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Updated: Jul 2, 2026
07:59
Rapid and Specific Detection of Acinetobacter baumannii Infections Using a Recombinase Polymerase Amplification/Cas12a-based System
Published on: April 25, 2025
Comprehensive identification of sequence types belonging to Acinetobacter baumannii clonal complexes.
Ruth M Hall1,2, Christopher J Harmer1,2
1School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.
Microbial Genomics
|July 1, 2026
Summary
A new Python workflow identifies more sequence types (STs) for Acinetobacter baumannii Global Clones 1 and 2. This expands our understanding of multiply antibiotic-resistant (MAR) bacteria, aiding in tracking and control efforts.
Area of Science:
- Microbiology
- Genomics
- Epidemiology
Background:
- Acinetobacter baumannii is a significant nosocomial pathogen, with multiply antibiotic-resistant (MAR) strains often belonging to Global Clone 1 (GC1) and Global Clone 2 (GC2).
- Existing Multi-Locus Sequence Typing (MLST) schemes, particularly the Pasteur scheme, simplify clone identification but require comprehensive catalogs of related sequence types (STs).
- A lack of systematic and updated ST catalogs for GC1 and GC2 hinders accurate epidemiological tracking.
Purpose of the Study:
- To develop and implement a computational workflow for identifying single-locus variants (SLVs) and double-locus variants (DLVs) of founder STs within A. baumannii.
- To create a comprehensive and up-to-date catalog of STs associated with GC1 and GC2.
- To evaluate the impact of including these variants on the characterization of A. baumannii clonal complexes.
Main Methods:
- A custom Python workflow was developed to identify SLVs and DLVs based on founder STs.
- The workflow was applied to identify STs related to ST1 (GC1) and ST2 (GC2).
- Publicly available A. baumannii genome assemblies (41,951) from GenBank were analyzed to assess the representation of identified STs.
Main Results:
- The workflow identified 63 STs associated with ST1 and 163 STs associated with ST2.
- Inclusion of SLVs and DLVs significantly increased the number of identified GC1 genomes (from 1,083 to 1,428) and moderately increased GC2 genomes (from 26,962 to 28,002).
- A relatively low proportion of identified SLVs/DLVs were found in existing genome assemblies, suggesting potential gaps in genome coverage or inaccuracies in MLST profiles.
Conclusions:
- The developed framework enables consistent definition and characterization of A. baumannii clonal complexes.
- This approach enhances the understanding of MAR A. baumannii epidemiology by accounting for clonal diversity.
- The methodology is adaptable for defining clones in other significant MAR bacteria, such as Klebsiella pneumoniae.
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