Unknown to science at the turn of the 20th century, the odd assemblage denoted by the term virus was wholly foreign to the conventional definitions of infectious agents and, indeed, life itself. As viruses were structurally and physiologically distinct from any known biological entity, including bacteria, the process of deciphering the riddles posed by their discovery and questions about how they reproduce and cause disease would remain for a time in the realm of bacteriology. This ownership was based not only on the fact that microbiologists rank among the earliest pioneers of virology research; it was also based on a fortuitous series of findings that coincided with the discovery of viruses.
The Smallest Shall Lead Them
Viruses are everywhere and can devour virtually every type of living matter. Scientists have identified only a small fraction of the number of conventional living organisms on our planet. Such ignorance is compounded by many magnitudes when applied to our understanding of the diversity of viruses. The current consensus is that the number of different viruses (the virome) vastly exceeds the number and diversity of all known and unknown prokaryotic and eukaryotic life.11 Whereas the bias of our own species often presumes the primary threat of viruses is focused upon humans, as evidenced by scourges such as Ebola, HIV, or influenza, viruses in general are just as troubling for bacteria as they are for any mammalian species.
The current renaissance in the discovery of new viruses reveals most humans (and indeed probably all vertebrates) cohabit with myriad viruses that do not cause disease and are either neutral or perhaps even helpful, much as we have already seen with bacteria. The human virome includes hundreds of species of recently discovered viruses known as anelloviridae.12 These small, ring-shaped viruses can be found throughout the body, but most have not yet been linked with disease. It is not too far-fetched to imagine that they may be beneficial in day-to-day life. For one example of how viruses can be beneficial, we turn to one group of viruses that helped scientists to understand how viruses function in the early days after their discovery and how these same viruses may provide unimagined future benefit. Understanding the set of bacterial viruses generally known as bacteriophage provided the gateway for understanding viral pathogens in humans, so we will begin there.
In the same year Martinus Beijerinck was verifying the discovery of very small pathogens targeting tobacco plants, the English bacteriologist Ernest Hanbury Hankin contributed a landmark breakthrough that revolutionized our view of disease.13 The setting for the discovery was quite murky. It seems Ernest became interested in the notorious fact that bathing in the fetid waters of the Ganges River in India was one of the most efficient means of self-induced illness. The “miasma” theory of disease still largely dominated the public view of infectious disease, and Hankin sought to dispel these ancient notions by demonstrating that bacteria were the cause of the intestinal and other maladies often arising from direct encounters with the Ganges.14 Hankin himself had trained as a bacteriologist in London and was an early proponent of utilizing aniline dyes to visualize bacteria under the microscope. After training with both Robert Koch and Louis Pasteur, the young English scientist had gained the credentials to begin an independent career in India, where he was granted the impressive title of Chemical Examiner, Government Analyst and Bacteriologist for the United Provinces, Punjab and the Central Provinces.15 Although this was certainly a promotion from his student days, Hankin’s detractors in the United Kingdom portrayed his departure to the Raj as a desperate flight away from ignominy suffered at home. The venom directed at Ernest was not based upon his progressive views of infectious disease but because Hankin had also gained quite a reputation as an advocate for the use of animal dissection as a means to promote scientific discovery and education. This view was anathema to many contemporaries, thus earning the ire of the animal rights community, which often posted hostile newspaper articles and letters to the editor, some of which threatened physical violence to “vivisectors” such as Hankin.
The rivers of India were (and sadly some remain) a bountiful source of waterborne diseases. One of Hankin’s early contributions to his new home was a demonstration that boiling the river water was sufficient to prevent the spread of cholera and other waterborne illnesses. As the practice spread and cholera rates correspondingly diminished, the life-saving contribution continued to be derided by his fringe animal rights enemies in Britain, who published the following in the June 26, 1896 edition of The Zoophilist:
Remarkable to state, a vivisector has made a beneficial—and common-sense discovery. The discoverer in this case is Mr Hankin an old antagonist of ours, whom we met in debate at Cambridge before he took ship and departed to serve as a bacteriologist in India, where he still remains.16
In that same year of 1896, Hankin published an article in the annals of the Pasteur Institute that would forever link him into the history of viruses, though he did not realize this at the time.17 In a rather obscure study buried in the institute proceedings, Hankin noted the presence of substances in the polluted waters of the Ganges and Jumna Rivers that thwarted the survival of the cholera bacterium. Hankin went on to contribute knowledge to a wide array of scientific thought (including zoology, microbiology, anthropology, political science, and architecture) until his death in 1939. Nonetheless, his most lasting impact would ultimately center upon the 1896 observations from the sacred but putrid waters of the Ganges.
