Insertion sequences disrupting mgrB in carbapenem-resistant Klebsiella pneumoniae strains in Brazil

Objectives: This study aimed to characterise insertional mutations disturbing themgrB gene in carbapenem-resistant Klebsiella pneumoniae (CRKp). Methods: A total of 118 clinical CRKp isolates were surveyed for polymyxin resistance and insertion sequence (IS) elements disruptingmgrB. Results: Of the 118 isolates, 78 (66.1%) displayed polymyxin resistance, of which 54% (42/78) hadmgrB::IS inserts. Sequencing analyses showed 13 insertion sites in mgrB. mgrB::ISSen4(IS3) was observed for the first time in CRKp. Conclusions: Ten different IS elements disruptedmgrB, with a predominance (76%) of IS5 sequences. (C) 2020 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy.

Automated summary

This study identified that the insertion mutations disrupting the mgrB gene in carbapenem-resistant Klebsiella pneumoniae mainly involved IS5 sequences, with the first observation of mgrB::ISSen4 (IS3) in CRKp.