Repurposing drugs with specific activity against L-form bacteria.

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Cell wall deficient bacteria, known as L-forms, are implicated in persistent and recurrent infections.
• L-forms exhibit complete resistance to conventional cell wall active antibiotics like β-lactams.
• There is a critical need for novel therapeutic agents targeting L-form bacteria.

Purpose of the Study:

• To identify and characterize FDA-approved drugs with specific activity against L-form bacteria.
• To explore the potential of these identified compounds as novel therapeutic agents for L-form-dependent infections.
• To investigate the mechanism of action of anti-L-form compounds.

Main Methods:

• Screening of a library comprising several hundred FDA-approved drugs.
• Identification of compounds exhibiting selective L-form killing activity.
• Mode of action studies to elucidate the cellular targets and effects of active compounds.

Main Results:

• Several FDA-approved drugs, including dihydropyridines (e.g., manidipine) and diphenylmethylpiperazines (e.g., flunarizine), demonstrated potent L-form killing activity.
• Mechanism of action studies indicated that these calcium channel blockers reduce bacterial membrane fluidity, inhibiting cell division.
• Significant variation in efficacy among different drug analogues suggests potential for optimization.

Conclusions:

• Calcium channel blockers represent a promising class of compounds for developing new treatments against L-form bacterial infections.
• Targeting bacterial membrane fluidity offers a viable strategy for combating antibiotic-resistant L-forms.
• Further modification of these compounds may lead to optimized drugs for L-form-dependent infectious diseases.