Plasmid-mediated colistin resistance among human clinical Enterobacterales isolates: national surveillance in the Czech Republic

Marketa Zelendova; Costas C Papagiannitsis; Petra Sismova; Matej Medvecky; Katarina Pomorska; Jana Palkovicova; Kristina Nesporova; Vladislav Jakubu; Ivana Jamborova; Helena Zemlickova; Monika Dolejska; Working Group for Monitoring of Antibiotic Resistance

doi:10.3389/fmicb.2023.1147846

Plasmid-mediated colistin resistance among human clinical Enterobacterales isolates: national surveillance in the Czech Republic

Front Microbiol. 2023 Apr 27:14:1147846. doi: 10.3389/fmicb.2023.1147846. eCollection 2023.

Authors

Marketa Zelendova^{1

2}, Costas C Papagiannitsis³, Petra Sismova^{1

2}, Matej Medvecky^{2

4}, Katarina Pomorska⁵, Jana Palkovicova^{1

2}, Kristina Nesporova², Vladislav Jakubu^{5

6}, Ivana Jamborova², Helena Zemlickova^{5

6}, Monika Dolejska^{1

2

7

8}; Working Group for Monitoring of Antibiotic Resistance

Affiliations

¹ Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Brno, Czechia.
² CEITEC VETUNI, University of Veterinary Sciences Brno, Brno, Czechia.
³ Department of Microbiology, University Hospital of Larissa, Larissa, Greece.
⁴ Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czechia.
⁵ NRL for ATB, The National Institute of Public Health, Centre for Epidemiology and Microbiology, Prague, Czechia.
⁶ Department of Microbiology, 3rd Faculty of Medicine, Kralovske Vinohrady University Hospital and National Institute of Public Health, Charles University, Prague, Czechia.
⁷ Department of Clinical Microbiology and Immunology, Institute of Laboratory Medicine, The University Hospital Brno, Brno, Czechia.
⁸ Department of Microbiology, Faculty of Medicine and University Hospital in Plzen, Charles University, Pilsen, Czechia.

Abstract

The occurrence of colistin resistance has increased rapidly among Enterobacterales around the world. We performed a national survey of plasmid-mediated colistin resistance in human clinical isolates through a retrospective analysis of samples from 2009 to 2017 and a prospective sampling in 2018-2020. The aim of this study was to identify and characterize isolates with mcr genes from various regions of the Czech Republic using whole genome sequencing (WGS). Of all 1932 colistin-resistant isolates analyzed, 73 (3.8%) were positive for mcr genes. Most isolates carried mcr-1 (48/73) and were identified as Escherichia coli (n = 44) and Klebsiella pneumoniae (n = 4) of various sequence types (ST). Twenty-five isolates, including Enterobacter spp. (n = 24) and Citrobacter freundii (n = 1) carrying the mcr-9 gene were detected; three of them (Enterobacter kobei ST54) co-harbored the mcr-4 and mcr-9 genes. Multi-drug resistance phenotype was a common feature of mcr isolates and 14% (10/73) isolates also co-harbored clinically important beta-lactamases, including two isolates with carbapenemases KPC-2 and OXA-48. Phylogenetic analysis of E. coli ST744, the dominant genotype in this study, with the global collection showed Czech isolates belonged to two major clades, one containing isolates from Europe, while the second composed of isolates from diverse geographical areas. The mcr-1 gene was carried by IncX4 (34/73, 47%), IncHI2/ST4 (6/73, 8%) and IncI2 (8/73, 11%) plasmid groups. Small plasmids belonging to the ColE10 group were associated with mcr-4 in three isolates, while mcr-9 was carried by IncHI2/ST1 plasmids (4/73, 5%) or the chromosome (18/73, 25%). We showed an overall low level of occurrence of mcr genes in colistin-resistant bacteria from human clinical samples in the Czech Republic.

Keywords: Enterobacterales; antibiotic resistance; human; mcr; plasmids.