Clinical Molecular and Genomic Epidemiology of Morganella morganii in China

Abstract

Objectives: Ongoing acquisition of antimicrobial resistance genes has made Morganella morganii a new clinical treatment challenge. Understanding the molecular epidemiology of M. morganii will contribute to clinical treatment and prevention.Methods: We undertook a 6-year clinical molecular epidemiological investigation of M. morganii 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.Results: Among all M. morganii isolates (n = 335), forty (11.9%) were recognized as multidrug resistant strains. qnrD1, aac(6′)-Ib-cr, blaTEM–104, and blaCTX–M–162 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 blaOXA–181-carrying IncX3 plasmid and a Proteus genomic island 2 variant carrying blaCTX–M–3, aac(6′)-Ib-cr coexisted in the same multidrug resistant strain zy_m28. Additionally, a blaIMP–1-carrying IncP-1β type plasmid was found in the strain nx_m63.Conclusion: This study indicates a clade of M. morganii is prone to acquire resistance genes, and multidrug resistant M. morganii are increasing by harboring a variety of MGEs including two newly discovered ones in the species. We should be vigilant that M. morganii may bring more extensive and challenging antimicrobial resistance issue.

Global prevalence, characteristics, and future prospects of IncX3 plasmids: A review

“…Interestingly, all plasmids carrying bla OXA-181 also carry the qnrS1, while plasmids carrying bla NDM-1 often also carry bla SHV-12 . This is consistent with the study by Xiang et al (2021) . IncX3 plasmids can disseminate bla OXA-181 and qnrS via an IS26-flanked composite transposon, or bla NDM and bla SHV-12 via a Tn125-like transposon.…”

Morganella morganii, an Emerging Cause of Bloodstream Infections

“…As a result, treatment with quinolones, aminoglycosides, co-trimoxazole, or carbapenems is usually recommended ( 3 – 6 ). However, the potential for Morganella morganii to acquire other resistance determinants has been increasingly recognized ( 7 ). Recent studies have found extensively resistant strains in sewage samples and among a range of animal sources ( 8 – 13 ).…”

Overview of Salmonella Genomic Island 1-Related Elements Among Gamma-Proteobacteria Reveals Their Wide Distribution Among Environmental Species

“…In the MDR region of the AGI1 variant of P. mirabilis PmBR607, the class 1 integron was followed by an ISCR1 element and the bla CTXM–2 ESBL gene. The MDR region of the recently described PGI2 variant of M. morganii zy_m28 ( Xiang et al, 2021 ) contained numerous copies of IS 26 elements and antibiotic resistance genes (ARGs), including the bla CTX–M–3 ESBL gene, the fosfomycin resistance gene fosA3 , and the fluoroquinolone acetylating aminoglycoside-(6′)- N -acetyltransferase gene aac (6′)-Ib-cr, as already described in PGI2-C55 ( Lei et al, 2020b ).…”