Characterization of IMI-4 carbapenemase-producing Enterobacter sp. isolated from humans and a companion animal in French Indian Ocean territories.

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are a significant public health concern, associated with high morbidity and mortality rates due to restricted antibiotic treatment options. Among the genetic determinants of CPE resistance, imipenemase (IMI) mediated resistance is an emerging problem in infections involving bacteria of the Enterobacter cloacae complex (ECC) and has been linked to worldwide clinical cases, including community-level outbreaks in the Indian Ocean region. Little is known about the potential role of animals as reservoirs of multidrug-resistant ECC bacteria.

OBJECTIVES

Characterize blaIMI-4 carbapenemase-producing ECC strains isolated from patients and a companion animal in the southwestern Indian Ocean region (Réunion and Mayotte islands).

METHODS

We used antibiotic susceptibility testing to determine available treatment and genome sequencing to characterize resistance gene variants and mobile genetic elements carrying blaIMI-4 genes.

RESULTS

blaIMI-4 ECC isolates are susceptible to new antibiotics active on Class A carbapenemase, notably β-lactams-inhibitors (ceftazidime-avibactam, meropenem-vaborbactam). The blaIMI-4 gene was identified on a common EcloIMEX-2 mobile integrative element in (i) ST 2370 Enterobacter sichuanensis isolated from a dog in Réunion and (ii) ST1845 Enterobacter roggenkampii clinical isolates from Réunion and Mayotte islands.

CONCLUSIONS

Companion animals may play a role in the persistence and spread of mobile genetic elements that confer carbapenem resistance in diverse Enterobacter species.