Visualization and quantification of phage-induced bacterial lysis by phosphotungstic acid-based SEM imaging
Abstract
Phage biocontrol, which employs bacteriophages for medical and industrial applications, has attracted increasing attention as an alternative to conventional antimicrobial strategies. However, rapid screening and quantitative evaluation of lytic phages remain major challenges for practical implementation. We propose a method based on phosphotungstic acid (PTA)-derived image contrast in scanning electron microscopy (SEM). This approach enables direct visualization of phage-induced bacterial lysis at the single-cell level and quantitative evaluation of cell damage associated with lysis using tabletop SEM. When Escherichia coli was mixed with T4 phage at a phage-to-bacterium ratio of 10:1 (MOI = 10), high-brightness cells indicative of cell damage became detectable within 30 min. Because PTA-stained cells exhibited increased brightness in images, the image-based damaged cell index was quantified as the proportion of high-brightness bacterial area within the total bacterial area, and used as an indicator of cell damage. Across MOIs ranging from 0.01 to 10, the index increased with increasing MOI, and the resulting growth inhibition was consistent with turbidity-based growth curves. Transmission electron microscopy confirmed intracellular PTA redistribution during lysis progression, along with progeny phage particles in pre-lysis cells. These results demonstrate the utility of this method for rapid detection of phage-induced lysis and evaluation of lytic activity.
Related
- Open-Source Framework for the Visualization, Quantification, and Analysis of 4D Flow and High-Dimensional Magnetic Resonance Images
- Fully automated open-source analysis and interactive visualization of magnetic resonance spectroscopic imaging (MRSI) data in Osprey-MRSI
- A high-throughput nanoscale imaging platform for direct visualization and rapid measurement of telomeres at single-molecule resolution
- Bioimaging With Fluorescent Nucleic‐Acid Aptamers for the Specific Detection and Quantification of Pseudomonas aeruginosa Alone and in Heterogeneous Bacterial Populations
- Strain resolution and wide relative abundance quantification of bacterial microbiomes with nanopore sequencing of the ribosomal RNA operon
BibTeX
@article{hisada2026visualization,
title = {{Visualization and quantification of phage-induced bacterial lysis by phosphotungstic acid-based SEM imaging}},
author = {Akiko Hisada and Takafumi Miwa and Yusuke Ominami and Fumiaki Hamazato},
journal = {Scientific Reports},
year = {2026},
month = oct,
doi = {10.1038/s41598-026-75191-y},
url = {https://www.nature.com/articles/s41598-026-75191-y},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Visualization and quantification of phage-induced bacterial lysis by phosphotungstic acid-based SEM imaging
AU - Akiko Hisada
AU - Takafumi Miwa
AU - Yusuke Ominami
AU - Fumiaki Hamazato
PY - 2026
DA - 2026/10/15
JO - Scientific Reports
DO - 10.1038/s41598-026-75191-y
UR - https://www.nature.com/articles/s41598-026-75191-y
AB - Phage biocontrol, which employs bacteriophages for medical and industrial applications, has attracted increasing attention as an alternative to conventional antimicrobial strategies. However, rapid screening and quantitative evaluation of lytic phages remain major challenges for practical implementation. We propose a method based on phosphotungstic acid (PTA)-derived image contrast in scanning electron microscopy (SEM). This approach enables direct visualization of phage-induced bacterial lysis at the single-cell level and quantitative evaluation of cell damage associated with lysis using tabletop SEM. When Escherichia coli was mixed with T4 phage at a phage-to-bacterium ratio of 10:1 (MOI = 10), high-brightness cells indicative of cell damage became detectable within 30 min. Because PTA-stained cells exhibited increased brightness in images, the image-based damaged cell index was quantified as the proportion of high-brightness bacterial area within the total bacterial area, and used as an indicator of cell damage. Across MOIs ranging from 0.01 to 10, the index increased with increasing MOI, and the resulting growth inhibition was consistent with turbidity-based growth curves. Transmission electron microscopy confirmed intracellular PTA redistribution during lysis progression, along with progeny phage particles in pre-lysis cells. These results demonstrate the utility of this method for rapid detection of phage-induced lysis and evaluation of lytic activity.
SN - 2045-2322
ER -