Review 1.1 Flashcards
Yeasts
single cells
colonies in culture.
creamy, mucoid.
facultative anaerobes
molds
multicellular, filamentous.
colonies in culture
fuzzy, velvety. obligate aerobes!!
Hyphae
threadlike filaments, main mode of growth
mycelium
hyphae interweave
pseudohyphae
not true hyphae, candida has both.
fungal cell wall
contains ergosterol, target of Azoles.
14a-demethylase
synthesizes ergosterol
1-3 b-D-glucan synthase
involved in the generation of beta-glucan in fungi.
It serves as a target for antifungal drugs
Mannan
a linear polymer of the sugar mannose, cell wall polysaccharide found in yeasts.
Candida Albicans
part of normal flora
found in skin, mouth, RT, bowel, vagina
Common infections:
thrush, vaginitis, balanitis, diaper rash, esophagitis, intra-abdominal abscesses, blood stream
pathogenic fungi
coccidiodes immitis/posadasii- dimorph
candida- opportunistic
Rhizopus- opportunistic
Dimorphic fungi
geographically restricted
Mold @ 25-30 degrees
Yeast @ 35-37 degrees
Virus definition
Little (20-300nM)
cannot replicate on their own- obligate intracellular
composed of nucleic acids and proteins, can have envelope.
No organelles
Prolific replication, many progeny at a time.
Tegument
a cluster of proteins that lines the space between the envelope and nucleocapsid of all herpesviruses. The tegument generally contains proteins that aid in viral DNA replication and evasion of the immune response
capsid
Protein shell, encloses the genetic material of the virus.
Oncogenic Viruses
HPV- cervical EBV- Lymphoma, nasopharyngeal KSHV- Kaposi's, lymphoma Hep B and c- hepatocellular HTLV-1- t-cell lymphoma
p53
the guardian of genome: prevents transmission of DNA mutations.
causes cell to stop growing, or apoptose.
Mutated in disease.
Rb
Retinoblastoma protein
prevents cell cycle progression
helps control normal cell division
Bacterial Cell wall
maintains cell shape,controls influx and eflux, protects against osmotic lysis.
Site for:
Respiratory chains, secretion systems, adhesins.
contains ligands for
G+
peptidoglycan, stains purple
G-
LPS, stains pink.
how are pathogens sserotyped?
Cell wall
O antigen
outermost polysaccharide
differences between bacteria and host
single, circular chromosome
no nucleus, organelles
cell wall components
70S ribosomes
metabolism and replication
mycobacteria
bacilli, obligate aerobes
high lipid content in wall,
MYCOLIC ACID- waxy coat
AFB
Acid fast bacilli
binds carbol fuchsin dye
acid fastness
resistance to decolorization by acid
MTB
tuberculosis, inhaled, persists in lymph nodes
primary lesion TB
foamy giant cells form caseous core that inhibits bacterial growth.
Latent TB
when TB persists in affected tisues, and lesion free tissues.
reactivated TB
cavitating lesion, when immunosuppressed, HIV or smoking.
very small minority, 5-10%, of people get activation.
ghon complex
calcified focus of infection and associate lymphnode
mycobacteria species
M. tuberculosis
M. avium-intracellulare
M. kansasii
rapid growers
M. leprae
viral replication
can have ssDNA, ssRNA, or ds either.
DNA viruses
if replication occurs in nucleus, they can use cellular RNA pol to make mRNA
dsDNA viruses
can use either cellular DNApol or make their own.
ssDNA viruses
have to first replicate their DNA using cellular DNApol
Poxviruses
if replication occurs in cyto, they bring their own machinery.
+ strand viruses
can make protein directly from their genome. acts as mRNA
- strand viruses
must make their own RNA-dependent RNA pol to make RNA
Retroviruses
must reverse transcribe their DNA and use cellular RNA pol
how are live attenuated vaccines generated?
genetic reassortment, make new virus that doesnt cause disease.
what surrounds the viral tegument?
envelope
what is the viral capsid made of?
protein
how do viruses infect a host cell?
bind to target cell endocytosis fusion, release of genetic material. replication- protein synth assembly budding release
Virion RTase
reverse transcriptase- brought along, with virus
AKA RdDp- RNA dependent DNA pol
Virion RdRp
RNA dependent RNApol, included in virus
Antigenic drift
slow, by point mutations. Leads to gradual small changes in antigen that can have a clinical significance
antigenic shift
more drastic, sudden change in genome.
**Two viruses one host!
Latent cycle
the virus exists as a circle (plasmid) in the nucleus and is replicated passively by the host DNA replication machinery –important for understanding drug sensitivity.
Latent transcription is restricted and has relevance for persistence and transformation
Lytic cycle
When reactivated, linear genomes are produced by a rolling circle mechanism
Viral transcription and DNA replication occurs in the nucleus; the particle assembles and exits from epithelial cells in the skin causing a primary infection.
where does herpes remain latent?
epithelial cells and neurons
as well as VZV
CMV latency locations
ductal epithelium and leukocytes
EBV latency locations
oropharyngeal epithelium and B lymphos
KSHV latency locations
Endothelium and B lymphos
antigenic variation
type of a phase variation, where an organism can change the antigen it expresses to evade host immune cells.
