Bio Presentation Questions

How is tuberculosis transmitted?

As an airborne pathogen (talking, coughing, etc.)

Why is Mycobacterium tuberculosis considered acid-fast?

It doesn’t stain easily with standard methods due to its unique waxy cell wall

Why does tuberculosis primarily infect the lungs?

Mycobacterium tuberculosis is an obligate aerobe, and the lungs provide a highly oxygen-rich environment. Additionally, TB is transmitted through inhalation of airborne droplets, so the bacteria naturally enter and settle in the lung tissue first

What are the 3 parts of Bacillus anthracis produced toxin, and which one is necessary for delivery of the toxin?

The 3 parts of the Bacillus anthracis toxin are the: protective antigen, edema factor, and lethal factor. The protective antigen is the delivery method of the toxin.

Briefly explain what antibiotics, antitoxins, vaccines do for Anthrax treatments?

Antibiotics kill bacteria, antitoxins block toxins from entering cells, vaccines train the immune system

What is the most dangerous route of infection, and why is it the most dangerous? What are the symptoms?

The most dangerous route of infection is inhaled anthrax, because once in the lungs, the toxins will quickly spread throughout the rest of the body and will quickly kill the host. Symptoms will start as a cold, but slowly progress, with the final symptom being swollen lymph nodes on the chest.

Explain why there is no vaccine for prion diseases

Prion diseases are caused by the misfolding of a protein common in the central nervous system. It is not a virus or a pathogen that could be targeted by vaccines or medication, and the immune system ignores it.

What is the difference between the peripheral and hereditary routes of infections for prion diseases? Which is more common?

The difference between peripheral and hereditary routed of infections for prion diseases is that peripheral infections are acquired from ingestion or contaminated surgical equipment, and hereditary prion diseases are genetic mutations which are inherited. Hereditary prion diseases are more common than peripheral infections.

True or False: PrPc is the infectious form of the prion protein that forms beta pleated sheets and is not susceptible to proteases.

False! The infectious form of the prion protein is the PrPSc protein. PrPc is the normal prion protein that is rich in alpha helices and susceptible to proteases.

What causes Lyme disease, and how is it transmitted to humans?

Lyme disease is a bacterial infection caused primarily by the bacterium Borrelia burgdorferi (and rarely B. mayonii in the U.S.), transmitted to humans through the bite of infected blacklegged ticks (deer ticks).

Why must an infected tick typically remain attached for 36-48 hours to efficiently transmit Lyme disease?

Infected ticks must typically remain attached for 36–48 hours to transmit Lyme disease because the bacteria (Borrelia burgdorferi) reside dormant in the tick's gut and require time to activate, migrate to the salivary glands, and enter the host through saliva.

How does the structure of B. burgdorferi help it invade and spread through human tissues?

Describe 2 roles microorganisms play in freshwater environments

Microorganisms handle nutrient recycling, as well as being the primary oxygen producers for the ecosystem

What would be an expected difference between a lake effected by an invasive species and one that is not

Invasive species compete for nutrients in the ecosystem; this will affect the overall ecosystems health. Another common difference is the effect on the healthy fish/animal health.

What conditions are typical for Algal Blooms to form?

They typically form in warm water with low wind and high nutrient content

What type of microorganisms causes influenza?

Influenza is caused by a virus, specially an enveloped single-stranded RNA virus

What are the high-risk populations

Children under 5, adults over 65, pregnant women, and immunocompromised individuals

Why must influenza vaccines be updated regularly?

Influenza viruses mutate rapidly through antigenic drift and sometimes shift. These processes change their surface proteins so immunity from previous vaccines may no longer be effective

What are the two types of enzymes in the process?

Hydrolase and oxidoreductase enzymes

What are the two types of microorganisms that create biofilms around microplastic particles?

Bacteria and fungi

What type of plastic is the most easily degraded by microbes?

PET (Polyethylene terephthalate)

Name three forms of antibiotic pollution and whether they impact the hydrosphere, lithosphere, or atmosphere

Hospital effluents, wastewater and sewage, and manure application in agriculture are three forms of antibiotic pollution. Hospital effluents, wastewater and sewage affect the hydrosphere, while manure application in agriculture affects the lithosphere.

Describe two ways E. Coli has developed antibiotic resistance. Why is it already more difficult to treat with antibiotics?

