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Identification and characterization of OXA-48 producing, carbapenem-resistant Enterobacteriaceae isolates in Turkey
Abdullah Kilic1, Zerin Aktas, Orhan Bedir
1Departments of Microbiology and Clinical Microbiology, Gulhane Military Medical Academy and School of Medicine, Ankara, Turkey. abkilic@gata.edu.tr
Abstract:
Carbapenem resistance in Enterobacteriaceae isolates has been reported from Turkey and is most often mediated by OXA-48 type carbapenemases. We report the identification and characterization of four carbapenem-resistant isolates (three Klebsiella pneumoniae and one Escherichia coli) among 515 clinical Enterobacteriaceae isolates collected during a 7-month study period in Ankara, Turkey. The four isolates were recovered from blood and urine specimens in patients with varied clinical manifestations. They had distinct pulsed-field gel electrophoresis patterns and harbored a variety of β-lactamases including bla(TEM-1), bla(SHV-12) genes, bla(SHV-11), and/or bla(CTX-M-15). PCR and sequencing analysis revealed that the bla(OXA-48) gene was present in all four isolates. Our data indicated that the OXA-48-type carbapenemase was the only mechanism for carbapenem resistance in our hospital.
Insights
Carbapenem resistance in Enterobacteriaceae is a growing concern. In Turkey, OXA-48 carbapenemase was identified as the sole resistance mechanism in four clinical isolates of Klebsiella pneumoniae and Escherichia coli.
Area of Science:
- Microbiology
- Infectious Diseases
- Molecular Biology
Background:
- Enterobacteriaceae isolates exhibiting carbapenem resistance have been documented in Turkey.
- OXA-48 type carbapenemases are frequently implicated as the primary mechanism of resistance.
Observation:
- Four carbapenem-resistant Enterobacteriaceae isolates (three Klebsiella pneumoniae, one Escherichia coli) were identified from 515 clinical samples over seven months in Ankara, Turkey.
- These isolates were obtained from blood and urine specimens of patients with diverse clinical presentations.
- The isolates displayed distinct pulsed-field gel electrophoresis patterns.
Findings:
- All four isolates harbored various beta-lactamase genes, including bla(TEM-1), bla(SHV-12), bla(SHV-11), and/or bla(CTX-M-15).
- Crucially, PCR and sequencing confirmed the presence of the bla(OXA-48) gene in all four isolates.
- The OXA-48-type carbapenemase was determined to be the exclusive mechanism conferring carbapenem resistance within this hospital setting.
Implications:
- This study highlights the prevalence and significance of OXA-48 carbapenemase in clinical Enterobacteriaceae isolates in Turkey.
- Understanding resistance mechanisms is vital for effective antimicrobial stewardship and infection control strategies.
- The findings underscore the need for continued surveillance of carbapenem resistance in healthcare settings.
