Abstract:
To date, most members of the Siphoviridae
family of bacteriophages remain unclassified, including the
46 staphylococcal phages for which the complete genome
sequences have been deposited in public databases. Comparative
nucleotide and protein sequence analysis, in
addition to available data on phage morphology, allowed us
to propose three new phage genera within the family
Siphoviridae: ‘‘3alikevirus’’, ‘‘77likevirus’’ and ‘‘Phietalikevirus’’,
which include related phages infecting
Staphylococcus aureus and Staphylococcus epidermidis.
However, six phages infecting S. aureus, Staphylococcus
pasteuri, Staphylococcus hominis and Staphylococcus capitis strains remain to be classified (orphan phages).
Overall, the former phages share morphological features
and genome organization. The three groups have conserved
domains containing peptidoglycan hydrolytic activities
clearly identified as part of tape measure proteins
(‘‘3alikevirus’’ and ‘‘77likevirus’’) or as individual virionassociated
proteins (‘‘Phietalikevirus’’). In addition, bacteriophages
belonging to the genus ‘‘3alikevirus’’ share
closely related DNA-processing and packaging proteins,
while bacteriophages included in the genus ‘‘Phietalikevirus’’
encode specific tail proteins for host interaction. These
properties are considered distinctive for these genera.
Orphan phages seem to have a more divergent organization,
but they share some properties with members of these
proposed genera.
