Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strains

ABSTRACT Antimicrobial resistance (AMR) is a growing problem, especially in Gram-negative Enterobacteriaceae such as Klebsiella pneumoniae. Horizontal transfer of conjugative plasmids contributes to AMR gene dissemination. Bacteria such as K. pneumoniae commonly exist in biofilms, yet most studies f...

Full description

Bibliographic Details
Main Authors: Sarah J. Element, Robert A. Moran, Emilie Beattie, Rebecca J. Hall, Willem van Schaik, Michelle M.C. Buckner
Format: Article
Language:English
Published: American Society for Microbiology 2023-08-01
Series:mSphere
Subjects:
Online Access:https://journals.asm.org/doi/10.1128/msphere.00170-23
_version_ 1797730317473153024
author Sarah J. Element
Robert A. Moran
Emilie Beattie
Rebecca J. Hall
Willem van Schaik
Michelle M.C. Buckner
author_facet Sarah J. Element
Robert A. Moran
Emilie Beattie
Rebecca J. Hall
Willem van Schaik
Michelle M.C. Buckner
author_sort Sarah J. Element
collection DOAJ
description ABSTRACT Antimicrobial resistance (AMR) is a growing problem, especially in Gram-negative Enterobacteriaceae such as Klebsiella pneumoniae. Horizontal transfer of conjugative plasmids contributes to AMR gene dissemination. Bacteria such as K. pneumoniae commonly exist in biofilms, yet most studies focus on planktonic cultures. Here we studied the transfer of a multi-drug resistance plasmid in planktonic and biofilm populations of K. pneumoniae. We determined plasmid transfer from a clinical isolate, CPE16, which carried four plasmids, including the 119-kbp blaNDM-1-bearing F-type plasmid pCPE16_3, in planktonic and biofilm conditions. We found that transfer frequency of pCPE16_3 in a biofilm was orders-of-magnitude higher than between planktonic cells. In 5/7 sequenced transconjugants (TCs) multiple plasmids had transferred. Plasmid acquisition had no detectable growth impact on TCs. Gene expression of the recipient and a transconjugant was investigated by RNA-sequencing in three lifestyles: planktonic exponential growth, planktonic stationary phase, and biofilm. We found that lifestyle had a substantial impact on chromosomal gene expression, and plasmid carriage affected chromosomal gene expression most in stationary planktonic and biofilm lifestyles. Furthermore, expression of plasmid genes was lifestyle-dependent, with distinct signatures across the three conditions. Our study shows that growth in biofilm greatly increased the risk of conjugative transfer of a carbapenem resistance plasmid in K. pneumoniae without fitness costs and minimal transcriptional rearrangements, thus highlighting the importance of biofilms in the spread of AMR in this opportunistic pathogen. IMPORTANCE Carbapenem-resistant K. pneumoniae is particularly problematic in hospital settings. Carbapenem resistance genes can transfer between bacteria via plasmid conjugation. Alongside drug resistance, K. pneumoniae can form biofilms on hospital surfaces, at infection sites and on implanted devices. Biofilms are naturally protected and can be inherently more tolerant to antimicrobials than their free-floating counterparts. There have been indications that plasmid transfer may be more likely in biofilm populations, thus creating a conjugation “hotspot”. However, there is no clear consensus on the effect of the biofilm lifestyle on plasmid transfer. Therefore, we aimed to explore the transfer of a plasmid in planktonic and biofilm conditions, and the impact of plasmid acquisition on a new bacterial host. Our data show transfer of a resistance plasmid is increased in a biofilm, which may be a significant contributing factor to the rapid dissemination of resistance plasmids in K. pneumoniae.
first_indexed 2024-03-12T11:42:33Z
format Article
id doaj.art-6396ef696095428d93b872d9ff04dcb9
institution Directory Open Access Journal
issn 2379-5042
language English
last_indexed 2024-03-12T11:42:33Z
publishDate 2023-08-01
publisher American Society for Microbiology
record_format Article
series mSphere
spelling doaj.art-6396ef696095428d93b872d9ff04dcb92023-08-31T14:26:40ZengAmerican Society for MicrobiologymSphere2379-50422023-08-018410.1128/msphere.00170-23Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strainsSarah J. Element0Robert A. Moran1Emilie Beattie2Rebecca J. Hall3Willem van Schaik4Michelle M.C. Buckner5Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham , Birmingham, West Midlands, United KingdomInstitute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham , Birmingham, West Midlands, United KingdomInstitute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham , Birmingham, West Midlands, United KingdomInstitute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham , Birmingham, West