Microbio Exam #4 Case studies

What is a protozoan? How is a protozoan parasite different from bacteria and multi-celled parasites such as intestinal worms? How does T. brucei differ from the closely related American trypanosome T. cruzi, the causative agent of Chagas disease, and from the P. falciparum parasite that causes malaria? Describe notable differences in morphology, life cycle, infectivity, transmission, geographical range, disease presentation, and treatment.

- a protozoan is a single-celled organism related to the group phyla. The protozoan parasite leads to infection and can harm human beings. The difference between bacteria and protozoans is that the bacteria are prokaryotes and protozoans are eukaryotes. -Difference between protozoan and intestinal worms is that both are parasitic infections but we get intestinal worms by eating or drinking dirty water and protozoan parasite infection enters our body by a parasite called tsetse fly. Worms enter our body and get attached to our intestinal tract and protozoan parasite works like a virus. T. brucei causes the African Trypanosomiasis disease called sleeping sickness and caused by a parasite in Sahara called tsetse fly but this disease is curable while T. cruzi can be transmitted through parasite but also can be transmitted through eating foods that contain T. cruzi and it is found in feces of reduviid bugs. Chagas disease which is caused by T. cruzi is similar to a bacterial infection, you can get it by foods, people, and the environment. T. cruzi is found in urban areas. P. Falciparum is also a protozoan parasite found in sub-Sahara Africa. The disease is caused by a female mosquito called Anopheles. The Plasmodium Facliparum is not genetically the same as T. brucei but the symptoms it shows and effects are similar. - This differs from the close relative T. cruzi, which is only located in America. Along with the fact that feces must enter a wound or body in different ways for the latter infection to be produced. Morphology: T. cruzi- has 3 forms, trypomastigote, the epimastigote, and the amastigote. Trypanosomes are present in the circulating blood. They have a thin, irregularly shaped membrane, which can be seen using scanning electron microscopy. They have a centrally prisoned nucleus and a kinetoplast located towards the posterior. A flagellum stems from the kinetoplast and runs through the remainder of the parasite and also extends beyond it. Inside the kinetoplast, the parasite has a single mitochondrion, which drives the flagellum. T. brucei- The parasite forms trypomastigotes in vertebrate hosts and epimastigotes in the insect vector. P. Falciparum- small trophozoites, have a rod-shaped nucleus, a peripheral form of cytoplasm and a central clear vacuole like area. Infectivity: T brucei life cycle- During a blood meal on the mammalian host, an infected tsetse fly injects metacyclic trypomastigotes into the skin tissue. The parasites enter the lymphatic system and pass into the bloodstream 1. Inside the host, they transform into the bloodstream trypomastigotes 2. are carried to other sites of the body, reach other blood fluids (e.g. lymph, spinal fluid), and continue the replication by binary fission 3. The entire life cycle African trypanosomes are represented by extracellular stages. The tsetse fly becomes infected with bloodstreams trypomastigotes when taking a blood meal on an infected mammalian host (4,5). In the fly's midgut, the parasites transform into procyclic trypomastigotes, multiply by binary fission 6, leave the midgut, and transform into epimastigotes 7. The epimastigotes reach the fly's salivary glands and continue multiplication by binary fission 8. The cycle in the fly takes approximately 3 weeks. Humans are the main reservoir for Trypanosoma brucei gambiense, this species can also be found in animals. T cruzi life cycle- blood-sucking vectors bite and defecate on the skin after the blood meals 2. Metacylic trypomastigotes rubbed into the wound made by biting vectors or into eyes 3. trypomastigotes enter the cell by phagocytosis. Reproduces intracellularly as amastigote 4. Cells releases amastigotes that affect other cells 5. Amastigotes in circulation transform into trypomastigotes. These remain in circulation 6. Bloodsucking insect ingests amastigotes or trypomastigotes 7. Trypomastigotes reproduced in the gut of insects asexually 8. Metacyclic trypomastigotes migrate into rectum or vector. P Falciparum life cycle- 1. Sporozoites injected by the mosquito 2. Exoerythrocytic schizogony in the liver 3. Erythrocytic and schizogony (asexual cycle) in red blood cells 4. Gametocytes are taken up by the mosquito 5. Sporogony (sexual cycle) and sporozoites production in the mosquito. All the processes above of 3 organisms repeat again. Transmission: of P. Falciparum occurs between Anopheles mosquito and human. Tsetse flies can transmit T. brucei. T. cruzi can be transmitted through vector-borne diseases. Triatomine bug can pass T. cruzi to humans. Geographical range: T. brucei is found in rural Africa, T. cruzi is found in America (in rural area of Latin America), P. Falciparum is found in Africa like T. brucei. Disease presentation: T. brucei symptoms are fever, severe headache, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints. For T. cruzi, fever, fatigue, swelling at the injection site, rash body aches, eyelids swelling, headache and loss of appetite. For P. Falciparum symptoms include, fever, headache and chills, if not treated soon, it could lead to death. Treatment: Malaria is treated with quinine, sulfate, and doxycycline. Alternatively, drugs like clindamycin can be used. The drugs that are used to treat T. brucei are suramin, melarsoprol, eflornithine, and nifurtimox. For T. cruzi, benznidazole and nifurtimox are used to treat. For P. Falciparum antimalarial medication, artemisinin, quinine, chloroquine, primaquine, and malaria vaccine.

Characteristics of Bordetella Pertussis include:

-gram-negative rod -strict aerobe -grows in 35-37 degrees Celsius -supplemental media used: Border-Gengou Media: >potato infusion (source of carbon and nitrogen), peptic digest from animal tissue (source of carbon and nitrogen), glycerol (nutrients), sheep blood (15%; nutrients and provides the possibility of hemolysis), sodium chloride (maintains osmotic pressure), agar (provides support for growth) -first isolated and described in 1909 by Jules Bordet and Octave Gengou in Paris

List hypotheses that would explain why S. aureus was susceptible to antibiotics in Brent's case but not in Kristen's case.

. In Brent's case, he had a strain of Staph aureus that had not been modified in any way. In Kristen's case, she has a strain of Staph aureus that has an altered penicillin-binding protein, which is encoded by the Mec. A gene. This altered penicillin-binding protein results in a lower strength in the binding between the protein and the beta-lactam, resulting in resistance to the Oxacillin.

Label the five major steps used by Ebola virus to infect cells. In what specific ways are these similar or different from those you labeled in the general virus life cycle?

1. Attachment: different because the Ebola virus requires the GP to attach to a specific receptor to invade the host cell, while the general virus binds to any receptor on the host cells, but similar because they both have to attach to the cell 2. Entry: similar it comes into the cell in and an enclosed vesicle forms the plasma membrane and gets delivered to the endosome 3. Replication: different because the Ebola virus relies on the low pH to modify GP and help it fuse with the membrane of the endosome. 4. Assembly: similar because once the viral genome is inside of the cell cytoplasm, viral synthesis can begin, including the genome replication transcription of viral genes, and translation of viral protein and they both use ribosomes during this process. 5. Exit: similar because one complete the virus can release from the cell to spread the infection without killing the cell

Answer the following questions based on the data presented in Fig. 3: a. In Table II, of those patients with ulcers, how many were positive for H. pylori? Of those patients with normal endoscopic results, how many were positive for the bacteria? b. Based on this data, Warren and Marshall hypothesized that there was a causal relationship between ulcers and bacterial infection. But there were 4 patients with ulcers that were negative for the bacteria. Why is this not significant? c. If there is a causal relationship between the presence of H. pylori and ulcers, how might you explain that 50% of the patients with a normal endoscopic examination were infected with the bacteria? d. In your own words, explain the results presented in Table III. What do you conclude from this data?

