Genomic characterization and integrative properties of phiSMA6
and phiSMA7, two novel ﬁlamentous bacteriophages
of Stenotrophomonas maltophilia
Received: 8 July 2013 / Accepted: 29 September 2013 / Published online: 11 December 2013
Ó Springer-Verlag Wien 2013
Abstract Two novel ﬁlamentous phages, phiSMA6 and
phiSMA7, were isolated from Stenotrophomonas malto-
philia environmental strain Khak84. We identiﬁed and
annotated 11 potential open reading frames in each phage.
While the overall layout of the functional gene groups of
both phages was similar to that of the known ﬁlamentous
phages, they differed from them in their molecular struc-
ture. The genome of phiSMA6 is a mosaic that evolved by
acquiring genes from at least three different ﬁlamentous S.
maltophilia phages and one Xanthomonas campestris
phage related to Cf1. In the phiSMA6 genome, a gene
similar to the bacterial gene encoding the mating pair
formation protein trbP was also found. We showed that
phiSMA6 possesses lysogenic properties and upon induc-
tion produces high-titer lysates. The genome of phiSMA7
possesses a unique structure and was found to be closely
related to a prophage present in the chromosome of the
completely sequenced S. maltophilia clinical strain D457.
We suggest that the other three ﬁlamentous phages of S.
maltophilia described previously also have the capacity to
integrate into the genome of their bacterial host.
In the past 50 years, extensive work has been done to
isolate and study ﬁlamentous bacteriophages belonging to
the genus Inovirus of the family Inoviridae. At present,
bacteriophages are found in many species of Gram-nega-
tive and Gram-positive bacteria, and despite their small
size, play an important role in the variability and evolution
of their bacterial hosts [1–11]. Many different aspects of
interaction of bacteria and ﬁlamentous phages belonging to
this group have been described. Some phages are known to
increase the ﬁtness of lysogens . Others, such as phage
Pf4, take part in the bioﬁlm development of host bacteria
[13, 14]. However, the greatest attention has been paid to a
detailed examination of ﬁlamentous phages that play an
important role in the emergence of human (e.g., Vibrio
cholerae, Escherichia coli, Yersinia pestis), and plant (e.g.,
Xylella fastidiosa, Ralstonia solanacearum) pathogens [12,
The best example of phages determining the toxigenic
properties of host bacteria is the phage CTXu of V. chol-
erae, which carries in its genome speciﬁc genes encoding
cholera toxin [4, 19, 20].
In addition, it should be noted that various approaches to
the application of ﬁlamentous phages in molecular biology
and bionanotechnology are now being intensively devel-
oped in many laboratories [21–24].
Against this background, only limited research has been
devoted to ﬁlamentous phages of Stenotrophomonas
maltophilia, although these bacteria are widespread in the
environment, and in recent years, in the clinic, where they
behave as opportunistic human pathogens, causing intra-
hospital infections in patients with weakened immunity
[25–28]. To date, only one ﬁlamentous phage of S.
maltophilia has been studied in detail , while two other
putative ﬁlamentous phages were revealed only in a rep-
licative form (RF) [HM150760; 30]. Almost nothing is
known of the integrative properties of these phages and
their role in lysogenic conversion.
M. Petrova Á N. Shcherbatova Á A. Kurakov Á S. Mindlin (&)
Institute of Molecular Genetics, Russian Academy of Sciences,
2 Kurchatov sq., Moscow 123182, Russia
Department of Microbiology, Moscow State University,
Arch Virol (2014) 159:1293–1303