Test 3- Ch. 9, 10, 14 – Flashcards

Unlock all answers in this set

Unlock answers
question
Drugs (definition)
answer
Chemicals that affect physiology in any manner
question
Chemotherapeutic agent
answer
drugs that act against diseases
question
Antimicrobial agents
answer
drugs that treat infections (against microbes)
question
what bacteria is the major cause of death from burns?
answer
S. pyogenes (1/2 of all deaths)
question
What did Paul Ehrlich and Alexander Fleming discover?
answer
Penicillium inhibited growth of bacteria on agar plates
question
What did Howard Florey and Ernest Chain contribute to Penicillin use? Who was their first patient?
answer
Discovered its use in humans and perfected the purification and solubility needed to treat.
- Albert Alexander (police officer- later died)
question
Gerhard Domagk
answer
Discovered the use of Sulfonilamide (Prontosil) which effects folic acid synthesis which is important for nucleotide synthesis. Tested on his own child who had streptococcal infection.
question
What are the two main categories of selective toxicity for antimicrobial action?
answer
Structure and Function
question
6 methods of antimicrobial action
answer
1. Inhibition of cell wall synthesis (Penicillins)
2. Inhibition of protein synthesis (Tetracyclines)
3. Disruption of cytoplasmic membrane (Polymyxins)
4. Inhibition of general metabolic pathway (Sulfonamides)
5. Inhibition of DNA or RNA synthesis (Actinomycin)
6. Inhibition of pathogen attachment or host recognition (Arildone)
question
Penicillin- what does it target and how does it work?
answer
-Prevent bacteria from increasing amount of peptidoglycan
-only effects newly reproduced bacteria
-interferes with linking enzymes that connect NAM subunits. Cells eventually burst due to osmotic pressure
question
Vancomycin and Cycloserine- what does it target and how does it work?
answer
-targets cell wall synthesis
-Affects Alanine-Alanine bridges between NAM molecules
question
Bacitracin- what does it target and how does it work?
answer
-targets cell wall synthesis
-Blocks secretion of NAG and NAM from cytoplasm
question
Isoniazid- what does it target and how does it work?
answer
disrupt arabinogalactan-mycolic acid (acid fast bacteria) in Mycobacterial species
*use for long period of time since reproduction is slow.
question
What step of protein synthesis do antibiotics usually target?
answer
Translation- Can differentiate between the 70s ribosomes of the prokaryotes and the 80s ribosomes of the eukaryotes
question
Streptomycin and Gentamicin (Aminoglycocides)- what does it target and how does it work?
answer
-Alter 30s subunit of ribosome (protein synthesis)
-mRNA is misread because it doesn't bind normally to the small subunit before translation
question
Tetracycline- what does it target and how does it work?
answer
- blocks tRNA docking site (protein synthesis)
question
Chloramphenicol- what does it target and how does it work?
answer
-binds between amino acids (protein synthesis)
-Blocks enzymatic activity of ribosome
question
Erythromycin (macrolide)- what does it target and how does it work?
answer
-bind to 50s, preventing mRNA from moving through ribosome (protein synthesis)
question
Amphotericin B (polyene)- what does it target and how does it work?
answer
attaches to ergosterol which is a molecule similar to cholesterol found in fungal membranes. (disruption of cytoplasmic membranes)
*Toxic to humans
question
Polymyxin- what does it target and how does it work?
answer
-disrupts cytoplasmic membranes of G- bacteria
*toxic to kidneys so used as topical
question
Pyrazinamides- what does it target and how does it work?
answer
disrupts transport across plasma membrane (tuberculosis)
-Disruption of Cytoplasmic membrane
question
Heavy metals- what does it target and how does it work?
answer
paralyze (parasitic worms), inactivate enzymes
-Metabolic antagonists (sulfonamides- Prontosil- PABA)
-Interferes with the conversion of normal PABA to folic acid. This doesn't interfere with us because we obtain our folic acid from outside sources.
question
Actinomycin- what does it target and how does it work?
answer
targets replication and transcription (binds to DNA)
question
Nucleotide analogs- what does it target and how does it work?
answer
Block DNA replications
question
Quinolones and fluoroquinolones- what does it target and how does it work?
answer
Inhibit DNA gyrase which coils and uncoils bacterial DNA
-no effect on eukaryotes or viruses
question
Rifampin- what does it target and how does it work?
answer
binds to RNA polymerase in bacteria (M. tuberculoses)
question
Reverse transcriptase inhibitors
answer
HIV cocktail
question
Amantadine & Rimantadine- what does it target and how does it work?
