Low but Increasing Prevalence of Reduced Beta-lactam Susceptibility Among Invasive Group B Streptococcal Isolates, US Population-Based Surveillance, 1998-2018

• Type of Material: Article
• Authors: Miwako Kobayashi, Centers for Disease Control and Prevention; Lesley McGee, Centers for Disease Control and Prevention; Sopio Chochua, Centers for Disease Control and Prevention; Mirasol Apostol, California Emerging Infections Program; Nisha B. Alden, Colorado Department of Public Health and Environment; Monica Farley, Emory University; Lee H. Harrison, University of Pittsburgh; Ruth Lynfield, Minnesota Department of Health; Paula Snippes Vagnone, Minnesota Department of Health; Chad Smelser, New Mexico Department of Health; Alison Muse, New York State Department of Health; Ann R. Thomas, Oregon Public Health Division; Li Deng, Centers for Disease Control and Prevention; Benjamin J. Metcalf, Centers for Disease Control and Prevention; Bernard W. Beall, Centers for Disease Control and Prevention; Stephanie J. Schrag, Centers for Disease Control and Prevention
• Language: English
• Date: 2021-02-01
• Publisher: Oxford University Press Inc.
• Publication Version: Final Published Version
• Copyright Statement: © 2021 Infectious Diseases Society of America
• License: Creative Commons Universal : Public Domain Dedication
• Final Published Version (URL): http://dx.doi.org/10.1093/ofid/ofaa634
• Title of Journal or Parent Work: Open Forum Infectious Diseases
• Volume: 8
• Issue: 2
• Start Page: ofaa634
• End Page: ofaa634
• Grant/Funding Information: The CDC provided financial support for the Active Bacterial Core surveillance program through cooperative agreements with the Active Bacterial Core surveillance sites.
• Keywords: whole-genome sequencing; reduced beta-lactam susceptibility; penicillin binding protein 2x; Science & Technology; Assay; Infectious Diseases; group B Streptococcus; Immunology; Resistance; Diagnosis; Life Sciences & Biomedicine; Microbiology
• Research Categories: Health Sciences, Immunology; Biology, Genetics; Health Sciences, Public Health; Biology, Microbiology

Abstract

Background: Invasive group B Streptococcus (iGBS) isolates with mutations in the pbp2x gene that encodes penicillin binding protein 2x can have reduced beta-lactam susceptibility (RBLS) when susceptible by Clinical and Laboratory Standards Institute (CLSI) criteria. We assessed the emergence and characteristics of RBLS strains in US iGBS isolates. Methods: We analyzed iGBS isolates from 8 multistate population-based surveillance sites from 1998 to 2018. During 1998-2014, phenotypic antimicrobial susceptibility was determined by broth microdilution; criteria for 6 antibiotics were used to identify RBLS, followed by whole-genome sequencing (WGS). WGS for all isolates was added in 2015; we used phenotypic and genotypic results of >2000 isolates to validate phenotypic RBLS criteria and genotypic predictions. Since 2016, WGS has been used to screen for RBLS with broth microdilution confirmation of predicted RBLS isolates. Results: Of 28 269 iGBS isolates, 28 (0.1%) were nonsusceptible by CLSI criteria; 137 (0.5%) met RBLS criteria. RBLS isolates were detected in all Active Bacterial Core surveillance sites. The RBLS proportion increased, especially since 2013 (odds ratio, 1.17; 95% CI, 1.03-1.32); the proportion that were nonsusceptible remained stable. Conclusions: The RBSL proportion was low but increasing among US iGBS isolates. Ongoing monitoring is needed to detect emerging threats to prevention and treatment of GBS infections.