Publikationsdatenbank

Recombination events that occur in a poxtA-carrying Enterococcus faecium during the conjugation process (2022)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Xu, Chunyan

Wang, Nannan

Li, Dexi

Schwarz, Stefan (WE 7)

Du, Xiang-Dang

Quelle

The journal of antimicrobial chemotherapy : JAC

Bandzählung: 77

Heftzählung: 5

Seiten: 1228 – 1236

ISSN: 0305-7453

Sprache

Englisch

Verweise

URL (Volltext): https://academic.oup.com/jac/article/77/5/1228/6524123

DOI: 10.1093/jac/dkac027

Pubmed: 35137120

Kontakt

Institut für Mikrobiologie und Tierseuchen

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51843 / 66949
mikrobiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Objectives:
To investigate transferability of the poxtA-carrying plasmids in Enterococcus faecium and the mechanism of recombination that occurs during the conjugation process.

Methods:
MICs were determined by broth microdilution. Transferability of the poxtA-carrying plasmids in E. faecium was investigated by conjugation. The mechanism of recombination that occurred during the conjugation process was explored by S1-PFGE and WGS.

Results:
E. faecium strain Fac90 carries two plasmids, designated pFac90-154 and pFac90-54, respectively. Six transconjugants with different characteristics were obtained. In transconjugant T90-1, a plasmid-chromosome fusion event led to the integration of plasmid pFac90-154 from the donor E. faecium strain Fac90 into the chromosomal DNA of the recipient strain Enterococcus faecalis JH2-2. In transconjugants T90-2, -3 and -4, losses or additions of different-sized plasmid segments most likely occurred due to IS1216-mediated recombination. In transconjugants T90-5 and -6, two large plasmids with sizes of 101 656 and 149 526 bp were formed by plasmid fusion.

Conclusions:
To the best of our knowledge, this is the first report showing the integration of pFac90-154 from E. faecium Fac90 into the chromosomal DNA of recipient E. faecalis JH2-2 via homologous recombination. Besides, we showed that five new plasmid types were formed by genetic rearrangements. These recombination events resulted simultaneously in the formation of various types of mosaic plasmids with multiple resistance genes and/or conjugation characteristics, which might promote the transmission of diverse plasmids encoding resistance genes among enterococci. Thus, these data significantly expand our knowledge regarding conjugative events, establishing a dual role of conjugation in both dissemination of resistance genes and plasmid evolution.