Nav: Home

For viral predators of bacteria, sensitivity can be contagious

January 10, 2017

Bacteriophages (phages) are probably the most abundant entities in nature, often exceeding bacterial densities by an order of magnitude. As viral predators of bacteria, phages have a major impact on bacterial communities by reducing some bacteria and enabling others to flourish. Phages also occasionally package host DNA and deliver it to other bacteria, in a process known as horizontal gene transfer (HGT).

The biology of phage infection has been extensively studied since the beginning of the 20th century. However, the fate of phages in complex bacterial communities resembling their natural ecosystem has not been studied at the cellular level. To investigate the biology of phage infection in complex bacterial communities, researchers followed phage dynamics in communities harboring phage-resistant (R) and phage-sensitive (S) bacteria, a common scenario in nature.

Now, in new research in the January 12 edition of Cell, researchers at the Hebrew University of Jerusalem's Faculty of Medicine provide the first demonstration of a mechanism by which bacteria entirely resistant to a given phage become susceptible to it upon co-incubation with sensitive bacteria.

The researchers show how phage-sensitive bacteria harboring phage receptor can deliver the receptor to nearby phage-resistant cells that lack the phage receptor, via a molecular transfer they call "acquisition of sensitivity" (ASEN). This process involves a molecular exchange driven by membrane vesicles (MVs), in which phage-resistant cells transiently gain phage attachment molecules released from neighboring phage-sensitive cells. By exploiting this novel delivery system, phages can invade bacteria lacking their receptor.

The researchers further posit that this mechanism enables phages to expand their host range and deliver DNA into new species, thus facilitating the attachment of phages to non-host species, providing an as-yet unexplored route for horizontal gene transfer (HGT).

"In the present study, we show for the first time how bacteria entirely resistant to a given phage become susceptible upon co-incubation with sensitive bacteria. Phage invasion into resistant cells could have a major impact on transfer of antibiotic resistance and virulence genes among bacteria. This aspect should be carefully considered when employing phage therapy, as phage infection of a given species may result in gene transmission into neighboring bacteria resistant to the phage," said Prof. Sigal Ben-Yehuda, who led the research at the Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, in the Hebrew University's Faculty of Medicine.

"Our work indicates that, similarly to the remarkable arsenal of entry and spreading strategies employed by viruses, phages utilize alternative, as yet unidentified spreading mechanisms, which could expedite the infection process and promote phage spread within cells of the same and different species," said the PhD student Elhanan Tzipilevich, who carried out this research.
-end-
An accompanying video can be seen at https://youtu.be/YQLvTBCsOtM.

The Institute for Medical Research-Israel Canada (IMRIC), in the Hebrew University of Jerusalem's Faculty of Medicine, is one of the most innovative biomedical research organizations in Israel and worldwide. IMRIC brings together brilliant scientific minds to find solutions to the world's most serious medical problems, through a multidisciplinary approach to biomedical research. More information at http://imric.org.

The Hebrew University of Jerusalem

Related Bacteria Articles:

Conducting shell for bacteria
Under anaerobic conditions, certain bacteria can produce electricity. This behavior can be exploited in microbial fuel cells, with a special focus on wastewater treatment schemes.
Controlling bacteria's necessary evil
Until now, scientists have only had a murky understanding of how these relationships arise.
Bacteria take a deadly risk to survive
Bacteria need mutations -- changes in their DNA code -- to survive under difficult circumstances.
How bacteria hunt other bacteria
A bacterial species that hunts other bacteria has attracted interest as a potential antibiotic, but exactly how this predator tracks down its prey has not been clear.
Chlamydia: How bacteria take over control
To survive in human cells, chlamydiae have a lot of tricks in store.
Stress may protect -- at least in bacteria
Antibiotics harm bacteria and stress them. Trimethoprim, an antibiotic, inhibits the growth of the bacterium Escherichia coli and induces a stress response.
'Pulling' bacteria out of blood
Magnets instead of antibiotics could provide a possible new treatment method for blood infection.
New findings detail how beneficial bacteria in the nose suppress pathogenic bacteria
Staphylococcus aureus is a common colonizer of the human body.
Understanding your bacteria
New insight into bacterial cell division could lead to advancements in the fight against harmful bacteria.
Bacteria are individualists
Cells respond differently to lack of nutrients.

Related Bacteria Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Moving Forward
When the life you've built slips out of your grasp, you're often told it's best to move on. But is that true? Instead of forgetting the past, TED speakers describe how we can move forward with it. Guests include writers Nora McInerny and Suleika Jaouad, and human rights advocate Lindy Lou Isonhood.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...