Lecture Exam 4 Flashcards
Where does Penicillin come from?
Fungi mold
Antibiotic
A chemical agent that kills/inhibits bacterial growth.
Who discovered Penicillin?
Alexander Fleming
Chemotherapeutic Index
Maximum dose tolerated by patient / Minimum dose that cures
- Finds the dose of antibiotic that will target the pathogen and not harm the host.
⇈ Index : Targets pathogen (Safe)
⇊ Index : Can potentially kill patient (More dangerous)
Selective Toxicity
Selective toxicity refers to the ability of the drug to targets sites that are relative specific to the microorganism responsible for infection.
Broad Spectrum Antibiotic
Kills a large variety of microbes
- Affects many gram positive and negative bacteria
Narrow Spectrum Antibiotic
Kills a very specific microbe
- Either gram positive or gram negative
When are broad spectrum antibiotics prescribed?
When an illness cannot be identified.
Bacteriocidal
Kills bacteria
Bacteriostatic
Inhibits the growth of bacteria
- Cell wall or other
Modes of Administration
Oral - Through the mouth, mmm yummy yummy
• Ex: Pills, cough syrup, etc.
Topical - Applied directly on the skin
• Ex: Neosporin
Parenteral - Injection
• Ex: Vaccines, morphine drip
Antibiotic Modes of Action
⓵ Inhibiting cell wall synthesis ⓶ Disruption of cell membrane ⓷ Disruption of translation at ribosome ⓸ Interference with metabolism ⓹ Inhibiting DNA/RNA production
Inhibition of cell wall synthesis
Beta-lactams: (FUNGAL)
- Destroy NAG/NAM chains and protein cross-links.
Disadvantages: Allergies, Bacterial resistance
-------------------
• Penicillin
• Synthetic penicillin
• Cephalosporins
• CarbapenemsWhat is a solution to combat Penicillin resistant bacteria?
Synthetic versions - Side chains are added to decrease enzyme degradation. (Broader spectrum)
- Serves as a “distraction”, bacteria attack additional chains rather than the drug itself.
RISK: Can destroy natural flora
Beta-Lactam Resistant Bacteria
Beta-lactamase (penicillinase) - An enzyme created by bacteria that destroys beta-lactam rings. Drug becomes ineffective.
Why are extreme broad spectrum antibiotics dangerous?
These antibiotics can destroy normal flora.
Clavulanic Acid
Chemical group in synthetic penicillin.
- Occupies penicillinase so the beta-lactam ring can work without being destroyed.
Disadvantage: Creation of resistant bacteria
Synthetic / Semi-synthetic Penicillin
Risk: Broader spectrum, create bacterial resistance
- Can be taken orally
What are Ethambutol and Isoniazid known to cure?
They are often used in combination to cure Tuberculosis.
What antibiotic is used to cure Legionnaire’s disease and atypical pneumonia?
Erythromycin (Macrolides)
Anti-viral Modes of Action
⓵ Block viral uncoating
⓶ Inhibit reverse transcriptase
⓷ Protease inhibitors
⓸ Cause mutations in DNA and RNA (Nucleoside
analogs)
⓹ Inhibiting DNA/RNA productionNucleoside Analogs
A fake nitrogenous base
- Drug that mimics a base in DNA/RNA
What is an Upper Respiratory Infection?
An acute URI is a contagious infection of your upper respiratory tract. Your upper respiratory tract includes the nose, throat, pharynx, larynx, and bronchi.
Viral Infections of the Upper Respiratory Tract
Common cold
- Caused by:
Rhinoviruses (50%)
Coronaviruses (20%)
AdenovirusesThe Common Cold (URI)
(VIRAL)
Signs/Symptoms:
﹥Scratchy throat, runny nose
Incubation period:
﹥1-2 days (Caused by a single virus)
Transmission:
﹥Droplets, fomites
Treatment:
﹥Cough suppressants, and antihistamines (There
isn't really a cure lol)Rhinovirus (URI)
- Binds specifically to cells in the nasal cavity
- Triggers an inflammatory response, mucus and
sneezing. - Reproduce at 33°C
Adenoviral pharyngitis (URI)
(VIRAL)
Signs/Symptoms:
﹥Common cold, fever
Incubation period:
﹥5-10 days
Transmission:
﹥Droplets, fomites
Treatment:
﹥Cough suppressants, and antihistamines (There
isn't really a cure lol)Streptococcal pharyngitis (URI) (Strep throat: S.pyogenes)
(BACTERIAL)
Signs/Symptoms:
﹥Sore throat, fever, malaise (fatigue), pus
production
Pathogen:
﹥Beta Hemolytic, has the ability to lyse blood cells.
