EXAM II MICROBIO Flashcards
1
Q
preserving bacterial cultures
A
deep freezing: helps draw cultures (-50C to -95C)
lyophilization: removes water, becomes powder form (-54C to 72C)
2
Q
Winograsky column
A
distributes microbes, preserved for years
“zones of development”
3
Q
gene sequences of ___ suggest there are more than 80 phyla
A
16 SrRNA
4
Q
4 phyla of bacteria
A
proteobacteria
actinobacteria
firmicutes
bacteroidetes
5
Q
proteobacteria
A
-gram negative stain
-diversity of form (various shapes)
-share common form of cell envelope
6
Q
5 classes of proteobacteria
A
alphaproteobacteria
betaproteobacteria
gammaproteobacteria
deltaproteobacteria
epsilonproteobacteria
7
Q
alphaproteobacteria
A
nitrogen fixing –> agricultural importance
obligate or facultative intracellular
oligotrophs: grow at low level of nutrients
8
Q
What is an illness of alphaproteobacteria
A
Rickettsia
-R. rickettsi: rocky mountain spotted fever (face rash)
infects ticks, human becomes infected after tick bite
9
Q
Betaproteobacteria
A
wide range of environments
Neisseria (gram -, coffee bean cocci) : fastidious, difficult to culture
-require moisture and CO2, grow on chocolate agar
*Gonnorhea
*Bacterial meningitis
10
Q
Gammaproteobacteria
A
largest subgroup of proteobacteria
PSEUDONOMAS:
gram negative bacillus
pyanocin: soluble green culture
aerobic
hospital acquired infections, cystic fibrosis
grow in low temp
grow on soaps, antibiotics
-anti drug resistant
11
Q
pseudonomas aeruginosa
A
aerobic, gram -, highly motile
grows in soil as decomposer
infect surgical wounds or form biofilms in CF
resistant to antibiotics and form biofilms
12
Q
Legionella pneumophila
A
related to pseudonomads
grow in warm waters
grow inside ameba and human macrophages
transmitted to humans via inhalation of aerosolized ameba with Legionella inside
13
Q
Deltaproteobacteria
A
sulfate or sulfur reducing
gram negative
Bdellovibrio: obligate aerobe, parasitic (feed on other bacteria)
Desulfovibrio: reduce sulfur, remove toxic wastes
Myxobacteria: colonies, live in soil by gliding
14
Q
Epsilonbacteria
A
slender gram negative rods, helical or curved
Campylobacter: spiral rod, microaerophilic, infect chicken, transmit to humans via uncooked chicken
Helicobacter: spiral rod, damage inner lining of stomach
motile flagella
14
Q
Gram positive is differentiated by
A
low or high G+C nucleotides in their DNA
15
Q
Firmicutes
A
form endospores ex. Clostridum, Bacillus to resist environment changes
-lactic acid
-LOW G+C
15
Q
Bacteria with gram positive cell walls
A
*firmicutes
*actinobacteria
15
Q
Bacillus
A
endospores
B. thuringiensis: insecticide
B. anthacis: anthrax
B. cerus: food poisoning
16
Q
Clostridium (forms neurotoxins)
A
obligate anaerobes
form endospores (club-shaped)
C tetani: tetanus, spastic paralysis
C botulinum: botulism, flaccid paralysis
C perfringens: has gangrene
C dificile: diarrhea, microbiota eradicated by antibiotics
17
Q
Mycoplasma (firmicutes)
A
lacks cell wall
18
Q
Actinobacteria
A
non- endospore forming
HIGH G+C
peptidoglycans in cell wall
19
Q
Listeria spp (firmicute)
A
intracellular pathogen causing diseases Gi tract and nervous system
-Listeria monocytogenes: delivery, miscarriage, stillbirth
20
Q
gram positive cocci (firmicute)
A
enterococcus
streptococcus (chains)
staphylococcus
21
Q
streptococcus
A
chains, aerotolerant
grow in O2, ferment sugar (lower pH to dimeralize)
lack ETC
oral cavity, skin, intestines
site: blood clot –> spread to other tissues
22
groups of streptococci
pyogene (strep throat)
viridans (dental carries)
23
blood agar hemolysis
destroys RBCs, complete RBC hemolysis - Beta hemolysis
- S pyogenes: strep throat
-S. agalactiae: neonatal sepsis, meningtis
23
alpha hemolysis of streptococci
incomplete hemolysis, greenish, hydrogen peroxide produced
presence of oxygen
S. pneumonae
S. mutans: causes dental caries
23
streptococcus structure
chains
24
staphyloccus
facultative anaerobe
grapelike cocci clusters
tolerate drying and high salt
nasal secretions
S. epidermis: skin scalded syndrome, bone infection
S. aureus: wound infection, antibiotic resistance, produces enterotoxin
24
enterococcus (nonspore firmicute)
fecal origin
found in intestinal tract, hands, bedding, hospitals
antibiotic resistance
E faecalis and faecium infect surgical wounds and urinary tract
vancomycin
25
Staph Aureus is resistant to
methicillium
MRSA (methillium resistant StaphA)
26
mycoplasma
pleomorphic
self- replicating
lack cell wall
M. pneumonae causes mild pneumonia
27
actinobacteria
-high G+C
-gram positive bacteria
-pleomorphic, some branching
28
actinomycetes
form mycelia with branching filaments
streptomyces
Streptomyces coelicolor: produces many antibiotics
Frankia: older trees, nitrogen-fixing
nocardia: acid fast
N. asteroides cause pulmonary infections
29
actinobacteria
mycolic acid, acid fast
dont form mycelia
Gardenella vaginalis
Corynebacterium diphterae: metachromatic granules white greyish membrane is formed blocking the air to reach lungs
DTap
Propionibacterium freduenrichii makes swiss cheese (ferm.)
