Targeted Genome Editing of Virulent Pseudomonas Phages Using CRISPR-Cas3.

The vast number of unknown phage-encoded ORFan genes and limited insights into the genome organization of phages illustrate the need for efficient genome engineering tools to study bacteriophage genes in their natural context. In addition, there is an application-driven desire to alter phage properties, which is hampered by time constraints for phage genome engineering in the bacterial host. We here describe an optimized CRISPR-Cas3 system in Pseudomonas for straightforward editing of the genome of virulent bacteriophages.

A SEVA-based, CRISPR-Cas3-assisted genome engineering approach for with efficient vector curing.

The CRISPR-Cas3 editing system as presented here facilitates the creation of genomic alterations in and in a straightforward manner. By providing the Cas3 system as a vector set with Golden Gate compatibility and different antibiotic markers, as well as by employing the established Standard European Vector Architecture (SEVA) vector set to provide the homology repair template, this system is flexible and can readily be ported to a multitude of Gram-negative hosts. Besides genome editing, the Cas3 system can also be used as an effective and universal tool for vector curing.

The phage-encoded PIT4 protein affects multiple two-component systems of .

More and more isolates have become resistant to antibiotics like carbapenem. As a consequence, ranks in the top three of pathogens for which the development of novel antibiotics is the most crucial. The pathogen causes both acute and chronic infections, especially in patients who are the most vulnerable.

The phage-encoded protein PIT2 impacts quorum sensing by direct interaction with LasR.

In recent decades, there has been a notable increase in antibiotic-resistant isolates, necessitating the development of innovative treatments to combat this pathogen. This manuscript explores the potential of different phage proteins to attenuate virulence factors of , particularly the type II secretion system (T2SS). PIT2, a protein derived from the lytic phage LMA2 inhibits the T2SS effectors PrpL and LasA and attenuates the bacterial virulence toward HeLa cells and .

Bacteriophage-antibiotic combination therapy against extensively drug-resistant Pseudomonas aeruginosa infection to allow liver transplantation in a toddler.

Post-operative bacterial infections are a leading cause of mortality and morbidity after ongoing liver transplantation. Bacteria causing these infections in the hospital setting can exhibit high degrees of resistance to multiple types of antibiotics, which leads to major therapeutic hurdles. Alternate ways of treating these antibiotic-resistant infections are thus urgently needed.

Bacteriophages as drivers of bacterial virulence and their potential for biotechnological exploitation.

Bacteria-infecting viruses (phages) and their hosts maintain an ancient and complex relationship. Bacterial predation by lytic phages drives an ongoing phage-host arms race, whereas temperate phages initiate mutualistic relationships with their hosts upon lysogenization as prophages. In human pathogens, these prophages impact bacterial virulence in distinct ways: by secretion of phage-encoded toxins, modulation of the bacterial envelope, mediation of bacterial infectivity and the control of bacterial cell regulation.