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Microbiology Unit 1
Unit 1
122
Microbiology
Undergraduate 4
09/21/2011

Additional Microbiology Flashcards

 


 

Cards

Term
Mutualism
Definition

Benefits the host.

microbes in human gut (enterobacteria)

aid in digestion

train immune system

Term
Commensalism
Definition

Microbe benefits, no help or harm to host usually

e.g. staphylococcus epidermis (lives on skin and eats sluffed off cells)

Term
Parasitism
Definition

Microbe benefits, host is harmed

Types:

Primary pathogens

Opportunistic pathogens

Commensal pathogens

Chronic pathogens

Term

Primary pathogens

 

Definition

Cause disease in otherwise healthy host

e.g influenza

Term

Opportunistic pathogens

 

Definition

only cause disease when the health of thehost is compromised.

e.g. pathogenic fungi- pseudomona aeruginosa (cystic fibrosis, burns susceptible)

Term
Commensal Pathogens
Definition

lie dormant for a while, eventually cause disease

e.g. mycobacterium tuberculosis

Term
Hall marks of bacteria
Definition

single celled

binary fission for replication (replicate DNA, split)

Cell wall (peptidoglycan)

No nucleus

single circular chromosome

Term
Hallmarks of viruses
Definition

obligate intracellular pathogen/parasite(need another cell to live)

enclosed by a membrane/protein coat

variety of nucleic acids for genome:

dsDNA, dsRNA, ssRNA, ssDNA

Term
Obligate intracellular pathogen/parasite
Definition
needs another cell to live
Term
Hallmarks of Fungi
Definition

eukaryote

cell wall (chitin)

heterotroph (all rely on braking down organic matter)

Term
Parasite
Definition

eukaryotes:

protozoa

helminth (worms)

Term
Koch's Postulates
Definition

1. microorganism should be found in organisms suffering from disease, but not in healthy organisms

2. Microorganisms must be isolated from infected organism and grown in pure culture.

3. implant into healthy organism

4. should be able to reculture organism from the infected individual.

Term
disease that Koch tested
Definition

Woolsorter's disease (bacillus anthrasis)

 

Term
Life Cycle of bacillus anthrasis 
Definition

1. Spores in environment 

2. spores enter host

3. spores germinate, spread

4. bacteria fight immune system, cause disease

5. host dies spores re-enter environment 

Term
steps for all pathogens
Definition

1. reservoir

2. attachment entry

3. replication and spread

4. fight immune system

5. exit

Term
Innate immune system
Definition

 all components that fight a pathogen the same way every time (no memory)

1st line of defense

 

Term
addaptive immune system
Definition

all components capable of learning.

host takes advantage of unique aspects of pathogens to destroy them.  

e.g. viral pathogens (RNA replication process)

Term
1st physical barrier
Definition

skin: epidermis is outermost (continually renewing)

outermost cornified dead layer is barrier to most organisms

can enter through cuts in skin, digestive system, lungs, use of additional organisms, hair follicles

Term
2nd physical barrier
Definition

Mucous membranes:

continuous secretion of mucous (keeps pathogens away from cells, eg goblet secreting cells in villi of pancreas)

cillia: wave particles out of lungs and up esophagus.

stomach: low pH, degrading enzymes

Term
Chemical barriers
Definition

1. anti-microbial peptides

2. anti-microbial proteins (larger, 3ary struct)

Term
anti microbial peptides
Definition

AKA defensins

short +charged, amphopathic

forms pores in cell walls of bacteria, lyses

selective for bacteria

Term
anti-microbial proteins
Definition

larger, tertiary structure

e.g. lysozyme (degrades peptidoglycan), albumin

RNAase (contra viral genomes)

lactoferrin: soaks up iron from bacteria (need iron to grow)

Term
types of antimicrobial proteins (aka serum)
Definition

1. heat stable (antibodies), due to disulfide linkage

2. heat labile (compliment)

Term
serine protease cascade
Definition

one protein is cleaven into two, one of which cleaves another, etc.

used in clotting

results in inherant amplification

Term
Alternative pathway
Definition
study it!
Term
classical pathway
Definition

study it!

 

uses antibodies

Term
opsonization 
Definition
covering a bacteria in protein
Term
lectin pathway
Definition

mannose/fructose pattern on bacterial surface is bound by manosbinding lectin (MBL)

triggers compliment cascade

MBLs recognize pathogens based on surface protein

Term
monocyte
Definition

originate in bone marrow, resides in blood

gives rise to macrophage or dendritic cell

Term
macrophage
Definition

tissue resident

long-lived

part of liver but originate in bone marrow

"Street sweepers" eat everything not supposed to be there 

Term
neutrophil
Definition

short-lived, live in blood

respond to infection

contain granulocyte (dense vesicle of protein, anamirobial peptides, lysozyme)

 

Also called Polymorphonuclear cells (PMN)

lobed nucleus allows neutrophil to squeeze into tight places

Term
actin monomer
Definition
microfilament
Term
rate limiting step of actin polumerization
Definition

nucleation (initiation of polymerization)

actin dimer is hardest to form, after that its down hill

Term
how does actin polymerization gain directionality
Definition

actin:atp is active form, actin:adp is inactive form

Arp2/3 is a nucleating protein, binds 3 actin polymers (overcomes rate limiting step)

Postive feedback: Arp2/3 binds to side of actin chain and initiates new chain, "webbing effect"

Term
CR1
Definition
compliment receptor, involved in phagocytosis
Term
How does actin polymerization cause phagocytosis?
Definition

phagocyte can bind to surface antibodies or compliment.

