Sequential Time-Kill, a Simple Experimental Trick To Discriminate between Pharmacokinetics/Pharmacodynamics Models...

Area of Science:

• Microbiology
• Pharmacology
• Computational Biology

Background:

• * Understanding bacterial resistance mechanisms is crucial for effective antimicrobial therapy.
• * Differentiating between heterogeneous subpopulations and adaptive resistance in Klebsiella pneumoniae is challenging.
• * Existing pharmacokinetic/pharmacodynamic (PK/PD) models require robust methods for validation.

Purpose of the Study:

• * To evaluate sequential time-kill (TK) experiments as a method to discriminate between PK/PD models.
• * To assess the ability of sequential TK to distinguish heterogeneous subpopulations from adaptive resistance in Klebsiella pneumoniae.
• * To validate a simple approach for PK/PD model discrimination using isogenic bacterial strains.

Main Methods:

• * Conducted sequential time-kill experiments using polymyxin B.
• * Utilized two isogenic Klebsiella pneumoniae strains: wild type (KP_WT) and a transconjugant with the mobile colistin resistance gene (KP_MCR-1).
• * Analyzed experimental data to discriminate between PK/PD models representing heterogeneous subpopulations and adaptive resistance.

Main Results:

• * Sequential TK experiments provided a straightforward method for model discrimination.
• * The approach successfully differentiated between PK/PD models incorporating two heterogeneous subpopulations versus adaptive resistance.
• * Polymyxin B activity against Klebsiella pneumoniae strains was assessed under sequential exposure conditions.

Conclusions:

• * Sequential TK experiments offer a simple yet effective strategy for PK/PD model discrimination.
• * This methodology aids in understanding complex bacterial resistance dynamics.
• * The findings support the application of sequential TK in antimicrobial research and drug development.