Activity of Tedizolid and Comparator Agents Against Gram-positive Isolates Causing Skin and Skin Structure Infections in Pediatric Patients in United States Hospitals (2015-2019)

Background: Tedizolid was approved by the United States Food and Drug Administration to treat acute bacterial skin and skin structure infections in adults in 2014, and in 2020, United States Food and Drug Administration expanded the approval of tedizolid to treat pediatric patients 12 years of age and older. This study assessed the activity of tedizolid and comparator agents against clinical surveillance isolates collected from pediatric patients with skin and skin structure infection in the United States. Methods: A total of 2747 gram-positive organisms (1 per patient) were collected in 2015 to 2019 from pediatric (<= 17 years old) patients with skin and skin structure infections. The isolates were collected from 33 US medical centers and susceptibility tested against tedizolid and comparators by reference broth microdilution methods. Susceptibility results for main pathogens were stratified by patient age: <= 1 years old (851 isolates), 2 to 5 years old (623), 6 to 12 years old (754) and 13 to 17 years old (519). Results: Staphylococcus aureus (n = 2163) was the main pathogen recovered from all age groups, followed by beta-hemolytic streptococci (n = 460). Tedizolid inhibited all S. aureus, including methicillin-resistant S. aureus (MRSA) isolates (41.0%), regardless of the age group. MRSA rates varied by age group; MRSA was highest among <= 1 years old (45.0%) and lowest in the 13 to 17 years old (32.7%) groups. Linezolid, daptomycin and vancomycin also displayed susceptibility rates of 100% against S. aureus isolates. Clindamycin (81.3%-98.5%), tetracycline (91.6%-97.1%) and trimethoprim-sulfamethoxazole (97.0%-100%) susceptibility rates varied among age groups and methicillin resistance profiles. Overall, tedizolid, linezolid, daptomycin and vancomycin inhibited all gram-positive pathogens in this collection. Conclusions: Tedizolid was very active against a large collection of gram-positive pathogens causing skin and skin structure infection in pediatric patients, including MRSA isolates.