Related Experiment Video

Updated: May 29, 2026

Long Term Chronic Pseudomonas aeruginosa Airway Infection in Mice
15:43

Long Term Chronic Pseudomonas aeruginosa Airway Infection in Mice

Published on: March 17, 2014

Pseudomonas aeruginosa is associated with increased lung cytokines and asymmetric dimethylarginine compared with

Linda E Sousse1, Collette C Jonkam, Daniel L Traber

  • 1Department of Anesthesiology, University of Texas Medical Branch, 610 Harborside Drive, Galveston, TX 77555, USA.

Shock (Augusta, Ga.)
|September 17, 2011
PubMed

Insights

Pseudomonas aeruginosa sepsis causes more severe lung injury than MRSA sepsis, linked to increased cytokines and ADMA. MRSA sepsis shows higher nitric oxide production due to less arginase activity.

Area of Science:

  • Pulmonary Medicine
  • Infectious Diseases
  • Biochemistry

Background:

  • Sepsis-induced acute lung injury (ALI) is a major cause of mortality.
  • Different bacterial pathogens may elicit distinct pulmonary responses.
  • Understanding these responses is crucial for developing targeted therapies.

Purpose of the Study:

  • To compare pulmonary responses to Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) sepsis.
  • To investigate lung cytokine expression, asymmetric dimethylarginine (ADMA) concentration, and the arginase pathway in ovine and murine models.
  • To elucidate the mechanisms underlying differential severity of lung injury.

Main Methods:

  • Ovine and murine models of sepsis were established via intratracheal instillation of P. aeruginosa or MRSA.
  • Pulmonary function, lung ADMA concentration, arginase activity, oxidative stress, and cytokine expression were assessed.
  • Plasma nitrate/nitrite concentrations were measured.

Main Results:

  • P. aeruginosa sepsis induced more severe lung injury than MRSA sepsis in both models.
  • P. aeruginosa sepsis was associated with increased lung ADMA and arginase activity.
  • MRSA sepsis showed significantly higher plasma nitrite/nitrate concentrations and less arginase activity.

Conclusions:

  • Increased cytokine expression and ADMA concentrations contribute to the severity of acute lung injury in P. aeruginosa sepsis.
  • Reduced arginase activity in MRSA sepsis may explain the elevated nitric oxide production.
  • These findings highlight distinct pathophysiological pathways for different bacterial sepsis types.

More Related Videos

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung07:46

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung

Published on: June 5, 2012

Pseudomonas aeruginosa Induced Lung Injury Model07:24

Pseudomonas aeruginosa Induced Lung Injury Model

Published on: October 29, 2014

Related Concept Videos

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 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...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Microbiota of the Respiratory Tract01:29

Microbiota of the Respiratory Tract

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...