Tigecycline-resistant Klebsiella pneumoniae strains from sewage in Norway carry heavy-metal resistance genes encoding conjugative plasmids

Vera Radisic; Francisco Salvà-Serra; Edward R B Moore; Nachiket P Marathe

doi:10.1016/j.jgar.2023.10.023

Tigecycline-resistant Klebsiella pneumoniae strains from sewage in Norway carry heavy-metal resistance genes encoding conjugative plasmids

J Glob Antimicrob Resist. 2024 Mar:36:482-484. doi: 10.1016/j.jgar.2023.10.023. Epub 2023 Nov 14.

Authors

Vera Radisic¹, Francisco Salvà-Serra², Edward R B Moore³, Nachiket P Marathe⁴

Affiliations

¹ Department of Contaminants and Biohazards, Institute of Marine Research (IMR), Bergen, Norway; Department of Biological Sciences, University of Bergen, Bergen, Norway.
² Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden; Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden; Microbiology, Department of Biology, University of the Balearic Islands, Palma de Mallorca, Spain.
³ Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden; Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
⁴ Department of Contaminants and Biohazards, Institute of Marine Research (IMR), Bergen, Norway. Electronic address: nachiket.marathe@hi.no.

PMID: 37972923
DOI: 10.1016/j.jgar.2023.10.023

Abstract

Objectives: Tigecycline is a last-resort antibiotic used for treatment of infections with carbapenem-resistant Klebsiella pneumoniae. The aim of the study was to understand the genetic mechanism of resistance and the genetic context of resistance genes in two tigecycline-resistant K. pneumoniae strains isolated from sewage in Bergen, Norway.

Methods: Complete genome sequencing of the two strains was accomplished using a combination of short-read Illumina MiSeq-based and long-read Oxford Nanopore MinION-based sequencing. Conjugation experiments were performed using filter mating and a green fluorescent protein (GFP)-tagged Escherichia coli strain.

Results: The complete genome sequences of strain K6-320.1 and strain K7-325 were assembled into two contigs for each strain, one contig representing the complete circular chromosomes of 5 223 440 bp (K6-320.1) and 5 263 092 bp (K7-325), respectively, and the other representing plasmids with sizes of 276 509 bp (pK6-320.1) and 246 731 bp (pK7-325). Strain K6-320.1 belonged to sequence type (ST)869, whereas strain K7-325 belonged to the pathogenic ST307. Both plasmids belonged to the IncFIB(K)/IncFII(K) group and carried several antibiotic resistance genes (ARGs), including tet(A) and bla_CTX-M. Both plasmids (pK6-320.1 and pK7-325) were transferred to a GFP-tagged E. coli strain, leading to the acquisition of resistance against multiple classes of antibiotics. Several heavy-metal resistance genes (HMRGs) encoding resistance against silver (sil), copper (pco), and arsenic (ars) were also present on both plasmids.

Conclusions: Our study demonstrates the presence of multidrug-resistant K. pneumoniae strains carrying conjugative plasmids encoding both ARGs and HMRGs that have potential for persistence in the environment and human microbiota.

Keywords: Heavy-metal resistance genes; Klebsiella pneumoniae; Multidrug resistance; Plasmids; Sewage-based surveillance; Tigecycline resistance.

MeSH terms

Anti-Bacterial Agents / pharmacology
Escherichia coli / genetics
Humans
Klebsiella pneumoniae / genetics
Metals, Heavy* / pharmacology
Norway
Sewage*
Tigecycline / pharmacology

Substances

Tigecycline
Sewage
Metals, Heavy
Anti-Bacterial Agents