cutibacterium: found in skin, acne
30
mycobacterium (actinobacteria)
high G+C
common in soils
acid fast bacilli (mycolic acids)
mycrobacterium tuberculosis
-tubercle: lumps/knots -> Grohns complex -> bacteria -> latent infection
M. leprae: PNS loss of sensitive disfigurement nodules
31
Deinococcota
-actinobacteria
-resist radiation
-unique DNA
-red or pink
32
Thermus aquaticus
hot spring in Yellowstone
source of Taq polymerase- thermotolerant enzyme used in Polymerase chain rx
33
gram negative nonproteobacteria
chlymydia
spirochetes
CFB
plantomycetes
34
chlamydias
lack cell wall but not mycoplasma
obligate parasites/ pathogens
35
life cycle of chlymadia
1. elementary body attach to host (infective, condensed DNA)
2. endocytosis
3. EB differentiates to reticulate body (cytoplasm, uncondensed- threadlike)
4.RB replicates
5.RB develop into EB
6. cell lyses - release EB
36
elementary body of chlymadia
small, dense and reisstant to drying and means of dispersal
specialized for infectious transmission
37
reticulate body of chlymadia
vegetative form, divide by binary fission
noninfectious
convert to elementary body when host cell disintegrates
38
types of chlymadia
trachomatis: blindness in humans, STD
psittaci: respiratory psittacosis (birds and humans)
pneumonae: pneumonia
39
spirochetes
twisted
spiral shaped
darkfield microscope
trepoma pallidum: syphillus
endoflagella in periplasm, outer sheath
genus Borrelia
B burgdorferi causes lyme disase
B recurrents cause Louse born relapse fever
40
CFB group
cytophaga
fuscobacterium
bacteroides
*nonproteobacteria gram negative
41
cytophaga
motile aquatic bacteria that glide (slimy substance is released)
degrade cellulose and chitin in soil
42
fuscobacteria
anaerobic
in mouth --> dental abscesses
43
bacteroides
obligate anaerobe
human colon: fermnent ingestible sugars and breakdown toxins
Bacteroides thetaiotamicron: in lumen of large intestine --degrades complex polysaccs
44
phototropic bacteria
both proteo and nonproteo
use sunlight as energy
oxygenic photosynthesis: cyanobacteria
anoxygenic photosynthesis
classified into sulfur and nonsulfur bacteria - hydrogen sulfide
45
purple and green sulfur bacteria use
reduced sulfur ie. Hydrogen sulfide and produce sulfur rather than oxygen
46
what compounds carry out anoxygenic photosynthesis
green sulfur bacteria: Chlorobi
green nonsulfur bacteria: Chloroflexi
purple sulfur and nonsulfur are proteo
47
cyanobacteriaa
oxygenic photoautotrophs
fix nitrogen
changed anoxic atmosphere -> oxygen
heterocysts - specialized cells
48
cyanobacteria bloomds
swimmers
peptide
toxins
*edible spirulina salad
49
purple sulfur bacteria
purple bc carotenoid pigments
capture light
transfer e- to bacteriochlorophyll
50
plantomycetes
gram negative, budding bacteria
cell wall resemble archae
organelle resemble eukarya
gamma obsuriglobus: membrane around DNA, resemble eukaryotic nucleus
51
Gemmata obscuriglobus
double membrane surrounding nucleoid resmbles a eukaryotic nucleus
52
enterobacteriacae (gammaproteobacteria)
enterics: intestinal tract
facultative anaerobes: motile, commensals + pathogens
flagella cell surface
53
salmonella
salmonella enterica: 3500 seratypes - serover --> salmonella externica - typhmminum - person to person via water and feces
salmonella enterica: food illness
salmonella typhi: typhoid fever (person to person)
54
Escherichia
e coli
-food contamination
-UTI
55
gammaproteobacteria
shigella
klebsiella
serratia
proteus
yestinia
erwina
56
shigella (gamma)
e. coli, shiga toxin
57
klebsiella
solid, nitogen fixing
k. pneuomnaie: causes pneumonia
58
serratia
produces red pigment
nosocominal infections- hospital acquired via catheters, saline irrigation tubes
59
proteus
swarming motility, colonies form concentric rings
-uti, kidney stones, pH alkaline
proteus mirabilis: concentric rings, have flagella in edges, center = loose flagella
60
yestinia
Y pestis causes plague
fleas
61
erwinia
plant pathogens
pectinase- hydrolyzes pectin
62
archae
pseudopeptidoglycan
five major phyla:
crenarcheota
euryaarcheota
korarcheota
nanoarcheota
thaumarcheota
63
crearcheota
aquatic organisms
aerobic: heterotroph
anaerobe: store sulfur
sulfolobus:
-thermophile, acidophile
-oxidizes sulfur; used for thermostable and acid- resistant protiens
thermoproteus:
-lipid monolayer instead if bilayer
-strictly anaerobic
-deepest branching genus of archae
-plants earliest forms of life
-reduce sulfur or hydrogen and use CO2 or CO as carbon source`
64
euryachaeota
methane producing archae
Halobacteria
-high conc of sodium chloride
-photosynthesis using bacteriorhodopsin
65
two main types of microbiota
permenant
transient: temporary -> pathogens
human microbiota: mutualistic relationship
66
mutuatlism (symbiotic)
both benefit
ex. e coli
66
amensalism
one is harmed, other is unaffected
67
commensalism
one is benefitted, other is unaffected
ex. S. epidermis (dead cells benefit) on skin
68
parasitism
one benefits, other is harmed
ex. influenza virus
69
neutralism
both are unaffected
70
acidic environment
inhibits growth of other pathogens
71
locatioons of commensal microorganisms
skin: Staph epidermis
oral cavity: no teeth - aerotolerent bacteria - streptolococcus between teeth - teeth gums - anaerobic - Streplolococci fuscobacterium
upper respiratory tract
intestines
urogenital tract: lactobacillus - vagina - glycogen and candida inhibit yeast grown in vagina
72
GI tract health is influenced by
host
genetics
diet lifestyle
73
adults (vaginal health)
lactobacillus -> lactic acid -> yeast infections
74
before puberty (vaginal health)
pH is neutral