Almost two decades after Hankin’s key observations, another English bacteriologist, engrossed in studies to improve the manufacturing of smallpox vaccine, built upon Hankin’s findings from India. In 1915 English bacteriologist Frederick Twort reported the discovery of a small agent that could pass through a Chamberland-Pasteur filter and was sufficient to kill staphylococcal bacteria.18 Twort postulated this might be a virus or enzyme that targeted bacteria but favored the latter, thus denying him conclusive title to a seminal discovery. The key breakthrough was instead to be made by the itinerant French-Canadian microbiologist Felix d’Herelle, who was fueled by booze.
A Parisian newborn was christened in 1873 with the name Hubert Augustin Felix Haerens, but his name was changed, likely by customs officials, after his parents moved the family to Montreal. Returning to Paris at the young age of six after the death of his father, d’Herelle completed high school and trained himself in the sciences. A not-so-grand tour of Europe by bicycle initiated a lifelong wanderlust, which drove him to explore South America and Turkey, mostly by bicycle, by the age of twenty.19 The fixation upon travel halted briefly as Felix met his future wife, Marie, in Anatolia and settled down for a few years. D’Herelle’s nervous energies were then directed, both personally and professionally, towards a new obsession: the science of fermentation. D’Herelle studied fermentation through books and by building a home laboratory (effectively a distillery). Ultimately, the pursuit of understanding and improving the fermentation process would propel d’Herelle to return to Canada, where he had been offered a commission to study the fermentation and distillation of maple syrup into schnapps. Although maple schnapps can still be obtained for a price, the precious cost of pure maple syrup (as compared with wheat, barley, potatoes, and other inexpensive sources of sugars and starch for the bacteria and yeast involved in fermentation) soon rendered this practice largely obsolete.
Unperturbed by the failure to launch maple syrup–based liqueurs, d’Herelle continued traveling the world to further his preoccupation with distillation (and because his poor investment skills compelled a constant need for income). D’Herelle accepted a job offer from the Guatemalan government to establish a bacteriological laboratory at the General Hospital in 1901. His primary goal was to help find ways to prevent the fungal infections that were damaging the local coffee crops (a task that he eventually achieved by acidifying the soils). On the side, d’Herelle also embraced an opportunity to ferment whisky from bananas, a product positively compared with Canadian Club, a high-end whisky from another of d’Herelle’s adopted countries.20 Later moving to Mexico, d’Here
lle again moved his family, this time to the Yucatan peninsula of Mexico, where he was commissioned by the government to develop a means to produce schnapps from the agave sisal. This plant was primarily harvested for its fiber but is related to the blue agave plant that is famously used to produce tequila. Using the “throwaway” material not useful for rope making, d’Herelle was able to develop a novel and exotic variant of schnapps that resembled the anise-flavored liquors (like ouzo) indigenous to the Mediterranean basin and Middle East.
Sisal-based schnapps would not ultimately subvert tequila as the principal liquor produced in Mexico, but it nevertheless became popular in d’Herelle’s native (though seldom-seen) France. This fact led d’Herelle back to Paris, where he helped oversee manufacturing and again did side jobs both for the money and the love of science. The side job was a request from the Mexican government to combat a locust outbreak. In preparation, Felix volunteered for an unpaid stint at the Pasteur Institute, where d’Herelle investigated the idea of developing and deploying bacteria that could kill locusts. The resulting discovery of the Bacillus thuringiensis was tested in Mexico and later Argentina, where it helped quash the devastation wrought by the insects.
