6.2 bacteria as pathogens Flashcards
how can bacteria be agents of infection?
via the production of endotoxins, exotoxins and host tissue invasion
why is it important that we understand how bacteria cause infection?
it helps us to avoid infection and treat infection effectively
give one example of a bacterial disease in humans
tonsilitis
give one example of bacterial disease in animals
soft roots
what are endotoxins?
they are lipopolysaccharides part of the outer layer of the cell wall of Gram -ve bacteria
where do they have an effect?
around the site of the infection
what are the pathogenic effects of endotoxins?
fever, vomiting and diarrhoea
are these diseases fatal?
no, but the symptoms can be
are these heat resistent?
very heat resistant (250’C)
what is an example of an endotoxin?
Salmonella spp.
how is salmonella spread?
by ingestion of foof and water contaminated with infected faeces
how can you avoid salmonella?
cook meat properly and washing hands after toutching raw meat and using the toilet
what are exotoxins?
soluble proteins produced and released by bacteria as they metabolise and reproduce produced by both Gram +ve and -ve bacteria
where do they have an effect?
widespread througout the body and act at a distance
what are the pathogenic effects of exotoxins?
1- damage to cell membranes causing cell membrane to break down/internal bleeding
2- some act as competitive inhibitors to neurotransmitters
3- some directly poison cells