ARP2/3 activated near binding site, membrane curves around bacteria, additional receptors bind.

rapid polymerization, envagination

Term
PIP3 kinase
Definition
phosphorylates PIP2 into PIP3, first stem in phagocytic binding of chemoattractants
Term
PIP3
Definition
leads to the activation of Rho in actin activation during phagocytosis
Term
Rho
Definition
small GTPase regulating actin assembly
Term
GAP
Definition
GTPase activating proteins, inactivate GTP
Term
GEF 
Definition

Guanine nucleotide exchange factor

Rho-lipid modification

activates Rho:GTP

Term
Rho:GTP
Definition
activated Rho, recruits N-Wasp (promotes binding of ARP2/3, polymerization away from the binding site)
Term
FC receptor
Definition
phage receptor for antibodies bound to bacteria
Term
respiratory burst
Definition
metabolic process, exposes the phagolysozome to "reactive oxidative species"  
NADPH oxidase complex removes elctron from NADPH, creates O2-. (superoxide) which is converted to H2O2 (highly destructive) 
Term
abcess
Definition
location where neutrophils and bacteria fighting it out
Term
two cytosolic components released by dead neutrophils
Definition

1. protein: calprotectin

2. DNA chromatin forms extracellular trap

Term
purpose of calprotectin release by dead neutrophils
Definition
4 ca2+ bound to, when released, Ca2+ is gone, calprotectin acts as metal sponge, absorbs Zn and MN (many bacteria and fungi need these to survive)
Term
purpose of DNA chromatin release by dead neutrophils
Definition
creat neutrophil extracellular trap (NET) which traps bacteria
Term
4 types of granulocytes
Definition

Neutrophil (esp. contra bact)

eosinophil (contra parasites)

basophils (allergy)

Mast cells (in tissue, release histamine)

Term
function of histamine
Definition

causes inflammation:

capillaries swell, allow neutrophils to spueeze through tissues, diffusion of necessary chemicals

Term
systeic inflammation
Definition
shock: entire circulatory system swells.  blood volume lost to internal organs.  
Term
anaphlactic shock
Definition

high increasein histamine.

treat with epinephrine (contraction of vasculature) eg epipen.

Term
APCs
Definition

professional antigen-presenting cells

work with adaptive immune system

Term
two types of APC's 
Definition

macrophage

dendritic cell

Term
PAI
Definition

Pathogen associated immunostimulant

any molecule made by pathogen that is not made by the host and which the host uses to detect infection

e.g small molecules, repeating patterns (PAMPs)

Term
three effects of PAI
Definition

inflammation

recruitment of phagocyte

phagocytosis

Term
N-formylated peptides
Definition

PAI 

unique tRNA for initial methionine start codon in bacterial transcription

Term

lipopolysaccharides (LPS)

 

Definition

important PAI in gram negative bacteria:

the outer leaflet of the outer membrane of gram negative bacteria is composed of LPS

variation in LPS structure among bacteria, but all share common core.

Term
Toll-like receptors
Definition
receptors in macrophage for PAIs
Term
TLR-4
Definition
receptor for LPS, activates many down stream effects, notably NFkB
Term
LTA
Definition

PAI

anchored in membrane, giant polymer protrudes through cell wall

fx: adherence, negatively charged

Term
TLR-2
Definition
binds LTA
Term
Bacterial DNA
Definition

serves as PAI

bacteria has  CpG motife.  In euk, cytosine methulated in fifth position, bacteria is normal.

 

Term
TLR-9
Definition
recognizes CpG in bacteria
Term
RNA in pathogen as PAI
Definition

used to recognize viruses

normal Euk RNA: mRNA, tRNA, rRNA

primarily single stranded

Double stranded in viruses (reovirus)

immune system recognizes dsRNA

Term
TLR-3
Definition
recognizes double stranded RNA in viruses
Term
flagellum as PAI
Definition

protein flagellin ("motor" structure)

 

TLR5 recognizes flagellin

Term
TLR-5
Definition
recognizes flagellin (protein in bacterial flagellum)
Term
cytokine
Definition

molecule released from one cell population that have an effect on themselves and/or other cell pop.s

 

Term
interleukins
Definition

cytokine important for growth and differentiation of the immune system.

