AUTHOR=Li Xiaohui , Wang Qian , Zheng Ji , Guan Yan , Liu Chennan , Han Jiangxue , Liu Sihan , Liu Tianjun , Xiao Chunling , Wang Xiao , Liu Yishuang 

TITLE=PHT427 as an effective New Delhi metallo-β-lactamase-1 (NDM-1) inhibitor restored the susceptibility of meropenem against Enterobacteriaceae producing NDM-1

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1168052

DOI=10.3389/fmicb.2023.1168052

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>With the increasingly serious problem of bacterial drug resistance caused by NDM-1, it is an important strategy to find effective inhibitors to assist β-lactam antibiotic treatment against NDM-1 resistant bacteria. In this study, PHT427 (4-dodecyl-<italic>N</italic>-1,3,4-thiadiazol-2-yl-benzenesulfonamide) was identified as a novel NDM-1 inhibitor and restored the susceptibility of meropenem against <italic>Enterobacteriaceae</italic> producing NDM-1.</p></sec><sec><title>Methods</title><p>We used a high throughput screening model to find NDM-1 inhibitor in the library of small molecular compounds. The interaction between the hit compound PHT427 and NDM-1 was analyzed by fluorescence quenching, surface plasmon resonance (SPR) assay, and molecular docking analysis. The efficacy of the compound in combination with meropenem was evaluated by determining the FICIs of <italic>Escherichia coli</italic> BL21(DE3)/pET30a(+)-<italic>bla</italic><sub><italic>N</italic>DM–1</sub> and <italic>Klebsiella pneumoniae</italic> clinical strain C1928 (producing NDM-1). In addition, the mechanism of the inhibitory effect of PHT427 on NDM-1 was studied by site mutation, SPR, and zinc supplementation assays.</p></sec><sec><title>Results</title><p>PHT427 was identified as an inhibitor of NDM-1. It could significantly inhibit the activity of NDM-1 with an IC<sub>50</sub> of 1.42 μmol/L, and restored the susceptibility of meropenem against <italic>E. coli</italic> BL21(DE3)/pET30a(+)-<italic>bla</italic><sub><italic>N</italic>DM–1</sub> and <italic>K. pneumoniae</italic> clinical strain C1928 (producing NDM-1) <italic>in vitro</italic>. The mechanism study indicated that PHT427 could act on the zinc ions at the active site of NDM-1 and the catalytic key amino acid residues simultaneously. The mutation of Asn220 and Gln123 abolished the affinity of NDM-1 by PHT427 <italic>via</italic> SPR assay.</p></sec><sec><title>Discussion</title><p>This is the first report that PHT427 is a promising lead compound against carbapenem-resistant bacteria and it merits chemical optimization for drug development.</p></sec>