answer
antiviral agent
-neutralize acidity of phagolysosome and prevent viral uncoating.
question
efficacy-diffusion susceptibility test
answer
antibacterial drug on disks. Plated to see how well they inhibit growth
question
Minimum Inhibitory Concentration (MIC)
answer
series of vials with increasing concentration of drug to identify the minimum needed to inhibit growth.
question
Minimum Bactericidal Concentration (MBC)
answer
min concentration to kill everything Follow up test to the MIC. Plate the clear tubes solutions to see which were killed
question
E- test
answer
strip of paper with increasing concentration of antibiotics. Used to identify the concentration needed to inhibit growth. Done on an agar plate.
question
4 types of antibiotic administration
answer
topical
oral
intramuscular
IV
question
3 categories of antibiotic side-effects
answer
1. toxicity (liver, kidney, pregnancy)
2. Allergies (minor --> anaphylactic shock)
3. Disrupt normal microbiota
question
Mechanisms of Antibiotic resistance (5)
answer
1. produce enzymes that destroy or deactivate the drug
2. slow or prevent entrance of the drug
3. alter target of drug
4. alter metabolic pathway or bypass it
5. pump the drug out
question
cross resistance
answer
resistance to drug with same structure
question
antibiotic combinations (synergism)
answer
2 or more at the same time
question
antibiotic combinations (antagonism)
answer
inhibition of one drug by other
question
Thermal death point
answer
lowest temperature that kills all cells in broth in 10 mins
question
Thermal death time
answer
time to sterilize volume of liquid at set temp
question
3 types of moist heat
answer
1. boiling (1000 C)
2. autoclaving (1210 C)
3. Pasteurization (30 min at 63 C or 15 sec at 72 C)
Ultrahigh temp sterilization (1-3 sec at 140 C)
question
Dry Heat (2 types)
answer
Flame (15000 C)
Ovens (171 C)
question
Refrigeration and Freezing
answer
low temps slow growth but don't kill unless ice crystals form
question
Desiccation
answer
Drying inhibits growth due to removal of water (does not kill)
question
Lyophilization
answer
long term preservation of microbe cultures by rapid freeze and vacuum (prevent ice crystal formation)
question
Filtration
answer
sterilization degree based on pore size. Does not kill, just removes.
question
Osmotic Pressure
answer
prevents bacterial growth
question
Radiation- Ionizing (1nm)- 3 types
answer
1. electron beam- good for thin layers
2. Gamma Rays- deeper penetration (can penetrate containers)
3. X-rays-deeper penetration but low energy. No practical
question
Radiation-Non ionizing
answer
wavelengths greater than 1nm
-excites electrons to form new bonds
-UV light causes thymine dimers in DNA but it does not penetrate well
-used for operating beds
question
what organisms are chemical methods most effective against?
answer
enveloped viruses
vegetative cells of bacteria, fungi, and protozoa
question
Phenol and Phenolics (examples and how it works)
answer
low level disinfectants (protein and plasma membrane)
-can remain active for prolonged time
-iister (carbolic acid), lysol, triclosan
question
Alcohols (examples and how it works)
answer
intermediate disinfectants (protein and plasma membrane)
-isopropanol, etoh
question
Halogens
answer
intermediate disinfectants (damage enzymes via oxidation or denaturing)
-iodine tablets, chlorine, bleach, bromine, chloramines
question
Oxidizing Agents
answer
high level disinfectant and antiseptic
-oxidation of microbial enzymes (peroxide, ozone for drinking water, peracetic acid for sporocide sterilizing equipment)
-hydrogen peroxide can disinfect and sterilize surfaces (not deep wounds
question
Soap (surfactant)
answer
hydrophilic and hydrophobic ends
-good degerming agents but not antimicrobial
question
Detergent (surfactant)
answer
positively charged organic surfactants- makes membranes soluble
-Zephiran
-QUATS (quaternary ammonium compounds)- colorless and tasteless- harmless to humans so used in medical and industrial applications
question
Heavy Metals
answer
low level agents (ions alter 3-D shape of proteins)
-thimerosal- preserve vaccines
-Copper- algal growth in reservoirs, fish tanks, etc. (interferes with chlorophyll)
-Silver Nitrate- prevent blindness caused by gonorrhea
question
Aldehydes
answer
-compounds with terminal -CHO groups
-denature proteins and inactivate nucleic acids (cross link with amino, hydroxyl, sulfhydryl and carboxyl groups)
-glutaraldehyde- disinfects (short exposure) and sterilizes (long exposure)
-formalin- embalming and disinfection of rooms and instruments
question
Gaseous Agents
answer
-ethylene oxide and propylene oxide (closed chamber)
denature proteins and DNE by cross linking functional groups
