AadA36, a novel chromosomal aminoglycoside nucleotidyltransferase from a clinical isolate of Providencia stuartii.

Abstract

In this study, we characterized a novel chromosome-encoded aminoglycoside nucleotidyltransferase (ANT), AadA36, from the Providencia stuartii strain P14 isolated from the sputum specimen of a burn patient at a hospital in Wenzhou, China. Among the functionally characterized ANTs, AadA36 shared the highest amino acid sequence identity of 51.91% with AadA14. The whole genome of P. stuartii P14 consisted of one chromosome and two plasmids (designated pP14-166 and pP14-114). A total of 19 genes with ≥80% similarity with functionally characterized antimicrobial resistance genes (ARGs) were identified in the whole genome, including aminoglycosides [aac(2')-Ia, aph(6)-Id, aph(3″)-Ib, aac(6')-Ib, ant(3″)-IIa, aph(3')-Ia], β-lactams (bla CMY-2 and bla OXA-10) and so on. Antimicrobial susceptibility testing showed that the aadA36 gene conferred specific resistance to spectinomycin and streptomycin, and the minimum inhibitory concentration (MIC) of these antimicrobials increased 128- and 64-fold compared with the control strain. The kinetic parameters of AadA36 were consistent with the MIC data of spectinomycin and streptomycin, with kcat /Km ratios of (1.07 ± 2.23) × 104 M-1 s-1 and (8.96 ± 1.01) × 103 M-1 s-1, respectively. The identification of a novel aminoglycoside resistance gene will help us further understand the complexity of the resistance mechanisms and provide deep insights into the dissemination of resistance genes in the microbial population.

• Authors: Mengdi Gao, Chunlin Feng, Yongan Ji, Yaokai Shi, Weina Shi, Lei Zhang, Shuang Liu, Anqi Li, Xueya Zhang, Qiaoling Li, Junwan Lu, Qiyu Bao, Hailin Zhang
• Journal: Frontiers in microbiology (Front Microbiol) Vol. 13 Pg. 1035651 ( 2022) ISSN: 1664-302X [Print] Switzerland
• PMID: 36386671 (Publication Type: Journal Article)
• Copyright: Copyright © 2022 Gao, Feng, Ji, Shi, Shi, Zhang, Liu, Li, Zhang, Li, Lu, Bao and Zhang.