ID ch 4-9 microbes: all others

20th feb class, all done notes and slides from class and socrative quiz, not all detail included cause seems like we dont need it

top to bottom label

bud, nucleus, bud scars, pseudohypha

hypha descr.

branching tubular filament that makes up the mycelium—the main vegetative body—of a fungus

what is the growth in yeast

spore-hyphae-mycelium

how are fungis cells connected? How can they communicate?

connected with septa but its punctured so they can communicate, can also dissolve the septa

how do fungi reproduce

by means of spores

what are mushrooms

molds with a visible fruiting body

what are all visible molds

filaments

what is the fungi modus operandi

extracellular digestion (of dead material often) by enzyme secretion, recycles molecules for new life to start

label

yeast, pseudohyphae, hyphae

what is the yeast-hyphal transition

from yeast to pseudohyphae (daughter cells do not dissociate), to hyphae formation (virulent)

pathogenic fungi descr. where, example

recyle the living, use digesting enzymes to dissolve enzymes, can be superficia, cutaneous, subcutaneous or systemic (agreesive), opportunistic; eg candida albican which make a mycelium (white on tongue)- sign of loss of immune competense

mycosis def

fungal infection

fungi by growth form

filamentous: growing as multinucleate branching hyphae, forming a mycelium
yeasts: growing as ovoid or spherical single cells, multiply by budding and division

protozoa descr. + egs

single-celled eukaryotic organisms, eg malaria, can be in most parts of the body, can be spread by mosquitos (vectors)

protozoa: cyst descr, oocyst descr

dormant stage of the parasite
oocyst: critical stage in life cycle of the parasite - transmission vehicles

helminths types

nematodes (roundworms), plathyhelminths (phylum) which can become cestodes (tapeworms) and trematodes (flukes, flatworms)

4 transmission routes of helminths

via intermediate host: accidental ingestion of larvae in tissue of another host
faecal-oral route: accidental ingestion of larvae or eggs from faeces of infected host
active skin penetration: larval stages invade through skin
injection by blood-sucking insect: larval stages develop to infectivity in insect intermediate host

example of a nematode

enterbius vermicularis, aquired by ingestion of eggs, in large intestine, incredibly common in <18s in europe

pinworm/threadworm descr. life cycle (5)

eggs on perianal folds (diagnostic stage - via scotch tape which is examined under a microscope), embryonated eggs injested by human (infective stage), larvae hatch in small intestine, adults in lumen of cecum, gravid female migrates to perianal region at night to lay eggs

cestodes example, basic transmission, treatment

T. solium- pig reservoir, attach in intestine and then get excreted and faeces get passed into the environment, treatment: praziquantel

arthropods desrc.

pathogen parasites or vectors

ectoparasite def + egs

arthropod that lands on/climbs on a human and starts eating from the human, on the outside, can have a permanent dwelling in eg hair, eg mosquitos, ticks, flees, etc.

vector arthropod

give you bacteria or virus, eg lyme disease from ticks

prions descr.

misfolded proteins - alpha helixes turn into beta sheet, primary sequence inchanged, resistant to protein digestion, faciliates conversion of healthy protein to diseased, sticks together, eg spongiform encephalopathy - makes holes in your brain to make it look sponge-like

how do yeasts typically gain entry

through small wounds or abrasions in the skin surface

primary mechanism that protozoa evade immune response

alternation of surface proteins to avoid detection

What is a key method by which helminths cause disease in their hosts?

physically obstructing organs or ducts within the host

In what way do arthropods affect the epidemiology of the diseases they transmit?

Through seasonal population fluctuations that affect transmission rates

Pathogenic fungi exhibit a range of morphological foms duing their lifecycle. Which fom is directly associated with the ability to invade host tissues?

Hyphae with the capability to penetrate physical barriers

What role do cysts play in the life cycle of some protozoan pathogens?

Serve as a mechanism for surviving harsh environmental conditions

How do arthropods primarily serve as vectors in the transmission of diseases to humans?

Through the injection of saliva containing pathogens during blood-feeding.

In helminth infections, how is host tissue damage most commonly induced?

Via the immune response of the host to the presence of the helminth

How do pathogenic fungi primaily invade host tissue?

Through the production of hydrolytic enzymes that break down host cells.

In terms of pathogenesis, how do protozoans typically damage their host?

Through the direct destruction of host cells for nutrients.