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Assessing Bacterial Invasion of Cardiac Cells in Culture and Heart Colonization in Infected Mice Using Listeria monocytogenes
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Assessing Bacterial Invasion of Cardiac Cells in Culture and Heart Colonization in Infected Mice Using Listeria monocytogenes

Published on: May 27, 2015

PATHOGENIC ORGANISMS OF THE GENUS LISTERELLA

C V Seastone1

  • 1Department of Animal and Plant Pathology of The Rockefeller Institute for Medical Research, Princeton, N. J.

The Journal of Experimental Medicine
|October 30, 2009
PubMed

Insights

Researchers identified closely related Gram-positive organisms causing infections in humans and animals. These bacteria trigger a significant monocyte increase and target the heart muscle, leading to necrosis.

Area of Science:

  • Veterinary Medicine
  • Human Infectious Diseases
  • Microbiology

Background:

  • Gram-positive organisms have been isolated from various animal diseases, including encephalitis in cattle and sheep, and myocardial infection in fowl.
  • Similar organisms have also been linked to meningitis in humans and generalized infections in rabbits.

Purpose of the Study:

  • To describe the cultural and serological properties of these closely related Gram-positive organisms.
  • To investigate the pathological effects and blood responses following experimental infection with these isolates.

Main Methods:

  • Isolation and characterization of Gram-positive organisms from diverse clinical cases.
  • In vivo studies involving intravenous injection into chickens, rabbits, and guinea pigs.
  • Hematological analysis to observe blood responses, particularly monocyte counts.
  • Histopathological examination to determine sites of organism localization and tissue damage.

Main Results:

  • Closely related Gram-positive organisms were isolated from meningitis (humans), encephalitis (cattle, sheep), myocardial infection (fowl), and generalized infections (rabbits).
  • Intravenous injection into experimental animals induced a marked increase in monocytes.
  • The organisms demonstrated a tendency to localize within the myocardium, causing necrosis.

Conclusions:

  • A group of related Gram-positive bacteria can cause significant disease across multiple species, including humans and various animals.
  • These organisms elicit a distinct hematological response characterized by monocytosis.
  • Myocardial localization and subsequent necrosis are key pathological features of infection with these bacteria.

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