- S. pyogenes
Incubation period:
﹥2-5 days
Transmission:
﹥Droplets, fomites
Treatment:
﹥10 days penicillin, erythromycinS. pyogenes Virulence Factors
C5 Peptidase:
- Enzyme that breaks down C5a compliment
M Protein:
- Allows bacteria to attach to host cells and
escape phagocytosis
Streptolysin (Hemolysin):
- Allows it to lyse RBCs
Streptokinases:
- An enzyme created to destroy blood clots and
spread through damaged tissues.
Hyaluronic acid capsule:
- Mimics your cells to avoid being destroyed
What is C5a?
A component that helps attract WBCs to a site to enhance phagocytosis of an infection.
Upper respiratory infections (UTIs)
- Pharyngitis
- Rhinitis
- Sinusitis
- Epiglottitis
What kind of virus survives on fomites?
Naked viruses
What does it mean for a bacteria to be beta-hemolytic?
Beta-hemolytic bacteria can lyse RBCs
Where did pus get it’s name?
Pyogenes = Pyogenic = Pus producing
S. pyogenes Infection Complications
- Rheumatic fever
- Scarlet fever
- Acute Glomerulonephritis
- Sydenham’s Chorea
Rheumatic Fever (S. pyogenes complication)
Occurs when the body produces antibodies to combat a S. pyogenes infection.
- Antibodies may cross react with muscle fibers, causing the heart valves to swell.
- Blood leakage, valves unable to shut.
Scarlet Fever
Pathogen:
- Only caused by S. pyogenes strains that produce
Erythrogenic Toxins
Transmission:
- Droplets/direct contact, occurs after initial Strep
Signs/Symptoms:
- Rash, high fever, strawberry tongue (It’s super
red)
Treatment:
- 10d of penicillin/erythromycin
Acute Glomerulonephritis
Accumulation of S. pyogenes antibodies in the kidneys, leads to inflammation.
- Sequela
Sydenham’s Chorea
Antibodies produced to combat S. pyogenes has the potential to attack the basal nuclei in the brain.
- Causes dysfunction, uncontrollable jerks
- Goes away in a few months
What is the importance of the basal nuclei?
It controls the coordination of muscle movements
Epiglottitis (URI)
Signs/Symptoms:
- High fever, trouble swallowing (Extreme
swelling in the epiglottis)
Cause:
- Haemophilus influenza type b (Hib).
Transmission:
- Droplets
Treatment:
- Immunization, ampicillin, 3rd gen cephalosporin,
HIB Vaccine
Protects against epiglottis and meningitis in children
Otitis Media (URI)
Infection of the middle ear
- Commonly affects children because they are
smaller.
Smaller ear canals allow for easy blockage.
Cause:
- Streptococcus pneumonia (+), alpha hemolytic
Treatment:
- Modified penicillin, amoxicillin
Diphtheria (URI)
Caused by Corynebacterium diphtheria
(+ pleomorphic rods)
Signs/Symptoms:
- Sore throat, fever, pseudomembranes, paralysis.
- Kills cells at the back of the throat lead to
inflammation and create a psuedomembrane
Incubation
- (2-4 days) Grow by snapping division and in
Chinese lettering patterns
Transmission:
- Spread through droplets, direct contact
Treatment:
- DTP Vaccine, antitoxin, erythro/penicillin
Pseudomembrane
The hardening of dead cells caused by diphtheria, blocks airways.
What does diphtheria mean?
It means leather in Greek
- Consistency of leather
What happens if diphtheria gets into the blood?
Can cause death, paralysis.
Spreads to the brain, and heart.
DTP Vaccine
Used for Diphtheria
- TOXOID: Inactive version of the bacteria.
What is an antitoxin?
Antibodies against the toxin.
- Surround and neutralize toxins
Whooping Cough (LRI) (Bordetella Pertussis)
Obligate Aerobe, Gram (-) coccobacillus.
Signs/Symptoms:
- Runny nose, violent coughing, convulsions
Transmission:
- Droplet/direct contact
Incubation:
- 1-3 weeks
Treatment:
- Erythromycin (early treatment), and DTaP Vaccine
Affects the Trachea!!Pertussis Virulence
Capsule is present in most strains
- Pertussis Toxin
- Tracheal cytotoxin
Pseudostratified ciliated epithelium
Lines the Respiratory Tract.
- Forms mucouciliary escalator (Production of
mucous), cilia moves mucous up and out to
avoid further infection.
