module 3: microbial disease & control, antibiotics, immune systems, and vaccines Flashcards
what does it mean to be “sterilizing”
sterile. 100% microbe free. absolutely no microbes
what does it mean to be “sanitizing”
acceptable.
what does it mean to be “antiseptic”
mouth wash or concerning the skin
what does it mean to be “disinfectant”
fomites. non-living things. wipes
what does it mean to be “microbicidal”
“to kill”; bactericidal, fungicidal, viricidal
what does it mean to be “bacteriostatic”
to slow the growth
what is a nosocomial infection, or HAI
Hospital Acquired Infection
list some chemical controls used to sanitize:
- antiseptic (alcohol hand sanitizer)
- disinfectants (chlorine)
- heavy metals
- detergents
what is the test used for antibiotic resistance?
Kirby Bauer test
list the main types of transmission:
- skin to skin
- respiratory
- indirect (shared through object)
- food
- insect
- rabid animal
MRSA - hospital acquired infection is referring to ____________________
antibiotic resistant Staphylococcus aureus
before the invention of antibiotics, what were the top 1 and 2 causes of death?
Pneumonia and Tb
after antibiotics, what are the top 1 and 2 causes of death?
heart disease & cancer
list the microorganisms that cause communicable/
infections disease
- bacteria: Tb
- fungi: yeast – mycosis
- parasites: malaria
- viruses: SARS-CoV 2
define “symptom”
some sort of physical condition that represents disease (ex. swelling)
what is an “opportunistic pathogen?”
an infection you get from a microbe that lives in/on you all the time, but all of a sudden causes disease
** example: yeast infection! Candida albicans **
what are “primary infections”
having a cold, the flu, or covid
what are “secondary infections”
12 days after the primary infection, getting a headache/mucus/sinus pressure
bacteria overtake from the damage the initial virus has caused, upsets the balance
what are “localized infections”
infection in a surgical wound, like a knee replacement
what are “systemic infections”
localized infection goes deeper and roots into the tissue, even into blood
what is “bacteremia”
bacteria in the blood. VERY bad
what is “septicemia”
bacteria progresses and infects organs. creates a massive immune system explosion which can lead to sepsis, and death
what are the 3 modes of transmission?
contact (direct, droplet, indirect)
vehicle (water, air, food)
vector (animal, insect, mite, tick)
what does it mean to be “antimicrobial”?
an umbrella term. any therapeutic chemical drug or treatment used to stop microbes (fungi, viruses, bacteria, etc)
what does it mean to be “antibacterial”?
a drug treating bacteria / bacterial infection. they are anti-living, and fight another living thing
how do antibacterial drugs work?
block vital processes in bacteria
kill the bacteria
stop them from multiplying.
all this relies on the patient having a working immune system
describe selective toxicity
antibiotics are toxic to bacteria, NOT human eukaryotic cells
where do antibiotics come from?
come from other microbes, but can now be synthesized in labs. in the past we’ve used soil bacteria
what decade was the start of antibiotics?
1940s
describe the chemotherapeutic index
ratio of the maximum tolerated dose of a chemical agent used in chemotherapy to its minimum dose. having a high therapeutic index is good!
what does it mean to have a high therapeutic index?
not toxic to us, but very toxic to bacteria
what is the broad vs narrow spectrum?
not every antibiotic is going to have the same effect on every pathogen
broad spectrum =
kill any
narrow spectrum =
very targeted
list some qualities of an ideal antibacterial drug:
- selective target
- bactericidal
- narrow spectrum
- high therapeutic index
- few adverse reactions
- various routes of administration
- good distribution to site of infection
- emergence of resistance is slow
MOA: Beta-Lactams
inhibit cell walls.
stops the building of peptidoglycan.
the drug targets transpeptidase, the peptidoglycan builder
MOA: Vancomycin
different structure from B-Lactams, but still attacks peptidoglycan in cell walls
MOA: Aminoglycosides, Tetracycline, and Macrolides
inhibits protein synthesis.
some stop transcription from happening at the mRNA step,
others stop translation with the ribosome.
has to find targets that are specific to prokaryotes
MOA: Polymixin
inhibits plasma membrane.
external only
contains 3 antibiotics (bacitracin, neomycin, polymixin) so the pathogens cannot mutate and take over all 3
MOA: Quinolones
external & extremely broad spectrum
Cipro targets DNA gyrase
and Rifampin targets RNA polymerase
MOA: Sulfonamides
inhibits a metabolic pathway through competitive inhibition
sulfonamide/trimethoprim act as imposters of the actual enzyme & block the building of folic acidsw
what do antivirals do?
have varying MOA but prevent viral uncoating, replication, or release
what do antifungals do?
inhibit the plasma membrane, specifically ergesterol
what do antiparasitics do?
