Lec Exam 3 Microbiology

• The 3 factors for an infectious disease are a susceptible host , the etiologic agent , and enviormet factors
• Pathogen : disease causing agent
• Symbiosis: association between 2 or more species
• Mutualism: both members benefit
• Parasitism: one organism benefits from the relationship and the other is harmed.
• Commensalism: neither organism benefits or is harmed.
• Contamination: the microorganisms are present.
• Infection: multiplication , invasion, or colonization of any parasite organisms within the hosts body.
• Disease: f an infection disrupts the normal functioning of the host its a disease.
• Pathogenicity: the capacity to produce disease. An organisms pathogenicity relies on its ability to invade, multiply , and avoid being damaged.
• Infectious dose: if only a small number the host can defend , if large number the host cannot defend and disease is caused.
• Virulence : intensity of disease caused by pathogen.
• Animal passage : rapid transfer of pathogen through .
• There are 10 times more microbial cells than eukaryotic cells.
• Microbe -free: glands, organs, muscles, sinuses, brain and spinal cord , circulatory system.
• Body fluids that are microbe free: blood , saliva , urine , semen.
• Prophylaxis: normal flora is disturbed or wiped out by diarrhea , pathogen can invade large intestine.
• Opportunists: non-pathogenic microbes that can affect under certain conditions such as failed normal host defenses , introduction to unusual body sites , disturbance of normal flora.
• Communicable : contagious.
• Non- communicable: not from one host to another.
• Causes of non-communicable disease include poison ,infection by normal microbial, infection by organisms in environment ( tetanus) , legionellosis ( form of pneumonia in conditioning system ).
• How do bacteria cause disease ?

  special structures and physiological characteristics, virulence factors ( pill ,capsule, enzymes ). Enzymes are hyaluronate , coagulase .
• Toxin : any substance synthesized in living organism that's poisonous to another organism
• Exotoxins : soluble substances secreted into host tissues on medium.
• Endotoxin: apart of gram- cell wall (LPS) and are released into Host -Tissue sometimes in large quantities when the bacterial cells divide and die.
• Toxemia: spread of exotoxins by blood from infection.
• Intoxicaton : food poisoning from ingestion of toxin.
• Neurotoxin : botulism which prevents muscle contraction
• Tetanus prevents muscle relaxation.
• Toxoid: inactivated toxin ( vaccine ).