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Assignment #10 Due: 11:59pm on Tuesday, May 30, 2017 You will receive no credit for items you complete after the assignment is due. Grading Policy

Microbiology Animation: Host Defenses: Overview

Click here to complete this activity. Then answer the questions.

Part A A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component? ANSWER:

Inflammation Antibodies The complement system Skin barrier

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Part B First line defenses have what aspect in common with each other? ANSWER:

They involve unique cells that attack invading pathogens. They are physical barriers against invading pathogens. They involve the production of antibodies. They recognize specific pathogens.

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Part C Both the innate and adaptive defenses of the immune system work to prevent ANSWER:

colonization by pathogens. disease. penetration by invading pathogens. the penetration and colonization by pathogens, and the diseases they cause.

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Part D If a new bacterial pathogen entered a human body through an accidental needle stick, the first cell that would try to kill the pathogen would likely be ANSWER:

an antibody-producing cell. a cytotoxic T cell. a phagocyte.

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Visualize It! Figure 2 You will label the types of leukocytes.

Part A Label the various leukocytes. Drag the appropriate labels to their respective targets. ANSWER:

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Visualize It! Figure 1 You will label the steps involved in phagocytosis.

Part A Label the steps of phagocytosis. Drag the appropriate labels to their respective targets. ANSWER:

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Microbiology Animation: Phagocytosis: Overview

Click here to complete this activity. Then answer the questions.

Part A Phagocytosis is defined as ANSWER:

the feeding of protozoans. the ingestion of solid material by a eukaryotic cell. cells of the immune system that ingest pathogens. the uptake of liquid material by a eukaryotic cell.

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Part B How is phagocytosis in the immune system different from protozoan phagocytosis? ANSWER:

Protozoan phagocytosis is used to fight infection; phagocytosis by immune cells is used to feed the cells. There is no difference between the two. Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.

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Microbiology Animation: Phagocytosis: Microbes that Evade it

Click here to complete this activity. Then answer the questions.

Part A How is Streptococcus pneumoniae able to avoid destruction by a phagocyte? ANSWER:

They prevent the fusion of the lysosome and phagosome. They cause the lysosomes to empty their contents into the phagocyte, killing it. Their capsules make them "slippery" to phagocytes.

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Part B Which microorganism requires the low pH inside a phagolysosome in order to reproduce? ANSWER:

Haemophilus influenzae Streptococcus pyogenes Streptococcus pneumoniae Coxiella burnetii

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Part C Which of the following microorganisms use M protein to avoid destruction of a phagocyte? ANSWER:

Haemophilus influenzae Streptococcus pneumoniae Coxiella burnetii Streptococcus pyogenes

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Microbiology Animation: Phagocytosis: Mechanism

Click here to complete this activity. Then answer the questions.

Part A What does the plasma membrane of a phagocyte attach to on a microorganism? ANSWER:

Pseudopods Glycoproteins Lysosomes Phagosomes

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Part B The process by which a phagocyte moves toward a chemical signal at the site of an infection is called ANSWER:

adherence. elimination. chemotaxis. digestion. exocytosis.

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Part C Which of the following phagocytic processes occurs last in the sequence? ANSWER:

Exocytosis Adherence Formation of the phagolysosome Chemotaxis of the phagocyte to the site of infection

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Part D What is the role of opsonins? ANSWER:

They are present on the surface of phagocytes. They aid in the formation of the phagolysosome. They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader. They attract phagocytes to the location of infection.

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Part E What is a phagolysosome? ANSWER:

A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest. A vesicle containing only an engulfed invading microorganism. The structure that results from the fusion of a phagosome and a lysosome. A vesicle containing only digestive enzymes and other antimicrobial compounds.

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Microbiology Animation: Inflammation: Steps

Click here to complete this activity. Then answer the questions.

Part A What direct effect do histamines and leukotrienes have on capillaries? ANSWER:

They allow capillary walls to open and become leaky. They decrease the diameter of capillaries. They prevent phagocytes from sticking to the walls of capillaries.

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Part B Emigration is ANSWER:

the attachment of phagocytes to the walls of capillaries. the increase in the diameter of blood vessels. the production and release of chemicals during inflammation. the migration of phagocytes through blood vessels to the site of tissue damage.

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Part C Why is vasodilation important to tissue repair? ANSWER:

It allows more phagocytes to travel to the site of damage. It allows for an increase in oxygen to the site of damage. It allows more nutrients to be delivered to the site of damage. It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.

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Part D Pus is comprised of ANSWER:

excess fluid from leaky blood vessels. collected cells from damaged tissue. unused histamines and leukotrienes. dead phagocytes.

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Part E Which of the following can release histamines? ANSWER:

Invading bacterial cells Cells from damaged tissues Wood from a splinter Cells from damaged tissues and the complement pathway The complement system

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Microbiology Animation: Inflammation: Overview

Click here to complete this activity. Then answer the questions.

Part A An inflammatory response would result from which of the following? ANSWER:

Jellyfish sting A headache Vomiting

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Part B If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred? ANSWER:

The ankle is red. The ankle is red, swollen, and warm to the touch. The ankle is very warm to the touch. The ankle swells.

