THE SOURCE OF THE MICROORGANISMS IN THE LUNGS OF NORMAL ANIMALS

Area of Science:

• Microbiology
• Veterinary Pathology
• Environmental Health

Background:

• The lungs of various animal species, including calves, rabbits, guinea pigs, rats, and mice, are frequently colonized by microorganisms.
• Commonly identified organisms include Streptothrix, molds, and Bacillus subtilis group bacteria, often found at the lung periphery.

Purpose of the Study:

• To investigate the origin and transmission of microorganisms found in animal lungs.
• To determine the impact of environmental factors, specifically dry foodstuffs, on lung microbial load.
• To assess the colonization of bronchial lymph glands by these organisms.

Main Methods:

• Culturing organisms from the lungs of various animal models (calf, rabbit, guinea pig, rat, mouse).
• Analyzing the microbial content of potential environmental sources, such as hay and straw.
• Manipulating environmental conditions (withholding or moistening food stuffs) to observe effects on lung microbial presence.
• Examining bronchial lymph glands for microbial presence.

Main Results:

• Dry food stuffs like hay and straw were identified as the primary source of lung-invading organisms.
• Reducing exposure to or moistening these materials led to a decrease in lung microorganisms.
• Introducing these materials to mice increased lung organism levels, comparable to larger animals.
• 66.7% of guinea pig bronchial lymph glands showed organisms similar to those in the lungs.

Conclusions:

• Airborne microorganisms from dry food sources readily invade animal lungs.
• Environmental control of food stuffs is crucial for managing lung microbial burden in animals.
• Bronchial lymph glands can serve as a reservoir for lung-associated microorganisms.