Exam 2 part B (from quiz 2 content and beyond) Flashcards
Where is opportunist pathogen normally observed?
Groups/individual vulnerable to opportunist infections.
found @ either normal microflora or in environment.
elderly & young individual undergoing chemotherapy or radiation treatment
cancer px (immunocompressed bc immune system gets into overdrive mode to kill cancer cell. B and T cell is exhuasted)
organ transplant px (bc on immunosuppressive drugs so organ wont be rejected by defense cell)
AIDS individual (bc HIV targets adaptive immune system (T helper)
common opportunist microbes and disease they cause
pnemocytis jerovicci (carinii):???
E coli: normal microflora of intestine. causes UTI
pnemocytis jerovicci (carinii): found @ lungs in healthy individual. but in AIDS px, can be lethal and cause death due to pneumocystis pneumonia. targets respiratory system of aids px.
staphlococcus aureus: normal microflora of nasal cavity. causes wound infection @ surgical site.
Yeast (candida sps): normal microflora of adult female. when on antibiotic, no longer in balance with competition bacteria and overgrows/outbreak.
CMV (cytomegvalovirus). member of herpes family. causes blindness in AIDS (retinitis) due to targeting retinal blood vessels and hemmoraghing.
(deafness in new born)
pseudomona sps (bacteria) (environment opportunist pathogen)
okay in normal px.
in burn px, this causes greenish/blue color.
in cystic fibrosis and burn px, is FATAL.
opportunist infection in AIDS px
protozoan:
pneumocystic spc, crytosporidium (accute diarrhea)
bacterial:
tuberculosis
fungal:
hisoplasma, candida spc (adult female yeast balance disrupted)
viral:
chicken pox, herpes simplex I and II, HPV
signs vs symptoms with examples
which is objective/subjective?
symptoms: subjective, felt by px.
(pain, headache, dizziness, fatigue)
signs: objective, observed by others
(swelling, rash, etc)
some can be both, reflecting same underlying cause:
nausea is symptom, vomit is sign. both have same underlying condition.
chills: subjective/symptoms
shivering : objective/sign
asymptomatic vs symptomatic
and diseases and whether it is or is not symptomatic in healthy px
STI in females, syphilis, chlamydia, cytomegalovirus, polio, in an IMMUNOCOMPETENT (healthy) individual is asymptomatic.
its there but you cant tell.
HIV have an extended asymptomatic phase.
5 stages in course of infectious disease.
which stage is critical?
incubation period:
time between entry into host to onset of illness (first sign/symptom)
prodromal period: after incubation, usually short. early sign/symptom. not clearly define, vague.
period of illness (invasive phase)
sign and symptom becomes apparant (pathogen multiply and tissue dmg set in)
CRITICAL PERIOD
period of decline:
susceptible to secondary infection (bc immune system is weak and exhuasted)
. sign symptoms fades, reduce malaise feeling.
period of convalescence:
px recover and regani stregnth. still have potential to spread disease.
incubation period
dependent on factors: name them
host resistance(px immune system health) (HIV infected individual have shorter incubation period bc immune cell are already targeted by HIV)
specific microorganism involved (prions, rabies, stomach flu, etc)
(common cold has shorter IP compared to AIDS or leprosy which may have extended IP)
(prions has long incubation period, kuru can be transmitted thorugh generation)
virulence: (ebola has high virulance, short incubation period)
(rabies has long incubation period, thus vaccine works)
infective dose of microbes:
megadose causes shorter incubation period.
incubation period:
ebola
prions (kuru)
common cold
rabies
and other info`
EBOLA: short IP (can easily be identified quickly and isolated)
prions: LONG IP. can be trasmitted through generation (kuru)
rabies: prolonged IP, thus vaccine works well.
common cold: short IP (compared to AIDS/leporosy)
Prodromal phase
2nd phase of course of infectious disease.
folow incubation period, usualy short.
early sign/symptom (body ache, etc)
not clear/vague
can be CLINICAL or SUBCLINICAL disease
CLINICAL: symptoms are apparant (like measles). full sign/symptom.
SUBCLINICAL: few/mild symptoms.
having a condition but not yet having any symptoms from the condition
Generally, the disease is in its most mild and earliest stages. Often, it has not progressed to the point of causing any symptoms, and it may be impossible for providers to diagnose.
ex: mono is due to ebstein barr virus (herpes fam), cold war between t and b cell.
(cold sore, tingling etc in HSV I AND II)
period of decline
why susceptible to secondary infection?
4th stage after period of illness (stage 3)
sign and symptom fades, reduce malaise feeling.
susceptible to secondary infection bc
immune system is weak/exhausted from previous battle.
