AUTHOR=Xiang Guoxiu , Lan Kai , Cai Yimei , Liao Kang , Zhao Mei , Tao Jia , Ma Yi , Zeng Jianming , Zhang Weizheng , Wu Zhongwen , Yu Xuegao , Liu Yuyang , Lu Yang , Xu Caixia , Chen Liang , Tang Yi-Wei , Chen Cha , Jia Wei , Huang Bin 

TITLE=Clinical Molecular and Genomic Epidemiology of Morganella morganii in China

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.744291

DOI=10.3389/fmicb.2021.744291

ISSN=1664-302X

ABSTRACT=<p><bold>Objectives:</bold> Ongoing acquisition of antimicrobial resistance genes has made <italic>Morganella morganii</italic> a new clinical treatment challenge. Understanding the molecular epidemiology of <italic>M. morganii</italic> will contribute to clinical treatment and prevention.</p><p><bold>Methods:</bold> We undertook a 6-year clinical molecular epidemiological investigation of <italic>M. morganii</italic> from three tertiary hospitals in China since 2014. Antimicrobial susceptibility testing was performed using a VITEK-2 system. All isolates were screened for β-lactam and plasmid-mediated quinolone resistance genes by PCR. Isolates carrying carbapenem-resistant genes were subjected to whole-genome sequencing (WGS). The variation and evolution of these mobile genetic elements (MGEs) were then systematically analyzed.</p><p><bold>Results:</bold> Among all <italic>M. morganii</italic> isolates (<italic>n</italic> = 335), forty (11.9%) were recognized as multidrug resistant strains. <italic>qnrD1</italic>, <italic>aac(6′)-Ib-cr</italic>, <italic>bla</italic><sub>TEM–104</sub>, and <italic>bla</italic><sub>CTX–M–162</sub> were the top four most prevalent resistance genes. Notably, phylogenomic and population structure analysis suggested clade 1 (rhierBAPS SC3 and SC5) associated with multiple resistance genes seemed to be widely spread. WGS showed a <italic>bla</italic><sub>OXA–181</sub>-carrying IncX3 plasmid and a <italic>Proteus</italic> genomic island 2 variant carrying <italic>bla</italic><sub>CTX–M–3</sub>, <italic>aac(6′)-Ib-cr</italic> coexisted in the same multidrug resistant strain zy_m28. Additionally, a <italic>bla</italic><sub>IMP–1</sub>-carrying IncP-1β type plasmid was found in the strain nx_m63.</p><p><bold>Conclusion:</bold> This study indicates a clade of <italic>M. morganii</italic> is prone to acquire resistance genes, and multidrug resistant <italic>M. morganii</italic> are increasing by harboring a variety of MGEs including two newly discovered ones in the species. We should be vigilant that <italic>M. morganii</italic> may bring more extensive and challenging antimicrobial resistance issue.</p>