Control Of Microbial Growth Flashcards
Infectious disease
Occurs when a microorganism in the body multiplies and causes damage to the tissue.
Pathogens
The microorganisms that cause infectious diseases
Opportunistic pathogens
The causative agents of infectious diseases caused by microorganisms normally present or on in the body that will not cause harm, unless favourably conditions exist for them to express their disease producing potential.
Endogenous diseases
Are causes of microorganisms in or on the body
Exogenous diseases
Are caused by microorganisms not normally present on or in the body; will contaminate the body from the outside
Toxigenic diseases
Exogenous microorganism is causing disease without entering and multiplying in the body (after eating food, in which mos have multiplied and produce toxins- botulism, staphylococcus food poisoning.
Bacteriophage
Viruses infect bacteria were discovered in 1915 and in 1922
Prion
Infection agent, composed entirely of protein, causing a rare degenerative brain disease in humans called creutzfeldt- jacob.
Prions are not microorganisms; prion diseases are usually rapidly progressive, and always fatal.
In animals cause bovine spongiform encephalopathy, called “ mad cow disease”.
4 Routes of entry into the body
1) Inhalation (breathing aerosol particles from Prophy angle)
2) ingestion (swallowing droplets of saliva/blood spattered into mouth)
3) mucous membranes (droplets of saliva/blood spattered and eyes, nose, or mouth)
4) breaks in the skin (directly touching microorganisms or being spattered with saliva/blood onto skin with cuts/abrasions/punctures with contaminated sharps.
Spores
One of the resistant forms of life against heat, drying and chemicals
Bacteria that develop a defence mechanism against death
Bacterial flora
Normally resides honour in body without causing harm
Has disease producing potential
Prodromal stage
Early symptoms (slight fever, headache, upset, stomach)
Acute stage
Very ill (host displays maximal symptoms of the disease)
Convalescent stage
Recovery phase (infectious agents are still present and may spread.)
Innate host defences
1) Physical barriers (unbroken skin, mucous membranes, respiratory)
2) mechanical barriers (nose hair, coughing, sneezing, washing of secretions and excretions (tears and urine), sticky mucus (traps).
3) antimicrobial chemicals (hydrochloric acid (stomach), lysosome, interferon (resistant to virus replication cells)
4) cellular barriers (WBC (neutrophils, and macrophages —> phagocytes.)