HGT
horizontal gene transfer
intergenic recombination, transformation, plasmid, exogenous DNA, conjugation, transposon, transduction, phage
Bacterial transformation
cell donates DNA to another, recipient incorporates it into genome
bacterial transduction
cell releases phage which infects recipient cell with genetic material, which is incorporated into genome.
bacterial conjugation
sex
transposon is incorporated into plasmid then shared. incorporated into other cell genome.
gram stain sequence and colors
- crystal violet- purple for G+
- iodine
- alcohol
- safranin. -pink for G-
G+ bacteria from lab
Staph, strep, bacillus, c. diptheroids, candida*
G- bacteria from lab
Neisseria, pseudomonas, E. coli, haemophilus
staph growth on media
white, large, beta hemolytic on blood
grows on chocolate and colistin naladixic acid
colistin naladixic acid
selects for G+ bacteria
MacConkey agar
selects for G-, but also lactose differential.
pink- lactose fermentor
yellow- non lactate fermentor
pseudomonas growth on media
grows on blood, beta hemolytic, grows on chocolate, grows on MAC, yellow- non lactose.
e. coli growth on media
grows on sheep and chocolate and MAC, beta hemolytic, , pink on mac= lactose fermentor
haemophilus
only grown on chocolate!!!!!!!!!!!!
fastidious.
Beta hemolysis
complete hemolysis, is a complete lysis of red cells in the media around and under the colonies: the area appears lightened (yellow) and transparent
alpha hemolysis
This is sometimes called green hemolysis because of the color change in the agar. Other synonymous terms are incomplete hemolysis and partial hemolysis.
protozoa
euks, harder to target since they are similar to us.
life cycles, clinincal manifestation, geography.
acanthamoeba sp.
Acanthamoeba is able to form metabolically inactive cysts which are resistant to fluctuations in temperature and pH levels.
Cysts are also resistant to attack by the host immune system and facilitate the recurrence of infection.
G: Most species are free-living bacterivores, but some are opportunists that can cause infections in humans and other animals.
found in fresh water.
leishmania donovani
It is a human blood parasite responsible for visceral leishmaniasis or kala-azar, the most severe form of leishmaniasis.
M: It infects the mononuclear phagocyte system inhibiting oxidative burst. Infection is transmitted by a species of sandfly
LC: Leishmania donovani is a digenetic parasite passing its life cycle in two different hosts.
most common amoeba
naegleria fowleri
free-living, thermophilic excavate form of protist typically found in warm bodies of fresh water.
LC: cyst, trophozoite, flagellate.
infects nervous system»> death!
taxoplasma gondii
come from cat poop.
cyst, trophozoite.
invades macros
toxoplasmosis when immunocompromised.
“tom and jerry” might cause behavior changes in mice, to transmit disease.
trypanosoma cruzi
trypomastigote, epimastigote, trypomastigote, infection.
uptaken by macros, escape phags with pore forming protein.
disseminaates into muscle and nervous tissue.
immune “control”
tripanosoma brucei
african sleping sickness
coma>death.
EXTRACELLULLAR REPLICATION AND DISEMINATION
evades immune sys through variable antigen, massive b-cell proliferation, IgM production
leishmania new world
brazilensis- muco,
donovani- visceral
leishmania old world
l. donovani
west
brucei gambiense
gamble out west
mostly human resevoir
CHRONIC
east
brucei rhodiense
rhoseisland back east
mostly antelope resevoir, subacute- weeks/months
Innate immunity
Rapid
fixed
limited number of specifities
constant during response*
Adaptive
slow response
variable
numerous highly selective specifities
improves during response.
acute inflamation
begins immediately, last minutes to days.
neutrophils, vessels, mast cells.
chronic inflamation
begins ~1 or more days later
Lymphos, macros, plasma cells
granulomatous inflamation
variant of chronic
aggregates of epitheloid histiocytes, giant cells, lymphocytes.
primary lymph organ
site where lymphocytes are born or mature.
only bone marrow, and thymus
secondary lymph organ
where lymphs are activated
what is the common effector mechanism of both immunity systems?
destruction of pathogens
when is an infection eradicated?
when the numbers are controlled.
how do innate and adaptive immune responses integrate?
phagocytes talk to T-cells in germinal centers
clonal distribution of receptors
clones of lymphocytes with distinct specificities express different receptors.
non-clonal distribution of receptors
clones of lymphocytes with distinct specifities express different receptors.
discrimination between self an non-self
both immune responses have this capacity.
lymphocytes
chronic granulomatous disease
defective NADPH oxidase
GP-91 subunit is deffective, X-linked.
PAMP
pathology associated molecular pattern- detected by TLR
TLR4
LPS, mannans, parasitic phospholipids, viral envelope proteins, heat shock proteins.
TLR5
flagellin
how do TLRs induce a response
recruitment of adapter proteins
recruitment and activation of protein kinases
activation of transcription factors
gene transcription
EPRESSION OF INFLAMMATORY CYTOKINES AN OTHER CYTOKINES.
MIC/HLA
MHC like receptor ligand that induce cell killing by NK cells.
generalized cytokine receptor signaling pathway
Jak-stat pathway
LOOK UP!!!!!!!!!
nice picture in review slides
IL-6
fever, induces acute phase protein production by liver.
TNF-a
increases vascular permeability, increases fluid drainage.
fever, mobilization of metabolites.
SHOCK
IL-1b
activates vascular endothelium
activates lymphocytes
local tissue destruction
increases access of effector cells
fever- production of IL-6
CXCL8
chemotactic factor, recruits PMNs and basos to infection site.
IL-12
activates NK cells
cytokines
secreted by macros
NF-κB
a protein complex that controls transcription of DNA. NF-κB is found in almost all animal cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, ultraviolet irradiation, oxidized LDL, and bacterial or viral antigens.
interferon gamma
kills bugs and recruits macros
interferon beta
paracrine, makes other antiviral
interferon alpha
.
C1 through 9 with 4 out of line
.
