Dynamic Gene Clusters Mediating Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates
Samy Selim1, Osama Ahmed Faried2, Mohamed S Almuhayawi3
1Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72341, Saudi Arabia.
Antibiotics (Basel, Switzerland)
|February 25, 2022
Summary
Multidrug-resistant Acinetobacter baumannii causes serious hospital infections. This study identified dominant bacterial lineages and found reduced effectiveness of antibiotics like imipenem in certain strains, impacting treatment strategies.
Area of Science:
- Microbiology
- Infectious Diseases
- Genetics
Background:
- Acinetobacter baumannii (A. baumannii) is a Gram-negative bacterium frequently linked to hospital-acquired infections.
- Multidrug-resistant (MDR) strains of A. baumannii pose a significant challenge in clinical settings.
- Understanding the genetic diversity and resistance mechanisms is crucial for effective infection control.
Purpose of the Study:
- To investigate the genetic lineages of clinical A. baumannii isolates.
- To identify factors contributing to carbapenem resistance in A. baumannii.
- To explore the binding affinity of imipenem with A. baumannii OXA beta-lactamase enzymes.
Main Methods:
- Repetitive extragenic palindromic (REP)-PCR was employed to analyze DNA fingerprints of 86 clinical A. baumannii isolates.
- Genotyping was performed to identify distinct bacterial lineages.
- Binding affinity studies were conducted for imipenem against various A. baumannii OXA beta-lactamase enzymes.
Main Results:
- Four distinct A. baumannii lineages were identified, with two dominant lineages accounting for 95% of isolates.
- Isolates belonging to genotype (A) exhibited reduced susceptibility to imipenem, amikacin, and ciprofloxacin due to enhanced antibiotic tolerance.
- Imipenem showed varying binding affinities to different A. baumannii OXA beta-lactamase variants.
Conclusions:
- The study highlights the clonal nature of A. baumannii infections, with specific lineages dominating.
- Enhanced antibiotic tolerance in certain genotypes contributes to treatment failure.
- Understanding imipenem-beta-lactamase interactions may inform the development of novel therapeutic strategies against MDR A. baumannii.
Keywords:
Acinetobacter baumanniicarbapenem-resistantdynamic geneimipenemnosocomial infectionrepetitive extragenic palindromicMore Related Videos
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