 

Term
chemoattractant
Definition
recruits PMN cells (neutrophils)
Term
TNF alpha
Definition

cytokine, made by macrophage, endothelial cells

results in inflammation, stimulates phagocytosis

by itself is responsible for gram negative sepsis

Term
IL 8
Definition

cytokine, produced by macrophage, epithelial, endothelial cells

PMN chemotaxis (signal to neutrophils)

Term

Interferon gamma (IFN gamma)

 

Definition

primarily made by T-cells (adaptive immune system)

signal to activate macrophage (wants signal for T cell swallows bacteria but doesn't kill cell outright until it gets IFN gamma from T cells)

Term
P-selectin
Definition

protein with lectin domain, binds carbohydrate on PMN, forming weak connection.

selectin anchored to actin filament in cytosol.

during blood flow, neutrophil rolls along endothelial surface.

Term
cytotoxic T cell
Definition
kills intracellular pathogen
Term
helper T cell
Definition
helps B and T cells fight extracellular pathogens
Term
bacillus
Definition
rod shaped bacteria
Term
coccus
Definition
round ball shaped bacteria
Term
Staphylococcus aureus (kingdom, phylum, class, genus, species)
Definition
bacteria, fermicute, bacillus, staphylococcus, aureus
Term
staph aur gram + or-?
Definition
gram positive
Term
metabolism of staph aur?
Definition
facultative anaerobe
Term
purpra fulminans
Definition

"purple lightning" 

cutaneous hemorrhages and necrosis in kids and youth

Term
S. aureus (gram stain, shape)
Definition
gram positive cocci
Term
group A streptococcus (gram stain and shape)
Definition
gram positive cocci
Term

group B streptococcus

(gram stain and shape)

Definition
gram positive cocci
Term
coagulase negative staph (gram and shape)
Definition
gram + cocci
Term
enterococci (gram and shape)
Definition
gram + cocci
Term
Neisseria (gram and shape)
Definition
gram neg cocci
Term
listeria (gram and shape)
Definition
gram + bacilli
Term
Clostridium (gram and shape)
Definition
gram+ bacilli
Term
corynebacterium (gram and shape)
Definition
gram + bacilli
Term
mycobacterium (gram and shape)
Definition
gram + bacilli
Term
Nocardia (gram and shape)
Definition
gram + bacilli
Term
e. coli (gram and shape)
Definition
gram - bacilli
Term
Klebsiella (gram and shape)
Definition
gram - bacilli
Term
pseudomonas (gram and shape)
Definition
gram - bacillus
Term
proteus (gram and shape)
Definition
gram - bacilli
Term
salmonella (gram and shape)
Definition
gram- bacilli
Term
yersinia (gram and shape)
Definition
gram- bacilli
Term
Brucella (gram and shape)
Definition
gram - bacilli
Term
enterobacter (gram and shape)
Definition
gram - bacilli
Term
Haemophilus (gram and shape)
Definition
gram - bacilli
Term
bordatella (gram and shape)
Definition
gram - bacillus
Term
moraxella (gram and shape)
Definition
gram - bacilli
Term
Francisella (gram and shape)
Definition
gram - bacilli
Term
campylobacter (gram and shape)
Definition
gram - bacilli
Term
three classes of spirochetes
Definition

tremonema

leptospira

borrelia

Term
treponema pallidum
Definition

syphilis

spirochete

can't gram stain

can't culture

STD

chronic infection (takes decades to progress to tertiary)

Term
dx of treponema pallidum
Definition

general serology

specific serology (antibodies for Lipoprotiens)

Term
mycobacterium TB
Definition

chronic infection

obligate aerobic

non gram staining

acid fast (stains mycolic acid)

facultative intracellular pathogen

high lipid content, waxy and hard to penetrate

Term
drug that can be used for acid fast bacteria
Definition
isonizid: blocks mycolic acid synthesis
Term
types of bacteria that form spores
Definition
clostridium and bacillus
Term
chlamydia
Definition

obligate intracellular

persistant chronic infections

non gram staining

can be stained with silver

human reservoir common

STD and ocular infection

Term
elemental body vs. reticular body
Definition

EB: extracellular (infectious)

RB intracellular (replicating)

Term
mycoplasma
Definition

no cell wall (no gram stain, no cell wall antibiotics)

shape changs

smallest bacteria

growth is fastidious and requires media with sterols

slow growth

 

Term
rickettsia
Definition

obligate intracellular

polymerize actin

geographically diverse

no culture

zoonotic

Term
how does ehrlichia block cellular digestion by phagosome?
Definition
blocks fusion of endosome and lysosome
Term
how does coxiella survive phagocytosis?
Definition
thrives in low pH of lysosome
Term
what causes rash in rickettsia?
Definition
damage to epithelial tissue, blood vessels dilate and RBCs escape
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