Strapholoccus, Streptolococcus
75
vaginal birth vs cesarian birth
vaginal: lactobacillus and bacteroides
ceserean: staph aureus; nosocomial pathogens
76
eukaryotes
fungi:
-microscopic
-hyphae filament
-yeast single cell
protozoa:
-first animal
-amoeba
-paramecia -> motile
algae:
-plants
-algae: chloroplast - motile
77
fungi and microsporidians
lack motility
tough cell walls
heterotrophs
lignin
78
cilates
cilia
some are parasites
79
apicomplexans
apical complex allows attachment and penetration of host cell
80
helminths
multocellular worms
81
arthopods
multicellular insects
82
fungi
many are beneficial: recycle vital elements
decompose dead plants, recycle elements -- Saprophytic
mycorrhizae form symbiotic relationships w plants and help absorb water
penecillin: antibiotic production
food: beer, cheese
83
mycology
study of fungi
chemoheterotrophs - decompose organic matter
aerobe or facultative anaerobe
84
aerobes
use sugar to produce carbon dioxide and water
85
facultative anaerobes
ferment to produce ethanol and CO2
86
fungi vegetative structures
-fungal thalamus (body) has hyphae filaments
-septate hyphae: contain cross walls (divided but cytoplasm connected)
-coenocytic hyphase: no septa (continuous)
87
hyphae
mass of hyphae is mycelium
hyphae grow by elongating at tips
88
vegetative vs aerial hyphae
vegetative: obtain nutrients
aerial: reproduction
89
pseudohyphae
doesnt divide but invades deeper tissues
90
yeasts (fungi vegetative)
unicellular
budding: 24 daughter cells; divides unevenly - sacchomyces
fission: divide evenly - schizosacchromyces
91
dimorphic fungi
yeast at 37C
mold at 25C
92
how do fungi reproduce
sexually and asexually via spore formation that detach from parent and germinate into new mold
93
life cycle of asexual spores
mitosis and cell division
formed by hyphae of one organism
-conidospore: not enclosed in sac
-anthroconidia: fragments septate hyphae
-blastoconidia: buds of parent cell
-chlamydoconidum: spore within hyphal segment
-sporagniospore: enclosed in sac
94
life cycle of sexual spores
fusion of nuclei from 2 opposite mating strains
diploid zygote
meoisis: diploid nucleus produces haploid nuclei (sexual spores)
95
fungi environmental and nutritional adaptations
grow best at pH 5
oxic/ anoxic:
-molds: aerobic
-yeasts: facultative anaerobe
grow in high sugar and salt, resistane to osmotic pressure
grow in low moisture
require less nitrogen than bacteria
metabolize complex carbs - lignin
96
medically important fungi
mucoromycota
microsporidia
asomycota
basidomycota
97
mucoromycota
conjugation
coenocytic hyphae
produced asexually: sporangiospore
sexually: zygospere - form when nuclei of two similar cells fuse
ex. Rhizopus stolonifer - common black bread mold
98
life cycle of Rhizopus (zygomycete)
-usually asexually
asexual reproduction
aerial hypha -> sporagium->spore -> hyphae
sexual:
plasmogamy: penetrates cytoplasm
zygospore forms -> meiosis -> sporagium -> spore -> hyphae
99
microsporidia
no sexual reproduction
no mitochondria
obligate intracellular parasites
diseases --
chronic diarhea
keratoconjunctivitis
100
ascomycota
sac fungi, septate hyphae
asexual rep by budding
some are anamorphic: lose ability to sexually reproduce
-asexual production: condiospore
-sexual production: ascospore
nuclei fuse in saclike ascus
sacchromyces, candida, aspergillus
101
basidomycota
mushroom
club fungi
septate hyphae
asexually produced: condiospore
sexually produced: basidospore
-formed on base pedestal called basidium
genera: amanita, agarius
amanita: highly poisonous
human fungal pathogen: crypotococcus
102
mycosis
fungal infection
chronic, slow growing
103
5 types of mycoses
systemic: deep within body
-soil -> inhaled -> lungs -> different tissues of organs
subcutaneous: beneath skin
superficial: localized (hair shaft)
oppurtunistic: fungi harmless in normal habitat but pathogenic in compromised host
104
cutaneous mycroses
affects hair, skin, nails
aka "dermatomycoses"
trichophyton: infect hair, skin, nails
microsporum: only hair or skin
epidermophyton: skin and nails only
105
subcutaneous mycroses
penetrate statum corneum
caused by soil fungi
wound -> spore
sporotrichosis enters wound, forms ulcer
106
histoplasmosis
dimorphic fungus
grows intracellularly in macrophages
negative tuberchlosis skin test
acquired from airbone condia in areas with bird or bat droppings - lower body temp - shed in feces
107
cocidiomycosis
valley fever
caused by coccidiodes immitis - dimorphic fungus
form a sphreule filled with endospores in tissues
fever, coughing, weight loss
resemble tuberchlosis
108
blastomyosis
caused by blastomyces dermatidis
-dimorphic fungus
-grows in soil
symptoms resemble bacterial pneumonia - cutaneous abcess, extemsive tissue damage
109
pneuomocystis pneumonia (PCP)
yeast like fungus
asymptomatic in immunocompetent causes pneumonia in immunocompromised
*indicates AIDS
-found in alveoli lining
-forms cysts
-cysts rupture, releasing 8 trophozoites
110
candidiasis
C. albicans
-forms pseudohyphae making it -resistant to phagocytosis (invade deeper tissues)
-mucous membranes and genitoruinary tract
trush = infection of oral cavity
results when antibiotics supress competing bacteria or changes in mucosal pH
111
glycogen increases
increases pathogens
112
Cryptococcosis
soil fungi
pigeon and chicken dropings
transmitted through respiratory route
immunocompromised: meningitis
*phagocytosis
113
aspergillas fumigatas
causes aspergillosis
airbone conidia - decaying vegetation
114
rhizopur and mucor
mold spores
predisposing factors - cancer, diabetes, immunocompromised state
115
mycotoxins
