cefoxitin (CFOX), ceftiofur (TIO), ceftriaxone (CTRX), chloramphenicol (CHL), gentamicin (GEN), kanamycin (KAN), nalidixic acid (NAL), streptomycin (STR), sulfamethoxazole (SSS), tetracycline (TET), and trimethoprim-sulfamethoxazole (SMX/TMP).