-used in hospitals and dental offices (hazardous, explosive, poisonous, carcinogenic)
question
use-dilution test
answer
culture metal rods with organism after 10 minutes in agent
question
In-use test
answer
swab before and after disinfection then plate for growth
question
Sterilization
answer
remove all microbes
question
disinfection
answer
remove many pathogens
question
Aseptic
answer
environment or procedure free of pathogens
question
Antisepsis
answer
skin, tissue
question
degerming
answer
physical removal, rubbing
question
Sanitization
answer
disinfection in public place
question
Pasteurizatino
answer
heat to kill pathogens
question
-stasis/-static
answer
halt growth , not kill
question
-cide/-cidal
answer
kill
question
Etiology
answer
study of the cause of a disease
question
Germ theory of disease
answer
disease caused by infections of pathogenic microorganisms
question
Pathogenicity
answer
ability of organism to cause disease
question
Virulence
answer
degree of pathogenicity (how they evade immune system and cause disease)
question
Virulence factors (4)
answer
1. adhesions
2. extracellular enzymes
3. toxins
4. anti-phagocytic factors
question
Adhesions
answer
process by which microorganisms attach themselves to cells
-specialized structures (lipoproteins or glycoproteins)
-attachment proteins (viruses)
-adhesins (bacteria)
question
extracellular enzymes
answer
enzymes secreted by pathogen that help pathogen dissolve structural chemicals in the body and invade further
(hyaluronidase, collagenase, coagulase, kinase)
question
Toxins- fucntion
answer
produced by pathogen- harm tissues or trigger host response that cause damage
-Toxemia- toxins in the bloodstream beyond the site of infection
question
2 types of toxins
answer
1. Exotoxins- cytotoxin, neurotoxin, enterotoxin
2. Endotoxins- Lipid A
question
Anti-Phagocyctic Factors
answer
1. Bacterial Capsule- composed of chemicals found in the body not recognized as foreign. Can be slippery and difficult for phagocytes to engulf
2. Anti-phagocytic chemicals- prevent fusion of lysosome and phagocytic vesicles OR destroys white blood cells (leukocidins)
question
Benefits of normal microbiota (2)
answer
1. antagonistic protection against pathogens
2. production of certain vitamins in the body
question
Normal sites of microbiota
answer
upper respiratory
digestive tract
Urinary and reproductive
skin and eyes
question
What conditions allow resident microbiota to cause disease
answer
immune suppression
changes in normal flora
introduction into unusual site in the body
question
Resident Microbiota
answer
bacteria that are a part of the normal microbiota throughout life (commensalism)
question
Transient Microbiota
answer
in/on the body hours to months before disappearing (same region as resident microbiota)
question
How are transient microbiota removed? (3)
answer
1. competition from other microorganisms
2. elimination by the body's defensive cells
3. chemical or physical changes in the body
question
when do we acquire our normal microbiota?
answer
during the birthing process and are established in the first months of life
question
Axenic
answer
womb generally free of microorganisms
question
How do pathogens enter the body? (4)
answer
skin
mucous membranes
placenta
parenteral route of administration (direct under the skin or mucous membrane)
question
contamination
answer
the presence of microbes in or on the body
question
Infection
answer
invasion and establishment by a pathogen
question
Disease
answer
pathogen alters the normal function of the body (morbidity)
question
5 stages of infectious disease
answer
1. incubation period (no signs or symptoms)
2. prodromal period (vague symptoms)
3. illness (most severe symptoms)
4. decline (declining symptoms)
5. convalescence (no signs or symptoms but still contagious)
question
Reservoirs of infection (definition and 3 types)
answer
sites where pathogens are maintained as a source of infection
1. animal
2. human carriers
3. nonliving reservoir
question
Zoonoses
answer
diseases that are spread from their animal reservoir to humans
-direct contact with animal or waste
-ingesting animals
-bloodsucking arthropods
question
Human carriers
answer
individuals who are asymptotic but infective to others
question
Nonliving reservoirs
answer
soil, water, food (often due to contamination by feces or urine)
question
3 groups of disease transmission
answer
transmission from either a reservoir or portal of exit
1. contact
2. vehicle (dust, water vapors, swimming pools, food)
3. Vector (flies and insects)
question
Methods of classification (4)
answer
1. body system effected
2. taxonomic groups of the causative agent
3. longevity and severity
4. how they are spread to host
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New