toxins produced by fungi
-blood diseases
-nervous system disorders
-kidney damage
-liver damage
-cancer
116
ergot poisoning
myxotoxins produced by Claviceps purpurea
-occurs in rye grains
-restricts blood flow (gangrene) and causes hallucinations
117
aflatoxin poisoning
mycotoxins produced by aspergillus flavus
-causes liver cirrhosis and liver cancer
118
aspergillus niger (fungi)
produces citric acid
119
aspergillus terreaus
statins inhibit cholestrol synthesis
120
saccharomyces cerevisae
bread, wine, hepatitis B vaccine
121
trichoderma
cellulase
degrades outer covering of fruit
122
taxomyces
taxol: anti-cancer drug
123
coniothyrium minitans
kills fungi on crops
biological pesticide
124
lichens
controlled parasitism
mutualism of green algae and fungus
3 categories:
crustose - encrusted on substratum
foliose- leaflike
fructicose - fingerlike
125
thalus (body) of lichens is made of
medulla - hyphae grown around algal cells
rhizines- hyphae below body
cortex- protective coating over algal layer
126
lichens first colonize on
rock or soil
-indicates air pollution
-superoxide
-differentiated based on morphology
127
alga produce and secrete
carbohydrates
fungus provides holdfast
128
importance of lichens
dyes - litmus, eryhtrolcetin - pH
antimicrobial - usnic acid
litmus
food for herbivores
129
algae
aquatic: nutrient reproduction
or phototrophic
unicellular or filamentous photoautotrophs
lack roots stems and leaves
mostly aquatic
130
characteristics of algae
location depend on nutrient availability, light wavelengths and surfaces to attach
pnemocyst: floating gas filled bladder
-have sexual and asexual reproduction
mostly photosynthetic, chrolorophyll
oomycotes: chemoheterotrophic
-fungus like algae, plant parasites, potatoes, soybeans
131
brown algae (kelp)
cellulose and alganic acid cellwalls
produce algin - thickener used in foods
132
red algae
multicellular
live in greater depths
harvested for agar and carrageenan
133
green algae
cellulose cell walls
unicellular or multicellular
store starch
chlorophyll a and b
134
diatoms
pectin and silica cell walls
unicellular or filamentous
produce domoic acid (cause neurological disease)
store energy
135
dinoflagellates
cellulose in plasma membrane
unicellular
plankton
neurotoxin (saxitoxin) cause paralytic shellfish poisoning
Pfiesteria piscicida: massive fish kills
136
roles of algae in nature
fix co2 into organic molecules
produce O2
algal blooms: increases in planktonic algae that result in toxin release or die and consume oxygen
oil production
symbioants of animals
137
protozoa
unicellular eukaryotes
plasmodium: cause malaria
trophozoite: feeding and growing form
138
life cycle of protozoa
asexual rep. = fission, budding, Schizogony (multiple fission)
sexual rep. = conjugation
some produce cyst (apicomplexan) to survive adverse conditions
139
characteristics of protozoa
require lots of water
outer protective pellicle
cillates wave cilia toward mouthlike cytosome
amebae phagocytyze food via lobes
food is digested: vaccule
wasted eliminated: anal pore
140
medically important protozoa
feeding groves (excavata)
-move by flagella
-Displomoands and Parabasalids lack mitochondria
-Euglenozoa (trypanosoma) blood parasites
Amoebozoa: move by pseudopods
Apicomplexa: nonmotile, obligate
Cilates: cilia
T.brucei: african sleeping sickness
T. cruzi: kissing bug - Chagas disease
141
conjugation
ciliate undergoes it
ex. paramecium
micronucleus (2n): reproduction
macronucleus: replication
142
diplomonad
no mitochondria, multiple flagella
143
parabasalid
no cyst stage
144
euglenozoa
photoautotroph or facultative chemotroph
-Hemoflagellates: transmitted by bites of blood feeding insects
145
Giardiasis
Giadia duodenalis
-flagellated protozoa
-forms cysts in feces
-trophozites in body
attaches to intestinal wall - malabsorption
-*diarrhea
-hydrogen sulfide in stools
resist chlorination: filtering/boiling
146
trichomoniasis
caused by Trichomonas vaginalis
grows when normal acidity of vagina is disturbed
147
Chagas disease
caused by Typanosoma cruzi
-flagellated protozoa
-reservoir in rodens, opposum, armadillos
vector: reduviid bug (kidding bug)
-defecates trypanosomes into bite wound
-fever, swollen gland
heart damage, megaesophagus, megacolon
bug - trypansoma - grows in gut - bite - wound - defecates
148
amebae
move by extending pseudopods
149
type of amebae
entamoeba histolyca: free living in water; causes amebic dysetnery
acanthamoeba: infect cornea, cause blindness, encepthelitis
balamuthia: free living, immunocompromised, amebic encephalitis
150
amebiasis cycle
1. cysts and trophozites passed in feces
forms: cyst
diarrhea: trophozoite
151
apicomplexa
obligate
apical complex(enzyme): parasite -> host cell
complex life cycle:
-malaria
-cryptosporidium: feces, waterborne illness
152
vectors are either
biological: sexual cycles, anthropod vector
mechanical: feet, body parts
153
hosts
definitive: sexually mature form of parasite
intermediate host: larval or asexual stage of helminth or protozoan
reservoir host: continual source of infection
vector: anthropod that carries disease causing organism from host to host
154
plasmodium (apixomplexa)
causes malaria
sexually reproduces in Anopheles mosquito
mosquito injects sporazoite which undergoes schizogony in liver
merozoites are produced
155
sporazoite undergoes
schizogony in liver; producing merozoitesm
156
merozoites
infect RBCs, form ring stage
when RBC ruptures, merozoites infect new RBCs
-toxic --> fevers, chills
157
plasmodium vivax
prevalent, widespread
vector: mosquitos resulting in sexual (definitive) and asexual (intermediate) rep.
