ABSTRACT: Bacteriophages of the C3 morphotype, characterized by very long heads that exceed their width several times, are extremely rare among the Podoviridae family members and constitute only 0.5% of over 5,500 phages that have been examined by the electron microscope (H. W. Ackermann, Arch. Virol. 152:227-243, 2007; H. W. Ackermann, Arch. Virol. 146:843-857, 2001). To date, among those phages proven to be C3, only coliphage phiEco32, Lactococcus phage KSY1, Vibrio phage 71A-6, and Salmonella enterica phage 7-11, but no avian pathogenic Escherichia coli (APEC) bacteriophages, have been completely sequenced (A. Chopin, H. Deveau, S. D. Ehrlich, S. Moineau, and M. C. Chopin, Virology 365:1-9, 2007; S. A. Khan, et al., Mol. Cell Probes 15:61-69, 2001; A. M. Kropinski, E. J. Lingohr, H. W. Ackermann,