Synergy between the Host Immune System and Bacteriophage Is Essential for Successful Phage Therapy against an Acute Respiratory Pathogen.

The rise of multi-drug-resistant (MDR) bacteria has spurred renewed interest in the use of bacteriophages in therapy. However, mechanisms contributing to phage-mediated bacterial clearance in an animal host remain unclear. We investigated the effects of host immunity on the efficacy of phage therapy for acute pneumonia caused by MDR Pseudomonas aeruginosa in a mouse model.

The search for therapeutic bacteriophages uncovers one new subfamily and two new genera of Pseudomonas-infecting Myoviridae.

In a previous study, six virulent bacteriophages PAK_P1, PAK_P2, PAK_P3, PAK_P4, PAK_P5 and CHA_P1 were evaluated for their in vivo efficacy in treating Pseudomonas aeruginosa infections using a mouse model of lung infection. Here, we show that their genomes are closely related to five other Pseudomonas phages and allow a subdivision into two clades, PAK_P1-like and KPP10-like viruses, based on differences in genome size, %GC and genomic contents, as well as number of tRNAs. These two clades are well delineated, with a mean of 86% and 92% of proteins considered homologous within individual clades, and 25% proteins considered homologous between the two clades.

Predicting in vivo efficacy of therapeutic bacteriophages used to treat pulmonary infections.

The potential of bacteriophage therapy to treat infections caused by antibiotic-resistant bacteria has now been well established using various animal models. While numerous newly isolated bacteriophages have been claimed to be potential therapeutic candidates on the basis of in vitro observations, the parameters used to guide their choice among billions of available bacteriophages are still not clearly defined. We made use of a mouse lung infection model and a bioluminescent strain of Pseudomonas aeruginosa to compare the activities in vitro and in vivo of a set of nine different bacteriophages (PAK_P1, PAK_P2, PAK_P3, PAK_P4, PAK_P5, CHA_P1, LBL3, LUZ19, and PhiKZ).

Tools from viruses: bacteriophage successes and beyond.

Viruses are ubiquitous and can infect any of the three existing cellular lineages (Archaea, Bacteria and Eukarya). Despite the persisting negative public perception of these entities, scientists learnt how to domesticate some of them. The study of molecular mechanisms essential to the completion of viral cycles has greatly contributed to deciphering fundamental processes in biology.

Comparative modelling of LysB from the mycobacterial bacteriophage Ardmore.

Given their potential as specific and natural biocontrol agents, bacteriophages and their associated proteins have become the focus of renewed attention over the last decade. The aim of this study was to use a comparative modelling approach to generate a predicted 3D structure for LysB; a 332 amino acid lipolytic enzyme encoded by the mycobacteriophage Ardmore. The GXSXG pentapeptide, characteristic of lipolytic enzymes, was located at amino acid position 166-170.

Cloning and expression of a mureinolytic enzyme from the mycobacteriophage TM4.

In this study, we describe the characterization, cloning, expression and purification of the lysin A gene of the mycobacteriophage TM4. The gene TM4_gp29 (gp29) is a 1644-bp gene that codes for a 58.6-kDa protein and contains peptidoglycan recognition protein, Zn-binding and amidase catalytic domains.

In silico analysis of Ardmore, a novel mycobacteriophage isolated from soil.

Ardmore is a novel mycobacteriophage isolated from a soil sample collected in County Waterford, Ireland. The genome of this phage has been fully sequenced and is composed of 52,141 bp of linear double stranded DNA with a GC content of 61.49%.