AUTHOR=Liu Ying-ying , He Dan-dan , Zhang Meng-ke , Pan Yu-shan , Wu Hua , Yuan Li , Liu Jian-hua , Hu Gong-zheng 

TITLE=The Formation of Two Hybrid Plasmids Mediated by IS26 and Tn6952 in Salmonella enterica Serotype Enteritidis

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.676574

DOI=10.3389/fmicb.2021.676574

ISSN=1664-302X

ABSTRACT=<p>To characterize the formation mechanism and characteristics of two cointegrate plasmids in <italic>Salmonella enterica</italic> serotype <italic>Enteritidis</italic> strain S13, plasmids from strain S13 and three corresponding transconjugants were subjected to whole genome sequencing and analyzed using bioinformatics tools. The traits of two fusion plasmids in transconjugants were characterized by stability and conjugation experiments. Sequence analysis indicated that strain S13 contained four plasmids, including <italic>mcr-1</italic>-bearing pS13-1, <italic>bla</italic><sub>CTX–M–55</sub>-carrying pS13-2, <italic>tet</italic>(M)-bearing pS13-3, and <italic>floR</italic>-carrying pS13-4. IncN1-F33:A–:B– plasmid pS13-2, respectively, fused with IncFI:A–:B– plasmid pS13-3 and IncX1 plasmid pS13-4, which generated two cointegrate plasmids, designated pS13D and pS13F, which involved in two intermolecular replicative mechanisms mediated by IS<italic>26</italic> and the novel transposon Tn<italic>6952</italic> (<italic>Δ</italic>Tn<italic>AS3</italic>-IS<italic>26</italic>-<italic>Δ</italic>IS<italic>Ecp1</italic>-<italic>ramA</italic>-<italic>Δ</italic>IS<italic>26</italic>-<italic>Δ</italic>Tn<italic>AS1</italic>), respectively. This is the first report of the fusion of the IncN1-F33:A–:B– plasmid and IncFI:A–:B– plasmid mediated by IS<italic>26</italic>, and with IncX1 plasmid mediated by Tn<italic>6952.</italic> The formation and evolution of cointegrate plasmids could expand the resistance and host spectrum of fusion plasmids.</p>