Abstract: From the *Viral Pathogenesis Laboratory, Vaccine Research Center, Bethesda, MD; †Department of Laboratory Medicine, Children's National Medical Center, Washington, DC; and Departments of ‡Pediatrics, §Pathology, and ¶Microbiology, Immunology, and Tropical Medicine, George Washington Medical Center, Washington, DC. The authors have no funding or conflicts of interest to disclose. Address for correspondence: Allison M. W. Malloy, MD, Vaccine Research Center, Bldg 40 Convent Dr, Bethesda, MD 20892. E-mail: [email protected]. The Concise Reviews of Pediatric Infectious Diseases (CRPIDS) series topics, authors and contents are chosen and approved independently by the Editorial Board of CRPIDS. CONTENTS Review of Carbapenemases and Amp C-β Lactamases Extended Spectrum β-lactamases EDITORIAL BOARD Co-Editors:Geoffrey A. Weinberg, MD, and Charles Woods, MD Issue Editor:Barbara Jantausch, MD Board MembersJohn S. Bradley, MD Margaret C. Fisher, MD Barbara Jantausch, MD Leonard R. Krilov, MD Charles T. Leach, MD Deborah Lewinsohn, MD Debra L. Palazzi, MD Jennifer Read, MD Geoffrey A. Weinberg, MD Leonard Weiner, MD Charles R. Woods, MD Theoklis Zaoutis, MD