Analysis of Bacteriophage–Host Interaction by Raman Tweezers

Abstract

Bacteriophages, or “phages” for short, are viruses that replicate in bacteria. The therapeutic and biotechnological potential of phages and their lytic enzymes is of interest for their ability to selectively destroy pathogenic bacteria, including antibiotic-resistant strains. Introduction of phage preparations into medicine, biotechnology, and food industry requires a thorough characterization of phage–host interaction on a molecular level. We employed Raman tweezers to analyze the phage–host interaction of Staphylococcus aureus strain FS159 with a virulent phage JK2 (=812K1/420) of the Myoviridae family and a temperate phage 80α of the Siphoviridae family. We analyzed the timeline of phage-induced molecular changes in infected host cells. We reliably detected the presence of replicating phages in bacterial cells within 5 min after infection. Our results lay the foundations for building a Raman-based diagnostic instrument capable of real-time, in vivo, in situ, nondestructive characterization of the phage–host relationship on the level of individual cells, which has the potential of importantly contributing to the development of phage therapy and enzybiotics.

Raman spectroscopy for viral diagnostics

“…Raman tweezers were used to identify herpes viral infection based on Raman frequencies of proteins and nucleic acids at 1004, 1093, and 1664 cm −1 (Hamden et al 2005 ). Pilat and team employed the Raman tweezer technique for analyzing the Staphylococcus aureus infected by two virulent phages JK2 and 80α, identifying band intensity at 746 cm −1 and at 1128 cm −1 attributed to heme required for energy production at the initial stage of infection (Pilat et al 2020 ). Phage replication inside the host was shown by following Raman spectra intensity corresponding to the phosphodiester bond (1095 cm −1 ).…”

“…Phage replication inside the host was shown by following Raman spectra intensity corresponding to the phosphodiester bond (1095 cm −1 ). As the host cells leak their cytoplasmic content during lysis, this leads to a decrease of cytosine and uracil peak at 782 cm −1 (Pilat et al 2020 ). The corresponding Raman analysis scheme is shown in Fig.…”

“…2 Bacteriophage invasion and corresponding molecular changes probed through Raman tweezer. Reprinted with permission from Pilat et al ( 2020 ) …”

Virus–Host Interaction Gets Curiouser and Curiouser. PART II: Functional Transcriptomics of the E. coli DksA-Deficient Cell upon Phage P1vir Infection

“…The virus–host interaction requires a complex interplay between two opposite targets: phage strategy of reprogramming the host machinery to serve its purposes of propagation, and host cell defense against the infection [ 27 ]. Thus, at the molecular level, a complicated arrangement of gene expression alterations takes place, the process that can be studied employing various methods, e.g., computational approaches or Raman tweezers [ 28 , 29 ]. In this work, we attempted to resolve the phenomenon of improved lytic development of P1 phage in the DksA-deficient E. coli host by using a high-throughput approach to obtain a general view on the phage–host interaction.…”