Bacteriophage imaging: past, present and future

Abstract

The visualization of viral particles only became possible after the advent of the electron microscope. The first bacteriophage images were published in 1940 and were soon followed by many other publications that helped to elucidate the structure of the particles and their interaction with the bacterial hosts. As sample preparation improved and new technologies were developed, phage imaging became important approach to morphologically classify these viruses and helped to understand its importance in the biosphere. In this review we discuss the main milestones in phage imaging, how it affected our knowledge on these viruses and recent developments in the field.

Centennial celebration of the bacteriophage research

“…In this special issue of Research in Microbiology, we present a collection of papers reflecting the diversity of research lines focusing on microbial viruses. Kropinski [27] and Almeida et al [28] provide historical overviews of different aspects of bacteriophage research and define new lines for future studies; Toussaint and Van Gijsegem [29], Atanasova et al [30], and Buttimer et al [31] describe novel microbial viruses and proviruses, providing further insights into the evolution and diversity of the corresponding virus families; Tkhilaishvili et al [32] and Vinner and Malik [33] describe novel technological developments in bacteriophage research; whereas Gelman et al [34] and Hoyle et al [35] focus on the therapeutic potential of bacteriophages against diverse bacterial pathogens in different models, including a case report of successful treatment of a cystic fibrosis patient. We hope that these articles will inspire more scientists to join the growing community of microbial virologists and perpetuate the exciting research on microbial viruses for the next 100 years.…”

Apoptosis like symptoms associated with abortive infection of Mycobacterium smegmatis by mycobacteriophage D29

“…Even though they were discovered in 1915 by Frederick Twort, the nature of the existence of the so-called “ contagium vivum fluidum ”—whether it was liquid or particulate, remained a topic of contention until they were visualized for the first time in the year 1939 with an electron microscope (EM) [ 4 , 5 ]. Several significant milestones were achieved by phage imaging, including their morphological classification [ 6 ].…”

Imaging Techniques for Detecting Prokaryotic Viruses in Environmental Samples

“…In contrast to uncultivated viruses, those that were cultivated in the laboratory have been extensively studied for decades, including via imaging techniques [19], and have substantially broadened our knowledge regarding viral morphologies and ultrastructure. Fundamental insights regarding how viruses interact with their hosts and regarding the discovery of novel viruses can be gained from using epifluorescence microscopy, electron microscopy (EM), helium-ion microscopy (HIM), and atomic force microscopy (AFM) (Figure 1, Table 1).…”

“…For studying the viral entry and egress mechanisms, scanning electron microscopy (SEM) was identified as one of the most suitable imaging techniques [28]. Analyses based on cryo-EM have provided important information not only on investigating and reconstructing the viral structure [19,29,30] but also on the genome injection mechanisms of viruses [31]. Additionally, HIM and AFM have been applied for studying virus-host interactions under high resolution [32,33].…”