(measle is a good example, esp bc it targets t and b cell in the battle)
spores and endospores
only made by Gr POSITIVE rods/bacillus (NOT any other types)
(bacillus sps clostridium sps)
1 bacteria per spore. NOT for multiplication. simply for survival/preservation.
sporulation (turn to spore in unfavorale environment)
germination: return to vegetative cell in favorable condition
endospore:
2 bacterial sps that makes spores.
are they used for multiplication?
*****role of dipicolinic acid and Ca ions in endospores
sporulation/germination
(bacillus sps clostridium sps)
1 bacteria per spore. NOT for multiplication. simply for survival/preservation.
**essential for resuming metabolism (jump start) when they germinate bacteria back to “alive”/vegetative state.
sporulation (turn to spore in unfavorale environment)
germination: return to vegetative cell in favorable condition
general overview of bacterial cell:
components of cell envelope
cell envelope:
- capsule/glycocalyx
- cell wall/peptidoglycan
- plasma membrane/inner membrane
general overview/info
_______________________________
capsule/glycocalyx:
2 types; can be either capsule (pathogenic) or slime layer(loosely organized)
fx: protection (passive defense barrier) (slippery nature and/or simlar chemical composition, prevent identification from host)
protection cell from dying (retain water molecule)
colonization (sticky nature help sticks)
nutrient (serve as nutrition source, hydrolyzed when needed)_
_______________________________________
cell wall/peptidoglycan:
backbone, tail, bridge
backbone: nag/nam (nam is attach poitn)
tail: L and D (L,D, L(3rd), D)
bridge: Penicillin building protein (PBP) connect 3 to 4.
(direct in gram negative, indirect in positive (variety of aa).
fx: provide rigidity (since plasma membrane have no cholesterol which wouldve made it rigid, but with no cholesterol, cell wall help make up for it)
(thick in pos, thin in neg)
_______________________________________
plasma membrane /inner membrane,
thin structure.
phospolipid bilayer
protein
glycoprotein
NO CHOLESTEROL (Thus no rigid, thus need cell wall)
(exception mycoplasma; have cholesterol, and thus no cell wall)
2 type of protein:
integral protein or peripheral protein
integral protein: extend into.through lipid bilayer. tunnels.
peripheral protein: attach inner or outte surface. function as enzymes, receptors.etc.
Glycocalyx /capsule
overview
concept of slime layer vs capsule w/example
stain detection, how?
functions:
role of passive defensive protection
capsule/glycocalyx:
composed mainly of polysacchrides (compositiion varies between diff bacterias)
synthesize inside cell and secreted to outside cell surface.
stain detection via negative staining using acidic/anionic dye (create halo effect as negative react to negative) capsule is made up on negative.
most is encoded by chromosomal DNA (thus negative)
exception is bacillus anthracis (plasmid DNA).
________________________
2 types of glycocalyx
; can be either capsule (pathogenic) or slime layer(loosely organized)
capsule: pathogenic bacteria have capsule. virulence factor. (S pneumoniae)
slimy layer: loose, disorganized. part of microflora bacterias present in intestine (help in many ways). ex: bacteroides
fx: protection (passive defense barrier) (slippery nature and/or simlar chemical composition, prevent identification from host)
protection cell from dying (retain water molecule)
colonization (sticky nature help sticks)
nutrient (serve as nutrition source, hydrolyzed when needed)_
__________
glycocalyx/capsule:
Bacillus anthracis
exception to ccomposition
instead of having capsule encoded by chromosomal DNA like most, it is made up of plasmid DNA.
glycocalyx/capsule:
difference between active and passive defense
capsule role in passive defense
2 ways capsule aid in protection against host defense cell
incomplete vs complete phagocytosis and role of capsule.
passive defense: built in
active: direct attack on host defense cells
capsule protection :
passive defense barrier
1)slippery nature
2) simlar chemical composition, prevent identification from host)
complete: slippery, slip away from phagocytosis (phagocytosis block by capsule)
or
incomplete phagocytosis: gets swallowed by do not die. block vesicle fusion with lysosome, instead, stay inside and reproduce inside (under cover)
How do S pyrogenes (strepthroat) capsule help impair/escape body immune recognition.
hyaluronic acid capsule
capsule/glycocalyx : hyaluronic acid capsule
has similar composition as host cell thus prevent detection by host cell. under cover.
Streptococcus pyrogenes (strepthroat) has hyaluronic acid- complex sugar on connective tissue matrix/portion.
help blend in with host cant recognizie it as foregin
The important human pathogen Streptococcus pyogenes (group A Streptococcus [GAS]) produces a hyaluronic acid (HA) capsule that plays critical roles in immune evasion
streptococcus pneumonae has 2 variant of capsule
capsulated form: pathogenic (escape host defense and colonise and cause disease.
noncapsulated form: non pathogenic, easily detectable thus pinned and eliminated because causing disease.
