Background/Objectives: The emergence and transmission of the tigecycline resistance efflux pump gene cluster
tmexCD-toprJ among humans, animals and the environment have posed a serious threat to public health. The objective of this study was to characterize
Pseudomonas strains carrying multiple copies of
tmexC6D6-toprJ1b
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Background/Objectives: The emergence and transmission of the tigecycline resistance efflux pump gene cluster
tmexCD-toprJ among humans, animals and the environment have posed a serious threat to public health. The objective of this study was to characterize
Pseudomonas strains carrying multiple copies of
tmexC6D6-toprJ1b from a pig farm and illustrate the genetic context of
tmexC6D6-toprJ1b in the NCBI database.
Methods: The characterization of
Pseudomonas strains FJFQ21PNM23 and FJFQ21PNM24 was determined by antimicrobial susceptibility testing, whole-genome sequencing, and RT-qPCR.
Results: The
tmexCD-toprJ-positive
P. mendocina strains FJFQ21PNM23 and FJFQ21PNM24 were isolated from nasal swabs in a pig farm. Sequence analysis showed that the two
P. mendocina strains harbored multiple antimicrobial resistance genes, including tigecycline resistance gene
tmexC6D6-toprJ1b. WGS analysis indicated that
tmexC6D6-toprJ1b gene was located on a classical transferable module (
int1-
int2-
hp1-
hp2-
tnfxB-
tmexCD-toprJ) and a multiresistance region in FJFQ21PNM24 and FJFQ21PNM23, respectively. Further analysis revealed that 39 additional
tmexC6D6-toprJ1b genes in the NCBI database were all identified in
Pseudomonas spp., and the genetic features of
tmexC6D6-toprJ1b were summarized into three distinct structures.
Conclusions: This study is the first to identify and report the tigecycline resistance gene
tmexCD-toprJ in a swine farm. Our findings summarize the three structures in the genetic context of
tmexC6D6-toprJ1b and reveal that
Pseudomonas serves as the only known reservoir of
tmexC6D6-toprJ1b.
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