Table 1_Closely related ST11 Klebsiella pneumoniae isolates with transient attenuation and re-emergence of carbapenem resistance during prolonged hospitalization: a case report.docx

Repeat antimicrobial testing confirmed these findings. Core-genome SNP analysis identified 16–20 pairwise differences among the three isolates, supporting close genomic relatedness despite their phenotypic discordance.</p>Conclusion<p>This case illustrates marked differences in carbapenem susceptibility and hypermucoviscosity among closely related ST11 K. pneumoniae isolates recovered during a single patient’s clinical course.

KPU2 retained ertapenem resistance despite susceptibility to other tested carbapenems. The genomic findings were more consistent with closely related isolates than with replacement by an unrelated strain, although direct ancestry and continuous persistence could not be established. Phenotypic changes should be interpreted alongside repeat microbiological testing, available genomic evidence, and the clinical context.</p>