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Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
Published on: January 4, 2017
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Putative Conjugative Plasmids with tcdB and cdtAB Genes in Clostridioides difficile.
Emerging Infectious Diseases
|August 21, 2020
Summary
Conjugative plasmids carrying Clostridioides difficile toxins (TcdB, CDT) were found in clinical isolates. These plasmids may contribute to the spread of C. difficile toxins in patient populations.
Area of Science:
- Microbiology
- Genetics
- Infectious Diseases
Background:
- Clostridioides difficile toxins (TcdA, TcdB, CDT) are typically chromosomally encoded.
- Understanding toxin acquisition and spread is crucial for controlling C. difficile infections.
Purpose of the Study:
- To investigate the presence and characteristics of toxin-encoding mobile genetic elements in clinical C. difficile isolates.
- To identify potential mechanisms for toxin gene dissemination beyond chromosomal integration.
Main Methods:
- Analysis of clinical C. difficile isolates from specific multilocus sequence typing (MLST) clades.
- Plasmid identification and characterization using molecular techniques.
- Detection of toxin genes (tcdB, cdtAB) on identified plasmids.
Main Results:
- Five instances of a putative conjugative plasmid family carrying tcdB and cdtAB were identified.
- These plasmids were found in clinical isolates belonging to MLST clades C-I, 2, and 4.
- This suggests a role for plasmids in toxin gene carriage in C. difficile.
Conclusions:
- Conjugative plasmids can carry major C. difficile virulence factors (TcdB, CDT).
- Plasmid-mediated toxin gene transfer represents a potential mechanism for C. difficile evolution and spread.
- Further research is warranted to explore the epidemiological impact of these toxin-encoding plasmids.
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