3a) Based on the evidence in Table II of those patients with ulcers 26 out of 30 had the bacteria. Of the patients with normal endoscopic results, 8 out of the 16 (50%) were positive for the bacteria. 3b) The 4 patients with ulcers but negative for the bacteria are not significant because they had taken non-steroidal, anti-inflammatory drugs known to reduce ulcers. 3c) Although gastric colonization with H. pylori induces histologic gastritis in all infected individuals, only a minority develop any apparent clinical signs of this colonization. The risk of development of these disorders in the presence of H. pylori infection depends on a variety of bacterial, host, and environmental factors that mostly relate to the pattern and severity of gastritis, so a patient can show normal endoscopic examination infected with the bacteria. 3d) The results of Table III conclude that out of the 100 patients tested 31 had normal gastritis and out of those 31, 29 had no bacteria grade and 2 had 1+ as the bacteria grade. Of the 29 out 100 patients that fell in the chronic gastritis category, 12 had no bacteria grade, 9 had 1+ as the bacteria grade, 7 had 2+ as the bacteria grade, and 1 showed 3+ as their bacteria grade. Furthermore, 40 out of the 100 patients that fell in the active gastritis category, 2 had no bacteria grade, 5 had 1+ as their bacteria grade, 15 had 2+ as their bacteria grade and 18 had their 3+ as their bacteria grade. So tying this all together with a total of 43 out of the 100 patients had no bacteria grade, a total of 16 had 1+ as their bacteria grade, a total of 22 had 2+ as their bacteria grade and lastly, a total of 19 had 3+ as their bacteria grade.

Relapse: a. How often do relapses of C. difficile disease occur? (Give a number, not a qualifier like "very.") b. What are the typical causes of these relapses? c. List two treatments that are used for patients with C. difficile relapses.

3a) Relapses occur in 20%-25% of patients 3b) The typical causes of these relapses are the failure to clear the pathogen and failure to restore the normal microbiome of the stomach. 3c) Two treatments used for patients with C. difficile relapse are fecal microbiota transplant, fidaxomicin, pooled IgG or pulsed AB

What is the nature of the Epstein-Barr virus? Be able to explain the following: a. the viral properties of this pathogen; b. the epidemiology, pathogenesis, treatment, and preventative measures of this pathogenic disease; and c. the potential reactivation of the virus.

3a. Viral properties of EBV include: it produces superantigens which are exotoxins that trigger an excessive, nonspecific stimulation of immune cells to secrete cytokines creating a strong immune and inflammatory response that can cause life-threatening effect, it requires glycoproteins for entry, and it attacks B cells because of their receptors and overall invades the immune response. 3b. The majority of patients that contract EBV virus are not hospitalized, but it seems to be more prevalent in teenagers and college students because of the route of transmission, the risks factors for EBV are EBV immune status, age at the time of infection and IL-10 polymorphisms. It infects the B cells and tries to live within the immune system of the host cell, causing damage to the host's immune response. Treatment for EBV is drinking fluids to stay hydrated, getting plenty of rest, and taking over the counter meds for pain and fever, no antibiotics are needed for treatment. Some preventative measures to take would be not to share drinks, food or personal items like toothbrushes with people and to not kiss people since the route of transmission is through saliva. 3c. The potential reactivation of EBV is a risk because it can remain latent in your body and several viruses (Hep C) and cytokines can reactivate it.

How do the actions of C. difficile toxins lead to ... a. diarrhea? b. sepsis (i.e., septic shock)?

4a) The action of the C. difficile toxins leads to diarrhea by the activation of the neurotoxins that affect the intestinal motility. 4b) The action of C. difficile toxins leads to sepsis when damage to the tight junction results in leakage.

What is a Monospot test? How does it work and why would it be useful for Blake's diagnosis?

A Monospot test is a blood test used to determine whether or not you are infected with the Epstein Barr virus. It works by placing a sample of blood on a microscope slide and mixing it with other substances and if heterophile antibodies are present then the blood will clump, this test can usually detect antibodies from 2 to 9 weeks after a person is infected. This would be useful for Blake's diagnosis because the test is specific for heterophile antibodies produced by the immune system in response to the EBV, so if he had it he would test positive for the Monospot test.

Compare the differences between a cellular and an acellular vaccine.

A cellular (whole cell) vaccine is inactivated and contains the whole pathogen that has been deactivated by heat, chemicals or radiation. For it to be effective, the inactivation process must not affect the structure of key antigens on the pathogens. Whereas, an acellular vaccine only exposes us to the key antigens of the pathogen, not whole cells or viruses. These subunit vaccines can be produced either by chemically degrading a pathogen and isolating its key antigens or by producing the antigens through genetic engineering.

What is a Gram-negative organism? How does the structure of a Gram-negative organism contribute to its virulence?

A gram-negative organism has a thin layer of peptidoglycan and the overall structure of their cell envelope is more complex than gram-positive. They have a gel-like matrix that occupies the periplasmic space between the cell wall and the plasma membrane, and there is a second lipid bilayer called the outer membrane, which is external to the peptidoglycan layer. This outer membrane is attached to the peptidoglycan by murein lipoprotein. The outer leaflet of the outer membrane contains the molecule lipopolysaccharide, which functions as an endotoxin in infections involving gram-negative bacteria, contributing to symptoms such as fever, hemorrhaging, and septic shock. Gram-negative bacteria tend to be more resistant to antibiotics.

What tests can be utilized to determine the most likely pathogen? Explain your rationale for all possible pathogens.

A test that can be utilized to determine the most likely pathogen would be the ELISA test. The chemical reaction or metabolites of the microorganism can be exposed and determined.

What is a vaccine?

A vaccine is a form of artificial immunity, it works by artificially stimulating the adaptive immune defenses which trigger memory cell production similar to which would occur during a primary response. In doing so, it allows us to mount a strong secondary response upon exposure to the pathogen, but without having to first suffer through an initial infection.

Label the key viral and cellular factors in the indicated areas of the diagram. Describe each of their roles.

A. GP (glycoprotein)- required for the virus to specifically bind to a receptor on its target host cell B.VP40- required for viral assembly and budding from the host cell C. L (RNA- dependent RNA polymerase)- required for transcription of viral mRNA D. RNA Genome- includes the viral genetic material E. mRNA- the transcripts that encode viral proteins F. Ribosome- helps with protein synthesis G. Receptor- required for the virus to attach to host cell

What are some symptoms associated with acute phase HIV infection? What are the symptoms of AIDS?

Acute phase HIV: rash fever chills headache fatigue sore throat night sweats loss of appetite ulcers that appear in the mouth, esophagus, or genitalia swollen lymph nodes muscle aches diarrhea AIDS: Rapid weight loss Recurring fever or produce night sweats Extreme and unexplained tiredness Prolonged swelling of the lymph glands in the armpits, groin or neck Diarrhea that lasts for more than a week Sores of the mouth, anus, or genitals Pneumonia Red, brown, pink, or purplish blotches on or under the skin or inside the mouth, nose or eyelids Memory loss, depression, and other neurologic disorders

Which structural features are in common to all viruses, and which are not?

All viruses have a nucleic acid genome and a capsid composed of protein, some eukaryotic viruses are surrounded by an envelope that is composed of a membrane with embedded proteins.

Why would an ECHO be scheduled for Ying? What other tests should be run to minimize potential complications?

An ECHO would be scheduled for Ying to see if the bacteria has spread to the heart since Ying has been sick for 6 days. Another test that would be run to minimize potential complications is a renal function test. The renal function test will evaluate the extent of damage suffered by the kidneys due to blood and proteins present in the urine.

What is an antibiotic? Which class of antibiotics works best for Bordetella pertussis?

An antibiotic is a drug specifically designed to kill or inhibit the growth of bacteria, they can stop the patient from being infectious within five days of taking them. The class of antibiotics that work best for Bordetella Pertussis is macrolide antibiotics which include: Azithromycin, Erythromycin, and Clarithromycin.

What other assessments should the medical student have taken to more fully determine Ying's condition?

An assessment that the medical students should preform is a rapid antigen test on a swab sample from Ying's throat.

How does an organism become more powerful in the midst of diminished vaccination?