158
ciliates
Balantidium coli
-human parasite
-dysentry
159
slime molds
plasmodium
cellular: look like fungi - floating bodies --> spores for dispersal
as a protist, motile over solid surface; decayed veg., bacteria
-phagocytosis; ingest fungi and bacteria
160
life cycle of cellular slime mold
ameoba reproduces
depletion of nutrients so cAMP signal goes off - dont duse, loose individually
ameba aggregate
stationary
cells differentiate
forms cellulose
spore is released
161
plasmodial slime molds
mass of protoplasm with multiple nuclei, moves as giant amoeba
cytoplasmic streaming: protoplasm moves and changes speed and direction to distribute oxygen and nutrients
162
helminths
free living
parasitic worms
two phyla:
Platyhelminths (flatworms)
Nematoda (roundworms)
163
characteristics of helminths
multicellular
live in host
lack digestive system - absorb nutrients from host
reduced nervous system
reduced/ lacking locomotion: transferred from host to host with no specific habitat
complex reproductive system
164
life cycle of helminths
dioecious: seperate male and female
monoecious (hermaphroditic): male and female reproductive systems in one
egg -> larvae -> adult
larvae: intermediate host
adult: definitive host
165
platyhelminth
trematodes (flukes)
-flat, leaf shaped
-ventral and oral sucker
-absorb food through cuticle
Paragonimus spp = lung fluke; get it by eating raw crawfish
Schistosoma = blood fluke
166
cestodes (tapeworm)
type of platyhelminth
-scolex: head that has sucker for attachment
-absorb food via cuticle
proglottids: body segments; contain both male and female reproductive organs
167
cestodes
humans: definitive host
eggs from proglottids are ingested
hatch into larvae
bore into intestinal wall
-produce cysticerci
Taenia solium: pork tapeworm
168
larvae of cestodes migrate to
lungs or liver
-develop hydratid cyst
Echinococcus granulosus:
dogs: definitive host
169
nematodes
roundworms
cylindrical
complete digestive system
dioecious: males contain spircules
free living and parasitic
170
nematodes
eggs infective for humans
171
ascaris lumbricode (nematode)
infects human intestine
172
baylisascaris procyonis
racoon roundworm
racoon: definitive host
173
trichuris thriciura
whipworm
spreads person to person by fecal-oral transmission, poor sanitation
174
enterobius vermicularis
pinworm
self-innoculation
contaminated clothing or bedding
175
strongyloides
re-emerging infection
abdominal pain
lungs cough
176
necator americanus and ancylosoma duodenale
hookworms
enter skin
carried to intestines
177
dirofilaria immitis
spread by mosquitoes
causes heartworm
adult stage is in the animals host
causes CHF
178
anthropods
animals with segmented bodies, hard extenral skelatons, jointed legs
vectors- carry pathogenic microorganisms
179
classes of anthropods
arachnida - 8 legged
crustacea - 4 antennae
insecta - 6 legged
180
anthropods as vectors
-mechanical transmission
-biological transmission: pathogen multiplies in vector
-definitive host: microbe's sexual reproduction occur in vector
181
scabies
caused by Sarcoptes scabiei mites
-burrow in skin to lay legs
human itch - skin - burrow - lay egg - hatch larvae - hair follicle - feeding - itching - scabs
182
lyme disease
Borreliela burgdorferi
-dont burrow as much as mice
-field mice are the most common reservoir
nymphal stage of lxodes tick feed on mice and infects humans
tick feed on mice carrying spirochete - digestive tract - salivary gland - host
183
spirochetes
ticks carry it and feed on deer
184
bedbugs
cimex lectularius
detect host from CO2
suck hosts blood and lay eggs
185
viruses are
obligatory intracellular parasites
acellular
need a host
contain DNA or RNA
protien coat
multiply within living host cell
no ribosome or ATP
186
host range of viruses
spectrum of host cells a virus can infect
tissue tropism
determubed by specific host attachment sites and cellular factors
187
bacteriophage
viruses that infect bacteria
188
virus structure
virion: complete, fully developed viral particle
nucleic acid DNA or RNA can be single or double-stranded; linear or circular
capsid - protien coat made of capsomeres (subunits)
envelope - lipid, protien and carb coating
spikes - projections from outer surface
189
nucleic acid
nucleic acid is linear or circular or segmented (influenza virus)
190
envelope
partially formed from plasma membrane of host cell when virus buds from cell
191
spikes
found on some enveloped viruses
-made of carbs and protien
-may be used for attachment
192
helical virus
hollow, cylindrical capsid that is helical
ex. rabies, ebola
193
polyhedral virus
many sided
icosahedron
ex. adenovirus, poliovirus
194
enveloped virus
roughly spherical
195
complex virus
complicated structures
ex. bacteriophage
196
taxonomy of virus
baltimore classification system: based on virus' nucleic acid and how its mRNA is produced
genus names end in -virus
family names end in -viridae
order names end in -ales
197
bacteriophages form
plaques
-clearing on a lawn of bacteria on the surface of agar
198
plaque forming unit (PFU)
each plaque corresponds to a single virus
199
growing animal viruses in living animals
mice, rabbits, guineas
some human viruses cant be grown in animals
200
growing animal viruses in embroyonated eggs
