MICROBIOLOGY Flashcards
what is an infectious disease
disease caused by microbial invasion/multiplication
what is the difference between a communicable disease and a contagious disease
communicable disease is an infectious disease that spreads through a path e.g. through water whereas contagious disease is one that passes between hosts
what is the 5 kingdoms of classification in order
kingdom-phylum-class-order-family-genus-species ( KING PHILIP CAME OVER FOR GOOD SOUP)
whats the difference between a prokaryote and eukaryote
prokaryote is unicellular while eukaryotes are multicellular
whats the difference in structure between prokaryote and eukaryote
- prokaryotes are smaller than eukaryotes
- prokaryotes have no carbohydrates and lacks sterols whereas eukaryotes have both
- prokaryotes have 50s and 30s subunits whereas eukaryotes have 60s and 40s subunits
- prokaryotes have 1 chromosome free floating and eukaryotes have multiple chromosomes
what are the different shapes of bacteria (six of them)
bacilli-rod cocci-shpere ovococci-oval spirrilum- spiral vibrio-comma spirochaetes-zig zag
what are the names of different arrangement
chains of cooci-streptococcus spp
clusters of cocci-staphylococcus
pair of cocci/diplococci-streptococcus pneumoniae
what is a bacterial capsule made of
polysaccharide
what is the purpose of the bacterial capsule
for immune resistance/evasion
what are the layers of the exoskeleton(outside to inside)
endoflagella-axial filament-cell membrane-periplasmic space
what is the cell wall made of
sugars linked by a small amino acid chain
N-acetyl-glucosamine and N-acetyl-muramic acid
whats the purpose of a cell wall
- cell shape determines growth,motility/reproduction
- restricts the transit of large molecules
- resistance to osmotic pressure
- aids in immune evasion
- assembly of proteins with various functions
whats the difference between gram positive and gram negative
gram positive has a thick peptidoglycan cell wall and a single layer underneath whereas the gram negative has a thin peptidoglycan cell wall and has two layers and has an outer lipposaccharide layer
what features do bacteria have
flagellum-to swim
fimbriae/pilus-for attachment to surfaces
what is a virus structure
it is acellular and has no metabolic capability
where does it get its energy
from harnessing the molecular machinery of the host cell
what kind of parasite is a virus
non-cellular obligate (needs a host)
how is the shape of a virus decided
by its protein caspid which also protects the genetic materials inside
what is the life cycle of a virus
adsorption-penetration-uncoating-early transcription-early translation-dna synthesis and late transcription-late translation-condensation-assembly-release
describe the process of the virus infection
first the viral capsid enters the cells nucleus and then there is synthesis of early mRNA which then synthesises proteins such as DNA polymerase. then the viral DNA and late mRNA leads to synthesis of late proteins such as capsid proteins which then enter the nucleus and the viral capsids are then released and they then invade other cells
how does fungi grow
binary fission
what is a fungal cell wall made of
chitin based- N-acetylglucosamine homopolymer
how does the fungal cell wall fold
it folds on itself enabling hydrogen bonds to form and it often binds to beta 1-3 glucan that anchors proteins
what is the fungal membrane made of
ergosterol
in what environment is it typically comfortable growing in
pH 5 , low moisture , at high osmotic pressure (lots of sugar and salt)
features of the protista/eukaryotes
unicellular eukaryotes and can ingest complex food particles through the cytostome
how do Protozoa move
amebas-move by extending cytoplasmic projections
flagellates-move by rotating whip like flagella
ciliates-move by synchronous beating of hair like cilia
sporozoa-generally non mobile
what are the stages of protozoa growth cycle
cyst-resistance stage thickened cell wall
trophozite-stage that actively feeds and multiples
flagellated-temporary non feeding stage
what is the name for parasitic worms and what are the two main categories
helminths divided into plathelminthes/flatworms (flat and have no true body cavity) and nemathelminthes/roundworms (worm like, separate sex, unsegmented roundworms)
what are the different classes of flatworms
Cestoda/tapeworms and Trematoda/flukes
what causes pityriasis/tinea versicolor
malasezia furfur, typical skin microbiota
what are the symptoms and affected areas
- scaly discoloured skin patches
- sometimes itchy
- affects the chest, back and neck
what color does gram positive and negative stain
positive-purple
negative-red
what are the stages of bacterial growth
lag phase-adaptation to new environment
log phase-adapted and optimal conditions for growth
stationary phase-nutrients become compromised and toxic waste accumulates
death phase-nutrients depleted and toxic waste leads to death