An organism becomes more powerful in the midst of diminished vaccinations by reducing herd immunity which increases the susceptibility of hosts leading to a potential outbreak.

What other dermatologic illnesses mimic rat bite fever?

Another dermatologic illness that mimics rat-bite fever is scarlet fever

Which treatments work best for giardiasis?

Antibiotics like metronidazole, Tinidazole, and Nitazoxanide are popular for the treatment of giardiasis.

Based on Blake's self-diagnosis, what problems exist with his use of amoxicillin, past or present?

Based on Blake's self-diagnosis, some problems that exist with his us of amoxicillin are that it was prescribed for a middle ear infection that was expired, he didn't finish the prescription because he felt better which can cause antibiotic resistance to occur, and it is a narrow-spectrum antibiotic so more than likely it wouldn't have treated him anyways since it is for specific infections.

Using the given tests and observations, what is your diagnosis?

Based on the given test and observations, my diagnosis would be Streptococcus pyogenes, because it has common symptoms like throat pain, swollen lymph nodes in the neck, fever, rash and body aches (abdominal tenderness).

Referring to the CDC statistics found in the graph in Figure 1, as well as the research-supported information provided in this case study, provide reasons as to why there is a resurgence of whooping cough.

Based on the information and the CDC statistics in the graph, there is a resurgence of whooping cough because due to the great success rates of the vaccines back in the 1940s and the 1980s, it created a widespread acceptance towards vaccines causing everyone to become vaccinated which increased herd immunity. Furthermore, due to the amazing benefits of vaccines, a certain amount of complacency emerged in response to vaccination because people tend to think the strain doesn't exist anymore or that it's rare so there's no need to vaccinate, so that's what leads to common outbreaks in infants and adults.

Now that you are provided with this additional information, what do you think is wrong with Ying?

Based on the information given Ying is experiencing multiple conditions. First, Ying is experiencing pain in his throat and ears. Ying has persistent coughing and cannot swallow without pain in his throat. Ying feels like his throat is burning and itching. Ying also has impetigo which is caused by the bacteria streptococcus. So, based on the signs and symptoms, Ying had strep throat and a respiratory infection. The respiratory infection and the bacteria, streptococcus, are spreading into Ying's ears causing pain. Additionally, it seems that there are blood and protein present in Ying's urine, meaning he has a urinary infection that is caused by the kidneys if they are damaged.

Record similarities and differences between the two patients.

Brent has a small abscess on his elbow that came out of nowhere, whereas Kristen had redness around an incision she had from her knee surgery. Brents's symptoms were the abscess which was swollen and painful, and Kristen's symptoms were the redness around the incision, pain in her knee, and a fever.

Kristen likely has a strain of staphylococcus aureus that is resistant to oxacillin/ beta-lactams.

Brent has a strain of Staphyloccocus aureus that is not resistant to beta-lactams, specifically oxacillin. Whereas Kristen has a strain of Staphyloccocus that is resistant to beta-lactams, specifically oxacillin.

What is the chance that this patient has Lyme disease? Why? A. She definitely has Lyme diseaseB. She definitely does not have Lyme diseaseC. Based upon her risk factors, she could have Lyme disease.

C. Based upon her risk factors, she could have Lyme disease because she has erythema around the bite and pruritus which are definite symptoms of Lyme disease. Although there is no fluctuance or purulence at the site of the bite and her vital signs and physical examination is normal other than the bite, she should still keep an eye out because erythema can be present without any other symptoms and if the tick was on the skin for around 36-48 hours she could definitely have Lyme disease. Additionally, the symptoms to come because of a lack of treatment can be super severe.

Based on your choice of antibiotic in Question 1 above, what is the medication's structure and why is it preferred over other medications? Be sure to include references to its structure-based activity, metabolism, and elimination.

Cephalexin will be given to Ying. The reason why this antibiotic is preferred over the over medications is that the antibiotic will inhibit bacterial cell wall synthesis causing the bacteria to die. The antibiotic will be taken orally and the potential side effects of the drug treatment include diarrhea, nausea, vomiting, and an upset stomach. To prevent Ying from getting sick again, he will need to practice good hand hygiene and not share any food or drinks at school.

Make a list of human pathogens that are endemic to sub-Saharan Africa and can be transmitted through bug bites or consumption of contaminated foods. Looking over your list, what do you think is the most likely cause(s) of Robert's illness?

Cholera, African Trypansomiasis, and Malaria. I think Robert has developed Malaria while on the safari. Robert informed his doctors that he recently returned from a 2-week safari in Central Africa. He told them he felt normal during the trip minus the numerous bug bites he received. He recalls eating unfamiliar foods that might have been prepared or stored under unsanitary conditions. Robert's symptoms included: general malaise (discomfort), myalgia (muscle pain), fever, headache, vomiting, diarrhea, and feeling weak and tired; looking back at my list for Robert's symptoms matched with Malaria.

What empiric treatment options should be considered given the resident's report? Fully explain your rationale.

Considering the report, the empiric treatment option would be antibiotics to fight against the bacteria that is forming in Ying's respiratory area.

What, if any, risk factors did Danielle have for developing C. difficile disease?

Danielle's risk factors were her being in the healthcare setting visiting her grandma and having previously been on antibiotics due to her getting her wisdom teeth out because antibiotics can wipe out the good intestinal bacteria as well, leading to the risk of less protection from her own microbiome.

What are the typical signs and symptoms of typhoid fever?

Fever, headache, weakness, and fatigue, muscle aches, sweating, dry coughing, loss of appetite, weight loss, abdominal pain, diarrhea, rash, swollen abdomen.

List five risk factors for developing Clostridium difficile disease.

Five risk factors for developing Clostridium difficile disease are: -taking other antibiotics or medications -staying in a healthcare facility -having a serious illness or medical procedure past C. diff infection -being 65 years or older

What are the pathogenic mechanisms of Salmonella enterica serovar typhi? What are its virulence factors?

Flagella allows for the pathogen to have motility and increases the invasiveness of the organism. Fimbriae allow for the attachment and colonization of host cells. Capsules allow for the pathogen to avoid phagocytosis.

Which class of antibiotics works best for typhoid fever?

Fluoroquinolones

List and explain the major routes of HIV transmission.

HIV can be spread through bodily fluids such as blood, semen and breast milk. This is usually spread through sex or from sharing needles.

What is the difference between HIV and AIDS?

HIV is a virus, and AIDS is a condition that occurs when HIV has caused serious damage to the immune system.

As a spokesperson for GlaxoSmithKline, what impact will Magic Johnson have on how HIVpositive people are viewed? What influence will he have on the future of GlaxoSmithKline? On other HIV-positive African-Americans? What ethical aspects can you think of associated with using Johnson as a spokesperson by a pharmaceutical company such as GlaxoSmithKline?

HIV used to be looked at as a disease that really only gay individuals got. So when Magic Johnson revealed he had it, that shed light on the realities of the virus. Having him as a spokesperson would improve the way people look at those who are HIV positive. By having Magic Johnson as a spokesperson, people will likely see the medication as reliable and effective. Overall, I think Magic Johnson revealed that he is HIV positive improved the way people look at individuals who are HIV positive, and the way HIV positive individuals look at themselves. An ethical problem could be that if the medications began to stop working, there would be a lot of attention on Johnson and the company.

List several types of host cells and the associated virus that binds to the host cell.

HIV- binds to natural killer cells and T cells Influenza- use HA protein to bind to respiratory epithelial cells Ebola virus- uses GP to bind to macrophages and dendritic cells

What is hepatosplenomegaly? What does it indicate and how is it useful for diff erentially diagnosing a patient with infectious mononucleosis?

Hepatosplenomegaly is a disorder where both the liver and spleen swell beyond their normal size, usually due to an infection such as mononucleosis or viral hepatitis. It indicates an enlarged liver and spleen due to an infection, blood disease, problems with the lymph system, etc. It is useful for differentially diagnosing a patient with infectious mononucleosis because it causes enlarged spleen and liver giving a clear indicator of an infection involving mononucleosis.

