Survey of Pathogenic Microorganisms Flashcards
What are viruses?
infectious particles with DNA or RNA surrounded with a capsid (protein coat)
What is the purpose of the lipid membrane around virus capisd?
to help with host cell recognition and spikes to aid in attachement ot cells
What cells do cold viruses target?
cells of the respiratory epithelium
Where does herpes viruses reproduce?
in nervous tissue
how do signs and symptoms manifest in viruses?
it depends on the way these viruses reproduce in cells or from the way the immune system responds to viral infection
what is a latent infection?
virus inserts itself into cell DNA and doesnt repicate (= no s/s) until a trigger such as s stress, infection with another pathogen, or a weakened immune defense activates the virus
Whre do HIV cells reproduce?
in t cells
What is bacteria?
microscopic, single-celled organism, w/o organelles
Shapes of bacteria?
cocci - round
bacilli - rodshaped
spirilla - spiral
spirochetes - corkscrew
vibrios - comma
What gives bacteria it’s key shape?
it’s cell walls
How does penicillin stop bacteria?
inteferes w/ correct cell wall construction = lyse
What is the gram stain?
thick walls = purple, thin walls = pink, in certain cells = easy identification
Examples of intracellular parasites + what r they?
chylamydias - STI
Rickettsias - transmitted by ticks = diseases like typhus and Rocky Mountain spotted fever
What are endospores?
some species of bacteria have them to stop them from drying out, lack of nutrients and extreme weather such as heat
in favorable conditions this endospore can germinate and produce bacteria
Bacteria that produce endospores include the causes
of ____________________________________
tetanus, botulism, and anthrax
Wjat is an endotoxin?
the potent toxin released by some bacteria into tissue when gram-neg bacteria die (can = life-threatening shock)
What is caused by toxin produced by bacterium Clostridium tetani?
tetanus- it interferes w/ muscles ability to relaxe = frozen, rigid, muscles
What are protozoa?
single-celled eukaryotic microorganisms that r larger than bacteria, found almost in every habitat, do not cause disease but can invade and destroy certain tissues
what are the types of protozoa
amoeboids - uses pseudopodia to move, ex is entamoeba histolytica (amoebic dysentery)
Flagellates - uses flagella to move, ex is trichomonas vaginalis which causes trichomoiasis (STI) and Giardia, causes giardiasis which is an intesitnal infection
ciliates - uses cilia to move
Sporozoans - not mobile, plasmodium causes malaria
Every year, more than ________ people worldwide become severely ill with malaria and more than ____ people die as a result.
500 million
1 million
Malaria kills mostly _______________________, largely in _______.
infants, young children,and pregnant women
in Africa
Plasmodium is transmitted via____________________
the bites of infected mosquitoes.
What are fungi?
single-celled or multicelled organisms
has cell walls that contain a polysaccharide called chitin absorbs nutrients w/ mycelia
has allergens which r the reproductive structures bearing spores
What are fungi?
single-celled or multicelled organisms
has cell walls that contain a polysaccharide called chitin absorbs nutrients w/ mycelia
has allergens which r the reproductive structures bearing spores