Streptococcus mutans’s capsule and colonization
specific or non specific attachment
extemely sticky capsule help stick to surface.
non specific.
colonization is as aspect of capsule/glycocalyx. play critical role in initial attachment (non specific),
colonoize tooth surface, ferment sugar and produce acid, destroy tooth surface.
Do capsule/glycocalyx play ayn role in transport process
NO
Can capsule polysaccrahride be used as vaccine
Yes.
covid 19 vaccineuse spike protein to trigger production of memory b cell (long lasting) via t dependent B cell activation.
pervnair13 vaccine
trademarked vaccine for pneumoniae.
capsule vaccine.
B cell activation concept
overview
(t independent vs t dependent)`
adaptive or innate immunity?
B cell are activated independent of T cell, proliferate and differentiate into antibody producing plasma cells as well as memory b cell.
memory cell can quickly differentiaste into plasma cell later in life for quick reponse time.
memory cell last long.
T dependent B cell activation is more robust.
B cell is part of adaptive immunity
Bacteria plasma membrane
prokaryotic plasma membrane consist of:
phospholipid bilayer
protein
glycoprotein
NO cholesterol (thus need cell wall, unlike eukaryotic)
exception mycoplasma (have cholesterol, thus no need for cell wall)
act as selective barrier, monitor flow in/out
2 type of protein:
integral protein or peripheral protein
integral protein: extend into.through lipid bilayer. tunnels.
peripheral protein: attach inner or outte surface. function as enzymes, receptors.etc.
mycoplasma membrane uniqueness
does not haev cholesterol unlike other bacteria’s plasma membrane which does (and need cell wall to make up for rigidity)
because mycoplama’s plasma mebrane has cholesterol, no need for cell wall.
Mycoplasma is a genus of bacteria that lack a cell wall around their cell membranes. This characteristic makes them naturally resistant to antibiotics that target cell wall synthesis
plasma membrane:
integral protein and peripheral protein
and examples
integral protein: extend into.through lipid bilayer. tunnels.
ex: Cholera ToxR (biosensor)
transmembrane protein (integral protein).
detect acidity adn eleavted temperature (sign of host digstiv system), Nh2 part reaches cytoplasm, Nh2 termianl domain bind to DNA sequence and in turn
activate cholera toxin synthesis and secretion.
________________________________
peripheral protein: attach inner or outte surface. function as enzymes, receptors.etc.
action of some membrane acting ANTIBIOTICS and disinfectants
polymyxin B
alcohol
lysol
polymyxin B:
common first aid ointment.
bind to phospholipid of plasma membrane and disrupt structural integrity, lead to cell lysis/death.
(thus never give ointment orally or IV, can hurt body cell, skin on other hand has keratisnised cell.
lysol and alcohol;
denature protein and dissolve lipid.
disrupt integrity of membrane and cell dies.
transport across plasma membrane
role:
bring in nutrient
expel waste
secrete (protein that are made inside but ship out as strucutural component on cell surface)
secrete virulence toxin
secrete enzyme (break down large substance for absorption)
transport process is functional outcome of activity of CHANNEL protein/transport protein
(integral protein) since its a tunne that go fully through membrane, allow to serv as a tunnel entrance.
plasma membrane:
surrogate mitochondria
bacteria cell plasma membrane sometimes called
surrogate mitochondria
bc no mitochondria.
many of rxn of energy metabolism like
electric trasnport chain
take place by plasma membrane (electric tansport chain)
THUS called: surrogate mitochondria
bacteria cell WALL (peptidoglycan)
overview
backboneunit
direct/indirect bridge
cell wall/peptidoglycan:
backbone, tail, bridge
backbone: nag/nam (nam is attach poitn) nag and nam is connected via O-glycosidic linkage.
tail: L and D (L,D, L(3rd), D)
bridge: Penicillin building protein (PBP) connect 3 to 4.
(direct bridge in gram negative, indirect bridge in positive (variety of aa).
fx: provide rigidity (since plasma membrane have no cholesterol which wouldve made it rigid, but with no cholesterol, cell wall help make up for it)
(thick in pos, thin in neg)
peptide interbridge reinforce and confer 2-3 dimensional stability.
cross bracing provide more strength to peptidoglycan layer cell wall)
PBP
penicillin building protein
role in peptidoglycan structure
connect 3rd and 4th amino acid in cell wall amino acid tail (D AND L)
ONLY connnect 3-4.
penicillin antibiotic target this to disrupt bridge (prvent it from forming by taking it’s “seat” like in a game of musical chair).