Which of these signs and symptoms did the 29-year old woman have?

High fever, constipation, dry cough, and low leukocyte count.

Propose biological and immunological reasons for why Magic Johnson's viral load levels are undetectable. Since Magic Johnson's virus load is undetectable, is he cured of HIV? Support your answer with biological reasons.

His viral load is likely undetectable because his medication is so effective that it brings the HIV levels so low that they can't be detected. No, HIV can't be completely cured because HIV integrates its viral genome into the host cell genome.

Do you think it ethical and appropriate for Marshall to have used himself as a test subject and swallowed a sample of Helicobacter pylori? What precautions did he take? Would you do it? Why or why not?

I do not find it ethical and appropriate that Marshall self-experimented. Some precautions he took were that he knew that H. pylori are sensitive to several antibiotics and that he had treated several patients in the past and that the culture he drank came from a man that's active gastritis was sensitive to metronidazole and was successfully cured by that, so he was confident that he could treat himself. I would not do it because antibiotic resistance strains can occur and that is such a high risk, as well as it could be fatal.

Based on the HIV life cycle, propose potential anti-HIV treatment targets. Which targets would be most effective in blocking HIV infection? Which targets would be least effective?

I think the best target would be the glycoprotein 160 because that is what even allows for the virus to bind to the human cells. The nucleoside reverse transcriptase inhibitors would also be effective because it would prevent the RNA from turning to DNA and being integrated into the host cell genome. I think the least effective would be targeting the gp41 and gp120, because if that treatment didn't work, then the virus would be able to bud off and then infect other cells.

Using the symptoms described above, make a list of 10 or more possible infectious diseases that might be plaguing Blake and explain why you have narrowed it down to these disorders. Use this information to guide you: http://www.cdc.gov/DiseasesConditions/

I've chosen these infectious diseases because of coinciding symptoms and based off Blake's summer activities ( tick, mosquito bites, handling wildlife, unprotected sex, etc.): Influenza Colorado Tick fever HIV Rabies Strep throat Malaria Anthrax West Nile Virus Tuberculosis Common Cold

Robert Koch was a German physician who identified the bacteria causing anthrax and tuberculosis. His methods established four criteria that must be met for a specific pathogen to be considered the cause of a disease. These four criteria are listed below. For each one, discuss whether Warren and Marshall fulfilled them and, if so, how. I. Th e pathogen should be found in the bodies of animals having the disease. II. Th e suspected pathogen should be obtained from the diseased animal and grown outside the body. III. Th e inoculation of that pathogen, grown in pure cultures, should produce the disease in an experimental animal. IV. Th e same pathogen should be isolated from the experimental animal after the disease develops.

I) Yes, the bacteria had been found in a dog before and in other animals. II) I don't think the pathogen was taken from an animal. III) Yes, the pathogen was able to grow in pure culture. IV) Yes, the same pathogen, in this case, H. pylori, was isolated from the experiment after the disease was developed.

If Danielle's symptoms are due to a relapse of C. difficile, what alternative treatments might you suggest for her?

If Danielle's symptoms are due to a relapse of C. difficile, some alternative treatments to suggest for her would be fidaxomicin, fecal transplant, pulsed antibiotics, or pooled IgG.

What would happen if T. brucei suddenly loss the ability to undergo antigenic variation?

If T. brucei lost its ability to undergo antigenic variation, it would cause it not to be able to conceal itself from white blood cells and our body would be able to attack it.

Formulate a hypothesis as to why there is more than one mechanism of viral entry into host cells.

If all viruses utilized a single mechanism of entry into the cell, it would be easier for a cell to protect itself against that mechanism and it may not continue to exist.

Predict what will happen to infection rates over time if drug resistant forms of HIV are allowed to spread through the population. What conditions might slow the spread of drug resistant strains?

If the drug resident forms can spread, then the infection rates will likely increase. The development of new effective drugs would slow the rates of HIV drug-resistant strains.

Infectious mononucleosis is more common in developed countries than developing countries. How do you explain this?

Infectious mononucleosis is more common in developed countries than in developing countries because the age at acquisition of primary EBV is older than it is in the developing world.

What are invasive trophozoites? What additional problems do they cause?

Invasive trophozoites are protozoa that have invaded in an organ or tissue of the body, in this particular case it would be the intestines. Additional problems that they cause are not being able to detect them because giardiasis diagnosis is performed by stool analysis, also they cause dysentery, and through spreading via the bloodstream could cause extraintestinal lesions such as liver abscesses.

Why is it difficult to grow Bordetella pertussis in a laboratory?

It is difficult to grow Bordetella Pertussis because it can be inhibited by components commonly found in the media and it is the slowest growing strain of Bordetella Pertussis.

What ideas do you have as to why the antibiotic did not work for Kristen?

Kristen likely has a strain of staphylococcus aureus that is resistant to oxacillin/ beta-lactams.

What is leukocytosis?

Leukocytosis is having an abnormal amount of white blood cells in the body.

What other illnesses mimic typhoid fever?

Malaria and Dengue Fever

Min and Wai are anxious about using conventional medicine. What can be done to assuage their concerns?

Min and Wai are concerned because they are not educated over the antibiotics and what Ying has contracted and the best thing to do is to continue providing information to the parents. The resident can explain the bacteria that Ying has contracted, what the antibiotics do exactly and the antibiotic will help Ying get better and lastly, how long it will take for Ying to get better

What is MLEE and why was it used here?

Multilocus Enzyme Electrophoresis was one of the first methods used for genetic and epidemiological studies and is a non-DNA method, being instead based on proteins (enzymes) polymorphism and gel electrophoresis. Different banding patterns of mobility may reveal alterations in the amino acid sequence. However, many nucleotide substitutions did not result in the amino acid change (silent mutations). Thus, MLEE presents low-resolution power to assess microevolutionary changes. The MLEE method was used here because it is a powerful discriminant tool, so it can differentiate the Candida albicans strains.

Do you think the Imodium® A-D that Danielle's grandmother took was a good idea for a patient with C. difficile? Why or why not?

No, I don't think the Imodium is an anti-diarrheal medication. This medication will cause prolonged exposure of the C. Diff toxin to the epithelial lining.

Based on the similarities and differences you identified earlier between T. brucei, P. falciparum, and T. cruzi, do you predict that P. falciparum and T. cruzi undergo similar antigenic variation? Why or why not?

No, because P. Falciparum is genetically different from T. brucei but its way of affecting is similar and they have other similarities too. Secondly, T. brucei and P. Falciparum are found in Africa and are caused by parasites. The symptoms are also similar which means that they might be treated in the same ways and have some of the same characteristics. Due to the genetic differences between T. brucei and P. Falciparum might affect some of their characteristics or the way of treatment.

Brent's pathogen did not contain the mecA gene. Was this pathogen MRSA?

No, his pathogen was not MRSA.

Which of these risk factors did Danielle's grandmother probably have?

Of these risk factors, Danielle's grandmother probably had an extended stay in the healthcare setting exposing her to the C. diff and she is older in age.

Which of these risk factors did the 28-year old man have?

Of these risk factors, the 28-year old man had a transplant, a chronic obstructive pulmonary disease and is a male.

Which of these risk factors did the 9-year old girl have?

Of these risk factors, the 9-year old girl contained was handling the rodents.

Which of these signs and symptoms did the 28-year old man have?

Of these signs and symptoms, the 28-year old man had a fever and chills, shortness of breath, a cough, and diarrhea.

Which of these signs and symptoms did the 9-year old girl have?

Of these signs and symptoms, the 9-year old girl had a fever, vomiting, diarrhea, widespread maculopapular rash, arthralgias, and myalgia.

Which of these signs and symptoms did the neonates have?

Of these signs and symptoms, the neonates had none they only contained fever and "not doing well" symptoms several hours after birth.