Expanding the idea of using one biological organism to kill another, d’Herelle became interested in ways to combat dysentery. War and disease have a long-standing relationship. As we have already seen, it is no coincidence that the Athenian plague coincided with the Peloponnesian War and the Antonine Plague was linked with the quelling of an uprising by the Parthians. As recently as the mid-19th century, some two thirds of the 620,000 Americans who lost their lives in the Civil War succumbed to disease rather than wounds. World War I holds the distinction of being the first conflict in which more people were killed by people than by microorganisms. This improvement in large part arose because of the recognition of infectious bacteria and viruses in general, and also because of efforts by investigators including Felix d’Herelle.21
The advent of motion pictures in the early 20th century gives modern viewers a semblance of the murky and muddy conditions that characterized trench warfare. A fact that may be less familiar is that the mazes of trenches in Western Europe spanned from the Belgian coast to Switzerland, collectively comprising a network more than twenty-five thousand miles in all.22 Amidst these horrible and widespread conditions, d’Herelle began a quest to identify natural agents that could kill the Shigella bacterium, which had been discovered by the Japanese scientist Kiyohsi Shiga just a few years before in 1897.23 Shigella infection causes a violent form of diarrhea that is better known as dysentery. This disease has a long linkage with warfare, claiming the lives of famous historical characters, including King John of England (the signer of the Magna Carta), the admiral Sir Frances Drake, the humanist Erasmus, and the explorer David Livingstone (of “Dr. Livingstone, I presume” fame). Given the damp, cramped, and unhygienic conditions of trenches during World War I, fear of dysentery was endemic.
At the peak of the bitter trench fighting in September 1917, d’Herelle announced the discovery of “an invisible, antagonistic microbe of the dysentery bacillus.” Specifically, Felix described an unknown biological (as opposed to chemical) substance that feasted upon Shigella bacteria.24 While the exact nature of the disease-killing activity of this seemingly magical substance was unknown at the time, d’Herelle initiated a new business to supply the French military with twelve million doses of the life-saving concoction as a medicine to combat dysentery.25 We now know that the efficacy of the substance capable of selectively and efficiently killing the causative agent of dysentery came from a bacteriophage.
D’Herelle continued his work to identify additional bacteriophage beyond the Great War, resuming his globetrotting ways both to identify new phage and to market the phage products he had already pioneered. In the midst and immediate aftermath of the Great War, d’Herelle isolated and marketed phage therapies to treat cholera, typhus, and other septic diseases. These products were broadly embraced, and a growing fame led to honorary degrees and, ultimately, a professorship at Yale University, the receipt of the prestigious Leeuwenhoek Medal, and eight nominations for the Nobel Prize.26, 27 Likewise, d’Herelle provided the inspiration for the lead character in Arrowsmith, a novel by Sinclair Lewis that won the 1926 Pulitzer Prize.28 All these well-earned awards were amassed despite the fact that d’Herelle lacked formal credentials and any idea of the composition of the beneficial concoction that he was marketing as a medicine or how the new treatments functioned. We now know that the magical substance was composed of bacteriophage (also known simply as phage), viruses that would seek out and kill harmful bacteria.
The impact of using bacteriophage to kill bacteria as a means to treat infection is reflected by the experiences of another great war. As we will see, the Soviet leadership embraced phage therapy, which was heavily deployed to treat soldiers wounded during the brief but fierce Winter War with Finland in 1939–40. Likewise, the leadership of the German Wehrmacht included strong advocates of phage-based therapy, and medical kits containing vials of phage were issued to the Afrika Korps and other German units.29 Indeed, there is rampant speculation amongst some historians that the German decision to divide their armies to include Georgia as an early target for the 1941 Operation Barbarossa was in large part driven by a desire to acquire the phage research and manufacturing facilities located outside Tbilisi. The Soviet capabilities targeted by the Wehrmacht provides a direct connection back to Felix d’Herelle and thereby allows us to return to his remarkable story.
