The Pediatric Infectious Disease Journal •  Volume 33, Number 8, August 2014 www.pidj.com | 837 ANTIMICROBIAL REVIEWS Background: Ceftaroline, the active form of ceftaroline fosamil, is a cepha- losporin with broad-spectrum bactericidal activity against resistant Gram- positive organisms, including methicillin-resistant Staphylococcus aureus, ceftriaxone-resistant Streptococcus pneumoniae and many Enterobacte- riaceae species. Ceftaroline fosamil is approved in the United States for treatment of acute bacterial skin and skin structure infections and commu- nity-acquired bacterial pneumonia in adults. Methods: A total of 5291 consecutive unique pediatric patient strains of clinical significance were collected from 157 US medical centers. The iso- lates were identified locally and forwarded to a central monitoring labo- ratory for reference antimicrobial susceptibility testing. S. pneumoniae isolates from the 2011 to 2012 respiratory season were serotyped. Suscepti- bility results were analyzed according to patient age as follows: ≤1 years old (yo; 1857 strains); 2–5 (1342); 6–12 (1281) and 13–17 (811). Results: Methicillin-resistant Staphylococcus aureus rates were slightly lower in isolates from patients 13–17 yo (39.9%) compared with other age groups (48.2–51.5%), and ceftaroline was consistently active against S. aureus isolates from all 4 age groups [minimal inhibitory concentration (MIC 50/90 ): 0.25–05/1 μg/mL; 99.8–100.0% susceptible]. Overall, 99.8% of methicillin-resistant Staphylococcus aureus were ceftaroline susceptible (MIC 50/90 : 0.5/1 μg/mL). All S. pneumoniae strains (1178) were ceftaroline susceptible (MIC 50/90 : ≤0.015/0.12 μg/mL), whereas ceftriaxone suscepti- bility varied from only 84.8 (≤1 yo) to 89.7% (13–17 yo). 19A was the most frequent serotype identified among S. pneumoniae and these isolates exhib- ited low susceptibility to ceftriaxone (42.4%) and most other antimicrobials tested. The highest ceftaroline MIC among Haemophilus influenzae (587 strains) was 0.12 μg/mL (100.0% susceptible), and β-lactamase production rates varied from 24.2 (13–17 yo) to 30.1% (6–12 yo); 27.9% overall. Cef- taroline was also active against β-hemolytic streptococci (556 strains, high- est MIC, 0.06 μg/mL). Extended-spectrum β-lactamase (ESBL)-phenotype rates among Escherichia coli/Klebsiella spp. were 6.0/5.1, 11.0/11.5, 5.1/8.3 and 11.4/14.7% for the ≤1, 2–5, 6–12 and 13–17 yo age groups, respectively. Ceftaroline exhibited good activity against non-ESBL pheno- type strains of E. coli and Klebsiella spp. (MIC 90 : 0.25 μg/mL for both organisms), but had limited activity against ESBL-producing strains. Conclusion: Ceftaroline demonstrated potent in vitro activity when tested against S. aureus, S. pneumoniae, H. influenzae, β-hemolytic streptococci and non-ESBL-phenotype E. coli and Klebsiella spp. strains isolated from pediatric patients, independent of patient age. Key Words: Ceftaroline, AWARE, MRSA, Streptococcus pneumoniae (Pediatr Infect Dis J 2014;33:837–842) A ntimicrobial resistance has been the subject of increasing con- cern to pediatricians, and it remains a major focus of clini- cal and microbiology research for pediatric infectious diseases specialists. 1,2 The major challenges to pediatricians are antimi- crobial resistance among organisms causing community-acquired respiratory tract infections and among infections acquired in the healthcare setting. Moreover, the emergence and dissemination of community-associated (CA), methicillin-resistant Staphylococcus aureus (MRSA) represent another important challenge for those physicians treating children. 3,4 Although much has been reported about antimicrobial susceptibility in the pediatric population, con- siderably less is understood regarding resistance profile patterns by pediatric patient age groupings. Ceftaroline, the active metabolite of ceftaroline fosamil, is a parenteral cephalosporin with potent activity against Gram-positive organisms, including MRSA and multidrug-resistant (MDR) Strep- tococcus pneumoniae, and common Gram-negative bacilli, but not those producing extended-spectrum β-lactamases (ESBLs). 5–7 Cef- taroline fosamil is approved by the US Food and Drug Administra- tion for the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections (ABSSSI) in adults, including ABSSSI caused by MRSA. 8 It is also approved by the European Medicines Agency for similar indications. 9 As part of the Assessing Worldwide Antimicrobial Resistance Evaluation Program, a global ceftaroline surveillance study, we evaluated the activity of ceftaroline tested against contemporary pathogens caus- ing infections in pediatric patients at US hospitals (2011–2012). MATERIALS AND METHODS Organism Collection Nearly 5300 consecutive unique pediatric patient isolates of clinical significance (Table, Supplemental Digital Content 1, http:// links.lww.com/INF/B844) were collected from 157 US medical centers as part of the Assessing Worldwide Antimicrobial Resist- ance Evaluation Program. 10 The participant centers were distrib- uted across all 9 US Census Regions, with 7–31 medical centers per region. These organisms were collected from January 2011 to December 2012. Susceptibility results were analyzed according to patient age as follows: ≤1 years old (yo; 1857 strains); 2–5 yo Copyright © 2014 by Lippincott Williams & Wilkins ISSN: 0891-3668/14/3308-0837 DOI: 10.1097/INF.0000000000000307 Ceftaroline Activity Tested Against Bacterial Isolates  From Pediatric Patients Results from the Assessing Worldwide Antimicrobial Resistance and Evaluation Program for the United States (2011–2012) Helio S. Sader, MD, PhD, Rodrigo E. Mendes, PhD, David J. Farrell, PhD, Robert K. Flamm, PhD, and Ronald N. Jones, MD Accepted for publication January 26, 2014. From the JMI Laboratories, North Liberty, IA This study was supported by Forest Laboratories, Inc. Forest Laboratories, Inc., was involved in the design of the study, but had no involvement in the collection, analysis, and interpretation of data, Scientific Therapeutics Information, Inc., provided editorial coordination, which was funded by Forest Research Institute, Inc. The authors have no other funding or conflicts of interest to disclose. Address for correspondence: Helio S. Sader, MD, PhD, JMI Laboratories, 345 Beaver Kreek Ctr, Ste A, North Liberty, IA 52317. E-mail: helio-sader@ jmilabs.com. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.pidj.com).