Related Experiment Video

Updated: Oct 11, 2025

Separating Bacteria by Capsule Amount Using a Discontinuous Density Gradient
05:52

Separating Bacteria by Capsule Amount Using a Discontinuous Density Gradient

Published on: January 7, 2019

14.4K

Phenotypic and Molecular Characterization of Commensal, Community-Acquired and Nosocomial Klebsiella spp

Marta Gómez1, Arancha Valverde2, Rosa Del Campo2

  • 1Department of Nutrition and Food Science, Complutense University of Madrid, 28040 Madrid, Spain.

Microorganisms
|November 27, 2021
PubMed

Insights

Commensal Klebsiella bacteria in healthy individuals possess virulence traits similar to those causing infections. These bacteria may act as a reservoir for antibiotic-resistant strains, but some also show potential for fighting infections.

Area of Science:

  • Microbiology
  • Genetics
  • Public Health

Background:

  • Klebsiella spp. are significant pathogens with increasing antibiotic resistance, posing a public health threat.
  • Research has primarily focused on Klebsiella causing infections, with limited understanding of commensal strains in healthy individuals.

Purpose of the Study:

  • To molecularly identify and phenotypically characterize commensal Klebsiella spp. from breast milk and infant feces.
  • To compare these commensal strains with isolates from community-acquired infections and a neonatal intensive care unit (NICU) outbreak.
  • To investigate the potential of commensal Klebsiella as a reservoir for virulence and antibiotic resistance.

Main Methods:

  • Phylogenetic analysis of the rpoB gene for accurate species identification.
  • Phenotypic characterization of virulence traits, including siderophores and biofilms.
  • Antimicrobial resistance profiling, including multi-drug resistance (MDR) and ESBL production.
  • Assessment of bacteriocin-like inhibitory activity.

Main Results:

  • Phylogenetic analysis identified several Klebsiella and Raoultella species, correcting misidentifications from biochemical methods.
  • Commensal Klebsiella strains exhibited virulence factors comparable to pathogenic isolates.
  • Multi-drug resistant (MDR) and ESBL-producing Klebsiella were found in NICU outbreaks, alongside an imipenem-resistant commensal K. quasipneumoniae.
  • A commensal K. pneumoniae strain demonstrated significant inhibitory activity against MDR Klebsiella isolates.

Conclusions:

  • The human microbiota can serve as a reservoir for potentially infectious Klebsiella strains.
  • Commensal Klebsiella spp. possess virulence traits and can harbor antibiotic resistance, highlighting their dual role in health and disease.
  • Commensal Klebsiella, particularly K. pneumoniae, may have therapeutic potential through bacteriocin production against resistant strains.
Keywords:
Klebsiellaantibiotic resistancebacteriocinsbiofilmsrpoBsiderophoresvirulence

More Related Videos

Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS06:34

Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS

Published on: July 11, 2016

19.3K
Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes08:58

Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes

Published on: March 3, 2023

6.9K

Related Concept Videos

Modern Molecular Taxonomy01:29

Modern Molecular Taxonomy

Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately...
250
Methods of Classification and Identification01:28

Methods of Classification and Identification

Bacterial identification relies on a diverse array of techniques to classify and understand microorganisms, each tailored to uncover specific characteristics. Traditional morphological approaches, while still valuable, are limited for closely related or structurally simple organisms. Modern methods integrate biochemical, serological, genetic, and advanced molecular tools to achieve greater accuracy.Morphological and Biochemical TechniquesMorphological characteristics, such as cell shape and...
318
Applications of Molecular Taxonomy01:20

Applications of Molecular Taxonomy

Molecular taxonomy has revolutionized the understanding and classification of bacteria, providing precise insights into their diversity, evolutionary relationships, and ecological roles. By utilizing molecular techniques such as DNA sequencing and fingerprinting, researchers have made significant strides in various fields related to bacterial studies.Resolving Taxonomic AmbiguitiesMolecular taxonomy has been instrumental in distinguishing closely related bacterial species initially thought to...
190