Midlands, United KingdomInstitute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham , Birmingham, West Midlands, United KingdomInstitute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham , Birmingham, West Midlands, United KingdomABSTRACT Antimicrobial resistance (AMR) is a growing problem, especially in Gram-negative Enterobacteriaceae such as Klebsiella pneumoniae. Horizontal transfer of conjugative plasmids contributes to AMR gene dissemination. Bacteria such as K. pneumoniae commonly exist in biofilms, yet most studies focus on planktonic cultures. Here we studied the transfer of a multi-drug resistance plasmid in planktonic and biofilm populations of K. pneumoniae. We determined plasmid transfer from a clinical isolate, CPE16, which carried four plasmids, including the 119-kbp blaNDM-1-bearing F-type plasmid pCPE16_3, in planktonic and biofilm conditions. We found that transfer frequency of pCPE16_3 in a biofilm was orders-of-magnitude higher than between planktonic cells. In 5/7 sequenced transconjugants (TCs) multiple plasmids had transferred. Plasmid acquisition had no detectable growth impact on TCs. Gene expression of the recipient and a transconjugant was investigated by RNA-sequencing in three lifestyles: planktonic exponential growth, planktonic stationary phase, and biofilm. We found that lifestyle had a substantial impact on chromosomal gene expression, and plasmid carriage affected chromosomal gene expression most in stationary planktonic and biofilm lifestyles. Furthermore, expression of plasmid genes was lifestyle-dependent, with distinct signatures across the three conditions. Our study shows that growth in biofilm greatly increased the risk of conjugative transfer of a carbapenem resistance plasmid in K. pneumoniae without fitness costs and minimal transcriptional rearrangements, thus highlighting the importance of biofilms in the spread of AMR in this opportunistic pathogen. IMPORTANCE Carbapenem-resistant K. pneumoniae is particularly problematic in hospital settings. Carbapenem resistance genes can transfer between bacteria via plasmid conjugation. Alongside drug resistance, K. pneumoniae can form biofilms on hospital surfaces, at infection sites and on implanted devices. Biofilms are naturally protected and can be inherently more tolerant to antimicrobials than their free-floating counterparts. There have been indications that plasmid transfer may be more likely in biofilm populations, thus creating a conjugation “hotspot”. However, there is no clear consensus on the effect of the biofilm lifestyle on plasmid transfer. Therefore, we aimed to explore the transfer of a plasmid in planktonic and biofilm conditions, and the impact of plasmid acquisition on a new bacterial host. Our data show transfer of a resistance plasmid is increased in a biofilm, which may be a significant contributing factor to the rapid dissemination of resistance plasmids in K. pneumoniae.https://journals.asm.org/doi/10.1128/msphere.00170-23carbapenemasecarbapenem-resistance plasmidKlebsiella pneumoniaeconjugationbiofilmgene expression
spellingShingle Sarah J. Element
Robert A. Moran
Emilie Beattie
Rebecca J. Hall
Willem van Schaik
Michelle M.C. Buckner
Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strains
mSphere
carbapenemase
carbapenem-resistance plasmid
Klebsiella pneumoniae
conjugation
biofilm
gene expression
title Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strains
title_full Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strains
title_fullStr Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strains
title_full_unstemmed Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strains
title_short Growth in a biofilm promotes conjugation of a blaNDM-1-bearing plasmid between Klebsiella pneumoniae strains
title_sort growth in a biofilm promotes conjugation of a blandm 1 bearing plasmid between klebsiella pneumoniae strains
topic carbapenemase
carbapenem-resistance plasmid
Klebsiella pneumoniae
conjugation
biofilm
gene expression
url https://journals.asm.org/doi/10.1128/msphere.00170-23
work_keys_str_mv AT sarahjelement growthinabiofilmpromotesconjugationofablandm1bearingplasmidbetweenklebsiellapneumoniaestrains
AT robertamoran growthinabiofilmpromotesconjugationofablandm1bearingplasmidbetweenklebsiellapneumoniaestrains
AT emiliebeattie growthinabiofilmpromotesconjugationofablandm1bearingplasmidbetweenklebsiellapneumoniaestrains
AT rebeccajhall growthinabiofilmpromotesconjugationofablandm1bearingplasmidbetweenklebsiellapneumoniaestrains
AT willemvanschaik growthinabiofilmpromotesconjugationofablandm1bearingplasmidbetweenklebsiellapneumoniaestrains
AT michellemcbuckner growthinabiofilmpromotesconjugationofablandm1bearingplasmidbetweenklebsiellapneumoniaestrains