Functional Genomic Analysis of Two Staphylococcus aureus Phages Isolated from the Dairy Environment

Abstract

The genomes of the two lytic mutant Staphylococcus aureus bacteriophages, vB_SauS-phiIPLA35 (phiIPLA35) and vB_SauS-phiIPLA88 (phiIPLA88), isolated from milk have been analyzed. Their genomes are 45,344 bp and 42,526 bp long, respectively, and contain 62 and 61 open reading frames (ORFS). Enzymatic analyses and sequencing revealed that the phiIPLA35 DNA molecule has 3-protruding cohesive ends (cos) 10 bp long, whereas phiIPLA88 DNA is 4.5% terminally redundant and most likely is packaged by a headful mechanism. N-terminal amino acid sequencing, mass spectrometry, bioinformatic analyses, and functional analyses enabled the assignment of putative functions to 58 gene products, including DNA packaging proteins, morphogenetic proteins, lysis components, and proteins necessary for DNA recombination, modification, and replication. Point mutations in their lysogeny control-associated genes explain their strictly lytic behavior. Muralytic activity associated with other structural components has been detected in virions of both phages. Comparative analysis of phiIPLA35 and phiIPLA88 genome structures shows that they resemble those of 12 and 11, respectively, both representatives of large genomic groupings within the S. aureus-infecting phages.

Characterization of Novel Phages Isolated in Coagulase-Negative Staphylococci Reveals Evolutionary Relationships with Staphylococcus aureus Phages

“…Numerous S. aureus phages have been isolated and characterized at the molecular level (2,6,22,32,33,36,37,39,42,44,46,47). They all belong to the order Caudovirales, with the most abundant being Siphoviridae phages, typically composed of a long noncontractile tail and an icosahedral head filled with doublestranded DNA.…”

Prevalence of Staphylococcus aureus and Lack of Its Lytic Bacteriophages in the Anterior Nares of Patients and Healthcare Workers at a Rural Clinic

“…23 The lytic phages are likely to modulate the rate of prevalence for one or more bacteria in different microbiological niches in the body. While lytic bacteriophages against S. aureus and MRSA have been isolated from different sources such as milk, 24 sewage influent, 25 cow slurry, 26 and septic wounds, 27 it is not known if they are prevalent in the anterior nares.…”

Physiology and Pathology of Multidrug-Resistant Bacteria: Phage-Related Therapy

“…Most of S. aureus phages belong to the Siphoviridae, such as lytic phage φMR11 [34] and lytic phage phiIPLA35 [35]. A small number of S. aureus phages belong to the Podoviridae like SAP-2 phage [36] and Myoviridae like Stau2 [37] and well-known phage K [38].…”