virus injected into egg
viral growth signaled by changes or death of embryo
used to grow viruses for vaccines
201
growing animal viruses in cell culture
-tissues are treated with enzymes to separate cells
-viruses infecting monolayer are detected via changes in monolayer cells aka cytopathic effect (CPE)
202
cell cultures
use diploid cell lines
-derived from human embroyos
-used for rabies virus for vaccine
203
continuous cell lines
from transformed (cancerous) cells
ex. HeLa cell line: isolated form of cancer of a woman
204
ELISA
virus is detected and identified by its reaction with antibodies
205
viral multiplication
invade host cell and take over its metabolic machinery
single virion can give to several of similar viruses in a single host cell
eclipse period: latent period
virions then released from host cell - burst
206
bacteriophages can multiply via
lytic cycle: phage causes lysis and death of host ex. Tequatrovirus (T even) that infect e. coli
lysogenic cycle: phage DNA incorporated in the host DNA
-phage conversion
-specialized transduction
207
T even bacteriophages lytic cycle
attachment: phage attaches to host cell
penetration: phage lysozome opens cell wall
biosynthesis: produces phage DNA and protiens; host cell protien synthesis is halted
maturation: viral components are assembled into virions
release: host cell lyses, new virions are released, lysozomes
208
bacteriophage Lambdavirus
lambda virus can initiate lytic or lysogenic cycle
lysogeny: phage remains latent
-no lysis of host
phage DNA incorporates into host cell DNA
-inserted DNA is known as prophage
209
malaria
mosquito borne disease caused by a parasite
-caused by several protozoan parasites in genus Plasmodium
P vivax is the most widespread
P falciparum is most serious
210
plasmodium
infect RBCs and transmit via Anopheles mosquitos
211
malaria diagnosis
plasmodium infected erythrocytes in blood smears
antigen detection
PCR: parasite nucleic acids detected
serology: detects antibodies against malaria parasites
212
prevention of malaria
prevent mosquito bites
use bug spray
deep windows or doors closed
empty standing water to prevent them from laying eggs
213
coronavirus
genus: beta coronavirus
-enveloped, spherical or pleomorphic single stranded plus RNA viruses
-contain club shaped glycoprotien spikes on surface
-crown
-bind to ACE2 cell receptors (angiotensin converting enzyme 2)
214
diagnosis of COVID
viral tests
- PCR
-Antigen tests (rapid test)
215
prevention of COVID
isolation
improve ventilation
wear mask or respirator around others
OTC to mild symptoms of fevers
216
three outcomes of lysogeny
1. lysogenic host cells are immune to reinfection by the same phage
2. phage conversion - host cell exhibits new properties, encoded by prophage DNA ex. production of diphtheria toxin
3. specialized transduction - specific genes transferred to another bacterium via phage
217
multiplication of animal viruses
attachment
entry via receptor mediated endocytosis or fusion
uncoating (seperating viral NA from capsid) by viral or host enzymes
biosynthesis: production of NA and protiens
maturation: nucleic acid and capsid protiens assemble
release by budding (enveloped) or rupture (nonenveloped)
218
biosynthesis of dna viruses
-DNA replicate in nucleus of host
synthesize capsid proteins in cytoplasm using host cell enzymes
capsid proteins migrate to nucleus where assembly occurs`
219
poxviridae
double stranded DNA
enveloped
cause skin lesions: small pox virus and M pox virus
assembly occurs in cytoplasm
220
herpesviridae
double stranded dna, enveloped
221
HHV1 and HHV2
simplexvirus; cold sores
-genital herpes
222
HHV3
varicellovirus
-chicken pox
223
HHV4
lymphocryptovirus
-causes mono
224
HHV5
cytomeglavoris
225
HHV6 and HHV7
roselovirus
226
HHV8
Rhadinovirus
HIV and AIDs
227
hepadnaviridae
double stranded, enveloped
hepatitis B virus
uses reverse transcriptase to make DNA from RNA
228
biosynthesis of RNA virus
virus multiply in host cell's cytoplasm using RNA dependent RNA polymerase
229
ssRNA (+) sense strand
viral RNA serves as mRNA for protien synthesis
230
ssRNA (-) sense strand
viral RNA is transcribed to a + stramd to serve as mRNA for protien synthesis
231
coronaviridae
single-stranded RNA, + strand, enveloped
-assembly involves ER and Golgi of host cell
232
RNA virus with mRNA
viral DNA is produced
DNA dependent RNA polymerase - catalyzes 2nd strand of RNA complimentary + strand infects the cell
233
positive sense
viral mRNA -> synthesis -> stop host translation using RNA dependent RNA polymerase
234
Rhabdoviridae
single stranded RNA
- strand
Lyssavirus: rabies
235
Reoviridae
double stranded RNA, nonenveloped
reovirus: respiratory enteric orphan
rotavirus: mild respiratory infections and gastrocenteritis
236
Reverse transcriptase
single stranded RNA -> DNA
viral DNA integrates into host chromosome as provirus
237
Retroviridae
lentivirus: HIV
oncovirus
238
Baltimore Scheme DNA viruses
relationship of genome to mRNA
Class I: double stranded DNA
Class II: single stranded positive or plus strand DNA
needs replicative form: dsDNA intermediate
239
Baltimore Scheme RNA viruses
cellular RNA polymerase need DNA template
-RNA viruses must carry in virion or encode in genome RNA replicase (RNA dependent RNA poly.)
