Activity of the old antimicrobial nitroxoline against Mycobacterium abscessus complex isolates

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Mycobacterium abscessus complex (MYABS) causes difficult-to-treat lung infections, particularly in cystic fibrosis patients.
• Drug-resistant MYABS strains pose a significant clinical challenge.
• Nitroxoline, an old antimicrobial, is being re-evaluated for treating resistant pathogens.

Purpose of the Study:

• To assess the in vitro activity of nitroxoline against drug-resistant MYABS isolates.
• To explore the potential repurposing of nitroxoline for MYABS infections.

Main Methods:

• In vitro susceptibility testing of nitroxoline against 16 clinical MYABS isolates.
• Broth microdilution method based on CLSI guidelines.
• Comparison of nitroxoline activity with standard antimicrobials.

Main Results:

• Nitroxoline demonstrated a promising MIC90 of 4 mg/L against MYABS isolates.
• All tested isolates were resistant to ciprofloxacin, imipenem, and doxycycline.
• Significant resistance to other standard antimicrobials was observed.

Conclusions:

• Nitroxoline exhibits potent in vitro activity against drug-resistant MYABS.
• Further research involving macrophage and in vivo models is warranted.