Newly discovered virus kills dormant bacteria in superbug breakthrough

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"... In hostile environments – such as when they’re exposed to antibiotics – bacteria can go into a form of hibernation, where they stop growing and dividing until things calm down. This makes it difficult to fully wipe them out and contributes to the growing problem of antibiotic resistance, which threatens to eventually make even basic infections deadly. ...

Scientists at ETH Zurich hypothesized that there must be some [bacteriophage] species that can attack bacteria in this dormant state. Now, after years of searching, they’ve identified just such a phage, which they’ve named Paride. The team found that Paride was able to infect the bacteria species Pseudomonas aeruginosa, which is responsible for a range of common infections like pneumonia and UTIs, and is increasingly becoming drug-resistant. ..."

"In brief

• For the first time, ETH Zurich researchers have isolated a bacteriophage from rotting plant material that can attack and kill bacteria in a dormant state.
• How the phage manages this is still unclear.
• Combination therapy with this phage and an antibiotic eradicates many dormant germs in pure culture and in the mouse model.

In nature, most bacteria live on the bare minimum. If they experience nutrient deficiency or stress, they shut down their metabolism in a controlled manner and go into a resting state. In this stand-​by mode, certain metabolic processes still take place that enable the microbes to perceive their environment and react to stimuli, but growth and division are suspended. ..."

From the abstract:

"Bacteriophages are ubiquitous viral predators that have primarily been studied using fast-growing laboratory cultures of their bacterial hosts. However, microbial life in nature is mostly in a slow- or non-growing, dormant state. Here, we show that diverse phages can infect deep-dormant bacteria and suspend their replication until the host resuscitates (“hibernation”). However, a newly isolated Pseudomonas aeruginosa phage, named Paride, can directly replicate and induce the lysis of deep-dormant hosts. While non-growing bacteria are notoriously tolerant to antibiotic drugs, the combination with Paride enables the carbapenem meropenem to eradicate deep-dormant cultures in vitro and to reduce a resilient bacterial infection of a tissue cage implant in mice. Our work might inspire new treatments for persistent bacterial infections and, more broadly, highlights two viral strategies to infect dormant bacteria (hibernation and direct replication) that will guide future studies on phage-host interactions."

Newly discovered virus kills "sleeping" bacteria in superbug breakthrough

A virus that kills sleepers (ETH Zurich) ETH Zurich researchers have found a virus that kills dormant bacteria. This rare discovery could help to combat germs that can’t be treated with antibiotics alone.

Phage Paride can kill dormant, antibiotic-tolerant cells of Pseudomonas aeruginosa by direct lytic replication (open access)

The paride phage (purple) is one of the few phages to attack dormant bacteria. 

Fig. 1: Most bacteriophages cannot replicate on deep-dormant E. coli or P. aeruginosa.