MOA is very specific and tricky, since parasites are eukaryotic just like human cells
describe the issue of drug resistance:
antimicrobial resistance is on the rise as a result of…
- selection of drug-resistant strains in clinical environments
- the overuse and misuse of antibacterials
- the issue of not completing a prescribed dose
- poor patient compliance with antibacterial drug therapies
what does broad spectrum antibiotic use increase?
increases the risk of resistance
describe “antibiotic resistant mechanism”
a whole gene going from one pathogen, getting shared with another via horizontal gene transfer. happens in a population as an accidental mutation
what is Augmentin?
contains penicillin & β-lactamase inhibitor
what are biofilm infections?
1,000x more resistant to drugs than other infections. inner ear, surgical sites, joint replacements
image with “blocked penetration, target modification, inactivation of enzymes, efflux pump”… what is this saying?
the image is saying all the ways bacteria can fight infections
define “innate defenses”
non-specific, no memory
what are the 3 kinds of innate defenses?
physical, chemical, cellular
physical defense: skin
protects us from the outside world
epidermis, dermis, microbiota
physical defense: lymphatic system
glands, lymph nodes, spleen
(lymph nodes = where white blood cells mature)
physical defense: respiratory system
coughing, sneezing… expelling microbes from the body
(misc: eyelids tearing, urinating. also examples of physical)
chemical defense:
natural compounds that inhibit bacteria growth.
chemicals produced by humans
list some examples of chemical defense mechanisms:
salt in sweat, tears, breast milk (lysozyme)
stomach acid, sebum, urine, earwax
antimicrobial peptides/proteins
complement proteins (attack proteins in plasma)
cytokines
describe/define cytokines
chemical communicators (like the commander).
signals that are communicated between cells.
produced by Leukocytes
what are the different kinds of cytokines?
- interferon: interferes with viral infection
- complement cascade: important 4 blood, attack proteins in plasma
- defensins: protein fighting microbe
- histamines: swells
- prostaglandins: temperature control
what are Interkeukins?
a type of cytokines, between white blood cells… they regulate immune responses
what are Leukocytes?
a general category of white blood cell
list the different roles of Leukocytes in the innate immune system:
- platelets: clot blood at cut sites
- basophils
- eosinophils
- neutrophils – most active in the blood. high %
(all 3 listed above are very active in innate immune sys) - macrophage/dendritic: gateway cells. important connection between innate & adaptive immune system
- natural killer
how are phagocytic cells activated?
cells have the ability to send signals to one another when something is foreign
describe the roles of TLR and PAMP
these match up, indicate “this is not us” then attack
what does PAMP stand for and what does it do?
Pathogen Associated Molecular Pattern
its a type of antigen… indication of a foreign thing
in regards to bacterial pathogens, how does phagocytosis play a role?
it can either clear up the bacterial infection by “gobbling it up”
OR
sometimes small particles are used to teach the acquired immune system what to target
what is an antigen presenting cell?
the gateway to teach the adaptive immune system by using PAMP and antigen
what 3 names all refer back to an antigen presenting cell?
can be called antigen presenting cell, macrophage, or dendritic cell
describe the main role of the antigen presenting cell
it presents an antigen to the acquired immune system by presenting the bacterial pathogen (antigen) to the MHC II
what is MHC II?
what the antigen presenting cells use to show invaders
what is MHC I?
the flaggers. they indicate “hey its me, I’m human”….
or it can tell your immune system “one of my cells isn’t doing well. I have a parasite. kill me”
what are natural killer cells?
one type of lymphocyte in the innate immune system. they take out your body cells that aren’t doing well.
how do natural killer cells attach to the MHC I complex?
they have a receptor called CD8
what do the 5 immunoglobulin cases mean?
antibody being made
define “antibody”
what your immune system makes to fight an invader
define “antigen”
found on the surface of the pathogen
live, attenuated vaccines:
reduce the virulence.
teaches the body the exact antigens without getting you sick
inactivated vaccines:
killed virus.
pathogen that’s going to cause disease is shown to your body, but is completely dead
subunit vaccines:
antigens.
break PAMP off microbe, but not the whole thing. no risk of causing infection/disease
conjugate vaccines:
antigen & carrier protein.
no whole bacteria. helper protein attaches to sugars outside the cell
briefly describe mRNA vaccines:
mRNA vaccines are injection to muscle cells. your ribosomes make polypeptides that say “fight this spike.” dendritic cells, deep in tissues, say “that’s not self” then make antibodies to fight it. they connect CD4 and helper T cells, and elicit the immune system.
how does mRNA exposure help your immune system?
it has your body cells make the mRNA message, then produce polypeptides. your immune system will see that and carry on making antibodies
MMR
live attenuated virus
measles, mumps, rubella (highly contagious, all viral)
HEP-B
subunit vaccine (not entire virus, just antigen)
Hepatitis B virus. liver disease.
Dtap, Tdap
subunit vaccine & toxoids.
upper respiratory infected
Hib
conjugate vaccine
polysaccharide antigen
PCV
Pneumococcal conjugate vaccine
fights Streptococcus pneumoniae
IPV
inactivated viral vaccine
polio
influenza
killed/inactivated virus - shot
live attenuated virus - spray
recombinant cell vaccine also available
varicella
live (attenuated) virus
chicken pox & shingles
