In:
Microbiology Spectrum, American Society for Microbiology, Vol. 11, No. 3 ( 2023-06-15)
Abstract:
Several variants of the plasmid-carried tigecycline resistance gene cluster, tmexCD-toprJ , have been identified. This study characterized another novel variant, tmexC6D6-toprJ1b , located on the chromosome of environmental-origin Pseudomonas mendocina . TMexC6D6-TOprJ1 mediates resistance to multiple drugs, including tigecycline. The promoter activity of tmexC6D6-toprJ1b and negative transcriptional repression by the upstream regulator tnfxB6 are crucial for the expression of tmexC6D6-toprJ1b . tmexC6D6-toprJ1b was found in the plasmids or chromosomes of different Pseudomonas species from six countries. Two genetic backgrounds, class 1 integrons and int -carrying integrase units, were found adjacent to the tmexC6D6-toprJ1b gene cluster and might mediate the transfer of this novel efflux pump gene cluster in Pseudomonas . Further phylogenetic analysis revealed Pseudomonas as the major reservoir of tmexCD-toprJ variants, warranting closer monitoring in the future. IMPORTANCE Tigecycline is one of the treatment options for serious infections caused by multidrug-resistant bacteria, and tigecycline resistance has gained extensive attention. The emergence of a transferable tigecycline resistance efflux pump gene cluster, tmexCD-toprJ , severely challenged the efficiency of tigecycline. In this study, we identified another novel tmexCD-toprJ variant, tmexC6D6-toprJ1b , which could confer resistance to multiple classes of antibiotics, including tigecycline. Although tmexC6D6-toprJ1b was found only in Pseudomonas species, tmexC6D6-toprJ1b might spread to Enterobacteriaceae hosts via mobile genetic elements resembling those of other tmexCD-toprJ variants, compromising the therapeutic strategies. Meanwhile, novel transferable tmexCD-toprJ variants are constantly emerging and mostly exist in Pseudomonas spp., indicating Pseudomonas as the important hidden reservoir and origin of tmexCD-toprJ variants. Continuous monitoring and investigations of tmexCD-toprJ are urgent to control its spread.
Type of Medium:
Online Resource
ISSN:
2165-0497
DOI:
10.1128/spectrum.00767-23
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2023
detail.hit.zdb_id:
2807133-5
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