Ending the Pandemic?
How a recent unsung discovery might lead to a cure for Coronavirus…
Covid-19 has brought our modern world to its knees. There is barely a country, town or village on the planet that has not been affected by the disease and its restrictions. For over a year now we have been engaged in a global battle against an invisible enemy with no respect for human life, institutions or borders.
The trouble with the Coronavirus is that it is what it says on the tin — a virus. Life would be so different if the spiky invader was a bacterium.
Bacteria are microscopic single-celled organisms, which vary in shape and structure. There are a lot of them in the world — about five million, trillion, trillion. (That’s five with 30 zeros). They live in the human body and the environment but only a handful cause diseases. (Think pneumonia, salmonella and strep throat for example.)
Bacteria have some similarities to human cells, but also some crucial differences. Targeting those differences without harming human cells is the main basis for treatment with antibiotics.
With viruses it’s a different story.
There are a lot of viruses too, about ten times more than bacteria. It is estimated the earth contains about 10 nonillion (10 to the 31st power) of them. That’s such a high number, it’s hard to visualize, so think of it this way: there are more viruses on earth than grains of sand on all the world’s beaches. They are woven into the fabric of our world as inextricably as atoms or energy.
Viruses are much smaller than bacteria and need living tissue or host cells to reproduce. Once inside they use the cell’s processes to replicate their own genetic material. During this hijack they may kill the cell, change it, or damage it.
Because the virus and the cell are so interconnected, it is very difficult to target the invader with antivirals without also killing the host cell. Just as with bacterial infection, you want to intervene at the points of difference. The problem is that there are so few of these in a viral infection.
Another problem is that viruses are so diverse. While bacteria all have double-stranded DNA genomes, viruses may have DNA or RNA genomes and single or double strands. Covid-19 is an RNA virus. Unlike a DNA virus, where long-lasting vaccines can be effective, RNA viruses mutate quickly, as we have seen with the emerging variants in the current pandemic.
Vaccine or Medicine?
Understandably, shellshocked governments around the world have focused on developing anti-Covid vaccines. This strategy doesn’t cure Covid-19, at best it slows the spread of the virus. The vaccine strategy comes with its own set of issues: there is the constant problem of mutant strains which vaccines may not protect against. In addition, scientists currently don’t know how long the vaccine is effective for or if there are any long-term side effects. In short, a vaccination program doesn’t mean the virus hasn’t been eliminated, just managed.
What’s needed is something to kill it.
According to the Online Etymology Dictionary, the use of the word ‘virus’ for a “poisonous substance” originated in the 14th century. It was from the Latin virus meaning “poison, sap of plants, slimy liquid.” The definition of virus as an “agent that causes infectious diseases” comes 400 years later.
Let us play with the “virus as poison” idea for a minute. The treatment to counteract poison is an antidote. It is not far-fetched to say that in order to end this pandemic, we need to develop an antidote, a medicine that can counteract Covid-19. Because of the complex nature of the disease, this will most likely be a medicine that doesn’t reverse the effect but kills the virus.
One solution could be to find a natural enemy that looks on viruses as prey.
Saying “kill the virus” implies that it is alive, but that is not necessarily the case. Whether or not a virus is a living thing is the subject of much debate. How so?
There are seven accepted factors which together meet the definition of life: movement, sensitivity, nutrition, respiration, reproduction, excretion and growth. Viruses don’t tick all the boxes. They don’t move, don’t excrete waste and don’t convert nutrition to energy. They also reproduce really oddly, requiring a take-over and reprogramming of the host cell to then replicate themselves. In short some believe that they are not “alive” in any normal understanding of the word.
Alive, semi-alive, zombie, whatever it is, the covid-19 virus needs to be stopped in its tracks. One solution could be to find a natural enemy that looks on viruses as prey. This makes sense because not only are viruses numerous they are also full of nutrients. There must be a ravenous organism out there somewhere that would wolf them down with relish. But the hunt for the elusive viral gourmand has been fruitless.
