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Characterization and Abundance of Plasmid-Dependent Alphatectivirus Bacteriophages
Boris Parra1,2,3, Veronika T Lutz4, Lone Brøndsted4
1Department of Environmental Engineering and Resource Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.
Abstract:
Antimicrobial resistance (AMR) is a major public health threat, exacerbated by the ability of bacteria to rapidly disseminate antimicrobial resistance genes (ARG). Since conjugative plasmids of the incompatibility group P (IncP) are ubiquitous mobile genetic elements that often carry ARG and are broad-host-range, they are important targets to prevent the dissemination of AMR. Plasmid-dependent phages infect plasmid-carrying bacteria by recognizing components of the conjugative secretion system as receptors. We sought to isolate plasmid-dependent phages from wastewater using an avirulent strain of Salmonella enterica carrying the conjugative IncP plasmid pKJK5. Irrespective of the site, we only obtained bacteriophages belonging to the genus Alphatectivirus. Eleven isolates were sequenced, their genomes analyzed, and their host range established using S. enterica, Escherichia coli, and Pseudomonas putida carrying diverse conjugative plasmids. We confirmed that Alphatectivirus are abundant in domestic and hospital wastewater using culture-dependent and culture-independent approaches. However, these results are not consistent with their low or undetectable occurrence in metagenomes. Therefore, overall, our results emphasize the importance of performing phage isolation to uncover diversity, especially considering the potential of plasmid-dependent phages to reduce the spread of ARG carried by conjugative plasmids, and to help combat the AMR crisis.
Insights
Researchers isolated Alphatectivirus phages from wastewater, which target bacteria carrying antimicrobial resistance genes (ARG) on plasmids. These findings highlight the potential of phages to combat the spread of antibiotic resistance and reduce public health threats.
Area of Science:
- Microbiology
- Genetics
- Public Health
Background:
- Antimicrobial resistance (AMR) is a significant global health concern.
- Conjugative plasmids, particularly IncP group, facilitate the rapid spread of antimicrobial resistance genes (ARG).
- Plasmid-dependent phages offer a potential strategy to control AMR by targeting plasmid-carrying bacteria.
Purpose of the Study:
- To isolate and characterize plasmid-dependent phages from wastewater.
- To investigate the potential of these phages in combating the dissemination of ARG.
- To understand the diversity and abundance of Alphatectivirus in wastewater environments.
Main Methods:
- Isolation of phages from wastewater using a Salmonella enterica strain with an IncP plasmid.
- Whole-genome sequencing and analysis of isolated bacteriophages.
- Host range determination using various bacterial strains carrying different conjugative plasmids.
- Culture-dependent and culture-independent methods to assess Alphatectivirus abundance.
Main Results:
- Only bacteriophages belonging to the genus Alphatectivirus were successfully isolated.
- Eleven Alphatectivirus isolates were sequenced, and their genomes were analyzed.
- Alphatectivirus were found to be abundant in wastewater, though their presence in metagenomes was low.
- Established the host range of isolated phages against diverse bacterial hosts and plasmids.
Conclusions:
- Alphatectivirus are prevalent in wastewater and can be effectively isolated using culture-dependent methods.
- Plasmid-dependent phages, like Alphatectivirus, represent a promising avenue for controlling the spread of ARG.
- Further research into phage isolation is crucial for uncovering microbial diversity and developing strategies against AMR.
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