Mibo Quiz 1

acellular

no cytoplasm, no membrane or membrane bound organelles

antoine van leeuwenhoek

first magnifier, called single celled microbe “animalcules”

Francesco redi

spontaneous generation- food coverings

John needham

spontaneous generation- heating broth

Lazaro spallanzani

spontaneous generation- capped vs uncapped broth

Louis Pasteur

found that air/environment brings agents in, biogenesis

Kochs postulates

1. microbes present in every disease

2. microbes isolated and grown in pure culture

3. microbes cause disease in healthy host

4. microbes isolate a second time

3 domains of life

bacteria, archaea, eukarya

bacteria (cell type, # of cells, peptidoglycan)

prokaryote, unicellular, yes

archaea (cell type, # of cells, peptidoglycan)

prokaryote, unicellular, no

eukarya (cell type, # of cells, peptidoglycan)

eukaryote, uni or multi, no

unicellular eukarya

yeast

multicellular eukarya

mold

resolution

distinguish

magnification

enlarge image

contrast

difference in color intensity

bright field microscope pros

efficient, cheap, little to no training

brightfield microscope cons

can’t see virus, cells are colorless, staining kills cells, refraction (needs oil)

steps of brightfield microscope

1. light from source is focused on specimen by condenser

2. light enters objective lens (varying mag)

3. ocular lens (10x)

total magnification of brightfield microscope

ocular (10) X objective (10, 40, 100)

dark field microscope pros

can see shape, arrangement, motility, high contrast

dark field microscope cons

sensitive to light scattering, expensive, training

dark field microscope use

detection of thin/narrow cells

phase contrast microscopy

refractive differences in cell components are transformed into differences in light intensity

phase contrast microscopy use

research

phase contrast microscopy pros

high detail, 3D, grey scale, features of microbe

phase contrast microscopy cons

expensive, long training

fluorescent microscopy

fluorophore attaches to antibodies, specific components are detected

fluorescent microscopy pros

specific, clinical detection, high specificity

fluorescent microscopy cons

colos overlap, kills sample

electron microscopy pros

surface detail, high resolution, internal structures (subcellular)

electron microscopy cons

cant add color, costly and timely, kills sample

common shapes of prokaryotic cells

coccus, rob, vibrio, spirillum, spriochele, pleomorphic c

coccus

ball

bacillus

rod

vibrio

humps

spirillum

wavy

spirochele

very wavy

pleomorphic

varies in shape

mycoplasma pneumoniae cell wall

none

peptidoglycan make up

2 sugars (NAM + NAG) + amino acid + possible peptide bridge

peptidoglycan also known as

cell wall

deviants of cell wall

Archae and mycoplasma

gram positive cell wall

1 phospholipid bilayer, thick cell wall, cell wall exposed to environment

teichoic acid

acidic component in all gram positive network, sensitive to antibiotics

gram-negative cell wall

2 phospholipid bilayer, covered by outer membrane

lipopolysaccharides (LPS) in gram negative

anchors cell wall, keeps cell safe

periplasmic space

between cell wall and cell membrane

passes through cytoplasmic membrane

gas, small hydrophobic molecules, water

does not pass through cytoplasmic membrane

sugar, ion, amino acid, ATP, macromolecules

nucleoid

chromosome and gel like region

plasmids

circular, supercoiled dsDNA

ribosomones

protein synthesis in cytoplasm

prokaryotic number

70S (antibiotics target 70S)

eukaryotic number

80S

structures exterior to cell wall

glycocalyx (sugar shell)

capsule vs slime layer

capsule distinct, slime layer diffuse

bacterial endospores

dormant internal cell, created in response to stress

clostridioides difficile (c. diff)

gram positive, anaerobic, rod or drumstick

serology

antibodies that identify unique proteins or sugars are used to id an organism, rapid test in clinic

phenotypic properties

microscopic morphology,

culture characteristics,

metabolic capabilities

serology

bacterial capsules and slime layers

exterior to cell wall

glycocalyx

sugar shell

capsule vs slime layer

capsule is distinct, slime layer is diffused

endospores

dormant internal cell, react to stress response

clostridiodes difficile (c. diff) characteristics

part of normal flora in digestive tract

gram positive

anaerobic (hates oxygen)

rod or drumstick

percent of humans with c diff

7%

c. diff habitat

colon

c. diff transmission

fecal oral

c. diff role of endospores

survive stress

c. diff treatment

antibiotics

c. diff repeat

20-30% recurrent, gets worse

serrate marcescens characteristics

colonies red at 22 degrees

pseudomonas aerguinosa characteristics

green pigment

streptococcus pyogenes (strep throat)

beta-hemolytic colonies on blood agar

metabolic capabilities- catalase

positive is bubbles, negative if none

metabolic capabilities- pH changes/sugar fermentation

color change

metabolic capabilities- breakdown of urea

color changes

serology

antibodies that identify unique problems or sugars are used to id an organism

genotypic properties

identify prokaryotes, can identify nucleotide sequence unique to species or groups

nucleic acid probes

need sample of DNA or RNA,

dsDNA → denatured → probe added → see if probe binds to new DNA

pros and cons of of nucleic acid probes

pros: quick and accurate

cons: mutation, does not tell time or severity, yes or no, bigger machine

nucleic acid amplification tests (PCR)

will copy DNA

nucleic acid amplification tests (PCR) pros and cons

pros- cost effective, widely used, smaller amount

cons- mutations, must know sequence, does not tell how much

fluorescent in situ hybridization (FISH) pros and cons

pros- gives yes/no, can look for different things at once and how much

cons- large, expensive, in teaching hospitals

clostridium characteristics

anaerobic, soil inhabitants, high nutrient to germinate endospore, ferment sugar and cellulose, toxins may be medically relevant

c. botulinum habitat

deep soil

c. botulinum transmission

food contamination, food borne illness, improperly canned foods

c. botulinum endospores

stress of soil turnover

c. botulinum treatment

antitoxin

infant botulism

consumption of honey before the age 1

65% of botulism cases

genus pseudomonas

aerobic

degrade synthetic and natural compounds

opportunistic pathogen

does not usually cause disease but can come mess things up, creates biofilms

p. aeruginosa habitat

soil, water, human body

p. aeruginosa transmission

direct contact, droplets

p. aeruginosa treatment

antibiotics, disrupts biofilm

opportunistic example

p. aeruginosa

where does p. aeruginosa thrive

sticky mucus (cystic fibrosis)

p. aeruginosa creates ____

biofilms

genus streptomyces

aerobic

forms mycelium with hyphae that forms conidia (produces geosmin)

synthesize medically useful antibiotics