Biology subjects

Sorensen, A. N.

Publications and source records attributed to Sorensen, A. N..

5 recordsLinked to original sources

bioRxiv2024

The branched receptor binding complex of Ackermannviridae phages promotes adaptative host recognition

Bacteriophages may express multiple receptor binding proteins, enabling the recognition of distinct and diverse bacterial receptors for infection of a broad range of strains. Ackermannviridae phages recognize diverse O-antigens or K-antigens as receptors by expressing multiple tail spike proteins (TSPs). These TSPs interact and form a branched protein complex protruding from the baseplate attached to the distal tail. Here, we aimed to mimic the evolution of the TSP complex by studying the acquisition of new TSPs without disrupting the functionality of the complex. Using kuttervirus phage S117 as a backbone, we demonstrated the acquisition of entire tsp genes from Kuttervirus and Agtrevirus phages within the Ackermannviridae family. A fifth TSP was designed to interact with the complex and provide new host recognition to expand the branched TSP complex. Interestingly, the acquisition of tsp5 resulted in new variants of the branched TSP complex due to the exchange or deletion of tsp genes. Overall, our study provides novel insight into the development of the branched TSP complex, enabling Ackermannviridae phages to adapt to new hosts.

microbiology↗

bioRxiv2023

Engineering of Salmonella phages into novel antimicrobial Tailocins

Due to the extensive use of antibiotics, the increase of infections caused by antibiotic resistant bacteria are now a global health concern. Phages have proven useful for treating bacterial infections and represent a promising alternative or complement to antibiotic treatment. Yet, other alternative exists, such as bacteria-produced non-replicative protein complexes that can kill their targeted bacteria by puncturing their membrane (Tailocins). To expand the repertoire of Tailocins available, we suggest a new approach transforming phages into Tailocins. Here we genetically engineered the virulent Ackermannviridae phage S117, as well as temperate phages Fels-1, -2 and Gifsy-1 and -2 targeting the food pathogen Salmonella, by deleting the portal vertex or major capsid gene using CRISPR-Cas9. We report the production of Tailocin particles from engineered virulent and temperate phages able to kill their native host. Our work represents a steppingstone to tape into the huge diversity of phages and transform them into versatile puncturing new antimicrobials.

synthetic biology↗

bioRxiv2023

Agtrevirus phage AV101 infect diverse extended spectrum β-lactamase E. coli by recognizing four different O-antigens

Bacteriophages in the Agtrevirus genus are known for expressing multiple tail spike proteins (TSPs), but little is known about their genetic diversity and host recognition apart from their ability to infect diverse Enterobacteriaceae species. Here we aim to determine the genetic differences that may account for the diverse host ranges of Agrevirus phages. We performed comparative genomics of 14 Agtrevirus and identified only a few genetic differences including genes involved in nucleotide metabolism. Most notably was the diversity of the tsp gene cluster, specifically in the receptor binding domains that were unique among most of the phages. We further characterized agtrevirus AV101 infecting nine diverse Extended Spectrum {beta}-lactamase (ESBL) E. coli and demonstrated that this phage encoded four unique TSPs among Agtrevirus. Purified TSPs formed translucent zones and inhibited AV101 infection of specific hosts, demonstrating that TSP1, TSP2, TSP3, and TSP4 recognize O8, O82, O153, and O159 O-antigens of ESBL E. coli, respectively. BLASTp analysis showed that the receptor binding domain of TSP1, TSP2, TSP3 and TSP4 are similar to TSPs encoded by E. coli prophages and distant related virulent phages. Thus, Agtrevirus may have gained their receptor binding domains by recombining with prophages or virulent phages. Overall, combining bioinformatic and biological data expands the understanding of TSP host recognition of Agtrevirus and give new insight into the origin and acquisition of receptor binding domains of Ackermannviridae phages. One sentence summaryAgtrevirus phage AV101 express four unique tail spike proteins that recognize different O-antigens of Extended Spectrum {beta}-Lactamase producing E. coli.

microbiology↗

bioRxiv2023

A collection of diverse bacteriophages for biocontrol of ESBL- and AmpC-β-lactamase-producing E. coli

Novel solutions are needed to reduce the risk of transmission of extended spectrum {beta}-lactamase and AmpC {beta}-lactamase producing Escherichia coli (ESBL/AmpC E. coli) in livestock to humans. Since phages are promising biocontrol agents, we established a collection of 28 phages against ESBL/AmpC E. coli and showed by whole genome sequencing that all phages were unique and could be assigned to 15 different genera. Host range analysis showed that 82% of 198 strains, representing the genetic diversity of ESBL/AmpC E. coli, were sensitive to at least one phage. Identifying receptors used for initial binding experimentally as well as in silico predictions, allowed us to combine phages into two different cocktails with broad host range targeting diverse receptors. These phage cocktails inhibit growth and kill ESBL/AmpC E. coli in vitro, thus suggesting the potential of phages as promising biocontrol agents. HIGHLIGHTSO_LI28 unique phages infecting ESBL/AmpC E. coli were isolated and characterized C_LIO_LIBroad host range phages targeting different receptors were used to compose phage cocktails C_LIO_LIPhage cocktails efficiently inhibit growth of ESBL/AmpC E. coli in vitro C_LI

microbiology↗

bioRxiv2023

A hybrid receptor binding protein enables phage F341 infection of Campylobacter by binding to flagella and lipooligosaccharides

Flagellotropic bacteriophages are interesting candidates as therapeutics against pathogenic bacteria dependent on flagellar motility for colonization and causing disease. Yet, phage resistance other than loss of motility has been scarcely studied. Here we developed a soft agar assay to study flagellotropic phage F341 resistance in motile Campylobacter jejuni. We found that phage adsorption was prevented by diverse genetic mutations in the lipooligosaccharides forming the secondary receptor of phage F341. Genome sequencing showed phage F341 belongs to the Fletchervirus genus otherwise comprising capsular-dependent C. jejuni phages. Interestingly, phage F341 encodes a hybrid receptor binding protein (RBP) predicted as a short tail fiber showing partial similarity to RBP1 encoded by capsular-dependent Fletchervirus, but with a receptor binding domain similar to tail fiber protein H of C. jejuni CJIE1 prophages. Thus, C. jejuni prophages may represent a genetic pool from where lytic Fletchervirus phages can acquire new traits like recognition of new receptors.

microbiology↗