Mint tea is sometimes used to relieve the pain of a sore throat. What other botanicals are used for patients with pharyngitis? Are there any OTC medications similar to mint's action for pharyngitis?

Other botanicals that are used for patients with pharyngitis are ginger root tea, apple cider vinegar, and chamomile tea. Some OTC medications similar to mint's action for pharyngitis are throat lozenges, throat spray, and even Listerine or Chloraseptic.

What other gastrointestinal illnesses mimic giardiasis?

Other gastrointestinal illnesses that mimic giardiasis are ulcerative colitis, cryptosporidiosis, celiac disease or urethral diverticulum.

What other illnesses mimic Candida albicans infections?

Other illnesses that mimic Candida albicans infections are contact dermatitis, balanitis, psoriasis, chronic paronychia, and vulvovaginal.

What other respiratory illnesses mimic Legionnaires Disease?

Other respiratory illnesses that mimic Legionnaires Disease are Pontiac Fever, or other types of pneumonia such as Streptococcus pneumoniae or Mycoplasma pneumoniae.

What other respiratory illnesses mimic whooping cough?

Other respiratory illnesses that mimic whooping cough are asthma, gastroesophageal reflux, bronchitis, adenovirus, parainfluenza, and influenza viruses, respiratory syncytial virus or even the common cold.

How do people become infected with T. brucei? What are the risk factors as far as behavior, lifestyle, and geographic location?

People become infected T. brucei by the parasite Trypanosoma brucei rhodesience, which is carried by the tsetse fly. A person will get East African Trypanosomiasis if he or she is bitten by a tsetse fly infected with the Trypanosoma brucei rhodesience parasite. Symptoms are usually within 1 to 3 weeks after an infective bite. Although, the proportion of tsetse flies that are infected with this parasite is low. The tsetse fly is found only in rural Africa. East African Trypanosomiasis is found in parts of Eastern and Southeastern Africa. More than 95% of cases are reported from Uganda, Tanzania, Malawi, and Zambia.

What does seropositive mean and how is a person tested for HIV?

Seropositive means having antibodies for certain antigens. A person is tested for HIV usually using the ELISA test, which looks for antibodies for HIV.

Which of these signs and symptoms did the 9.5-year old girl have?

Signs and symptoms the 9.5-year-old girl had were chronic abdominal pain and diarrhea or pasty stools.

What diagnostic microbiological tests should be run to rule out potential pathogens?

Some diagnostic microbiological tests that should be run to rule out potential pathogens would be Viral capsid antigen (VCA)-IgM, VCA IgG, D early antigen (EA-D), Epstein Barr nuclear antigen (EBNA), or the Monospot test.

What factors could cause a relapse in C. difficile disease?

Some factors that could cause relapse in C. difficile disease include being older than 65, taking other antibiotics for a different condition while being treated with antibiotics for C. diff infection and having a severe underlying medical disorder, such as chronic kidney failure, inflammatory bowel disease or chronic liver disease.

What innate and acquired protective mechanisms should have been elicited in response to Blake's viral infection?

Some innate and acquired protective mechanisms that should have been elicited in response to Blake's viral infection are natural killer cells attacking the foreign bacteria, CD4 T cells signaling other cells in the immune system, CD8 t cells killing the pathogen, and neutrophils should be engulfing the virus.

Discuss and evaluate the methods used to identify Bordetella pertussis.

Some methods used to identify Bordetella Pertussis are biochemical tests, polymerase chain reaction (PCR), direct fluorescent antibody (DFA), and serologic test.

What are some of the reasons why parents may refuse to have their children vaccinated?

Some reasons parents may refuse to have their children vaccinated could be due to the fear and mistrust of vaccines, the side effects of the whole-cell vaccine, the myth of vaccines causing autism, not wanting their child to be in pain, allergic reactions, or if the child is immunocompromised and they don't want to take the risk of causing reverse affects.

What are the risk factors for developing giardiasis?

Some risk factors for developing giardiasis are living and working with children because they are more likely to come in contact with feces especially if they wear diapers or you are toilet training them or spending time in a childcare facility. Another factor is not having access to safe and clean drinking water and people that have anal sex.

What are the pathogenic mechanisms of Candida albicans? What are its virulence factors?

Some virulence factors of Candida albicans include: pleomorphism: ability to exist as different pleomorphic forms; so strains can adapt to many different biological niches; each pleomorphic form provide critical functions required for pathogenesis extracellular hydrolytic enzymes: lipases, phospholipases and aspartyl proteinase; digestion of host cell membranes and molecules of the host immune system to avoid antimicrobial attack by the host adherence: to host buccal and vaginal epithelial cells represents the first step in the internalization process

How does the army of new viruses get out of the cell to infect the nearby cells?

Some viruses with envelopes bud from the host cell, taking pieces of the host cell membrane with incorporated viral proteins, others leave by exocytosis in vesicles that bud from the endoplasmic reticulum or Golgi apparatus. However, viruses without envelopes lyse or break open the host cell and leave that way, often killing the cell in the process.

How does this case illustrate the role of technology in scientific progress?

This case illustrates the role of scientific progress because technology has advanced over the years and it has helped scientists discover the pathogens that are known today. Technology was able to assist Marshall in discovering H. pylori in the stomach.

Read the note below about horizontal gene transfer. Discuss how Staphylococcus aureus could have acquired the mecA gene. Natural selection can drive the phenotypes and genotypes present in a species population over generations. Environmental forces may allow only individuals with a certain characteristic to survive. Bacteria have a way of passing DNA to one another in a process known as horizontal gene transfer (HGT). HGT can occur through a process called conjugation in which one bacterial cell directly passes DNA to a recipient cell. In the case of MRSA, one MRSA cell may contain a gene that protects it from antibiotics. Th is cell may then conjugate with a recipient cell that does not have the antibiotic resistant gene and pass a copy of that gene to the recipient cell, resulting in another antibiotic resistant cell (Amabile-Cuevas & Chicurel 1993). HGT allows existing S. aureus cells to gain DNA that allows them to become MRSA or antibiotic resistant cells.

Staph aureus likely acquired the mecA gene through a mutation of the Staph aureus gene, which was able to survive, multiply, and spread. In addition to the passing of the mecA gene from a person, it can use horizontal gene transfer to pass DNA containing mecA to another cell and spread that mecA gene.

What are some of the microbiological properties and virulence factors produced by this pathogen? Explain the typical mode of transmission and the epidemiological properties. If immunological tests had been run, what are some specific cytokines produced in response to a streptococcal infection?

Streptococcus have M protein and lipoteichoic acid for attachment purposes, a capsule is made up of hyaluronic acid which helps inhibit phagocytosis, other extracellular products are also presented such as pyrogenic toxin which causes the rashes of scarlet fever. The typical mode of transmission and epidemiological properties of streptococci is that it belongs to group A beta-hemolytic and it is spread due to respiratory secretion. If the immunological tests had been run then the specific cytokines produced in response to streptococci are TNF-alpha, IFN-gamma, IL-6, IL-10, and IL12.

How does this case illustrate the tentative nature of science?

This case illustrates the tentative nature of science because new bacteria are forming and others are disappearing. Some bacteria are stronger than others and some bacteria live longer than others. There are so many types of bacteria present in this environment.

How is T. brucei infection diagnosed? What factors often make diagnosis difficult?

T brucei infection is diagnosed by laboratory methods. This is due to the fact that the clinical features of the infection are not sufficiently specific. The diagnosis texts on finding the parasite in body fluid or tissue by microscopy. Once the parasite is identified via microscopy the diagnosis can be made. T. brucei. rhodesiense parasites can be found easily in the blood, unlike T. brucei gambiense parasites. It is required that all patients diagnosed with this infection have their cerebrospinal fluid examined to determine if the central nervous system has been damaged. The diagnosis is quite difficult because trypanosomes are rare and difficult to detect in cerebrospinal fluid.

Synthesize the information provided above. Come up with an argument as to the best treatment plan for Terry.

