Lecture 8 Flashcards
Name three key features of Syphilis
Mild and localised
Causes liver failure, heart failure and insanity
Caused by a spirochete bacterium
Unable to survive without a host
Name two key features of the HIV virus
It has a long incubation period
Infects CD4+ cells, macrophages and dendrites
What are pathogens?
Micro-organisms that cause disease
What are parasites?
Larger pathogens
What is the pathogenicity of an organism?
Mechanisms employed to bring about disease
What is the virulence of an organism?
Ability to cause disease, relative, measles virus is more virulent than cold virus
What are opportunistic pathogens?
Pathogens which do not normally cause disease however may cause disease when the body is compromised.
Give four examples of opportunistic pathogens
E.coli when in the urinary tract causes disease
Pseudomonas aeruginosa burns patients when the skin is destroyed
Pneymyocystis carnii infects lungs of immunocompromised patients
Staphyloccocus aureus causes problems in immunosuppressed patients
What are obligate pathogens?
Pathogens which have evolved virulence factors that cause disease in healthy hosts as part of their normal life cycle
Give three examples ob obligate pathogens
Vibrio cholerae, makes a powerful toxin to induce diarrhoea
Salmonella typhi, causes typhoid fever
Mycobacterium tubercolosis causes TB
HIV causes AIDs
What are biofilms?
Mucilaginous surface communities
How can biofilms cause problems in patients?
If they are catheterised for a long period of time they can be contaminated by a biofilm
What are the common features of pathogens?
Infect the host
Reproduce in the host
Transmit to another host
Give three examples of horizontal transmission
Aerosols Faecal-oral route Vector borne Bodily contact Breast feeding Warts eBV sTDs Zoonoses
What is vertical transmission?
From parent to child
How does vertical transmission occur?
Infections found in developing foetus
Infection transmitted when the mother gives birth
What are the stages in a case of measles?
Contact Incubation period Prodromal period Acute ohase Crisis Decline period Convalescence Host defences
Give three examples of non-specific host defences
Innate
Hot defences
General barriers
Give three examples of specific defence mechanisms
Antibody binding
Mucosal immunity
Humoral immunity
Cell mediated immunity
