Klebsiella

Klebsiella is a genus of Gram-negative, encapsulated, facultatively anaerobic bacteria in the Enterobacteriaceae family. With 141 file mentions across the vault, Klebsiella is one of the most frequently referenced opportunistic pathogens. The dominant species is klebsiella pneumoniae, but the genus-level page captures the shared biology — particularly the metal-dependent virulence and siderophore arsenal that drive Klebsiella's expansion during dysbiosis.

For species-level detail, see klebsiella pneumoniae.

Metal Dependencies

  • Iron: Klebsiella produces multiple siderophores — enterobactin, yersiniabactin (a dual iron/nickel metallophore), and salmochelin — giving it one of the most comprehensive iron acquisition toolkits among enteric pathogens [1].
  • Nickel: NiFe-hydrogenases support anaerobic hydrogen oxidation in the inflamed gut, providing competitive advantage [2] [3].
  • Manganese: Required for superoxide dismutase (MnSOD) defense against the oxidative burst.
  • Co-selection: Metal resistance genes co-located with carbapenem resistance on shared plasmids — environmental metal exposure drives the evolution of carbapenem-resistant Klebsiella (CR-KP), one of the most urgent AMR threats globally [4] [5].

Dysbiosis Bloom

Klebsiella expansion is part of the characteristic Enterobacteriaceae bloom during inflammation:

  • IBD: Enriched alongside E. coli in both Crohn's and UC [6] [7].
  • NEC: Enriched in preterm infant gut before NEC onset; nickel in formula may fuel expansion [3].
  • CKD: Part of uremic toxin-producing Enterobacteriaceae enrichment [5].

Cross-References

References (7)

  1. Summer D Bushman, Eric P Skaar, N Luisa Hiller (2025). Bushman 2025 — The Exploitation of Nutrient Metals by Bacteria for Survival and Infection in the Gut. PLOS Pathogens
  2. ★Robert J. Maier, Stéphane L. Benoit (2019). Role of Nickel in Microbial Pathogenesis. Inorganics. doi:10.3390/inorganics7070080
  3. Karen Pendergrass (2026). Nickel as a Catalytic Driver of Necrotizing Enterocolitis: Dietary Nickel, Microbial Metallomics, and the Activation of Nickel-Dependent Virulence Pathways in the Preterm Gut. Zenodo Preprint. doi:10.5281/zenodo.18200348
  4. Baker-Austin C, Wright MS, Stepanauskas R et al. (2006). Baker-Austin 2006 — Co-selection of Antibiotic and Metal Resistance. Trends in Microbiology. doi:10.1016/j.tim.2006.02.006
  5. María V. Miranda, Fernanda C. González, Osvaldo S. Paredes-Godoy et al. (2022). Miranda 2022 — Characterization of Metal(loid)s and Antibiotic Resistance in Bacteria of Human Gut Microbiota from CKD Subjects. Biological Research. doi:10.1186/s40659-022-00389-z
  6. Babak Khorsand, Hamid Asadzadeh Aghdaei, Ehsan Nazemalhosseini-Mojarad et al. (2022). Khorsand 2022 — Overrepresentation of Enterobacteriaceae and Escherichia coli is the major gut microbiome signature in Crohn's and UC: comprehensive metagenomic analysis of IBDMDB datasets. Frontiers in Cellular and Infection Microbiology. doi:10.3389/fcimb.2022.1015890
  7. Haijing Wang, Yuanjun Wang, Libin Yang et al. (2024). Wang 2024 — Integrated 16S rRNA sequencing and metagenomics insights into microbial dysbiosis and distinct virulence factors in inflammatory bowel disease. Frontiers in Microbiology. doi:10.3389/fmicb.2024.1375804

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