Test 3 Flashcards
Antiseptic methods were first introduced by
Lord lister
the term vaccine was coined by
pasteur
Define the theory of spontaneous generation.
The theory of spontaneous generation suggested that living organisms could arise from non-living matter. For example, people believed that maggots could arise from rotting meat.
Which historical figure is famous for introducing hygienic practice into surgery?
Lord Lister. He introduced antiseptic techniques in surgery using carbolic acid to reduce infections
Which disease assisted Jenner in making the smallpox vaccine?
Cowpox.
In 1796, England
Jenner noticed that the milkmaids who contracted cowpox did not contract small pox.
He inoculated James Phipps
with fluid from milkmaid’s
cowpox pustule
He then exposed the boy to small pox and noticed that the boy was immune.
Describe how Fleming discovered penicillin?
In 1928, Fleming observed that a mold growing in his petri dishes was inhibiting the growth of a bacteria, staphyloccus aureus. This bacteria was identifies as penicillium notatum, and helped discover the first antibiotic.
What are the 4 postulates of Robert Koch?
The suspected microorganism is present in every case of the disease and absent from healthy animals.
One must isolate and grow the microorganism in pure culture.
Injection (infection) of a healthy host with the microorganism in pure cultures must cause disease.
One must be able to isolate the microorganism from the new host.
Who produced the first vaccine against rabies and anthrax
Louis pasteur
What are microbes
Microorganisms or microbes- these microscopic organisms are essential to life on earth. they are commonly called “germs, viruses, agents…” but not all cause disease and can be useful.
What is microbiology
Microbiology is the study of very small living organisms called microorganisms or microbes, these include bacteria, algea, protozoa, fungi, viruses, and helminths
Which is bigger, virus, bacteria, protozoa?
Protozoa are the largest, then bacteria, then viruses.
Name three ways by which bacteria are classified?
- Classification by shape
- Cell wall classification by gram stain
Gram positive: thicker cell wall
Gram negative: thinner cell wall - Classification by dependence on oxygen
Anaerobes: grow and survive in environment where there is no oxygen
Aerobes: dependence on oxygen
Name two ways by which bacteria cause disease
- Using cells for food: The bacteria break down healthy cells for food, destroying tissues
- Releasing toxins: The bacteria produce a toxin that is released into the bloodstream where it can disrupt normal activity and damage tissues
Name three differences between viruses and bacteria
Viruses – non living organisms, unaffected by antibiotics, they only reproduce inside living cells/by infecting other organisms, no cytoplasm.
Bacteria – they are prokaryotic, contains a rigid cell wall, cytoplasm and ribosomes, affected by antibiotics, reproduce through binary fission.
Give examples of a fungi, protozoa, and helminth
Fungi – Candia, molds, yeast, mushrooms, penicillium, tinea
Protozoa – plasmodium which causes malaria
Helminth – worms eg tapeworm, hookworm, flatworm, round worm
Which helminth enters through walking on infected soil?
Hookworm
What colour are Gram-negative bacteria?
Red/pink because they do not retain the crystal violet dye but do take up the red.
What are the basic shape classifications of bacteria?
Rods: bacilli
Spiral: spirilla
Round: cocci
Describe the host, disease transmission and symptoms of tubercolosis
Host: Human
Disease transmission: Airborne (infected person coughs or speaks)
Symptoms: Prolonged cough, cheat pain, weakness weight loss, fever
Which disease was considered fashionable in the late 19th century?
Tuberculosis
Which infectious disease is transmitted by a mosquito and resides in the liver then blood cells?
Malaria
Which infectious disease is thought to have crossed to humans from African primates?
HIV/AIDS
What infectious disease has the highest R value?
measles = 16
Name 2 infective diseases with virtually 100% mortality.
Rabies
Mad cow disease
What infectious disease is worsened by the ingestion of aspirin?
Reye disease
Which childhood disease usually gives lifelong immunity once infected?
measles
The glass test helps diagnose which infection?
meningitis
Describe the different mechanisms of bactericidal and bacteriostatic antibiotics. Give examples.
Bactericidal antibiotics - Kills bacteria, reduces bacterial load
Bactericidal agents inhibit synthesis of bacterial cell walls by affecting peptidoglycans
Examples of bactericidal antibiotics:
Penicillins & cephalosporins
Amoxicillin
Bacteriostatic - Inhibit growth and reproduction of bacteria by affecting bacteria protein production and dna synthesis.