Pertussis Toxin
Attaches to epithelial cells. Creates mass amounts of mucous
Tracheal Cytotoxin
Toxin paralyzes and kills cilia, no way to push mucous out of the epithelium
- Violent cough (wheezing)
Pertussis progression
1) Incubation: 1-3 weeks
2) Catarrhal: prodromal phase, mild symptoms that last for a while
3) Paroxysmal: Violent coughing, lasts 6 weeks.
4) Convalescence
Tuberculosis (LRI)
Mycobacterium Tuberculosis
Obligate aerobe, acid fast
Incubation/Generation time:
- 12-24 hrs (Long gen time), 3 month incubation
- Resistant to drying/disinfectants
Signs/Symptoms:
- Night sweats, fever, weight loss, cough
Transmission:
- Droplets
Treatment:
- Isoniazid + Rifampin + Streptomycin + Ethambutol
for 2 months
- BCG Vaccination
Tubercle
Big ball of macrophages
- Used to prevent bacteria from spreading to the rest
of the lungs.
- Collagen fibers help seal off the infection by
building up around it
Primary Tuberculosis
Inapparent infection
- No symptoms and not contagious
IF their immune system is weak –> Secondary tuberculosis
Secondary Tuberculosis
Very contagious
- Bacteria is reactivated, Bacteria gains access to
blood
Disseminated Miliary Tuberculosis
Tuberculosis that can potentially spread to other organs in the body
Anthrax
3 forms: Inhalation, skin, and GI form
NOT CONTAGIOUS
Endospores: 8k-50,000k (infective dose)
Signs/Symptoms:
- Initial cold/flu. Eventual violent coughing, nausea,
vomiting, death, fainting, shock
Treatment:
- Aggressive treatment with drugs, draining of
lungs, most people who are affected die.
Vaccine:
- Given to military because Anthrax is considered as
a potential bio-weapon
- Given to animal handlers
Which form of anthrax is the deadliest?
Most contagious?
1) Inhalation
2) Cutaneous (skin)
What is Woolsorter’s Disease?
Inhalation Anthrax.
- Named because endospores could attach to
sheep hide, wool, and dust
Where do anthrax endospores germinate?
In the lungs
What does the anthrax toxin do?
The anthrax toxin kills and causes edema
Pneumococcal Pneumonia - Adult pneumonia
Streptococcus Pneumoniae
83 different types
Capsule controls virulence factor (+ causes disease)
Signs/Symptoms:
- Cough, fever, chills, Rust colored Sputum
Transmission:
- Droplet
Incubation:
- 1-3 days
Pathogenesis:
- Fill lungs with fluid and destroy cells.
Treatment:
- Penicillin, 3rd gen ceph, erythromycin,
chloramphenicol
- Pneumovax Vaccine: given to elderly and nurses
Which bacteria is responsible for causing Lobar Pneumonia?
Streptococcus Pneumonia
Pneumococcal
What antibiotic is best suited for curing pneumonia?
Erythromycin
Klebsiella Pneumoniae
Hemorrhagic
Signs/Symptoms:
- Cough, fever, bloody sputum,
Transmission:
- Droplets
Treatment:
- Cephalosporin + AminoglycosideWhat is the most common type of pneumonia?
Klebsiella Pneumoniae
Why is Klebsiella Pneumoniae considered Hemorrhagic?
When a person is infected, this causes lots of bleeding in the lungs.
Destroys alveoli
Walking pneumonia
Mycoplasma pneumoniae
Signs/symptoms:
- cough, malaise, eventual fever
Incubation:
- 2-3 weeks
Transmission:
- Droplet
Treatment:
- ErythromycinChlamydial Pneumonia
A type of pneumonia Resembles mycobacterial pneumonia - Transmitted through the respiratory route Treatment: - Erythromycin
Legionnaire’s Disease
A type of pneumonia
- Caused by legionella
- high fever, cough, and death
- Transmitted through air conditioning, spas,
humidifiers, and water fountains
Incubation
- 2-10 days
Treatment:
- ErythromycinInfluenza (LRI)
Enveloped virus containing spike proteins: - H spike, N spike Incubation time: - 1-3 days Signs/Symptoms: - Cough, sudden fever, pharyngitis Treatment: - Amantadine + Tamiflu
Hemagglutinin spike
Antigenic, attach to target cells
Neuraminidase spike
Weakly antigenic, liberation from host cell
Antigenic Drift
A slight change in a strain of virus
Antigenic Shift
When 2 flu viruses infect the same cell, creating a completely new virus.
