Summary of chapter 4,5,6

Archaea

Archaea has

many features in common with eukarya

archaea's features in common with eukarya are

replication, transcription, translation.

archaea features in common with bacteria are

metabolism

unique archaea elements

unique rRNA gene structure

methanogenesis - make methane gas

archaea is

highly diverse

archaea is known for

growth in anaerobic, hypersaline, pH extremes, and high temperature

extremophile

archaeal membranes

isoprene units

ether linkages

monolayer structure

archaeal cell envelopes

S layer

Capsules and slime layers

Pseudomurein - fake wall

- N-acetyltalosaminuronic acid

- N-acetylglucosamine

- All L-peptides

- B (1,3)-glycosidic bonds

archaea has

NAT and NAG

only ------- gas an outer membrane

ignicoccus

Eukaryotes

two groups possess microbial members

a) protists

b) fungi

eukaryotic microorganisms have

cell wall

flagella

cilia

Taxonomy of Fungi

90,000 fungal species have been described, possible 1.5 million

fungi dont

have the roots

six major fungal groups based on

reproductive structure

what are the 6 major fungal groups

Chytridiomycota

Microsporidia

Mucoromycota

Glomeromycota

Ascomycota

Basidiomycota

Chytridiomycota

only one with flagellated cells

Microsporidia

obligate intracellular parasite

Mucoromycota

sexual spore is thick-walled and ornamented

glomeromycota

reproduce asexually ONLY

ascomycota (sac fungi)

includes yeast, truffles and morels

Basidiomycota (club fungi)

includes mushrooms

fungal distribution is

primarily terrestrial, few aquatic species

fungal distribution has

saprophytes (decomposers)

many fungal distributions are

pathogenic

the optima growth temperature for fungi is

< bacteria

some form associations:

mycorrhizae and lichens

industrial importance of fungal distribution

a) fermentation

b) organic acids - citric acid

c) certain drugs - cortisone

d) antibiotics - penicillin

e) immunosuppressive agents - cyclosporin

fungal structure

fungal structure includes

chitin -N-acetylglucosamine polysaccharide

chitin is

a polymer of single sugar

single celled microscopic fungi =

yeasts

body/vegetative structure of a fungus =

thallus (pl. thalli)

multicellular fungi are called

molds

Thallus consists of long, branched ___ filaments tangled into a ___ mass

hyphae, mycelium

hyphae are

hairlike extensions

a septum

separates nuclei

medically important fungi

mycoses can divided into

a) superficial

b) cutaneous

c) subcutaneous

d) systemic

Dimorphic (two shapes) fungi

e) opportunistic

ex of opportunistic mycoses: pathogens:

Candida albicans

C. auris

example of systemic mycoses: disease:

Cryptococcosis

Histoplasmosis

Histoplasmosis

histoplasmosis is caused by

Histoplasma capsulatum var. capsulatum

dimorphic fungus

from bird and bat droppings

histoplasmosis is

disease of the lungs

histoplasmosis can become

systemic

histoplasmosis is

flu-like symptoms or asymptomatic

histoplasmosis grows inside

macrophages

endemic within

the Mississippi, Ohio, and Rio Grande River basins

Cryptococcosis

Cryptococcosis caused by

Cryptococcus neoformans (yeast)

invasive fungus

systemic mycosis

Cryptococcosis due to

inhalation of spores

dried pigeon droppings

contaminated soil

the pathophysiology of Cryptococcosis is

33% mortality rate

immunocompromised (AIDS)

meningitis

immunocompetent

mild or pneumonia like

Nosocomial Candidiasis

Candida albicans (yeast)

normal microbiota

spread by sexual contact.

up to

10% of nosocomial bloodsteam infections

C. auris has a mortality rate of

around 50%

most infections involve

skin or mucous membranes

Medically important protozoan

alternative life stages for

survival outside of the host

transmitted by

arthropod vectors, contaminated food and water, or direct contact.

elderly and immunocompromised individuals at

highest risk of infection

Brain eating amoeba

primary amoebic meningoencephalitis (PAM)

brain eating amoeba caused by

Naegleria fowleri (protozoa)

does NOT need to be ingested

Naegleria fowleri (protozoa) directly invades

the central nervous system (CNS)

PAM is fatal within

10 days

Amebiasis

caused by

Entamoeba histolytica

intestinal amebae

amoebic dysentery

Amebiasis includes

cysts

Amebiasis symptoms are

asymptomatic to fulminating dysentery, appendicitis, and abscess of lungs

who are most likely to develop amebic liver

men, rather than women

Giardia

Giardia is a

protist

Giardia caused by

Giardia intestinalis

low infectious dose

10 cysts

only need to get a few cysts to get an infection

in the US

it is the most common cause of intestinal parasitic disease

Giardia can be

zoonotic - goes from animals to humans

human carriers are asymptomatic

Cyst -> trophozoites in the

duodenum

Giardia may interfere with

nutrient absorption

Malaria

malaria caused by

Plasmodium spp.

apicomplexa

falciparum -> vivax -> malariae -> ovale -> knowlesi

the vector for malaria is

mosquito

malaria treatment by

pyrotherapy (therapy using heat)

- Dr. Julius Wagner-Jauregg

African sleeping sickness - Protist

african sleeping sickness also known as

Human African Trypanosomiasis (HAT)

African sleeping sickness commonly by

Trypanosoma brucei subspecies gambiense

apicomplexa

the resevoir for African sleeping sickness is

domestic cattle and wild animals

the vector for African sleeping sickness is

tsetse flies (the bite humans)

VSG switching -

antigenic variation

accumulation of antibodies due to African sleeping sickness causes a

coma

toxoplasmosis

Toxoplasma gondii

apicomplexa

the resevoir for toxoplasmosis is

wild rodents, birds, small mammals

toxoplasmosis transmitted by

fecal-oral transmission from infected animals

toxoplasmosis is usually

asymptomatic or resembles mononucleosis

tachyzoites cross the placenta and infect fetus, causing

serious congenital defects or death

15-40% of domestic cats have been infected with

T. gondii at some point in their lives

cats currently shedding infectious oocysts is around 0-1%

Acellular microbes