While d’Herelle gained considerable fame and wealth throughout the Jazz Age of the 1920s, he and his remarkable products had been all but forgotten within a decade. Phage therapy was destined to lose its luster considering the growth first in sulfa-based medications and later in antibiotics such as penicillin (innovations that were largely focused upon the English-speaking democracies during the Second World War). The reasons for the rapid diminution of phage-based medicines include their unknown mechanism of action. Because of this, it was virtually impossible to assess how efficacious, if at all, a particular batch of phage drug might be. Unsurprisingly, this vulnerability was exploited by unscrupulous or low-quality manufacturers fixated upon quick and disproportionate profits from inferior products. Such irregularities increased consumer skepticism amidst the discovery and product launch of attractive new sulfa drugs and antibiotics introduced in the 1930s and 1940s, respectively.
Unlike the advances that characterized the scientific revolutions of the interwar era, phage therapy persisted in the Soviet Union, in no small measure because of Felix d’Herelle himself. In 1934, d’Herelle received an invitation from no less than Josef Stalin to join the Tbilisi Bacteriophage Institute. Stalin had become aware of d’Herelle’s work conducted by an old friend from the Pasteur Institute, George Eliava, who was pioneering phage-based medicines in the Soviet Union. For a while, it seemed that d’Herelle might finally settle down once and for all. Again, fate intervened as d’Herelle learned that Eliava had established his institute over the head of the regional Soviet party head, Lavrenti Beria.30 Eliava had also gone over Beria’s head to petition Stalin directly to extend the invitation to d’Herelle. These relatively mild actions were particularly dangerous given the figure of Beria, who embraced a paranoid hatred of influence by foreigners such as Felix. Compounding this, Beria’s major responsibility was not mediating his role as overseer of Soviet Georgia but rather serving as the head of state security—the notorious NKVD.
It is thus unsurprising that when Beria and the NKVD initiated a purge of intelligentsia suspected of corruption by foreign influence, Eliava and his family were among the first corralled. On the evening of January 22, 1937, the knock on the door was quickly followed by charges of treason and the execution of George Eliava. While d’Herelle had initiated the construction of an intended permanent home in Tbilisi, he was in France at the time of Eliava’s arrest and never returned to the USSR. Despite his considerable achievements and perh
aps because of the decline of phage therapeutics, d’Herelle did settle down, but his fame and business declined, and d’Herelle died in 1949 in almost complete obscurity. However, his legacy may again be revived by a new wave of interest in phage technology as a potential solution for the emergence of antibiotic-resistant bacteria.31
Spreading Like Viruses
Despite declining therapeutic application of phage technology, increasing understanding of bacteriophage greatly accelerated the emerging new science of virology.32 Arguably, the most famous bacteriophage is known as T4. This particular phage has been the experimental model of choice for multiple Nobel Prize laureates, including Frank Macfarlane Burnet, Andre Lwoff, Max Delbruck, Salvador Luria, Alfred Hershey, James D. Watson, and Francis Crick.33, 34 Despite these illustrious credentials, the discovery of T4 has largely been lost to time. The earliest reference was a 1943 paper from Salvador Luria, Max Delbrück, and Thomas F. Anderson of Vanderbilt University, who described an electron microscope analysis of bacteriophage that revealed sperm-shaped viral particles.35 With technology improvements came greater resolution, and we now know that bacteriophage T4 looks like a cross between an Apollo landing craft and a mosquito. A hollow and mathematically precise icosahedral head contains the genetic material (in this case DNA) and sits atop a ring-laden collar, which in turn sprouts an array of tail fibers that look like the spindly legs of an otherworldly insect. Rather than being used for locomotion, the tail fibers are tasked with acting like fingers that probe their environment in a never-ending search to seek out new prey. The interaction with a new bacterial victim triggers a landing sequence (again reminiscent of the Apollo lander) as the phage docks upon its soon-to-be bacterial victim. Once firmly attached, the phage body plunges down upon the bacterial surface with sufficient force to compromise the bacterial cell wall. This allows it to inject its genetic material into the bacterium. Once the DNA gains access to the interior, it efficiently hijacks the bacterial machinery to force the production of thousands of new progeny that literally burst forth from its bacterial victim like the shocking scene from the 1979 Ridley Scott sci-fi classic Alien. This entire sequence of events take place within a mere thirty minutes. The bursting forth of progeny multiples the infection and thereby allows the phage to quickly destroy massive swarms of bacteria within a remarkably short time.
Between Hope and Fear Page 17