240
Class IV (RNA)
ss+ RNA viruses, genome is mRNA
241
Class V (RNA)
ss-, RNA virus
must carry in virion or encode in genome RNA replicase (RNA dependent RNA poly.)
242
Class III (RNA)
dsRNA similar replication as class V
243
Class VI (RNA)
retroviruses
ss+
replicate via DNA intermediate
reverse transcription copies RNA into DNA catalyzed by reverse transcriptase
ex. HIV
244
Class VII
dsDNA that replicates through RNA intermediate
ex. hepatitis B
-uses reverse transcriptase
245
RNA viruses release via
budding
rupture (nonbudding) kills host
envelopes --> coronavirus translate in ER and fuses w Golgi
246
sarcoma
cancer of connective tissue
247
adenocarcinoma
cancer of glandular epithelial tissue
248
proto-oncogenes
genes that encode proteins involved in stimulating normal cell growth
mutated proto-oncogenes become oncogenes
249
oncogenes
transform normal cells into cancerous cells
250
transformation
cells acquire distinct properties leading to cancer
251
oncogenic virus
become integrated into host cell's DNA and induce tumors
252
transformed cell harbors a
tumor specific transplantation antigen (TSTA) on surface and are irregularly shaped
253
DNA oncogenic viruses
adenoviridae
herpesviridae: Epstein Barr virus (Burkitts Lymphona)
poxviridae
papovaviridae: HPV
hepadnaviridae: hepatitis B virus
254
retroviridae
viral RNA transcribed to DNA using reverse transcriptase which can integrate into host DNA
HTLV1 and HTLV2 cause adult T cell leukemia and lymphoma
FeLV: feline leukemia virus
255
latent virus
remains in asymptomatic host cells for long periods
-all herpesvirus are capable for latency
-reactivates due to changes in immunity
-HHV1: cold sores
Varicellovirus: shingles, chicken pox`
256
persistent viral infection
occurs gradually over a long period
257
dormancy
viruses dont cause symptoms of disease and are difficult to detect
258
chickenpox
virus moves to dorsal root ganglion where it remains latent
259
shingles
in adulthood, immune system depression can retrigger Herpes varicella- zoster
260
plant virus
replicate in insects via wound -> changes -> color stunted growth
enter through wounds or via insects
261
viroids
short pieces of naked RNA
no protien coat
cause potato spindle tuber disease
262
virusoids
viroids enclosed in a protein coat
Hepatitis D
coinfection of Hep. B
263
prions
doesnt kill by cooking
inherited and transmitted by ingestion
hereditary -> PcP gene - human to human
Kuru: infected tissues fed to family member
264
Spongiform encephalopathies
mad cow diease - meat
Credutzfeldt Jakob disease: neurodegenerative
Gerstmann Straussler Scheinker: neurodegenerative
Fatal familial insomnia: PRP gene
Shreep scrapie
265
PrPc
normal cellular prion protien on cell surface
266
PrPSc
scrapie protien
accumulates in brain cells forming plaques
267
prion disease is caused by
normal host glycoprotien PrPc into misfolded PrPsc
268
DNA
genetic blueprint
269
RNA
transcription product
270
messenger RNA is translated into
protien (amino acid sequence)
271
Nucleotides
DNA and RNA are polynucleotides
3 components: pentose sugar (ribose or deoxyribose), nitrogenous base, phosphatep
272
purines
A,G
in both RNA and DNA
273
pyrimidine
C, U, T
C: both
U: only RNA
T: only DNA
274
nucleoside
has pentose sugar and nitrogenase base, no phosphate
275
vertical gene transfer
flow of genetic info from one generation to the next
276
leading strand
5' to 3'
277
lagging strand
3' to 5'
278
start codon
translation begins with AUG, encodes N-formylmethionine in bacteria and methionine in archae and eukarya
279
shine delgardo sequence
ribosome binding site (RBS)
ensures proper reading frame in bacteria
280
stop (nonsense) codon
terminate translation
UAA, UAG, UGA
281
open reading frame
AUG followed by number of codons and a stop codon
282
translation
in bacteria, can begin before transcription is complete
283
transcription in eukaryotes
transcription occurs in nucleus
translation occurs in cytoplasm
exons: DNA region that codes for protien
introns: DNA region that does NOT code for protien
284
small nuclear ribonucleoprotiens (snRNPs)
remove introns and splice exons together
285
wild type strain
isolated from nature
286
mutant
cell or virus from wild type that carried a nucleotide sequence (genotype) change
287
genotype
designated by three lower case letters
-His C involved in histidine biosynthesis
mutations designated his C1
288
phenotype designated by
capital letter and two lowercase letters then +/-
ex. His+ makes histidine
289
gene expression is regulated by
temperature
290
mutation
permanent change in base sequence of DNA
-neutral, beneficial or harmful
mutagens: agents that cause mutations
spontaneous mutations: occur in absence of mutagen
291
missense mutation
base substitution results in change in AA
292
nonsense mutation
base sub results in nonsense (stop) codon
293
frameshift mutation
insertion or deletion of 1 or more nucleotide pairs
-shifts translational "reading frame"
causes changes in AA downstream from site of the original mutation
294
chemical mutagens
nitrous acid: causes A to bind with C instead of a T
nucleoside analog: similar to normal nitrogenous bases but incorporate into DNA in place of a normal base and cause mistakes in base pairing
frameshift mutagen: chemicals that cause small deletions or insertions resulting in frameshifts
295
radiation
ionizing radiation (xrays and gamma rays) causes formation of ions that oxidize nucleotides and break deoxyribose phosphate backbone
296
UV radiation causes
thymine dimers which prevent proper replication and transcription of DNA
297
bacteria can repair UV induced damage
photolyase (light repair enzyme): use light to seperate thymine dimers
nucleotide excision repair: enzymes cut out incorrect bases and fill in correct bases
298
Mutagenesis
SOS repair
-coordinated cellular responses can introduce mutations to save the cell
299
mutations are heritable
if damage can be corrected before cell division, no mutation occurs
300
what activates SOS repair in bacteria?
