An intricate colony of millions of the single-celled bacterium Pseudomonas aeruginosa, a common culprit in the more than 700,000 hospital-acquired infections estimated to occur annually in the United States. CREDIT: Scott Chimileski and Roberto Kolter, Harvard Medical School, Boston

“We have found five new species that we believe are unknown to science,” said associate professor Clare Kirkpatrick, who studies bacterial stress-response at the Department of Biochemistry and Molecular Biology at the University of Southern Denmark (SDU).

The somewhat surprising discovery was made during the coronavirus pandemic, when some of Kirkpatrick’s students could not carry out their normal microbe studies in the laboratory and were therefore sent on field trips to local creeks to see if they had any interesting microbes to offer. 

Viruses are everywhere

The fact that viruses exist in nature is not surprising, as they are the world’s most widespread organism. They are everywhere and part of all kinds of microbial cycles and ecosystems, but the fact that five potentially new species have appeared in local creeks did surprise Kirkpatrick. 

While four of the five have not yet had their genome mapped in a genome sequencing, one species has now been fully sequenced, scientifically described, named and published in Microbiology Resource Announcements. The name is Fyn8. 

Many viruses are so-called bacteriophages (phages), i.e. that they kill bacteria, and Fyn8 is no exception. It can attack and kill the bacteria Pseudomonas aeruginosa

Pseudomonas aeruginosa is a bacterium found naturally in soil and water. It is normally harmless towards healthy people, but like many other bacteria it has developed resistance to antibiotics and is found in hospitals. 

For example, patients with wounds (e.g. burn patients) and ventilator patients are at risk of getting an infection that cannot be fought with antibiotics. 

The researchers have no doubt that Fyn8 can effectively kill Pseudomonas aeruginosa

We could see it with the naked eye: Clear holes appeared in the layer of Pseudomonas aeruginosa bacteria in our petri dishes, where Fyn8 had infected the bacterial cells, killed them, multiplied and proceeded to attack the next.

Especially used in Eastern European countries 

Considering that the world is facing a resistance crisis, where more people will die from an infection with resistant bacteria than from cancer, the new finding is of course interesting and raises the question; Can phages help us in the fight against resistant bacteria? 

Research in this field has been uncommon until recently, both in academic research institutions and in pharmaceutical companies. In the past and in other parts of the world however, there has been some research, and phages have also been used to treat infections in Eastern European countries in particular. 

The phages were discovered at the beginning of the 20th century by researchers who had their bacterial cultures destroyed by virus infections.

The benefits of that discovery were obvious, but antibiotics, not phages, became the absolutely most widespread cure against bacterial infections. 

No more antibiotics? 

One reason was perhaps that antibiotics were easy to produce and easy to use, while the phages were difficult to isolate and give to patients.  

Another reason was probably also that an antibiotic dose could kill many different bacteria, while a phage only matches with a single bacterial species. 

But today it is relatively easy to make precision medicine for the individual patient. First you find out what exact bacteria a patient is infected with, and then you can treat the patient with exactly the phage that will kill the bacteria, explained Kirkpatrick.

Read more at SDU or EurekAlert.