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

Published on: February 23, 2014

TOXIC SUBSTANCES PRODUCED BY PNEUMOCOCCUS.

R Cole1

  • 1Hospital of The Rockefeller Institute for Medical Research, New York.

The Journal of Experimental Medicine
|October 30, 2009
PubMed
Summary
This summary is machine-generated.

Pneumococci extracts and peritoneal washings can induce anaphylaxis-like symptoms in animals. Dissolving pneumococci in bile salts consistently causes toxicity, suggesting preformed bacterial substances are responsible.

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Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins

Published on: September 30, 2014

Area of Science:

  • Microbiology
  • Immunology
  • Toxicology

Background:

  • Pneumococci are a significant bacterial pathogen.
  • Understanding bacterial toxicity mechanisms is crucial for developing treatments.

Purpose of the Study:

  • To investigate the toxic effects of pneumococci preparations in animal models.
  • To identify the source and nature of pneumococcal toxicity.

Main Methods:

  • Injected filtered rabbit serum, pneumococcal extracts, and peritoneal washings into guinea pigs and rabbits.
  • Dissolved pneumococci in bile salt solutions and administered intravenously.
  • Assessed toxicity through observed symptoms and mortality rates.
  • Investigated the effect of heat on toxicity.

Main Results:

  • Filtered pneumococcal serum was non-toxic.
  • Pneumococcal extracts showed variable toxicity, causing anaphylaxis-like symptoms and death.
  • Peritoneal washings induced frequent anaphylaxis-like reactions and mortality.
  • Bile salt solutions of pneumococci consistently produced anaphylaxis-like symptoms and death in tested animals.
  • Toxicity was linked to preformed bacterial substances, not protein digestion.
  • Heating above 55°C reduced or abolished toxicity.

Conclusions:

  • Pneumococci contain toxic substances that can elicit severe anaphylaxis-like reactions.
  • Bile salt solutions effectively release these preformed toxins.
  • Heat inactivation demonstrates the proteinaceous nature of the toxic components.