Terry's doctor was trying to assemble quick action to help her survive the Ebola virus which included four different methods: vaccine, a standard antiviral medication, an immunotherapy-based method of treatment or using serum from an Ebola patient that had dully recovered. Vaccines could potentially provide protection against a viral infection when used prior to contracting the disease and it takes time. Antiviral therapies are only effective if administered in the first 48 hours of infection. Immunotherapy with the investigational treatment ZMapp is a treatment method that uses three unique antibodies against Ebola GP made in tobacco plants, it prevents viral attachment to the cells and thus does not allow entry or viral replication. The serum from a patient who had recovered from an Ebola infection of the same strain would be rich with Ebola-specific antibodies to enhance immune response, but the method of treatment would require identifying an Ebola survivor who had blood type compatibility with Terry who was willing and able to donate serum in a timely fashion. The vaccine wouldn't work because it would need to be administered before contracting the virus and the antiviral therapy wouldn't work because Terry was already in the late stages of the Ebola virus and there is no Ebolaspecific antiviral medicine available, and lastly the serum had too many specific and serious requirements that took time and the doctor needed to act quick. So, I believe immunotherapy would probably be the best treatment because the ZMapp will bond to the glycoprotein on the Ebola virus and prevent viral attachment to the cells and thus not allow entry or viral replication.

Which of these risk factors did the 9.5-year old girl have?

The 9.5-year-old girl is still a child, she probably attends grade school with younger children too.

How did the colloidal bismuth subcitrate (CBS) experiment provide evidence supporting Warren and Marshall's hypothesis?

The CBS experiment provided evidence to support Marshall and Warren's hypothesis because it greatly reduced the relapse rate in those with gastric peptic ulcers meaning that it has anti-microbial properties, so when the zone of inhibition occurred it proved that a bacteria specifically, in this case, H. pylori was causing gastritis.

How are natural selection and microevolution illustrated in this scenario?

The HIV Viruses that mutate will not be able to be killed, so then she will survive through natural selection. Those viruses then replicate and are able to be passed on. For a while doctors thought it was important for patients to stay strictly on the HAART regiments, however there is now a new therapy doctors have been prescribing that alternates time on and off of the antiviral drugs, to try to induce immune system control of HIV.

What does the Helicobacter story tell us? What lessons can be learned from this story?

The Helicobacter story tells us that the pathogen is able to survive in extremely acidic environments and can potentially cause ulcers, and Marshall was able to prove his hypothesis by performing a self trial.

Why does T. brucei infection cause the symptoms that led to the term "African Sleeping Sickness"?

The T. brucei infection causes the symptoms that led to the term "African Sleeping Sickness". This is because the Trypanosoma brucei parasite infects the brain and the spinal cord. It lives in the blood of the host and migrates to the central nervous system. If the central nervous system is damaged by the parasite, the patient can no longer be cured by treatment, eventually dying. The World Health Organization (2013) states that "T. brucei lasts for several years until it causes the patient to go into a coma, from which the patient cannot be woken". Thus is called the "African Sleeping Sickness".

What is the Widal test?

The Widal test is used to detect Salmonella Typhi. It does this by detecting agglutinating antibodies against the O and H antigens of Salmonella Typhi.

The patient is not happy when you try to reassure her. What should you do? Why?A. Cave in and give her the antibioticB. Give her a slip for a blood testC. Reassure her once againD. Refer her to a psychiatrist

The answer to the previous question is: C. Reassure her once againAs stated above, reassurance is the best thing to do at this point. If the patient's concerns are so severe as to seem pathologic, then perhaps further investigation for anxiety disorder might be warranted, but referring her to a psychiatrist at this point is not indicated.

The patient is terrified that she might have Lyme Disease, since her friend had it and she was very sick. She demands both a test for it and immediate treatment. What should you do and why? A. Prescribe doxycycline 100 mg twice daily for 21 daysB. Order Lyme serologyC. Both A and BD. Reassure the patient that no testing or therapy is required, but to call if she develops any additional symptoms.

The answer to the previous question is: D. Reassure the patient that no testing or therapy is required, but to call if she develops any additional symptoms.Treatment of this patient should include reassurance, for several reasons. First of all, because the tick was only attached for about 24 hours, the likelihood of her developing Lyme disease is extremely low. Second of all, even if she were to have contracted Lyme disease, it would be so early in the disease that it would probably be impossible to confirm it, since it takes time for the antibody response to develop. Finally, the chance of toxicity or adverse effect from the antibiotic is much greater at this point than the potential benefit.Symptoms of Lyme disease can vary widely and may include a rash at the site of the tick bite, cold or flu-like symptoms, arthritis, or other non-specific symptoms. Early localized Lyme disease, which is the first stage of the disease, causes a skin rash called erythema migrans (EM), and typically occurs within one month of the tick bite. Although EM occurs in approximately 90% of patients, some patients do not notice the rash, and they may go on to develop later stages of Lyme disease without knowing they have been infected.Early disseminated disease occurs days to months after the tick bite and may present with rheumatologic, neurologic, or cardiac sequelae. Late Lyme disease occurs months to years after the onset of infection, and includes the most serious complications of Lyme arthritis and neuroborreliosis. There is effective treatment for all stages of Lyme disease, but some patients have post-Lyme disease symptoms, which the lay public has coined "chronic Lyme disease" but is more accurately referred to as "post-Lyme disease syndromes".Appropriate treatment for early Lyme disease involves oral antibiotic therapy with doxycyline, amoxicillin, or cefuroxime. Doxycycline is probably preferred, but should be avoided in pregnant patients and in those intending to sunbathe.Therapy for early disseminated disease varies depending upon which type is present. Patients with asymptomatic disease and those with isolated facial nerve palsy can be treated for oral disease, while those with neurologic disease, such as meningitis, and cardiac disease, such as conduction system deficits, should be treated with intravenous therapy.Treatment for late disease also varies based upon which type is present. Patients with early Lyme arthritis may be treated with oral therapy, while those with later Lyme arthritis (such as with recurrent disease) and any form of Lyme neurologic disease may be treated with intravenous antibiotics.

What are trophozoites?

Trophozoites are the active, feeding, multiplying stage of most protozoa.

Investigate the different parts of the human immune system and explain which cells/products of innate and adaptive immunity are responsible for recognizing antigens on the surface of T. brucei and clearing the parasite.

The central nervous system fluid confirms the presence of parasites and tells that the disease has not progressed. Bacteria crosses the brain barrier and affects the nervous system and it is the first stage. The result depends on what kind of bacteria is causing this. The bacteria can either cause a coma or can lead to the death of a person.

Which class of antibiotic worked best for the infections? What is its mode of action?

The class of antibiotic that worked best for the infections are polyenes, it works by disrupting the fungal cell membrane by binding to ergosterol, the main sterol in the membrane.

Which class of antibiotics works best for Legionnaires Disease?

The class of antibiotics that work best for Legionnaires Disease are fluoroquinolones and macrolides.

Which class of antibiotics works best for rat bite fever?

The class of antibiotics that work best for rate bite fever is beta-lactams and tetracycline.

What are the clinical manifestations and symptoms of African trypanosomiasis? Compare and contrast these with the symptoms of malaria.

The clinical manifestations and symptoms of African trypanosomiasis include fever, headache, joint pains, itching, confusion, sensory disturbances, poor coordination, disrupted sleep cycles, and irreparable neurological damage. In comparison, some of these symptoms are similar to those of malaria such as fever, headache, joint pains, and sensory disturbances. On the other hand, in contrast, some of the symptoms for malaria are different such as nausea, vomiting, diarrhea, anemia and bloody stools.

What are the consequences of diminished vaccination? What impact does reduced vaccination have on herd immunity?

The consequences of diminished vaccination are increasing the risk of pertussis resurgence, especially if unvaccinated persons cluster the potential for an outbreak is high. Additionally, reduced vaccination and lack of adherence to vaccine booster schedules can set the stage for transmission of pertussis. Although the extent of the disease will be milder in this group of individuals, but the potential for transmission of pertussis in infants and those victims not immunized will remain.

