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Characterization of Emerging Pathogens Carrying bla _KPC-2 Gene in IncP-6 Plasmids Isolated From Urban Sewage in Argentina.

ABSTRACT: Untreated wastewater is a reservoir for multidrug-resistant bacteria, but its role in the spread of antibiotic resistance in the human population remains poorly investigated. In this study, we isolated a KPC-2-producing ST2787 Klebsiella quasipneumoniae subsp. quasipneumoniae (WW14A), recovered from raw sewage at a wastewater treatment plant in Argentina in 2018 and determined its complete genome sequence. Strain WW14A was resistant to all β-lactams, ciprofloxacin and amikacin. A core genome phylogenetic analysis indicated that WW14A was closely related to a GES-5-producing Taiwanese strain isolated from hospital wastewater in 2015 and it was clearly distinct from strains isolated recently in Argentina and Brazil. Interestingly, bla _KPC-2 was harbored by a recently described IncP-6 broad-spectrum plasmid which was sporadically reported worldwide and had never been reported before in Argentina. We investigated the presence of the IncP-6 replicon in isolates obtained from the same sampling and found a novel non-typable/IncP-6 hybrid plasmid in a newly assigned ST1407 Enterobacter asburiae (WW19C) also harboring bla _KPC-2. Nanopore sequencing and hybrid assembly of strains WW14A and WW19C revealed that both IncP-6 plasmids shared 72% of coverage (~20 kb), with 99.99% of sequence similarity and each one also presented uniquely combined regions that were derived from other plasmids recently reported in different countries of South America, Asia, and Europe. The region harboring the carbapenem resistance gene (~11 kb) in both plasmids contained a Tn3 transposon disrupted by a Tn3-ISApu-flanked element and the core sequence was composed by ΔISKpn6/bla _KPC-2/Δbla _TEM-1/ISKpn27. Both strains also carried genes conferring resistance to heavy metals (e.g., arsenic, mercury, lead, cadmium, copper), pesticides (e.g., glyphosate), disinfectants, and several virulence-related genes, posing a potential pathogenic risk in the case of infections. This is the first study documenting bla _KPC-2 associated with IncP-6 plasmids in K. quasipneumoniae and Enterobacter cloacae complex from wastewater in Argentina and highlights the circulation of IncP-6 plasmids as potential reservoirs of bla _KPC-2 in the environment.

SUBMITTER: Ghiglione B

PROVIDER: S-EPMC8421773 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Klebsiella pneumoniae carbapenemase (KPC) producers are an emerging threat to global health, and the hospital water environment is considered an important reservoir of these life-threatening bacteria. We characterized plasmids of KPC-2-producing Citrobacter freundii and Klebsiella variicola isolates recovered from hospital sewage in Japan. Antimicrobial susceptibility testing, whole-genome sequencing analysis, bacterial conjugation, and transformation experiments were performed for both KPC-2 producers. The blaKPC-2 gene was located on the Tn3 transposon-related region from an IncP-6 replicon plasmid that could not be transferred via conjugation. Compared to the blaKPC-2-encoding plasmid of the C. freundii isolate, alignment analysis of plasmids with blaKPC-2 showed that the blaKPC-2-encoding plasmid of the K. variicola isolate was a novel IncP-6/IncF-like hybrid plasmid containing a 75,218-bp insertion sequence composed of IncF-like plasmid conjugative transfer proteins. Carbapenem-resistant transformants harboring blaKPC-2 were obtained for both isolates. However, no IncF-like insertion region was found in the K. variicola donor plasmid of the transformant, suggesting that this IncF-like region is not readily functional for plasmid conjugative transfer and is maintained depending on the host cells. The findings on the KPC-2 producers and novel genetic content emphasize the key role of hospital sewage as a potential reservoir of pathogens and its linked dissemination of blaKPC-2 through the hospital water environment. Our results indicate that continuous monitoring for environmental emergence of antimicrobial-resistant bacteria might be needed to control the spread of these infectious bacteria. Moreover, it will help elucidate both the evolution and transmission pathways of these bacteria harboring antimicrobial resistance. IMPORTANCE Antimicrobial resistance is a significant problem for global health, and the hospital environment has been recognized as a reservoir of antimicrobial resistance. Here, we provide insight into the genomic features of blaKPC-2-harboring isolates of Citrobacter freundii and Klebsiella variicola obtained from hospital sewage in Japan. The findings of carbapenem-resistant bacteria containing this novel genetic context emphasize that hospital sewage could act as a potential reservoir of pathogens and cause the subsequent spread of blaKPC-2 via horizontal gene transfer in the hospital water environment. This indicates that serial monitoring for environmental bacteria possessing antimicrobial resistance may help us control the spread of infection and also lead to elucidating the evolution and transmission pathways of these bacteria.

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Characterization of Emerging Pathogens Carrying bla _KPC-2 Gene in IncP-6 Plasmids Isolated From Urban Sewage in Argentina.

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Characterization of Emerging Pathogens Carrying bla KPC-2 Gene in IncP-6 Plasmids Isolated From Urban Sewage in Argentina.

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OmicsDI is part of the ELIXIR infrastructure

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Characterization of Emerging Pathogens Carrying bla _KPC-2 Gene in IncP-6 Plasmids Isolated From Urban Sewage in Argentina.