Klebsiella pneumoniae causing urinary tract infections in companion animals and humans: Population structure, antimicrobial resistance and virulence genes

Objectives: To characterize the population structure, antimicrobial resistance and virulence genes of Klebsiella spp. isolated fromdogs, cats and humans with urinary tract infections (UTIs). Methods: Klebsiella spp. from companion animals (n=27) and humans (n=77) with UTI were tested by the disc diffusion method against 29 antimicrobials. Resistant/intermediate isolates were tested by PCR for 16 resistance genes. Seven virulence genes were screened for by PCR. All Klebsiella pneumoniae fromcompanion animals and third-generation cephalosporin (3GC)-resistant isolates fromhumans were typed by MLST. All Klebsiella spp. were compared after PFGE XbaI macro-restriction using Dice/UPGMA with 1.5% tolerance. Results: blaCTX-M-15 was detected in >80% of 3GC-resistant strains. K. pneumoniae high-risk clonal lineage ST15 predominated in companion animal isolates (60%, n=15/25). Most companion animal ST15 K. pneumoniae belonged to two PFGE clusters (C4, C5) that also included human strains. Companion animal and human ST15- CTX-M-15 K. pneumoniae shared a fimH-1/mrkD/entB/ycfM/kfu virulence profile, with a few (n=4) also harbouring the yersiniabactin siderophore-encoding genes. The hospital-adapted ST11 K. pneumoniae clonal lineage was detected in a cat (n=1) and a human (n=1); both were MDR, had 81.1%Dice/UPGMA similarity and shared several virulence and resistance genes. Two 3GC-resistant ST348 strains with 86.7% Dice/UPGMA similarity were isolated from a cat and a human. Conclusions: Companion animals with UTI become infected with high-risk K. pneumoniae clonal lineages harbouring resistance and virulence genes similar to those detected in strains from humans. The ST15-CTX-M-15 K. pneumoniae clonal lineage was disseminated in companion animals with UTI. Caution must be applied by companion animal caretakers to avoid the spread of K. pneumoniae high-risk clonal lineages.