Why is this discovery significant? Do you think it is worthy of a Nobel Prize?

The discovery is significant because it educates the people about the pathogen and informs the people about how to treat the infection and what actions must be taken. I do think it is worthy of a Noble prize because Marshall was able to rule out the idea that ulcer disease was caused by the bacteria H. pylori.

What tests should doctors conduct to confirm this diagnosis?

The doctor should conduct a blood test as the Malaria parasite can be identified by examining under the microscope from a drop of the patient's blood, spread out in a "blood smear" on a microscope slide. Prior to the examination, the specimen is stained to give the parasite a distinctive appearance.

What are the structures that need to be put together during viral assembly? Consider the key structural components of viruses described earlier.

The key viral structure to be assembled are the glycoproteins, genome (RNA/DNA), and capsid proteins, additionally, certain viral enzymes may be packages within the particle as well.

Describe the life cycle of Giardia sp.

The life cycle of Giardia sp. starts off as a cyst which are hardy and can survive several months in cold water. Once ingested by a human through contaminated water, food or the fecal-oral route the cysts will end up in the small intestines where excystation releases trophozoites (each cyst produces 2 trophozoites. The trophozoites multiply by binary fission, remaining in the lumen of the proximal small bowel where they can be free or attached to the mucosa by a ventral sucking disk. Encystation occurs as the parasites transit toward the colon. Additionally, the cyst is the stage found most common in nondiarrheal feces and because the cysts are infectious when passed in the stool or shortly afterward, person-to-person transmission is possible.

What protein does the mecA gene encode for? How does this allow MRSA to be antibiotic resistant?

The mecA gene encodes for the penicillin-binding protein. The alteration in the protein causes a lower avidity/binding between the protein and oxacillin, causing resistance to the protein.

What are the pathogenic mechanisms of Giardia sp.? What are its virulence factors?

The pathogenic mechanisms of Giardia sp are trophozoite adhesion to epithelial cells by the ventral sucking disc, using non-specific mechanical forces and/or specific interactions with lectins and annexins. The interaction between the suckling disc and enterocytes generates a lesion on microvillus border of the epithelium, which alter the ionic cell equilibrium, augmenting the peristalsis and producing diarrhea. There is also an increase in intestinal permeability caused by modifications in the zonulaoccludens tight junction. Furthermore, these Giardia trophozoites have evolved to colonize an adverse environment, therefore the parasite is able to modify and manipulate it milieu in several different ways one being antigenic variation to avoid immune attack. Also, it has proteinase secretions protect that protect trophozoites by degrading secreted IgA, or perhaps acting like a caspase aimed to promote apoptosis. Lastly, interaction Giardia enterocytes induce goblet cell hyperplasia and consequently produces cellular gaps on the epithelial barrier.

Describe how mutations could lead to drug resistance in the RT enzyme.

The medications will not be able to work if the targets are mutated.

Which of these risk factors did the neonates have?

The neonates are newborns born through the mother's vaginal canal and vertical transmission is increased because of vaginal colonization of Candida albicans.

List the potential pathogens you think Ying may have and the rationale for including these options.

The potential pathogen I think Ying may have is streptococcus because of the signs and symptoms he is showing and expressing.

What is the rationale for suggesting a lack of strenuous physical activity to a patient with an EBV infection?

The rationale for suggesting a lack of strenuous physical activity to the patient with an EBV infection comes from the fear of splenic rupture because splenic enlargement can be unpredictable and the risk for splenic injury is higher for them.

Does the presence of the mecA gene confirm that Kristen is infected with MRSA? Why?

The resistance/alteration of the penicillin-binding protein is encoded within the MecA gene.

What are the risk factors for developing Candida albicans infections?

The risk factors for developing Candida albicans are recent antibiotic use, pregnancy, diabetes mellitus, oral-contraceptives, inadequate therapy, impaired immune system, uncontrolled diabetes, and increased estrogen levels.

What are the risk factors for developing Clostridium difficile disease?

The risk factors for developing Clostridium difficile disease are taking certain antibiotics or medicines usually for a long period of time, age, a weakened immune system, complicated medical care, and extended stays in healthcare settings like hospitals or nursing homes, and lastly, having had previous infection of C. diff or known exposure to the germ.

What are the risk factors for developing Legionnaires Disease?

The risk factors for developing Legionnaires Disease are current or past smoking, diabetes mellitus, age of 50 years or older, chronic obstructive pulmonary disease, immune system compromise, male sex, and receipt of a transplant or chemotherapy.

What are the risk factors for developing rat bite fever?

The risk factors for developing rat-bite fever are handling rodents with a disease, being in close contact with rat urine and feces, bites or scratches from infected rodents, or even consuming food or drink contaminated with the bacteria from rodent droppings or urine.

What is the role of spores in the development of C. difficile disease?

The role the spores play in the development of C. diff disease is that it enables the bacteria to survive for extended periods of time in the environment under harsh conditions, such as the passageway through the stomach.

Describe how the story of Warren and Marshall's discovery illustrates the process of science.

The story of Warren and Marshall's discovery illustrates the process of science because it involves the discovery/examination, the experiments, cases, the research, the hypothesis, and the results.

Did all of the strains isolated from all three neonates have a common source? Why or why not?

The strains isolated from all three neonates did not have a common source since no types were shared between mothers, they couldn't consider any nosocomial transmission to the cases, the results strongly suggested a mother origin to the infective strains.

What are the pathogenic mechanisms of Bordetella pertussis? What are its virulence factors?

The three major virulence factors of Bordetella Pertussis are toxins, hemolysins, and adhesins. The Pertussis Toxin (PT) works to disrupt phagocytic activity, the filamentous hemagglutinin (FHA) allows adherence to ciliated cells, Adenylate cyclase reduces the amount of phagocytic activity and initiates the infection, Pertactin causes attachment to airways, and lastly, Tracheal cytotoxin causes paralysis of the ciliated cells. So all in all, these substances enable the organisms to adhere to the respiratory epithelial cells and paralyze the cilia, causing the infamous "whoop". The virulence of the pathogen then causes inflammation of the respiratory tract, which interferes with the clearing of pulmonary secretions and allows mucus to build up. The pertussis toxin mediates colonization and creates errors in phagocytic activity. As the organism proliferates, pertussis toxins lead to lymphocytosis with diminished phagocytosis.

What are three major ways in which a virus enters a host cell to deliver its genome?

The three major ways in which a virus enters a host cell to deliver its genome are: a) direct injection of its genome (RNA or DNA) into the host cell at the cell surface b) the binding of the virus to the plasma membrane, followed by the fusion of the viral envelope with the host membrane to transfer viral genome (DNA or RNA) into the host cell c) for the virus to bind the host cell membrane and become internalized into the host cell via the endocytic pathway

How do the toxins of C. difficile contribute to the signs of disease?

The toxins of C. diff TcdA and TcdB affect the actin cytoskeleton by glucosylating RhoGTPases. This causes cell death. They can activate neurons in the intestines and change the motility of the intestines causing diarrhea. This also causes inflammation and disruption of tight junctions which results in leakage of bowel fluid. This leakage can then enter the bloodstream and lead to shock. Binary Toxin disrupts the actin by ADP Ribosylation.

What are the typical signs and symptoms of Candida albicans infections?

The typical signs and symptoms of Candida albicans are: itching and irritation in the vaginal and vulva a burning sensation, especially during intercourse or while urinating Redness and swelling of the vulva vaginal pain and soreness vaginal rash thick, white, odor-free discharge with a cottage cheese appearance watery vaginal discharge

What are the typical signs and symptoms of Legionnaires Disease?

The typical signs and symptoms of Legionnaires Disease are pneumonia, fever or chills, nausea, vomiting, confusion, diarrhea, shortness of breath, coughing, headache, and other neurological effects.

What are the typical signs and symptoms of giardiasis?