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Part C What is the function of inflammation in response to a burn from a hot iron? ANSWER:

To repair the damaged tissue To destroy the agent causing injury, to limit the effects of the agent on the rest of the body, and to repair the damaged tissue To destroy the agent causing injury To limit the effects of the agent on the rest of the body

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Clinical Case: Evaluating an Abnormal CBC Clinical Case: Evaluating an Abnormal CBC Roger Brown, an African American cancer patient, received a chemotherapeutic agent as a treatment for his disease. The drug used to destroy the cancer also produced an undesirable condition known as bone marrow depression. The complete blood count (CBC) profile shown here indicates that this patient is in trouble. Review the lab values, 1. Platelet count is low. 2. White blood cell count and types of WBCs are abnormally low. 3. Red blood cell count, hemoglobin level, and hematocrit are all low. Red blood cell size and hemoglobin content are normal.

Part A Why would bleeding time be increased in this patient?

Hint 1. Recall the blood elements needed to form a physiologic "band-aid."

ANSWER:

Platelet count is decreased. Red blood cell numbers are decreased. White blood cell numbers are decreased. Neutrophil numbers are decreased.

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Part B What is the most expedient way to increase the blood cell and platelet counts of this patient right now?

Hint 1. One medical procedure will directly impact the blood cell and platelet counts.

ANSWER:

intramuscular antibiotic injection intramuscular iron injections blood transfusion intravenous fluids

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Part C What aspect of this patient's immune function would be most directly impacted by this condition?

Hint 1. Consider the factors involved in innate immunity.

ANSWER:

mucus production bleeding gums phagocytosis interferon production

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Part D What does anemia mean?

Hint 1. This relates to the oxygen carrying capacity of the blood.

ANSWER:

increased urine production decreased platelet numbers decreased red blood cell numbers decreased white blood cell numbers

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Clinical Case: A Stealth Invader in the Lungs The Stealth Invader Tim is often seen walking around campus, hanging out at the coffee shop, laughing with friends, and, as he puts it, "investing time with the ladies." Tim started smoking in high schoo and has never tried to kick the habit. He jokes about the "smoker's cough" that has punctuated his conversations over the summer and start of the fall semester. Recently, the cough has been getting worse, his throat is scratchy, his head hurts, and he is tired all the time. Tim wonders if he has some long-lasting flu, though he hasn't had a fever. In October, after month of progressively worse coughing, he's had enough; he heads to the campus clinic right after his morning classes. The clinic physician notes the persistence and worsening of Tim's cough and that Tim has no fever. To rule out a bacterial infection, she orders a routine sputum culture (a test of material coughed up from Tim’s lungs), which comes back negative. Tim is sent home with the advice to quit smoking. A week later, he’s back, coughing nonstop, short of breath, sweaty, and aching. A different doctor orders a chest X-ray exam and several blood tests. The X-ray film reveals fluid in Tim’s lungs, and a blood test confirms an infection of Mycoplasma pneumoniae. Regular sputum testing doesn’t detect this Gram-negative bacterium, which lacks cell walls and doesn’t stain well. Mycoplasma pneumoniae infects and disrupts the mucous membranes of the lungs, invading and disrupting the epithelium. Most patients get better on their own, but not Tim. Smoke has compromised the lungs’ innate immunity. A course of an antimicrobial drug— azithromycin - clears Tim's lungs of the bacterium within a week. Tim decides to quit smoking.

Part A Which of the following factors in the first line of defense are affected by Tim’s smoking?

Hint 1. The first line of defense in the lungs includes intact mucous membranes, mucus production, antimicrobial peptides, lysozyme, normal flora, and cilia.

ANSWER:

mucus expulsion and normal microbiota mucus production production of antimicrobial peptides and lysozyme migrating phagocytes

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Part B Consider the effect of Mycoplasma pneumoniae as it burrows between respiratory epithelial cells. Which element(s) of the second line of defense will be most effective in fighting this invader?

Hint 1. Which phagocytes are likely to be found in lung tissue?

ANSWER:

lysozyme wandering macrophages interferons IgG antibodies

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Part C Tim was treated with azithromycin, a macrolide drug. This family of drug targets __________.

Hint 1. Review the mode of action for macrolide antibiotics.

ANSWER:

cell wall synthesis the normal microbiota protein synthesis mucus production

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Part D Ideally, antibiotic therapy should target the pathogen and not the normal flora. Given the spectrum of activity for macrolides, azithromycin is most likely to have an effect on normal flora of the __________.

Hint 1. Macrolides are most effective against Gram-positive microbes.

ANSWER:

gastrointestinal tract blood stream skin urinary tract

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Video Tutor: Inflammation Watch the Video Tutor on Inflammation and then answer the questions below.

Part A Basophils, platelets, and _____ are all capable of secreting histamines.

Hint 1. Interstitial Cell These cells are similar to basophils, but inhabit the interstitial spaces outside of the blood.

ANSWER:

monocytes neutrophils complement mast cells

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Part B Which of the following groupings contain things that are all true indicators of inflammation?

