# Characterizations of Newly Isolated Erwinia amylovora Loessnervirus-like Bacteriophages from Hungary

## TL;DR

This study identifies two new bacteriophages that effectively target Erwinia amylovora, the bacteria causing fire blight, and could offer a solution to antibiotic resistance.

## Contribution

The paper introduces two novel lytic phages with strong antimicrobial potential against Erwinia amylovora.

## Key findings

- Ea PF 7 and Ea PF 9 phages lysed 95% of 37 tested Erwinia amylovora strains.
- The phages showed high burst sizes and short latent periods, indicating rapid bacterial inhibition.
- They exhibited stability at moderate temperatures and pH levels, with resistance to desiccation and UV-B radiation.

## Abstract

This study explores alternative methods to combat bacterial infections like fire blight caused by Erwinia amylovora (Ea) using bacteriophages as potential antimicrobial agents. Two lytic phages, Ea PF 7 and Ea PF 9, were isolated from apple samples and classified as Loessnervirus-like based on their genomes. Both phages showed strong efficacy, lysing 95% of the tested 37 Ea strains. They inhibited bacterial growth for up to 10 h, even at low infection rates. The phages had a short latent period of 10 min and produced high burst sizes of 108 and 125 phage particles per infected cell. Stability tests revealed that both phages were stable at moderate temperatures (37–45 °C) and within a pH range of 4–10. However, their viability decreased at higher temperatures and extreme pH levels. Both phages exhibited notable desiccation tolerance and moderate resistance to UV-B radiation during UV testing. The phages were exposed to carefully controlled irradiation, considering factors like lamp type, radiation intensity, exposure time, and object distance. This method introduces a complex approach to research, ensuring repeatable and comparable results. These findings suggest that Ea PF 7 and Ea PF 9 hold promise as antimicrobial agents for therapeutic and biotechnological applications, potentially helping to combat antibiotic resistance in the future.