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oai:figshare.com:article/34053729 2026-10-02T04:38:57Z category_696 portal_316 item_type_3 month_year_10_2026

Table 1_Closely related ST11 Klebsiella pneumoniae isolates with transient attenuation and re-emergence of carbapenem resistance during prolonged hospitalization: a case report.docx Mingquan Zeng (25161627) Yu Jiang (234328) Fei Yan (128878) Yuting Sun (3323220) Heng Liao (4256218) Weiguo Zhou (746301) Genetic Immunology carbapenem resistance genomic relatedness hypermucoviscosity Klebsiella pneumoniae KPC phenotypic discordance ST11 Background<p>Apparent transitions in carbapenem susceptibility among sequential Klebsiella pneumoniae isolates are often interpreted as strain replacement. However, phenotypic variation among closely related isolates may also produce similar phenotypic shifts, particularly in heavily treated patients.</p>Case presentation<p>We report a 91-year-old long-term hospitalized patient from whom three sequential ST11 Klebsiella pneumoniae isolates were recovered from blood and urine over a 3-month period. The initial bloodstream isolate (KPB1) exhibited a hypermucoviscous phenotype, KPC production, and carbapenem resistance. A subsequent urinary isolate (KPU2) lost the hypermucoviscous phenotype and showed attenuation of carbapenem resistance, becoming susceptible to imipenem, meropenem, and doripenem while remaining resistant to ertapenem. A later urinary isolate (KPU3) reverted to carbapenem resistance while remaining non-hypermucoviscous. 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> 2026-10-02T04:38:57Z Dataset Dataset 10.3389/fimmu.2026.1857429.s002 https://figshare.com/articles/dataset/Table_1_Closely_related_ST11_Klebsiella_pneumoniae_isolates_with_transient_attenuation_and_re-emergence_of_carbapenem_resistance_during_prolonged_hospitalization_a_case_report_docx/34053729 CC BY 4.0