Related Experiment Video

Updated: May 20, 2026

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
11:32

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

Increased chain length promotes pneumococcal adherence and colonization

Jesse L Rodriguez1, Ankur B Dalia, Jeffrey N Weiser

  • 1Departments of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.

Infection and Immunity
|July 25, 2012
PubMed

Insights

Streptococcus pneumoniae chain length impacts colonization. Longer chains enhance bacterial adherence to epithelial cells, improving upper respiratory tract colonization in a murine model.

Area of Science:

  • Microbiology
  • Pathogenesis
  • Bacterial Morphology

Background:

  • Streptococcus pneumoniae is a leading cause of mucosal infections.
  • Pneumococcal chain length influences immune evasion, with shorter chains being less immunogenic.
  • The role of pneumococcal chain length in epithelial colonization is not well understood.

Purpose of the Study:

  • To investigate the impact of Streptococcus pneumoniae chain length on epithelial cell adherence and colonization.
  • To determine if longer pneumococcal chains provide a competitive advantage during upper respiratory tract colonization.

Main Methods:

  • In vitro adherence assays using A549 human epithelial cells.
  • In vivo colonization studies in a murine model.
  • Analysis of pneumococcal chain length distribution in wild-type and mutant strains.

Main Results:

  • Chain-forming mutants and wild-type pneumococci grown to promote chain formation exhibited increased adherence to A549 cells.
  • Adherence to A549 cells selected for longer chains within the wild-type population.
  • Chain-forming mutants outcompeted the parental strain in a murine model of colonization.

Conclusions:

  • Pneumococcal chain length is a critical factor in upper respiratory tract colonization.
  • Longer pneumococcal chains enhance bacterial adherence to epithelial surfaces, promoting colonization.
  • Morphological heterogeneity in Streptococcus pneumoniae may be a key strategy for successful colonization.

More Related Videos

Investigating the Effects of Probiotics on Pneumococcal Colonization Using an In Vitro Adherence Assay09:20

Investigating the Effects of Probiotics on Pneumococcal Colonization Using an In Vitro Adherence Assay

Published on: April 28, 2014

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness12:21

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness

Published on: September 28, 2022

Related Concept Videos

Pneumonia I: Introduction01:29

Pneumonia I: Introduction

Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...
Pneumonia I: Introduction01:30

Pneumonia I: Introduction

Pneumonia is an acute respiratory infection that targets the lungs, specifically the alveoli. These tiny air sacs, essential for oxygen exchange, become engorged with pus and fluid, severely hindering breathing, decreasing oxygen absorption, and causing significant pain and discomfort during respiration.
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Colonisation of Pathogens01:25

Colonisation of Pathogens

Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Pneumonia II: Pathophysiology01:29

Pneumonia II: Pathophysiology

The pathophysiology of pneumonia involves the following steps:
Fimbriae, Pili, and Axial Filaments01:28

Fimbriae, Pili, and Axial Filaments

Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...