AUTHOR=Wang Fengling , Wang Dongguo , Hou Wei , Jin Qian , Feng Jiao , Zhou Dongsheng 

TITLE=Evolutionary Diversity of Prophage DNA in Klebsiella pneumoniae Chromosomes

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.02840

DOI=10.3389/fmicb.2019.02840

ISSN=1664-302X

ABSTRACT=<p>Mobile gene elements play an important role in the continuous evolution of the prophage DNA of bacteria, promoting the emergence of new gene structures. This study explored the evolution of four strains of <italic>Klebsiella pneumoniae</italic> harboring prophages, 19051, 721005, 911021, and 675920, and 16 genomes of <italic>K. pneumoniae</italic> from GenBank. The results revealed a wide range of genetic variation in the prophage DNA inserted into the <italic>sap</italic> sites of <italic>K. pneumoniae</italic> chromosomes. From analysis and comparison of the sequences of the 20 prophage DNAs determined from the four strains and the 16 GenBank genomes of <italic>K. pneumoniae</italic> using high-throughput sequencing and antimicrobial susceptibility tests, we identified a novel transposon, Tn<italic>6556</italic>. We also identified at least nine large genetic structures with massive genetic acquisitions or losses and five hotspot sites showing a tendency to undergo insertion of gene elements such as IS<italic>1T</italic>, IS<italic>1R</italic>, IS<italic>26</italic>, IS<italic>Kpn26</italic>, IS<italic>Kpn28</italic>, Tn<italic>6556</italic>, MDR, and In27<italic>-</italic>related regions as variable regions; however, the only highly conserved core genes were <italic>int</italic> and <italic>umuCD</italic> among the 20 prophage DNAs. These findings provide important insights into the evolutionary diversity of bacteriophage DNA contained in <italic>K. pneumoniae</italic>.</p>