Leclercia Adecarboxylata From Human Gut Flora Carries Mcr-4.3 And Bla(Imp-4)-Bearing Plasmids

A clinical Leclercia adecarboxylata strain harboring the mcr-4.3 and bla(IMP-4) genes was isolated from active rectal screening of carbapenem-resistant Enterobacteriaceae (CRE) in a patient. The isolate was found to harbor seven plasmids, including a 94,635 bp bla(IMP-4)-bearing IncN plasmid and a 9,782 bp mcr-4.3-bearing ColE10-type plasmid. The isolate was susceptible to colistin despite carrying the mcr-4.3 gene, suggesting that this MCR-4 variant may not be functional. Carriage of antibiotic resistance genes in human gut L. adecarboxylata strain suggests that close surveillance of resistance strains in the human gut flora should be included as a routine clinical practice to prevent occurrence of infections, especially among immunocompromised patients.