Animal Microbiology, Detecting Infectious Agents Flashcards
What is microbiota or microflora?
Microbiota or microflora refers to a community of microorganisms (bacteria, archaea, viruses, fungi, protozoa) in a specific environment, such as a body site or soil sample.
How does the microbiome differ from microbiota?
The microbiome refers to the genomes of microorganisms in an environment, emphasizing their genetic content. It is analyzed using culture-independent methods like genomic sequencing.
Why are gut microbes crucial for herbivorous mammals?
Gut microbes produce enzymes that break down polysaccharides like cellulose and hemicellulose in fibrous diets, which herbivores cannot digest themselves.
What is fermentation in the context of digestion?
Fermentation is the anaerobic breakdown of substances by bacteria, yeasts, or other microorganisms, producing products like volatile fatty acids (VFAs) from polysaccharides.
How do fore-gut fermenters differ from hind-gut fermenters?
Fore-gut fermenters (e.g., ruminants) ferment food in chambers like the rumen before digestion, whereas hind-gut fermenters (e.g., horses) ferment food in the caecum and colon after digestion.
Define symbiosis in relation to gut microbiota.
Symbiosis is the association where one species (e.g., ruminant) provides habitat and food to microbes for digestion, while microbes provide essential enzymes and nutrients like VFAs to the host.
What role does saliva play in the rumen of ruminants?
Saliva helps regulate ruminal pH, maintaining an optimal environment for microbial fermentation by neutralizing acids and removing fermentation gases.
What are volatile fatty acids (VFAs) in digestion?
VFAs are fermentation products (e.g., acetate, butyrate) that ruminants absorb from the rumen into the bloodstream, serving as a major energy source.
Describe the composition of rumen microflora.
Rumen microflora includes bacteria, protozoa, fungi, methanogenic archaea, and bacteriophages, each contributing to digestion through their enzymatic activities.
How does diet influence rumen microflora?
High-grain diets increase starch fermenting bacteria like Streptococcus, altering the microbial balance and potentially causing conditions like lactic acidosis in ruminants.
How can infectious diseases be controlled?
Infectious diseases can be controlled by eliminating the pathogen, reducing exposure to it, increasing animal resistance, controlling predisposing factors, and treating infected animals.
What does eliminating the pathogen involve?
Eliminating the pathogen requires eradicating it from the animal population and preventing its reintroduction through strict quarantine policies and ensuring introduced animals are free of infection.
How can exposure to pathogens be reduced?
Exposure can be reduced by isolating diseased animals, reducing stocking rates, and implementing all-in-all-out production systems to segregate different classes of stock.
How can animal resistance to pathogens be increased?
Animal resistance can be enhanced through vaccination to generate acquired immunity, ensuring young animals receive colostrum for passive immunity, and optimizing general health and stress management.
What factors can be controlled or eliminated to reduce disease risk?
Factors exacerbating disease can be controlled by managing exposure to other pathogens and adverse environmental conditions that compromise animal health.