name the 5 names of bacteria in terms of their optimum temperature from lowest to highest temp
psycrophiles, psychrotrophs, mesophiles, thermophiles, hyperthermophiles
name the 5 names of bacteria in terms of their optimum pH in terms of lowest pH to highest pH
extreme acidophiles, acidophiles, neutrophiles, alkalophiles, extreme alkalophiles
what is the pH range for each category of the bacteria
extreme acidophiles- 0-2 acidophiles- 2-5 neutrophiles- 6-8 alkalophiles- 9-12 extreme alkalophiles-12-14
what are the different types of medium
general (non selective) - contains nutrients for growth of a large of bacteria
selective - contains nutrients for growth of selected organisms
differential - contains nutrients that enable growth and differentiation of various organisms
what’s the difference between microbiota and microflora
they’re the same but microflora is the old term
what’s the difference between microbiota, microbiome and metagenome
the microbiota have a taxonomic classification eg culture, biochemistry
metagenome is the collection of genomes and genes from the members of a microbiota
microbiome includes all the microorganisms, their genomes and bionic and abiotic factors- basically is the environment
how do microbiota benefit the immune system
exposure of T regulatory cells to intestinal microbes decreases the reactions to self antigens as well as non harmful pathogens
how are microbiota a source of essential nutrients
extract nutrients from undigested carbohydrates and aids in maintenance of pH
an example of healthy bacteria on the surface of our skin
staphylococcus epidermidis
which bacteria is the most common bacteria responsible for skin and soft tissue infections
staphylococcus aureus
which environment does staphylococcus grow better in
moist and higher pH
which other bacteria grow in moist conditions
corynebacteria and candida spp
which area supports anaerobic organisms on the body
the hair follicles and sebaceous glands for propionibacterium acnes
which bacteria makes up 90% of the bacteria in your mouth
streptococcus spp
what are other examples of bacteria in your mouth
gemella spp, granulicatella spp, velionella spp
whats the distribution of gram positive and gram negative between rural Africa and Europe
rural Africa has more gram positive than Europe and Europe has more gram negative than rural Africa
what is mycobiology referring to
fungi
what type of fungi is present in wet areas
candida leads to candidiasis
what type of fungi is present in dry areas
malasezzia leads to pityriasis
what type of fungi is present in dry and acidic areas
aspergillum leads to aspergillosis
which bacteria makes up most of the bacteria in the gut
bacteroidetes
which of the two bacteria do you have in the vagina( can’t be present together)
prevotella or lactobacillus
which of the two bacteria do you have on the skin ( can’t be present together )
propionibacterium or staphylococcus
which of the two bacteria can you have in your mouth ( can’t be together )
streptococcus or tanerella
what happens in GI tract disorders
the patients exhibit decreased microbial population and functional diversity which is decreases firmicutes and increased bacteroidetes
what happens in metabolic disorder
increase in firmicutes and decrease in bacteroidetes
what is dysbiosis
when there is a misbalance between the microbiota in the human gut leading to illness
what is the path to dysbiosis
commensal microbiota – changes intestinal micro biome– vulnerable to pathogens–inflammation and mucosal tissue damage– predisposes to pathologies – colonization factors ( toxins) e.g. chrones disease
what type of bacteria are proteobacteria
gram negative
what type of bacteria are firmicutes
gram postive
what group of bacteria are pseudomonas aeruginosa, escheria coli
proteobacteria
what group of bacteria are staphylococcus aureus, staphylococcus epidermidis, streptococcus oralis
firmicutes
which type of environment is propionibacterium most commonly found
sebaceous sites
what type of site is corynebacteria most commonly found
moist sites
what type of site is staphylococcus most commonly found
moist sites
what type of site is proteobaceria most commonly found
dry sites
what type of site is bacteroidetes most commonly found
dry sites
what conditions are linked to skin dysbiosis
acne, psoriasis, atopic dermatitis and rosacea
what bacteria is most likely to cause atopic dermatitis
staphylococcus
where is regIII gamma (C-type lectin) expressed
skin lesions of psoriasis
what is the function of regIII gamma
it is an antimicrobial ad regulates proliferation and differentiation of keratinocytes to promote wound healing
what type of bacteria produces regIII gamma
gram negative through peptidoglycan and flagellin
what is the relationship between antibiotic treatment and regIII gamma production
as antibiotic increases the production of regIII gamma decreases
