An outbreak of ertapenem-resistant, carbapenemase-negative and porin-deficient ESBL-producing Klebsiella pneumoniae complex

Mihaela Matovina; Maja Abram; Davorka Repac-Antić; Samira Knežević; Marina Bubonja-Šonje

doi:10.18683/germs.2021.1257

An outbreak of ertapenem-resistant, carbapenemase-negative and porin-deficient ESBL-producing Klebsiella pneumoniae complex

Germs. 2021 Jun 2;11(2):199-210. doi: 10.18683/germs.2021.1257. eCollection 2021 Jun.

Authors

Mihaela Matovina¹, Maja Abram², Davorka Repac-Antić³, Samira Knežević⁴, Marina Bubonja-Šonje²

Affiliations

¹ PhD, Division of Organic Chemistry and Biochemistry, Rudjer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia.
² MD, PhD, Department of Microbiology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia and Department of Clinical Microbiology, Clinical Hospital Center Rijeka, Krešimirova 40, 51 000 Rijeka, Croatia.
³ MD, Department of Microbiology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia and Department of Clinical Microbiology, Clinical Hospital Center Rijeka, Krešimirova 40, 51 000 Rijeka, Croatia.
⁴ MD, Department of Infectology, Clinical Hospital Center Rijeka, Krešimirova 40, 51 000 Rijeka, Croatia.

Abstract

Introduction: Carbapenem-resistant Klebsiella pneumoniae is an emerging healthcare-associated pathogen with dynamic molecular epidemiology. This study presents a retrospective analysis of the distribution and antibiotic resistance patterns of ertapenem-resistant ESBL-producing K. pneumoniae strains recovered during an outbreak from 2012 to 2014 in a Croatian University hospital.

Methods: We aimed to estimate genetic relatedness of clinical isolates and underlying mechanisms that conferred the ertapenem-resistant phenotype.

Results: Expression analysis of genes involved in the antibiotic resistance showed reduced expression of major non-selective porin channel OmpK35. Reduced expression of OmpK36 porin channel in isolates resistant to at least one more carbapenem, apart from the ertapenem, was found to a lesser degree. Pulsed-field gel electrophoresis analysis of genomic DNA revealed that almost all isolates belonged to the same genetic clone.

Conclusions: Caution regarding ertapenem-resistant, carbapenemase-negative porin-deficient mutants of K. pneumoniae is required as they are widespread, and under selective pressure this could result in a local clonal outbreak.

Keywords: Ertapenem; Klebsiella pneumoniae; drug resistance; molecular epidemiology; outbreak.

GERMS.