aac(6’)-Iaq, a novel aminoglycoside acetyltransferase gene identified from an animal isolate Brucella intermedia DW0551

作者：Naru Lin, Wen Xu, Da‐Wei Huang, Chaoqun Liu, Junwan Lu, Mei Zhu, Qiyu Bao, Wei Pan · 发表于：Frontiers in Cellular and Infection Microbiology · 年份：2025 · DOI：10.3389/fcimb.2025.1551240 · 被引用次数：3 · 研究领域：Antibiotic Resistance in Bacteria、Bacteriophages and microbial interactions、RNA and protein synthesis mechanisms

Background Bacterial resistance to aminoglycoside antimicrobials is becoming increasingly severe due to their use as commonly prescribed antibiotics. The discovery of new molecular mechanisms of aminoglycoside resistance is critical for the effective treatment of bacterial infections. Methods Bacteria in goose feces were isolated by plate streaking. The identification and characterization of a novel resistance gene from the bacterial genome involved various techniques, including molecular cloning, drug susceptibility testing, protein expression and purification, and enzyme kinetic analysis. Additionally, whole-genome sequencing and phylogenetic studies were performed. Results Brucella intermedia DW0551, isolated from goose feces, was resistant to 35 antibiotics, and the minimum inhibitory concentration (MIC) was particularly high for most aminoglycoside antibiotics. The novel aminoglycoside resistance gene aac(6’)-Iaq encoded by B. intermedia DW0551 conferred resistance to netilmicin, sisomicin, amikacin, kanamycin, gentamicin, tobramycin, and ribostamycin. The amino acid sequence of AAC(6’)-Iaq shared the highest identity (52.63%) with the functionally characterized aminoglycoside acetyltransferase AAC(6’)-If. AAC(6’)-Iaq contained all the conserved sites of the acetyltransferase family NAT_SF. The enzyme exhibited strong affinity and catalytic activity toward netilmicin and sisomicin. The mobile genetic element (MGE) was not found in the flanking regions of the aac(6’)-Iaq ...