Horizontal gene transfer provides resistance to E. coli through the uptake of resistance genes via plasmids. Biofilm formation is another advantage for E. coli because it limits drug penetration when the bacteria are clustered together. E. coli without these advantages is already rather difficult to treat because it is Gram-negative, having an outer membrane that further blocks antibiotics

Describe a solution to antibiotic pollution and resistance and explain why it works.

One solution to antibiotic pollution is ensuring that there are proper disposal instructions for the public and prescription companies when disposing of prescriptions. This way, less antibiotics are released into the environment, which interact with less bacteria and mitigate the increase in antibiotic resistance.

How could technology improve antibiotics in the future?

New technologies like AI can help scientists discover antibiotics faster. This is because AI can analyze large amounts of data to find the most effective compounds. This is important when it comes to fighting bacteria resistance. These advancements in technology could lead to safer and more effective treatments

What is the purpose of having different types of penicillin?

There are different kinds of penicillin to account for different treatments needed for diseases. While natural penicillin is good for treating some infections, semi-synthetic and combined penicillin are essential for the treatment of infections and diseases that are too advanced for natural penicillin.

How does penicillin work as an antibacterial drug?

Penicillin works best against Gram-positive bacteria by attacking the peptidoglycan layer. It binds to the enzyme (known as transpeptidases or PBPs) responsible for the strong cross links within the layer, causing the peptidoglycan layer to become weak and leaky. This ultimately leads to the bacterial cell bursting, allowing the immune system to attack the bacteria faster.

Explain why rabies remains a major public health issue in developing countries, and remains relatively rare in developed countries

Rabies is a major public health issue in developing countries as vaccination programs and PEP access is limited

Why is prompt post-exposure prophylaxis (PEP) important after exposure to rabies and what does treatment involve?

PEP is critical after exposure to rabies because the virus initially replicates in muscle tissue and then travels through nerves to the nervous system. Once it reaches the brain and clinical symptoms appear, rabies is almost always fatal, so early treatment is critical. PEP involves two main steps: thorough cleaning of the wound and a series of rabies vaccines. Treatment is highly effective when given immediately after the incident.

How does the mechanisms of the rabies virus suppress the human immune system?

One way the rabies virus suppresses the immune system is by interfering with the production of interferons. Afterwards the rabies virus will spread further into the nervous system.

A neighborhood water pump is causing a cholera outbreak. What could be a source of contamination of the water source?

Poorly built cesspits surrounding the groundwater could degrade and seep into the water source. As well as water treatment plants obtain their water downstream from sewage runoff.

Describe the specific roles of antibodies and memory cells in providing immunity against Vibrio cholerae.

Secretory IgA prevents bacteria from colonizing the intestinal lining, while IgM kills bacteria in the blood. IgG neutralizes the cholera toxin and helps to prevent dehydration. Memory B cells will provide long-term resistance by being able to rapidly produce antibodies if the body comes in contact with the pathogen again.

Why can the Epstein Barr Virus stay in the body for life?

EBV integrates its DNA into memory B lymphocytes and remains dormant. The virus will continually produce small metabolic viral proteins while in the dormant cycle.

What is the difference between the lytic and lysogenic life cycles of the Epstein Barr Virus?

The lytic cycle of EBV takes place in epithelial tissue, while the lysogenic cycle occurs in memory B lymphocytes

How does the immune system respond to the Epstein Barr Virus?

Infected cells signal other cells to become infection-resistant, and T cells release cytotoxins to kill off the infected memory B cells. In latent infections T cells constantly monitor for latent proteins produced by the infection.

What bacteria cause tetanus, and what are the basis facts.

The bacteria are called Clostridium tetani. It is Gram-positive and thrives in anaerobic conditions.

What are the two main sources of infection?

Spores enter the body through puncture wounds, commonly form rust nails, and improperly sterilized medical equipment

What is the role of Tetanus Immune Globulin (TIG) in treating tetanus?

TIG neutralizes the toxins in the body that have not bound to nerves yet but cannot reverse damage done already

Are salmonella and E.coli acute, chronic or latent illnesses?

They are both acute sicknesses. They both occur after one exposure and last up to hours or weeks, but with a defined timeline

What is one similarity and one difference when it comes to causes of Salmonella and E.coli infection?

You can obtain both illnesses by consuming tainted food or water. For Salmonella, you can also obtain the illness from improperly handled food and infected surfaces or animals, and in an E. coli infection, it can be obtained person-to-person by fecal-oral contact

When are antibiotics appropriate for treating these food-borne infections and when might they be harmful?

Antibiotics are appropriate for both infections when there are several cases. However, antibiotics can be harmful in E.coli infections if a person has kidney failure.