Characteristics of ESBL-positive Klebsiella pneumoniae isolated from paired children with and without diarrhea.

Background: Klebsiella pneumoniae producing extended-spectrum β-lactamase (ESBL) colonizing and transmitting in the intestine, especially in children, have significant public health implications. Investigating antibiotic resistance, antibiotic resistance genes (ARGs), virulence factor genes (VFGs), and genetic relationships may help us to explore the characteristics and differences of ESBL-positive K. pneumoniae in children with and without diarrhea.

Methods: After selecting and pairing, 26 pairs of 52 ESBL-positive K. pneumoniae strains were isolated from 323 children with diarrhea and 393 children without diarrhea. Antimicrobial susceptibility test and whole genome sequencing were performed to explore antibiotic resistance, ARGs, and VFGs. The genetic relationship was explored by conducting a maximum likelihood phylogenetic tree and investigating plasmid and sequence type (ST).

Results: All strains showed resistance to cephalosporins, with ESBL-producing genes widely carried (98.1%). Carbapenem-resistant K. pneumoniae (CRKP) were found in both groups. Hypervirulent K. pneumoniae (hvKP) were isolated from children with diarrhea carrying iucA on plasmid. The emergence of ST5670 CRKP and ST2108 hvKP highlighted the necessity for close monitoring of community-acquired K. pneumoniae.

Conclusions: Severe drug resistance was found among ESBL-positive K. pneumoniae strains isolated from children with and without diarrhea. Attention must be paid to ESBL-positive K. pneumoniae colonized in the intestine of children, and pathogen and ARG monitoring in children should be strengthened, even in healthy people.