AUTHOR=Fu Jiafang , Liu Yayu , Wang Fengtian , Zong Gongli , Wang Zhen , Zhong Chuanqing , Cao Guangxiang 

TITLE=Glabridin inhibited the spread of polymyxin-resistant Enterobacterium carrying ICEMmoMP63

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1188900

DOI=10.3389/fmicb.2023.1188900

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>The role of integrative and conjugative elements (ICEs) in antibiotic resistance in <italic>Morganella morganii</italic> is unknown. This study aimed to determine whether an ICE identified in the <italic>M. morganii</italic> genome contributed to the polymyxin resistance.</p></sec><sec><title>Methods</title><p>Whole-genome sequencing was performed followed by bioinformatics analyses to identify ICEs and antibiotic resistance genes. Conjugation assays were performed to analyze the transferability of a discovered ICE. A drug transporter encoded on the ICE was heterogeneously expressed in <italic>Escherichia coli</italic>, minimum inhibitory concentrations of antibiotics were determined, and a traditional Chinese medicine library was screened for potential efflux pump inhibitors.</p></sec><sec><title>Results</title><p>An antibiotic resistance-conferring ICE, named ICE<italic>Mmo</italic>MP63, was identified. ICE<italic>Mmo</italic>MP63 was verified to be horizontally transferred among Enterobacteriaceae bacteria. G3577_03020 in ICE<italic>Mmo</italic>MP63 was found to mediate multiple antibiotic resistances, especially polymyxin resistance. However, natural compound glabridin was demonstrated to inhibit polymyxin resistance.</p></sec><sec><title>Discussion</title><p>Our findings support the need for monitoring dissemination of ICE<italic>Mmo</italic>MP63 in Enterobacteriaceae bacteria. Combined glabridin and polymyxin may have therapeutic potential for treating infections from multi-drug resistant bacteria carrying ICE<italic>Mmo</italic>MP63.</p></sec>