The virus eaters
In September 2020, a team of eight scientists published an original paper in Frontiers in Microbiology. They were investigating the eating habits of marine protists. A protist is a microscopic organism, usually single-celled, whose cells contain a nucleus. It is most often defined by what it is not: “a protist is not a plant, animal or fungus” mainly because it doesn’t have tissue or organs. If you think of it as a microbe pac-man gobbling stuff up, that might help. The protists in this study live in the ocean. (In fact, most protists live in water or damp environments.)
The study was started ten years ago. Scientists focussed on protists living in seawater samples from two different areas: the Mediterranean and the Gulf of Maine. They wanted to know what the little creatures had eaten. To do this, as an article in the New York Times put it, they “split the cells open, one at a time, and analyzed their contents. Any genetic material that differed from a protist’s, the team reasoned, was probably the signature of something the microbes had eaten.”
the team is almost certain that protists really do gobble up viral snacks.
During the analysis the scientists made a remarkable discovery — marine protists from the choanozoan and picozoan groups appeared to eat viruses.
There is further work to be done to confirm that the viral genetic material they found in the protists comes from consumption rather than infection or accidental contact. However, the team is almost certain that protists really do gobble up viral snacks.
This discovery appears to confirm a theory put forward in 1994 by two scientists, Juan M. Gonzalez and Curtis A. Suttle from Oregon State University and the University of Texas. Their paper said back then: “Our results confirm that being grazed by protists is one of the possible fates for viruses in aquatic ecosystems.”
The September 2020 story of the virus-eating protists attracted a little bit of attention in the media at the time, particularly in the scientific journals. But no-one seems to have considered this:
Perhaps these microbes could be used to create a medicine that kills coronavirus.
This may be naively way off the mark. Perhaps marine protists only eat marine viruses. (Although that could be because that’s all that is on offer. For all we know, the covid-19 virus could be a protist’s idea of a gourmet meal.) Yet many of our most potent medicines are made from microbes, including most antibiotics.
While it may be a maverick idea to put a choanozoan or picozoan protist in a dish with a coronavirus and see what happens, it wouldn’t be a difficult test to perform. Results would emerge in a matter of weeks. If the tests proved successful, enough microbes to treat the entire planet could be grown rapidly and cheaply. A tablet could be produced for less than a dollar.
The bit about penicillin you probably don’t know
It wouldn’t be the first time that nature had provided a solution to our biggest medical problem.
The discovery of the “mould juice”penicillin back in 1928 revolutionised global medicine and saved millions of lives. Dr. Alexander Fleming, a bacteriologist at St Mary’s Hospital, London, returned from holiday to find his petri dishes containing the bacterium Staphylococcus aureus had been contaminated by a green mould, Penicillium notatem. Fleming noticed that the mould had stopped the bacterium growing. Fourteen years later, the first patient received a dose of penicillin which successfully treated her potentially fatal blood poisoning.
Penicillium notatem couldn’t produce enough to make an antibiotic viable. They needed another source.
Why the big time lag? Because Fleming didn’t have the resources to take the research further at the time. Surprisingly, he kind of left it at that. It was only when Oxford University professor of pathology Dr. Howard Florey came across Fleming’s academic paper in 1938 that the penicillin story got its happy ending.
Even then it wasn’t without problems. “Fleming’s” fungus Penicillium notatem couldn’t produce enough to make an antibiotic viable. They needed another source. It was scientists in the USA working with the Oxford team, who by chance, found the answer when a lab assistant noticed a golden mould on a cantaloupe melon that had started going bad. This mould was Penicillium chrysogeum which ended up, after some scientific processes, producing 1000 times more penicillin than Fleming’s original fungus. The rest, as they say, is history.
Taking the next step
The point of the story is this: By chance Fleming found a natural organism that stopped a deadly bacterium. The resultant antibiotic only went global because years later, a scientist decided to take Fleming’s research further. The penicillin we know today, which has saved millions of lives all over the world, is not the one Fleming found in his contaminated petri dish. But that was what sparked the breakthrough.
Twenty-six years after Gonzalez and Suttle published their theory that protists may feed on viruses, a new team of scientists have found that two marine microbes probably do just that. Is it too much of a leap to hope this might help us in our current Covid-19 nightmare?
Maybe, like a viral equivalent of penicillin, these natural organisms are the key to developing a medicine to end the pandemic forever. It just needs some enterprising scientists to take things one step further.
Is there anyone out there?