Genetic characterization and virulence determinants of multidrug-resistant NDM-1-producing Aeromonas caviae

Abstract

The emergence of carbapenemase significantly threatens public health. It is prevalent worldwide but rare in Aeromonas caviae. Unlike most bacterial species, A. caviae has two distinct flagella systems, which are closely related to biofilm formation. The ability to form biofilms on host tissues or inert surfaces constitutes an important cause of many persistent infections, which causes difficulties in clinical treatment. Here, we report on a multidrug-resistant (MDR) A. caviae carrying blaNDM–1 with a novel sequence type 1,416. The strong ability of biofilm formation of FAHZZU2447 was verified by a crystal violet assay. The resistome profile and location of the blaNDM–1 gene were determined by antimicrobial susceptibility testing, S1 nuclease pulsed-field gel electrophoresis (S1-PFGE), and Southern blot analysis. Moreover, the strain underwent whole-genome sequencing to identify its genomic characteristics. In addition, the blaNDM–1 gene was located on a ∼243 kb plasmid with genetic context IS1R-blaNDM–1-ble-trpF-dsbD-hp-sul1-qacE. Phylogenetic analysis indicated the transmission of A. caviae in China, Japan, and Thailand. Our study aimed to elucidate the genomic features of blaNDM–1-producing A. caviae, thereby clarifying the distribution of A. caviae worldwide and emphasizing the harmfulness of biofilm formation to the clinic. Further comprehensive surveillance of this species is needed to control further dissemination.

ST11 KPC-2-Producing Klebsiella pneumoniae Isolated from Patient with Acute Myelocytic Leukemia

“…Additionally, these isolates also contain genes encoded type 3 fimbriae genes ( mrkCDHJ and fimCDHK ) which play a significant role in bacterial adherence, the initial step that precedes colonization. 16 According to the results of the string test, all strains were not hypermucoviscous. The biofilm formation capacity was assessed using crystal violet.…”

“… 15 The abilities of biofilm formation of eight strains were quantitatively determined as a previous study. 16 The interpretation of results as following: non-adherent (OD ≤ ODc), weakly to moderately adherent (ODc < OD ≤ 2 × ODc), and strongly adherent (2 × ODc < OD). Each assay was performed in triplicate.…”