Pseudomonas aeruginosa bacteriophage PA1Ø requires type IV pili for infection and shows broad bactericidal and biofilm removal activities.

Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
Applied and Environmental Microbiology (Impact Factor: 3.95). 06/2012; 78(17):6380-5. DOI: 10.1128/AEM.00648-12
Source: PubMed

ABSTRACT We isolated a new lytic Pseudomonas aeruginosa phage that requires type IV pili for infection. PA1Ø has a broad bactericidal spectrum, covering Gram-positive and Gram-negative bacteria, and can eradicate biofilm cells. PA1Ø may be developed as a therapeutic agent for biofilm-related mixed infections with P. aeruginosa and Staphylococcus aureus.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Most prokaryotes contain CRISPR-Cas immune systems that provide protection against mobile genetic elements. We have focused on the ability of CRISPR-Cas to block plasmid conjugation, and analyzed the position of target sequences (protospacers) on conjugative plasmids. The analysis reveals that protospacers are non-uniformly distributed over plasmid regions in a pattern that is determined by the plasmid's mobilization type (MOB). While MOBP plasmids are most frequently targeted in the region entering the recipient cell last (lagging region), MOBF plasmids are mostly targeted in the region entering the recipient cell first (leading region). To explain this protospacer distribution bias, we propose two mutually non-exclusive hypotheses: (1) spacers are acquired more frequently from either the leading or lagging region depending on the MOB type (2) CRISPR-interference is more efficient when spacers target these preferred regions. To test the latter hypothesis, we analyzed Type I-E CRISPR-interference against MOBF prototype plasmid F in Escherichia coli. Our results show that plasmid conjugation is effectively inhibited, but the level of immunity is not affected by targeting the plasmid in the leading or lagging region. Moreover, CRISPR-immunity levels do not depend on whether the incoming single-stranded plasmid DNA, or the DNA strand synthesized in the recipient is targeted. Our findings indicate that single-stranded DNA may not be a target for Type I-E CRISPR-Cas systems, and suggest that the protospacer distribution bias might be due to spacer acquisition preferences.
    RNA biology 03/2013; 10(5). · 5.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Bacterial viruses (bacteriophages) have a key role in shaping the development and functional outputs of host microbiomes. Although metagenomic approaches have greatly expanded our understanding of the prokaryotic virosphere, additional tools are required for the phage-oriented dissection of metagenomic data sets, and host-range affiliation of recovered sequences. Here we demonstrate the application of a genome signature-based approach to interrogate conventional whole-community metagenomes and access subliminal, phylogenetically targeted, phage sequences present within. We describe a portion of the biological dark matter extant in the human gut virome, and bring to light a population of potentially gut-specific Bacteroidales-like phage, poorly represented in existing virus like particle-derived viral metagenomes. These predominantly temperate phage were shown to encode functions of direct relevance to human health in the form of antibiotic resistance genes, and provided evidence for the existence of putative 'viral-enterotypes' among this fraction of the human gut virome.
    Nature Communications 09/2013; 4:2420. · 10.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Phage therapy for Pseudomonas aeruginosa infections has been used for more than 50 years. Controlled investigation into its use dates from the early 1990s when positive laboratory studies of local and systemic infection were followed by clinical studies: symptomatic improvement and phage multiplication were seen in a pet dog with otitis and a human with an infected burn. Antibiotic resistance has renewed interest in this approach. There have been recent positive reports in the treatment of experimental animal infection including systemic and respiratory infections. Phages have shown promise against experimental biofilms. Two small recent clinical trials in otitis, of dogs and of human patients have provided some encouraging results. Phage has potential in the treatment of antibiotic resistant infection by P. aeruginosa. Hence, full scale clinical trials are needed.
    Expert Review of Anti-infective Therapy 01/2014; 11(9). · 2.07 Impact Factor


Available from