Presentation Information
[P02-237]Characterization and comparison of mobile genetic elements carrying carbapenem resistance genes in Leyte, the Philippines
○Rin Yamazaki1, Maho Tokuda2, Zoe Mallonga3, Kazuhide Kimbara1, Masato Suzuki4, Masaki Shintani1,2,5,6 (1. Graduate School of Integrated Science and Technology, Shizuoka University (Japan), 2. Faculty of Engineering, Shizuoka University (Japan), 3. Division of Natural Sciences and Mathematics University of the Philippines Tacloban College (Philippines), 4. AMR Research Center, National Institute of Infectious Diseases, Japan Institute for Health Security (Japan), 5. Japan Collection of Microorganisms, RIKEN BioResource Research Center (Japan), 6. Research Institute of Green Science and Technology, Shizuoka University (Japan))
Keywords:
plasmids,Tn3-family transposons,class 1 integrons
The emergence and spread of antimicrobial-resistant bacteria (ARB) has been facilitated by the horizontal transfer of antimicrobial resistance genes (ARGs) via mobile genetic elements (MGEs)1). In areas with inadequate public health management, water containing high concentrations of ARB and ARGs may circulate between humans, animals, and the environment2). Therefore, to monitor ARB, it is essential to elucidate the distribution of each ARGs and the MGEs responsible for their dissemination.
Here, we aimed to characterize carbapenem (meropenem)-resistant bacteria present in the Philippines and to investigate the association between ARGs and MGEs. Microbial samples were collected from a hospital wastewater treatment plant and river water in Tacloban City, the Philippines. Meropenem-resistant bacteria were isolated from these samples in 2023 and 2024. Additionally, exogenous plasmid capture was performed using Metapseudomonas resinovorans CA10dm4RGFP as a recipient. The complete nucleotide sequences of meropenem-resistant isolates and transconjugants were determined with long-read and short-read sequencing.
A total of 17 meropenem-resistant bacteria were isolated, and six complete genome sequences were successfully determined. Among these, two isolates obtained from hospital wastewater were identified as Acinetobacter towneri, both of which harbored a R3-T45 plasmid, with the co-occurrence of blaNDM-1 and tigecycline resistance gene tet(X7)3). Another wastewater isolate, Pseudomonas inefficax harbored a plasmid named pPT23-C1_1, a member of PInc-18 plasmid group4). pPT23-C1_1 contained a blaVIM-2, within a class 1 integron. From river water, Stutzerimonas stutzeri was isolated, and found to harbor pPT24-E1E, a member of rep_cluster_1516 plasmid group. pPT24-E1E carried blaIMP-26, embedded within a Tn402-like class 1 integron. Each of these integrons was suggested to be mobilized by a Tn3-family transposon. Mating assays further confirmed the self-transmissibility of pPT23-C1_1 and pPT24-E1E.
Furthermore, we captured six transferable PInc-94) plasmids from wastewater by exogenous plasmid capture. All of which carried blaIMP-26, within a Tn402-like class 1 integron. Eight IncC plasmids were captured from wastewater and river water;all carried blaNDM-1, but the gene was associated with different MGEs.
In additoin to carbapenem resistance genes, all plasmids harbored different ARGs against aminoglycosides, tetracyclines and other agents. Further studies should quantity these ARGs and their associated MGEs.
1) Partridge et al., Clin Microbiol Rev, 2018, 31(4):e00088-17.
2) Hounmanou et al., Front Public Health, 2025, 12:1525873.
3) Mallonga, et al., J Glob Antimicrob Resist, 2025, 41:287-289.
4) Nishimura et al., bioRxiv, 2025, doi:10.1101/2024.09.03.610885.
Here, we aimed to characterize carbapenem (meropenem)-resistant bacteria present in the Philippines and to investigate the association between ARGs and MGEs. Microbial samples were collected from a hospital wastewater treatment plant and river water in Tacloban City, the Philippines. Meropenem-resistant bacteria were isolated from these samples in 2023 and 2024. Additionally, exogenous plasmid capture was performed using Metapseudomonas resinovorans CA10dm4RGFP as a recipient. The complete nucleotide sequences of meropenem-resistant isolates and transconjugants were determined with long-read and short-read sequencing.
A total of 17 meropenem-resistant bacteria were isolated, and six complete genome sequences were successfully determined. Among these, two isolates obtained from hospital wastewater were identified as Acinetobacter towneri, both of which harbored a R3-T45 plasmid, with the co-occurrence of blaNDM-1 and tigecycline resistance gene tet(X7)3). Another wastewater isolate, Pseudomonas inefficax harbored a plasmid named pPT23-C1_1, a member of PInc-18 plasmid group4). pPT23-C1_1 contained a blaVIM-2, within a class 1 integron. From river water, Stutzerimonas stutzeri was isolated, and found to harbor pPT24-E1E, a member of rep_cluster_1516 plasmid group. pPT24-E1E carried blaIMP-26, embedded within a Tn402-like class 1 integron. Each of these integrons was suggested to be mobilized by a Tn3-family transposon. Mating assays further confirmed the self-transmissibility of pPT23-C1_1 and pPT24-E1E.
Furthermore, we captured six transferable PInc-94) plasmids from wastewater by exogenous plasmid capture. All of which carried blaIMP-26, within a Tn402-like class 1 integron. Eight IncC plasmids were captured from wastewater and river water;all carried blaNDM-1, but the gene was associated with different MGEs.
In additoin to carbapenem resistance genes, all plasmids harbored different ARGs against aminoglycosides, tetracyclines and other agents. Further studies should quantity these ARGs and their associated MGEs.
1) Partridge et al., Clin Microbiol Rev, 2018, 31(4):e00088-17.
2) Hounmanou et al., Front Public Health, 2025, 12:1525873.
3) Mallonga, et al., J Glob Antimicrob Resist, 2025, 41:287-289.
4) Nishimura et al., bioRxiv, 2025, doi:10.1101/2024.09.03.610885.
Comment
To browse or post comments, you must log in.Log in