ISOLATION, CHARACTERIZATION AND COMPLETE GENOME SEQUENCE OF LY218: A BACTERIOPHAGE OF Pseudomonas aeruginosa ATCC 27853

Abstract

It has become widely accepted that bacteriophages are extremely abundant and are enormously influential on the biosphere. Bacteriophages kill between 4-50% of the entire bacteria population daily (Suttle, 2005). The aim of this study was to screen soil samples for Pseudomonas aeruginosa lytic phages, select and characterize an isolate morphologically for genome analysis using next generation lllumina sequencing. The lytic isolate was detected using the spot method on lawns of P. aeruginosa. Using the described procedure (Jordan, et al. 2010), LY218 was successfully isolated from soil samples. Transmission electron microscopy (TEM) performed by the University of Alabama at Birmingham (UAB), High Resolution Imaging Facility (HRIF) and Illumina Next Generation Sequencing (NGS) also at UAB, were performed to determine the morphology of the phage. The TEM images reveal that this isolate has a short tail when compared to other Myoviridae phages. Upon performing the Blast NCBI sequence comparison analysis, it was determined that this isolate is 73083 bp and it is 97% identical to the Pseudomonas phage Phi176, a phage isolated and sequenced in Bath, England. Phi176, was submitted to the GenBank database with accession number KM411960. A total of 88 presumptive genes have been identified. Presumptive function of 86 proteins were called based on homology determined by Predict Protein. The 3% difference between these two phage sequences is centered on two proteins of indeterminant function. Sequencing of the LY218 genome revealed a dsDNA with 54.9% G+C content and 356 open reading frames (ORFs) were predicted to be coding sequences. The full nucleotide sequence of the genome of LY218 has been determined, and this has been deposited (the NCBI accession number in MN906996).