Unit 7 Discussion Questions (Zoom) Flashcards
- If any of the adhesion mechanisms in the objectives are inactivated, then what do you think would be the effect?
- No adhesion: Without the ability to attach, pathogens would not be able to colonize tissues or invade deeper layers of the host, making it harder to cause disease.
- Decreased virulence: Many pathogens rely on specific adhesion factors (such as adhesins or ligands) to bind to host receptors. Inactivation of these factors would reduce the pathogen’s ability to infect or spread within the host.
- Increased immune response: If pathogens cannot adhere to cells or tissues, the immune system might be able to clear them more effectively, as the pathogens would be more easily recognized and removed by the body’s defenses.
- Some strains of Staphylococcus aureus produce exfoliative toxin, a chemical that causes portions of the entire outer layer of the skin to be sloughed off in a disease called scalded skin syndrome.
Given that cells of the outer layer are going to fall off anyway, why is this disease.
The toxin induces the premature and widespread separation of the skin layers, which results in the loss of the outer skin’s protective barrier.
This leads to:
Increased vulnerability to infection: The loss of the protective outer skin layer leaves the underlying tissues exposed to pathogens and environmental harm, increasing the risk of secondary infections.
Fluid loss and dehydration: The sloughing off of skin can also result in excessive fluid loss, which can lead to dehydration and electrolyte imbalances.
Systemic complications: In severe cases, the damage to the skin can result in systemic effects such as infection spreading through the bloodstream (sepsis)
- Sweat glands in the armpits secrete perspiration with a pH close to neutral (7.0). How does this fact help explain body odor in this area as compared to other parts of the skin?
Contributes to body odor because of the specific conditions it creates for bacterial growth.
- Neutral pH environment: Bacteria, particularly Gram-positive bacteria like Staphylococcus species, thrive in neutral pH conditions.
These bacteria break down the proteins and lipids found in sweat, producing compounds that have a characteristic strong odor.
- High concentration of sweat glands: The armpits have a high density of apocrine sweat glands, which are more active in producing sweat that contains proteins, lipids, and other organic compounds.
These substances are food sources for odor-causing bacteria.
- Using your knowledge of microbiota, why do you think that people are taking probiotics (active “good” bacteria) capsules to help them stay healthy?
By replenishing good bacteria, probiotics can support digestive health, strengthen the immune system, and help prevent the overgrowth of harmful pathogens.
Which the microbiota plays a crucial role in
- During tummy tuck surgery, the plastic surgeon accidentally punctured the patient’s intestine but didn’t realize it because it was the size of a period. Twenty-four hours after surgery, the patient had a fever, swelling, and redness surrounding the sutures, and had severe abdominal pain. At the ER, the doctor took samples from the surgical site and did blood work. Various enteric bacterial species, such as E. coli were identified.
Do you think it is possible that the infection was due to the patient’s microbiota? Explain.
Yes, it is possible that the infection was due to the patient’s microbiota, specifically from the bacteria like E. coli that naturally reside in the intestines.
When the surgeon accidentally punctured the intestine, it allowed these normally harmless bacteria to enter the sterile abdominal cavity, causing an infection.
- Scientists can raise “germ-free” animals in axenic environments. Would such animals be as healthy as their worldly counterparts?
No, germ-free animals would not be as healthy as their counterparts in the natural environment because they lack the beneficial microbiota that play a crucial role in digestion, immunity, and protection against pathogens.
Without these microbes, their immune systems would be underdeveloped, and they may suffer from various health issues, including poor nutrient absorption and increased susceptibility to infections.
- Mary, age 65, has had diabetes for 40 years, with damage resulting to the small blood vessels in her feet and toes. Her circulation is impaired. How might this condition affect her vulnerability to infection?
Mary’s impaired circulation due to damaged blood vessels in her feet reduces the delivery of immune cells and nutrients to the affected areas, making it harder for her body to fight off infections.
Additionally, poor blood flow can lead to slower healing of wounds, increasing the risk of infections becoming more severe or chronic.
- What might happen to someone whose body did not produce C3? C5?
If someone’s body did not produce C3, their complement system would be severely impaired, preventing efficient opsonization, immune cell recruitment, and the formation of the MAC, making them more vulnerable to infections.
Similarly, the lack of C5 would disrupt the inflammatory response and prevent the formation of the MAC, further compromising the body’s ability to defend against pathogens.
- A patient has a genetic disorder that prevents him from synthesizing C8 and C9.
What effect does this have on his ability to resist bloodborne Gram-negative and Gram-positive bacteria?
What would happen if C3 and C5 fragments were also inactivated?
If a patient is unable to synthesize C8 and C9, they would have a reduced ability to resist bloodborne Gram-negative bacteria, as these components are crucial for forming the membrane attack complex (MAC) that helps kill bacteria by disrupting their cell membranes.
Gram-positive bacteria are less affected by C8 and C9 deficiency, as they lack the outer membrane that Gram-negative bacteria possess, making them less reliant on the MAC.
If C3 and C5 fragments were also inactivated, the patient would face even greater difficulty in fighting infections.
Without C3, the body would lack the ability to efficiently opsonize pathogens and activate the complement cascade, impairing both the immune response and the formation of the MAC.
Without C5, the inflammatory response would be diminished, and the immune system would be less effective in recruiting immune cells to sites of infection.
- Scientists are interested in developing antimicrobial drugs that act like the body’s normal antimicrobial peptides. What advantage might such a drug have over antibiotics?
An antimicrobial drug that mimics the body’s natural antimicrobial peptides could target a broader range of pathogens, including drug-resistant strains, without disrupting the normal microbiota.
Additionally, since these peptides are part of the innate immune system, they could reduce the risk of resistance developing.
- A patient has a genetic disorder that makes it impossible for her to synthesize complement protein 8 (C8). Is her complement system nonfunctional? What major effects of complement could still be produced?
No, the complement system would not be entirely nonfunctional if the patient cannot synthesize C8, but some key functions would be impaired.
For example, the formation of the membrane attack complex (MAC), which is essential for directly killing pathogens, would be hindered,
but other complement activities such as opsonization and inflammation could still occur through alternative pathways.
- While using a microscope to examine a sample of pus from a pimple, Maria observed a large number of macrophages. Is the pus likely from an early or a late stage of infection? How do you know?
Late stage because pus is made of dead phagocytes
The pus is likely from the later stage of infection because macrophages are typically involved in the resolution phase of infection, where they clean up dead cells and pathogens.
In the early stages, neutrophils are the predominant immune cells responding to the infection.
- How do drugs such as aspirin and ibuprofen act to reduce fever? Should you take fever-reducing drugs or let a fever run its course?
Aspirin and ibuprofen reduce fever by inhibiting the production of prostaglandins, which are chemicals that promote fever as part of the body’s inflammatory response.
Whether to take fever-reducing drugs or let a fever run its course depends on the severity of the fever and the underlying cause, but generally, it is advisable to manage fever if it becomes too high or uncomfortable.
