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/ColR, CPR/ColR, and CPR/ColS. 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: blaCTX-M-groups, blaNDM, blaKPC, blaTEM, qnr alleles, aac(6')Ib-cr, ermB, and plasmid incompatibility groups (Inc). Results: All isolates belonged to the same clone, to ST258 and harbored blaCTX-M-14, blaCTX-M-15, qnrA1, qnrB1, aac(6')Ib-cr, and wzi154 (capsule-locus KL107). One isolate had additional wzi gene, wzi109 (capsule-locus KL36). In CPR isolates, the pattern was explained for blaNDM-1 or blaNDM-1/blaKPC-2 presence, and in ColR for IS5-like element insertion in mgrB at different positions. Co-mobilization of blaNDM-1/qnrA1 was associated to a different plasmid Inc (A/C-FII) in both blaNDM-1 donors. Mobilization of blaCTX-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 blaNDM-1/blaKPC-2-producing K. pneumoniae ST258 in Latin America.

First characterization of K. pneumoniae ST11 clinical isolates harboring blaKPC-3 in Latin America.

Antimicrobial resistance due to carbapenemase production in Enterobacteriaceae clinical isolates is a global threat. Klebsiellapneumoniae harboring the blaKPC gene is one of the major concerns in hospital settings in Latin America. The aim of this study was to characterize the antibiotic resistance mechanisms and to typify four carbapenem-resistant K. pneumoniae clinical isolates from the city of Manizales, Colombia. We identified blaKPC-3 in all four isolates by polymerase chain reaction and subsequent sequencing. The plasmid-mediated quinolone resistance genes qnrB19-like and aac(6')Ib-cr; fosfomycin resistance gene fosA and an insertion sequence IS5-like in mgrB (colistin resistance) were also detected. Sequence types ST11 with capsular type wzi75, and ST258 with wzi154, were characterized. The blaKPC-3 gene was mobilized in a 100-kb IncFIB conjugative plasmid with vagCD toxin-antitoxin system. This work reports multiple resistance genes in blaKPC-producing K. pneumoniae and the first occurrence of ST11 clinical isolates harboring blaKPC-3 in Latin America.