In Vivo High Plasticity of Multi-Drug Resistant ST258 Klebsiella pneumoniae

Carbapenemase production in Enterobacterales clinical isolates is a global threat. Multi-drug resistant Klebsiella pneumoniae harboring carbapenemases are a major concern among the hospital settings in Latin America. Aim: The aim of this study was to analyze the genetic relatedness between three isolates of K. pneumoniae recovered from one patient in the same bacteriological round on the same day, which exhibited different susceptibility profiles to carbapenems (CP) and to colistin (Col). Isolates' profiles were as follows (susceptible-S/resistant-R): CPS/Col(R), CP(R)/Col(R), and CP(R)/Col(S). Pulse-field gel electrophoresis, multilocus sequence typing, and whole genome sequencing were performed. Conjugation assays were carried out and PCR determination in transconjugants (Tcs) was made for: bla(CTX-M-groups), bla(NDM), bla(KPC), bla(TEM), qnr alleles, aac(6 ')Ib-cr, ermB, and plasmid incompatibility groups (Inc). Results: All isolates belonged to the same clone, to ST258 and harbored bla(CTX-M-14), bla(CTX-M-15), qnrA1, qnrB1, aac(6 ')Ib-cr, and wzi154 (capsule-locus KL107). One isolate had additional wzi gene, wzi109 (capsule-locus KL36). In CP(R) isolates, the pattern was explained for bla(NDM-1) or bla(NDM-1)/bla(KPC-2) presence, and in Col(R) for IS5-like element insertion in mgrB at different positions. Co-mobilization of bla(NDM-1)/qnrA1 was associated to a different plasmid Inc (A/C-FII) in both bla(NDM-1) donors. Mobilization of bla(CTX-M-14) was related to IncI1 in one donor. Conclusion: These findings highlight the potential plasticity of ST258 K. pneumoniae clone. To the best of our knowledge, this is the first description of bla(NDM-1)/bla(KPC-2)-producing K. pneumoniae ST258 in Latin America.