Examples of bacteriostatic antibiotics:
Tetracyclines
Chloramphenicol
List 5 factors contributing to antimicrobial resistance.
Overprescription, overuse, misuse and inappropriate use of antibiotics
* Use of outdated medications
* The delivery of more complex health care which may require longer use of antibiotics
* Prolonged hospitalisation
* Use of antibiotics in foods
Describe the mechanism of four types of vaccines: live attenuated, inactivated, subunit, and toxoid.
Live attenuated: contain weakened form of live pathogen. Requires 1-2 doses. Examples: Measles, mumps, rubella, smallpox
Inactivated: contain killed pathogen. Requires several doses (booster shots). Examples: Hepatitis A, rabies, inactivated poliovirus vaccine
Subunit: contain killed, pieces of the pathogen (eg protein). Requires several doses (booster shots)
Examples: Hepatitis B
Toxoid: Contains toxins made by pathogen. May require booster shots.
Examples: Tetanus
Types of microbes
- Bacteria (prokaryotes)
- Viruses
- Fungi
- Protozoa
- Helminths
The most common types of microorganisms
bacteria, viruses and fungi.
describe gram positive and gram negative bacteria
Gram positive: thicker cell wall
Gram negative: thinner cell wall
What is the R0 value
How many infected people will infect more people.
benefits of sporulation
- Resistant to heat, chemicals, radiation
- Dormant, non-dividing state
- Can germinate and return to normal division once stress has passed
how can antibiotic resistance be reduced
- In the community
General practice
Not prescribing antibiotics for colds and flu
Delayed prescribing
Pharmacies
Offering symptomatic support for cold and flu - In the home
Not taking antibiotics that haven’t been prescribed for you
Discarding old antibiotic medicines appropriately - In industry
Investing in research and development for antimicrobials
Describe the host, disease transmission and symptoms of cholera. also if its gram neg or pos
Host: Humans
Transmission: Is water borne, so drinking contaminated water or food
Symptoms: mild symptoms, or watery diarrhea, vomiting, resulting in massive fluid loss
- Gram –ve bacteria
Describe the host, disease transmission and symptoms of HIV/AIDS.
Host: humans
Transmission: Transmitted through unprotected sex, needle sharing, blood products
Symptoms: weak immune system, fever.
fatigue.
headache.
Describe the cause, host, disease transmission and symptoms of small pox
Caused by variola virus
Host: humans
Transmission: infective droplets during close contact with infected people who have symptoms of the disease, or in some cases through contaminated clothing and bedding.
Symptoms: Fatigue, abdominal pain, then rash with pus that later develops a crust.
Describe the host, disease transmission and symptoms of the black death (plague). and if its gram negative or positive
Host:* Host is a rodent.
Transmission:Flea bites rodent and acquires disease. Flea bites
human. Human transmits to human via respiratory droplets in
pneumonic form.
Symptoms: flu like symptoms, vomiting, swollen lymph nodes
gram negative bacteria
mortality vs morbidity
mortality - number of deaths
morbidity - specfic illness
Approximately what % of microbes cause disease in human?
3
Define the term epidemic, endemic, pandemic
Epidemic: disease occurrence of an infectious disease in a community at a particular time.
Endemic: disease or condition present among a population at all times. Ex: malaria is always in Africa because of the mosquitoes.
Pandemic: a disease or condition that spreads across regions. Ex: Covid 19
What is active and passive immunisation? What advantages and disadvantages exist in their use?
Active immunisation: Involves stimulating the immune system to produce its antibodies and memory cells (e.g., vaccines).
Advantages: Long-lasting immunity.
Disadvantages: Takes time to develop immunity, might require booster doses.
Passive Immunisation: Involves the direct transfer of antibodies (e.g., from mother to baby or via antibody-containing products).
Advantages: Immediate protection.
Disadvantages: Temporary immunity, no long-term memory.
What are mRNA vaccines?
mRNA vaccines carry genetic material that teaches our cells how to make a harmless piece of “spike protein,” which is found on the surface of a virus.
What is attenuation and inactivation? What advantages and disadvantages exist in the use of vaccines generated by these two methods?
Attenuation: Weakening the pathogen so it can’t cause serious disease but still stimulates an immune response.
Advantages: Strong, long-lasting immunity.
Disadvantages: Risk of causing disease in immunocompromised people.
Inactivation: Killing the pathogen so it can’t replicate, but it can still trigger an immune response.
Advantages: Safe for immunocompromised individuals.
Disadvantages: May require booster doses for lasting immunity.
