0000000000390518
AUTHOR
Cindy Given
Preceding Host History of Conjugative Resistance Plasmids Affects Intra- and Interspecific Transfer Potential from Biofilm
Conjugative plasmids can confer antimicrobial resistance (AMR) to their host bacterium. The plasmids disperse even between distantly related host species, rescuing the host from otherwise detrimental effects of antibiotics. Little is known about the role of these plasmids in the spread of AMR during antibiotic treatment. One unstudied question is whether the past evolutionary history of a plasmid in a particular species creates host specificity in its rescue potential or if interspecific coevolution can improve interspecific rescues. To study this, we coevolved the plasmid RP4 under three different host settings; solely Escherichia coli or Klebsiella pneumoniae, or alternating between both …
Tissue-Specific Dynamics in the Endophytic Bacterial Communities in Arctic Pioneer Plant
The rapid developments in the next-generation sequencing methods in the recent years have provided a wealth of information on the community structures and functions of endophytic bacteria. However, the assembly processes of these communities in different plant tissues are still currently poorly understood, especially in wild plants in natural settings. The aim of this study was to compare the composition of endophytic bacterial communities in leaves and roots of arcto-alpine pioneer plant Oxyria digyna, and investigate, how plant tissue (leaf or root) or plant origin affect the community assembly. To address this, we planted micropropagated O. digyna plants with low bacterial load (bait pla…
Plasmid Viability Depends on the Ecological Setting of Hosts within a Multiplasmid Community
Plasmids are extrachromosomal genetic elements, some of which disperse horizontally between different strains and species of bacteria. They are a major factor in the dissemination of virulence factors and antibiotic resistance. Understanding the ecology of plasmids has a notable anthropocentric value, and therefore, the interactions between bacterial hosts and individual plasmids have been studied in detail. However, bacterial systems often carry multiple genetically distinct plasmids, but dynamics within these multiplasmid communities have remained unstudied. Here, we set to investigate the survival of 11 mobilizable or conjugative plasmids under five different conditions where the hosts h…
Beta-Lactam Sensitive Bacteria Can Acquire ESBL-Resistance via Conjugation after Long-Term Exposure to Lethal Antibiotic Concentration
Beta-lactams are commonly used antibiotics that prevent cell-wall biosynthesis. Beta-lactam sensitive bacteria can acquire conjugative resistance elements and hence become resistant even after being exposed to lethal (above minimum inhibitory) antibiotic concentrations. Here we show that neither the length of antibiotic exposure (1 to 16 h) nor the beta-lactam type (penam or cephem) have a major impact on the rescue of sensitive bacteria. We demonstrate that an evolutionary rescue can occur between different clinically relevant bacterial species (Klebsiella pneumoniae and Escherichia coli) by plasmids that are commonly associated with extended-spectrum beta-lactamase (ESBL) positive hospita…
Indirect Selection against Antibiotic Resistance via Specialized Plasmid-Dependent Bacteriophages
Antibiotic resistance genes of important Gram-negative bacterial pathogens are residing in mobile genetic elements such as conjugative plasmids. These elements rapidly disperse between cells when antibiotics are present and hence our continuous use of antimicrobials selects for elements that often harbor multiple resistance genes. Plasmid-dependent (or male-specific or, in some cases, pilus-dependent) bacteriophages are bacterial viruses that infect specifically bacteria that carry certain plasmids. The introduction of these specialized phages into a plasmid-abundant bacterial community has many beneficial effects from an anthropocentric viewpoint: the majority of the plasmids are lost whil…
Multi-plasmid clash in a bacterial community: plasmid viability depends on the ecological setting of hosts
AbstractPlasmids are genetic elements that disperse horizontally between different strains and species of bacteria and a major factor in the dissemination of virulence factors and antibiotic resistance. Understanding the ecology of plasmids has a notable anthropocentric value and therefore the interactions between bacterial hosts and individual plasmids have been studied in detail. However, bacterial systems often carry multiple genetically distinct plasmids, but dynamics of these multiplasmid “clashes” has remained unstudied. Here, we set to investigate the survival of 11 mobilizable or conjugative plasmids in five different ecological settings. The key incentive was to determine whether p…