AUTHOR=Lu Junwan , Sha Yuning , Gao Mengdi , Shi Weina , Lin Xi , Li Kewei , Bao Qiyu , Feng Chunlin 

TITLE=Identification and characterization of a novel aminoglycoside O-nucleotidyltransferase ANT(6)-If from Paenibacillus thiaminolyticus PATH554

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1184349

DOI=10.3389/fmicb.2023.1184349

ISSN=1664-302X

ABSTRACT=<sec><title>Background</title><p><italic>Paenibacillus thiaminolyticus</italic>, a species of genus <italic>Paenibacillus</italic> of the family <italic>Paenibacillaceae</italic>, exists widely in environments and habitats in various plants and worms, and occasionally causes human infections. This work aimed to characterize the function of a novel aminoglycoside <italic>O</italic>-nucleotidyltransferase resistance gene, designated <italic>ant(6)-If</italic>, from a <italic>P. thiaminolyticus</italic> strain PATH554.</p></sec><sec><title>Methods</title><p>Molecular cloning, antimicrobial susceptibility testing, enzyme expression and purification, and kinetic analysis were used to validate the function of the novel gene. Whole-genome sequencing and comparative genomic analysis were performed to investigate the phylogenetic relationship of ANT(6)-If and other aminoglycoside <italic>O</italic>-nucleotidyltransferases, and the synteny of <italic>ant(6)-If</italic> related sequences.</p></sec><sec><title>Results</title><p>The recombinant with the cloned <italic>ant(6)-If</italic> gene (pMD19-<italic>ant(6)-If</italic>/DH5α) demonstrated a 128-fold increase of minimum inhibitory concentration level against streptomycin, compared with the control strains (DH5α and pMD19/DH5α). The kinetic parameter <italic>k</italic><sub>cat</sub><italic>/K</italic><sub>m</sub> of ANT(6)-If for streptomycin was 9.01 × 10<sup>3</sup> M<sup>−1</sup>·s<sup>−1</sup>. Among the function-characterized resistance genes, ANT(6)-If shared the highest amino acid sequence identity of 75.35% with AadK. The <italic>ant(6)-If</italic> gene was located within a relatively conserved genomic region in the chromosome.</p></sec><sec><title>Conclusion</title><p><italic>ant(6)-If</italic> conferred resistance to streptomycin. The study of a novel resistance gene in an unusual environmental bacterium in this work contributed to elucidating the resistance mechanisms in the microorganisms.</p></sec>