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Interspecies transfer of blaIMP-4 in a patient with prolonged colonization by IMP-4-producing Enterobacteriaceae
Hanna E Sidjabat1, Claire Heney2, Narelle M George2
1The University of Queensland, UQ Centre for Clinical Research, Herston, Queensland, Australia h.sidjabat@uq.edu.au.
Abstract:
A patient was colonized by IMP-4-producing Enterobacter cloacae and Escherichia coli strains for 7 months. IMP-4-producing E. cloacae strains were first and last isolated at day 33 and at 8 months after admission, respectively. IMP-4-producing E. coli strains were first and last isolated at days 88 and 181 after admission, respectively. The E. cloacae and E. coli isolates shared identical genetic features in terms of blaIMP-4, blaTEM-1, qnrB2, aacA4, HI2 plasmids, and ISCR1. This study shows the first prolonged colonization with in vivo interspecies transfer of blaIMP-4.
Insights
This study details prolonged colonization of a patient with IMP-4 producing bacteria, including Enterobacter cloacae and Escherichia coli, for seven months. It highlights the first documented instance of in vivo interspecies transfer of the blaIMP-4 gene.
Area of Science:
- Microbiology
- Infectious Diseases
- Molecular Biology
Background:
- Antimicrobial resistance is a growing global health threat.
- Carbapenemase-producing Enterobacteriaceae (CPE) are of particular concern due to limited treatment options.
- Understanding the mechanisms and dynamics of resistance gene spread is crucial for effective control strategies.
Observation:
- A patient exhibited prolonged colonization (7 months) with both Enterobacter cloacae and Escherichia coli strains carrying the IMP-4 carbapenemase gene.
- Both bacterial species harbored identical genetic elements, including the blaIMP-4 gene, blaTEM-1, qnrB2, aacA4, HI2 plasmids, and ISCR1.
- The temporal isolation patterns suggest the persistence and potential transfer of these genetic elements between species within the patient.
Findings:
- This study reports the first documented case of prolonged in vivo interspecies transfer of the blaIMP-4 gene.
- The genetic relatedness of the isolates indicates a shared source or successful horizontal gene transfer event.
- The co-occurrence of multiple resistance genes (blaIMP-4, blaTEM-1, qnrB2, aacA4) on transferable plasmids (HI2) amplifies the resistance phenotype.
Implications:
- Prolonged colonization with multidrug-resistant organisms poses a significant risk for healthcare-associated infections.
- The findings underscore the potential for rapid dissemination of carbapenem resistance genes between different bacterial species in clinical settings.
- This highlights the need for enhanced surveillance and infection control measures to prevent the spread of IMP-4 and other carbapenemases.
