Genomic Study of bla IMI-Positive Enterobacter cloacae Complex in Singapore over a Five-Year Study Period.

The bla IMI gene is rarely detected outside the Enterobacter genus. Genomic characterization of 87 bla IMI-positive Enterobacter cloacae complex members revealed that the largest phylogenomic clade was made up of E. cloacae subsp. cloacae (71.3%), followed by the newly described species E. bugandensis (13.8%), E. sichuanensis (10.3%), and E. roggenkampii (4.6%). IMI-1 was the predominant carbapenemase variant (86/87, 98.9%). All the bla IMI genes were associated with chromosomally integrated Xer-dependent integrative mobile elements (IMEXs), with two new variants detected.