# Quantifying phage-bacteria dynamics in vitro: rapid emergence of phage-resistant mutants for Klebsiella pneumoniae

## TL;DR

This study examines how phage-resistant mutants of Klebsiella pneumoniae rapidly emerge when exposed to a specific bacteriophage in laboratory experiments.

## Contribution

The study provides quantitative estimates of phage-bacterial dynamics and the emergence of phage-resistant mutants in Klebsiella pneumoniae.

## Key findings

- Phage-resistant mutants of Klebsiella pneumoniae rapidly emerge and outcompete susceptible strains.
- Mathematical modeling was used to estimate key parameters of phage-bacterial interactions.
- Quantitative insights may help improve theoretical models of phage-bacterial dynamics.

## Abstract

In the quantitative description of evolving phage-bacterial systems, a central challenge lies in accurately identifying the key parameters governing the dynamics of both bacterial and phage populations. This is especially relevant in the case of multidrug-resistant pathogenic bacteria such as
Klebsiella sp
. This pathogen poses serious health problems due to antibiotic overuse, which causes the emergence of antibiotic-resistant strains and great difficulty in eradicating bacterial infections with antibiotics. Research on phage-bacteria thus becomes a very important topic to provide alternative strategies to eradicate multidrug-resistant bacteria, and thus quantitative descriptions of these processes are of paramount importance. Despite increasing research on this topic, key structural parameters of the populations, such as bacterial growth rates, the impact of phages on bacterial dynamics or the probability of emergence of phage-resistant strains, are often scarce. In this study, we investigated a battery of growth experiments for
Klebsiella pneumoniae
alone and with the presence of bacteriophage vB_Kpn_2-P4. Using mathematical models we estimate key parameters for these experiments, showing the rapid growth and emergence of phage-resistant mutants which outcompete the susceptible bacteria strains. Our results provide quantitative estimates of these processes and may be useful for understanding phage-bacterial dynamical systems and parameterizing future theoretical and computational models.