major DNA damage
initiates many DNA repair processes
allows DNA repair to occur without template resulting in errors and mutations
301
constitutive genes
-expressed at fixed rate
-always turned on
-other genes are expressed only as needed
302
repression
inhibits gene expression, decreases enzyme synthesis
-default: ON but needs substrate to turn it off
303
Induction
turns on gene expression
-default: OFF but needs to turn it on
304
negative control of transcription
prevents transcription
305
promoter
segment of DNA where RNA poly initiates transcription of structural genes
306
operator
segment of DNA that controls transcription of structural genes
307
operon
set of operator and promoter sites and the structural genes they control
308
inducible operson
must be turned on
structural genes are not transcribed unless an inducer is present
309
lac operon of E. coli
3 enzymes encoded by lac operon needed to metabolize lactose
-structural genes for Z,Y,A enzymes are adjecent and transcripton is regulated together
310
control region includes
promoter: where transcription begins
operator: stop or go signal
311
lactose present
lac repressor is released from operator, transcription occurs
312
lactose absent
lac repressor binds to operator, transcription is blocked
313
positive regulation
regulator protein facilitates transcription
catabolite repression inhibits cells from using carbon sources other than glucose to help digest lactose
cAMP builds up when theres no glucose
314
cAMP
alarmone - chemical that promotes cell's response to environmental stress
binds to catabolic activator protien (CAP) that binds the lac promoter initiating transcription and allows cell to use lactose
315
riboswich
mRNA molecule that binds to a substrate and changes in the mRNA structure
-translation is initiated or stopped
316
microRNAs (miRNA)
base pair with mRNA to make it double-stranded
double stranded RNA is enzymatically destroyed, preventing production of a protien
317
genetic recombination
exhange of genes between two DNA molecules to form new combinations of genes
*genetic diversity
318
vertical gene transfer
cell -> offspring
319
horizontal gene transfer
cell - cell (same generation)
part of donor DNA is incorporated into recipient DNA (recombinant)
320
plasmids and transposons
genetic elements outside chromosomes
mobile genetic elements: move from one chromosome to another or from one cell to another
321
plasmids
self-replicating circular pieces of DNA
toxin production
322
conjugative plasmid
carries genes for sex pilli and transer of the plasmid
323
dissimilation plasmid
encode enzymes for catabolism of unusual compounds
324
resistant factors (R factor)
encode antibiotic resistance, sometimes to multiple different antibiotics
-some can be transferred horizontally
325
transposon
segments of DNA that can move from one DNA region to another
contain insertion sequences that code for transposase that cuts and reseals DNA
may inactivate genes if they insert within genes
326
complex transposon
carry other genes ex. in antibiotic resistance, enterotoxin production
327
transformation
genes transferred from one bacterium to another as naked DNA
328
conjugation
plasmids transferred from one bacterium to another through cell to cell contact
gram negative: attachment and transfer via sex pili
gram positive: sticky substance holds cells together
329
cells must be
opposite mating types
-donor: conjugative plasmid
-recipient: lacks conjugative plasmid
330
conjugation in e coli requires
F factor (fertility factor)
331
when an F factor is transferred from donor (F+) to recipient (F-)
F- cell converts to F+ cell
332
when an F factor is integrated into F+ cell
high frequency of recombination (Hfr) cell
333
when a Hfr donor passes its chromosome into a F- recipient
a recombinant F- cell results
334
donor cells carry
plasmid F factor = F+ cells
335
when conjugating, the recipient F- becomes
F+
when it recieves plasmid
336
High frequency recombinant cells
contain F factor integrated into chromosome
-Hfr cells transfer chromosinal genes as well as part of F factor
-recipient does not become F+ since it doesnt receive entire F factor
337
conjugation can be used to
map the location of genes on a chromosome
338
generalized trasduction
random bacterial DNA packaged in a phage and transferred to a recipient cell
339
specialized transduction
specific bacterial genes packaged inside a phage and transferred to a recipient cells
340
sensing and signal transduction
two-component regulatory systems
prokarya regulate cellular metabolism in response to environmental fluctuations
-external signal: transmitted directly to target
-external signals may be detected by sensor and transmitted to regulatory machinary (signal transduction)
341
sensor kinase
in cytoplasmic membrane
-detects environmental signal and autophosphorylates at specific histidine residue (histidine kinase)
342
response regulator
in cytoplasm
DNA binding protien that regulates transcription, recieves phosphate from sensor kinase
343
two point regulatory systems have
feedback loop
-terminates response
-uses phosphotase that removes phosphate from response regulator
