Related Experiment Video
Updated: Mar 11, 2026

Antimicrobial Synergy Testing by the Inkjet Printer-assisted Automated Checkerboard Array and the Manual Time-kill Method
Published on: April 18, 2019
Macrolide and Clindamycin Resistance in Group a Streptococci Isolated From Children With Pharyngitis
Gregory P DeMuri1, Alana K Sterkel, Phillip A Kubica
1From the *Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, †Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, ‡Department of Pathology and Laboratory Medicine, University of Wisconsin, and §Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Abstract:
Group A streptococcus (GAS) is responsible for 15%-30% of cases of acute pharyngitis in children. Macrolides such as azithromycin have become popular for treating GAS pharyngitis. We report macrolide resistance rates in a primary care setting in our geographic area over the past 5 years and discuss the implications of resistance in making treatment decisions. Throat swabs were collected from children with pharyngitis from May 2011 to May 2015 in a primary care setting in Madison, Wisconsin. Susceptibility testing was performed for erythromycin and clindamycin using the Kirby-Bauer disk diffusion method. GAS was identified on 143 throat cultures. Overall, 15% of GAS isolates demonstrated nonsusceptibility for both clindamycin and erythromycin. Inducible resistance (positive D-test) was detected in 17 isolates (12%). The rate of detection of nonsusceptibility in each year of the study did not change over time. Azithromycin should only be used for patients with pharyngitis and substantial manifestations of penicillin hypersensitivity and when used, susceptibility testing should always be performed.
More Related Videos
08:58Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
09:17A Robust Pneumonia Model in Immunocompetent Rodents to Evaluate Antibacterial Efficacy against S. pneumoniae, H. influenzae, K. pneumoniae, P. aeruginosa or A. baumannii
Published on: January 2, 2017
Related Concept Videos
Development of Antibiotic Resistance
Acute Pharyngitis
Acute pharyngitis is the inflammation of the back of the throat (pharynx), commonly resulting in a sore throat. It is a frequently encountered condition that prompts individuals to seek medical advice.
Classification
Acute pharyngitis can be categorized based on its underlying cause:
Bacterial Phylum Chlamydiae
Defense Against Bacterial Pathogens
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...