Hint 1. Signs of Inflammation The signs of inflammation stem from vasodilation and increased permeability.

ANSWER:

redness, heat, edema, pain, fever redness, heat, edema, pain redness, coolness, numbness, fever blueness, coolness, edema, pain

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Part C

Increased permeability of the vessels leads to _____ and pain.

Hint 1. Permeability Increased permeability means that the vessels are leaking some of their contents into the surrounding tissues.

ANSWER:

redness fever edema heat

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Part D The process of blood clotting leads to the formation of _____ a potent mediator of inflammation.

Hint 1. Inflammatory Mediators The body's cells release many chemicals during inflammation, but only one is the product of clotting.

ANSWER:

histamine bradykinin prostaglandin leukotriene

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Part E Histamines are released when mast cells are exposed to _____, which are fragments of complement proteins.

Hint 1. Innate Immunity A major component of innate immunity involves these soluble protein fragments, which are responsible for inflammation and chemotaxis.

ANSWER:

platelets C3 and C5 bradykinins C3a and C5a

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Part F Inflammatory mediators such as bradykinin and histamine cause blood vessels to _____.

Hint 1. Increased Flow The diameter of a blood vessel can be increased to allow more blood flow. This is similar to the action of the iris within one's eye when it becomes larger to allow more

light to flow inward.

ANSWER:

lengthen vasodilate vasoconstrict increase permeability

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Part G Leukocytes have the ability to cross the vessel wall out of the blood stream and into the tissues. This process is known as _____.

Hint 1. Crossing a Vessel Wall Leukocytes use a "false foot" to squeeze "across" the epithelial cells of the vessel.

ANSWER:

phagocytosis apoptosis phagocytosis diapedesis

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Part H Acute and chronic inflammations differ in that acute inflammation _____.

Hint 1. Acute Inflammation Acute inflammation occurs first and is rarely followed by chronic inflammation.

ANSWER:

always involves a fever involves the formation of pus develops slowly, lasts a long time, and is potentially damaging develops quickly, ends quickly, and is typically beneficial

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MicroFlix Activity: Immunology -- Infection and Initial Response Can you label the cause of infection and some structures involved in fighting that infection? To review the body's response to infection, watch this MicroFlix animation: Infection.

Part A - Infection and Initial Response Label the cause of infection and some structures involved in fighting the infection.

Hint 1. Structures involved in rhinovirus infection

Epithelial cells form a barrier between the environment and the tissue. Specialized areas of the tissue secrete mucus that is moved by the cilia up the nasal passages, into the throat, and swallowed for degradation in the stomach.

ANSWER:

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MicroCareers: Thinking Outside the Box: Enhancing Innate Immunity to Fight Infection An emerging area of research in both academia and biotechnology is the innate immune response. Classic approaches to treating infection have focused on attacking the pathogen (e.g., antibiotics) or enhancing the host’s adaptive immune response. Exploiting the non-specific nature of the innate response could help protect individuals from a greater number/variety of pathogens. Furthermore, stimulation of the innate response would avoid the problem of antibiotic resistance in bacteria. You are an independent consultant hired by a new biotech start-up company interested in designing drugs that will stimulate innate immune responses as a way to fight infection. You are in the initial stages of the project--investigating possible innate immune pathways to target with the new therapeutics.

Part A One of your first ideas is to look at probiotics to enhance the host’s normal microbiota. The use of probiotics to stimulate the normal intestinal microbiota and promote general health has gained increasing popularity in recent years. There are several ways in which our normal microbiota protects us from infection. Which of the mechanisms below is no a protective mechanism of our normal microbiota? Which statement about protective mechanisms employed by normal microbiota is false?

Hint 1. Normal microbiota A variety of microbes (bacteria, fungi, viruses) are present on and in our bodies. Under normal conditions, these organisms do not cause disease; in fact, many of them have an important role in protecting us against infection by creating an environment that is inhospitable to invading organisms.

ANSWER:

Normal microbiota consume nutrients. Normal microbiota stimulate the second line of defense. Normal microbiota alter the pH of their environment. Normal microbiota spreading to locations where they are not normally found to prevent colonization from pathogens.

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Part B Phagocytosis eliminates pathogens that have evaded the first line of defense. The process can be broken down into six main steps. Enhancing any of those steps could lead to more efficient bacterial elimination during infection.

Arrange the following steps in order to describe the chronological order of the events in phagocytosis.

Hint 1. "Eating by a cell" The process of phagocytosis is a key component of our innate immune system. There are a variety of cells that have phagocytic ability, including macrophages and dendritic cells. While the word phagocytosis means "eating by a cell", the process is a bit more complicated involving a series of events designed to get the phagocyte to the site of infection and ultimately get rid of the bacteria.

Hint 2. Mechanisms of ingesting Organisms can take in molecules by two main mechanisms. Phagocytosis can occur via the extension of pseudopods ("arms") that engulf the molecules. Molecules can also be engulfed via receptor-mediated endocytosis where the molecule binds to a specific receptor. The molecule/receptor complex is then engulfed by the cell.

Hint 3. Chemotaxis Chemotaxis describes movement ("taxis") in orientation to a chem...