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Updated: May 9, 2025
A Novel Method to Determine the Longitudinal Antibacterial Activity of Drug-Eluting Materials
Published on: March 3, 2023
In vitro activity of omadacycline against bacterial isolates from bone/joint infections and rare pathogens in the
Michael D Huband1, Paul R Rhomberg1, Kelley A Fedler1
1Element Materials Technology (JMI Laboratories), North Liberty, IA, USA.
Objectives:
Omadacycline is an aminomethylcycline (tetracycline class) antibacterial approved by the United States Food and Drug Administration (2018) for treatment of adults with acute bacterial skin and skin structure infection (ABSSSI) and community acquired bacterial pneumonia (CABP) caused by indicated organisms (oral and iv formulations). Omadacycline has activity against bacterial isolates expressing common tetracycline resistance mechanisms (ribosomal protection proteins and efflux pumps), which render older generation tetracyclines inactive. Omadacycline in vitro activity was assessed against 919 bacterial isolates collected from patients with bone/joint infections in the United States and Europe (2015-2023) and 3945 rarely encountered bacterial pathogens from patients (multiple infection sites) in the United States (2015-2023) as part of the SENTRY Antimicrobial Surveillance Program.
Methods:
Broth microdilution susceptibility testing followed Clinical and Laboratory Standards Institute M07 (2024) and M100 (2024) guidelines.
Results:
Omadacycline demonstrated susceptibilities of ≥90.0% (FDA breakpoints) against Staphylococcus aureus (including MRSA), Staphylococcus lugdunensis, Enterococcus faecalis (including vancomycin-resistant), and streptococci including Streptococcus anginosus, Streptococcus pneumoniae, and Streptococcus pyogenes from patient with bone/joint infections. Omadacycline demonstrated potent in vitro activity against rare Gram-positive pathogens (multiple infection sites), inhibiting 97.3%, 91.3%, and 99.4% of uncommon staphylococci, streptococci, and enterococci isolates at or below current FDA approved ABSSSI breakpoints for S. aureus, S. pyogenes, and E. faecalis.
Conclusions:
The potent omadacycline activity observed in this study suggests potential clinical utility for treatment of bone/joint infections and rarely encountered Gram-positive infections caused by various staphylococci, streptococci, and enterococci isolates and supports ongoing clinical trials for these disease indications.
Insights
Omadacycline shows strong in vitro activity against Gram-positive bacteria, including resistant strains, suggesting its potential for treating bone/joint and rare Gram-positive infections.
Area of Science:
- Microbiology
- Infectious Diseases
- Pharmacology
Background:
- Omadacycline is a tetracycline-class antibiotic approved for acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP).
- It exhibits activity against bacteria with common tetracycline resistance mechanisms, unlike older tetracyclines.
- The SENTRY Antimicrobial Surveillance Program collected isolates for this study.
Purpose of the Study:
- To assess the in vitro activity of omadacycline against bacterial isolates from bone/joint infections.
- To evaluate omadacycline's efficacy against rarely encountered Gram-positive pathogens.
Main Methods:
- Broth microdilution susceptibility testing was performed.
- Testing adhered to Clinical and Laboratory Standards Institute (CLSI) guidelines (M07 and M100, 2024).
Main Results:
- Omadacycline demonstrated ≥90.0% susceptibility against key bone/joint pathogens, including Staphylococcus aureus (MRSA), Enterococcus faecalis (VRE), and Streptococcus species.
- Potent in vitro activity was observed against rare Gram-positive pathogens, with inhibition rates exceeding 90% for uncommon staphylococci, streptococci, and enterococci.
Conclusions:
- Omadacycline's potent activity supports its potential clinical use for bone/joint infections.
- The findings suggest utility against rarely encountered Gram-positive infections caused by staphylococci, streptococci, and enterococci.
- Ongoing clinical trials are supported by these results for expanded indications.
