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Updated: Nov 6, 2025
Identification of Antibacterial Immunity Proteins in Escherichia coli using MALDI-TOF-TOF-MS/MS and Top-Down Proteomic Analysis
Published on: May 23, 2021
Identification and Characterization of a Novel SXT/R391 Integrative and Conjugative Element in a Proteus mirabilis
Jieyuan Lu1, Kang Zhao1, Huadong Xie2
1College of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, China.
Abstract:
Proteus mirabilis is an opportunistic human pathogen. In this study, a novel SXT/R391 integrative and conjugative element (ICE), named ICEPmiChnS012, was identified in the multidrug-resistant P. mirabilis strain S012 that was isolated from retail chicken in China. Whole genome sequencing revealed that ICEPmiChnS012 carried 22 resistance genes including aac(6')-Ib-cr, fosA3, blaOXA-1, blaCTX-M-65, and blaHMS-1. ICEPmiChnS012 harbored 10 copies of IS26 and IS26-mediated genetic new rearrangements caused variations in HS4 region. To our knowledge, an unusual gene cassette array dfrA1-ereA1-aadA2 was found in P. mirabilis in this study for the first time. And this is the first report of identification of aph3-VI and blaHMS-1 in VRIII region in P. mirabilis. The conjugation experiments proved that ICEPmiChnS012 could be transferred to Escherichia coli EC600 through conjugation. These findings demonstrated that ICEPmiChnS012 was a special ICE that carried the largest number of antimicrobial resistance genes in the family of SXT/R391 ICEs. This element could serve as an important vehicle for the dissemination of antibiotic resistance genes and should receive great concern.
Insights
A novel integrative and conjugative element (ICE), ICEPmiChnS012, was found in multidrug-resistant Proteus mirabilis from chicken. This element carries 22 resistance genes, making it a significant vehicle for antibiotic resistance gene dissemination.
Area of Science:
- Microbiology
- Genetics
- Antimicrobial Resistance
Background:
- Proteus mirabilis is an opportunistic pathogen.
- Antimicrobial resistance is a growing global health concern.
- Integrative and conjugative elements (ICEs) play a role in spreading resistance genes.
Purpose of the Study:
- To identify and characterize a novel ICE in a multidrug-resistant P. mirabilis strain.
- To investigate the genetic content and potential for gene transfer of the identified ICE.
- To assess the role of this ICE in the dissemination of antimicrobial resistance.
Main Methods:
- Whole genome sequencing of P. mirabilis strain S012.
- Identification and characterization of the novel ICE, ICEPmiChnS012.
- Conjugation experiments to assess transferability to E. coli.
Main Results:
- ICEPmiChnS012, identified in P. mirabilis S012 from retail chicken, carries 22 antimicrobial resistance genes, including notable ones like blaCTX-M-65 and fosA3.
- The element contains multiple IS26 insertion sequences, leading to genetic rearrangements and an unusual dfrA1-ereA1-aadA2 gene cassette array.
- ICEPmiChnS012 was successfully transferred to Escherichia coli via conjugation, demonstrating its mobility.
Conclusions:
- ICEPmiChnS012 is a unique SXT/R391 ICE carrying an exceptionally high number of antimicrobial resistance genes.
- This ICE represents a significant mechanism for the spread of antibiotic resistance in bacteria.
- Further monitoring and research are warranted due to the potential public health implications of such mobile genetic elements.