The typical signs and symptoms of giardiasis are foul-smelling diarrhea, abdominal pain, flatulence, anorexia, weight loss, nausea, and possible dehydration. In patients with chronic giardiasis, there are periods of constipation or diarrhea with steatorrhea, nutrient malabsorption, and lactase deficiency.

What are the typical signs and symptoms of rat bite fever?

The typical signs and symptoms of rat-bite fever vary but some specifics are: fever malaise headache vomiting diarrhea the eruption of macules, papules, and purpuric vesicles or pustules, with acral accentuation migratory arthritis or arthralgias myalgia

What artificial or selective pressures could influence prevalence of antibiotic resistant microbes?

The use of antibiotics when they are not needed wipes out good bacteria. The bacteria that are bad may be killed, but those that are bad, but have been mutated will then survive and be able to multiply.

Why is viral attachment to the host cell specific between one virus and one type of cell?

The viral attachment is specific due to the type of glycoprotein on the viral surface that specifically binds a host cell receptor onto the target cell.

What are the pathogenic mechanisms of Legionella pneumophila? What are its virulence factors?

The virulence factors of Legionella pneumophila are: the secretion system which inserts proteins in the endosomal membrane of the macrophages; these proteins prevent lysosomal fusion, allowing L. pneumophila to continue to proliferate within the phagosome Biofilms are also produced making it hard to get rid of the bacteria flagella help with motility, finding the host, biofilm colonization and virulence Pili are responsible for the attachment to host mucosa Phospholipases cause cell disintegration

What are the pathogenic mechanisms of Streptobacillus moniliformis? What are its virulence factors?

The virulence factors of Streptobacillus moniliformis are lipopolysaccharides which contribute to the structural integrity of the bacteria as well as providing protection from chemical substances by physically blocking access to other parts of the cell wall and amphitrichous flagella which allow for the bacteria to adhere and infect the host

Describe the essential cell "machinery" that viruses use to make a new virus.

The virus uses enzymes in the nucleus (such as DNA polymerase and DNA helicase) for transcription and the ribosome, tRNA, Golgi apparatus, and rER to make proteins and copies of viral RNA/DNA which will be assembled into new viruses particles.

Which of these risk factors did the 29-year old woman have?

The woman had traveled to India for 3 months.

How could MRSA or other "super bugs" become antibiotic resistant?

Their genes are altered in some way that reduces or eliminates the effectiveness of the genes. Those superbugs then survive while other bacteria are killed by antibiotics, leaving the superbugs to multiply and spread to other people.

Ying's doctor approaches you to talk to Wai and Min. She needs to attend to a few more patients before rounds. She wants you to explain the mechanism of action of what you would consider the best choice of antibiotic. Include other points of the pharmacology that may be relevant.

There are different antibiotics that could be given for strep such as penicillin, amoxicillin, and cephalexin. I would recommend Cephalexin for the patient to treat the bacteria. I would also have the patient take over the counter medication for the pain and the headache.

What benefits are associated with Magic Johnson's announcement concerning his HIV-positive status? What risks or drawbacks can you think of associated with his announcement?

There was probably more awareness brought to the disease and showed how he was living and surviving with HIV. Some risks or drawbacks are that people probably thought different of him.

The answer to the previous question is: Based upon her risk factors, she could have Lyme disease.

This patient has been bitten by a tick and there is a possibility that she could have contracted Lyme disease. Important factors to consider when trying to determine the risk of contracting Lyme Disease from a tick bite include:1. The type of tick - Deer ticks, which are typically smaller than other varieties of tick are the primary carrier of Borrelia burgdorferi, which is the bacteria that causes Lyme disease.2. How long the tick was attached to the patient - There is a long period of time between the tick's first contact with its host and the potential time of infection. It takes between 36 to 72 hours of attachment for a tick to transmit Lyme disease.3. Other risk factors - Patients who spend large amounts of time outdoors and who have pets are at higher risk for contracting Lyme disease.4. Geographic locale - Patients who live in certain states (Massachusetts, Connecticut, Maine, New Hampshire, Rhode Island, New York, New Jersey, Pennsylvania, Delaware, Maryland, Minnesota, and Wisconsin) are more likely to get Lyme disease because of higher rates there.

Albert Gyorgyi, 1937 Nobel Laureate in Physiology and Medicine, once said in his Nobel award speech: "Discovery consists of seeing what everybody has seen and thinking what nobody has thought." Describe how this statement applies to Warren and Marshall's pioneering work on peptic ulcer disease.

This statement applies to Warren and Marshall's pioneering work on peptic ulcer disease because originally, Italian pathologist Giulio Bizzozero described the presence of spiral bacteria in the stomach of dogs. But Marshall discovered more information over the bacteria and what it is and how it is capable of infecting a person.

Define compliance.

To be in accordance to established guidelines.

What are the risk factors for developing typhoid fever?

Traveling to tropical destinations, being in close contact with someone infected, drinking contaminated water.

What is the advantage of using multiple targets during HAART? 5. Do you agree with the statement "The drugs he takes are available to everyone"? What are some factors that might make this an overstatement?

Using multiple targets allows for the viral life cycle to be attached from many different angles. Lowering the probability of it being able to complete the life cycle and bud off. No, I don't agree that the medicine he takes is truly available to everyone. It may technically be available to everyone, however, not everyone will actually have the financial means to buy the medications, given that it's about $1,000 per month.

Using data for normal blood values, compare Blake's differential blood test results. How, if at all, do Blake's values differ?

Using the data for normal blood values, I found that Blake's values differ in his leukocyte and platelet count. The normal range for platelets is between 150,000-500,000 with an average of 350,000, he only had 110,000 uL of platelets which isn't abnormally low but it is low indicating some infection. Additionally, the normal range of leukocytes is 5,000-10,000 uL and he had 13,200 uL, again it is a bit high indicating infection. Furthermore, he obtained really high monocyte and lymphocyte counts and a low PMN count.

Formulate a hypothesis as to what would happen to viral replication and budding from the cell if the ribosomes did not make VP40. 3. What is one structural component of the Ebola virus to target for a vaccine that prevents infections like Terry's? Explain your answer. Keep in mind the Ebola virus structures and that vaccines are developed to prevent viral infections (for example, the flu vaccine contains a weakened form of the influenza virus that does not cause disease)

VP40 is a vital component that offers support to the structures, maturing as well as the assemblage of the Ebola virus. If the host ribosome cell does not make it to VP40, then the virus most likely will not be capable of enduring because protein are vital for proceeding the spread.

Describe vertical transmission in this context.

Vertical transmission in this context is referring to the passage of a disease-causing agent from mother to baby during the period immediately before or after birth. Transmission might cross over the placenta, in the breast milk, or through direct contact during or after birth and in this example, it was during birth.

What is meant by virus load?

Viral load refers to how many copies of HIV are present in a millimeter sample of blood.

Why are viruses considered parasites?

Viruses are considered parasites because they lack metabolic machinery of their own to generate energy or to synthesize proteins, so they depend on host cells to carry out these vital functions.

Why do viruses need the machinery to make more viruses? Why can't they replicate on their own?

Viruses need the host cell machinery because they do not contain enzymes and organelles for synthesis and assembly of new viruses particles.

What can be done to prevent MRSA from becoming more dangerous?

We can limit the use of antibiotics to only when they are absolutely necessary, so that the microbes aren't able to survive, and or become resistant to more antibiotics than they already are.

What role did chance, assumptions, and curiosity play in Warren and Marshall's research on Helicobacter pylori?

When Marshall was examining the hematoxylin and eosin-stained section of the stomach, he stumbled across a spiral-shaped bacteria and was curious about how the bacteria were able to grow and stay alive inside of the stomach knowing that the acidity prevented pathogens from growing. His curiosity is what made him risk his own body and find the answer he wanted to prove to the world what he discovered.

Provide a description for whooping cough. Include symptoms, mechanism, duration, and recovery in your description.

Whooping cough is a respiratory illness that is transmitted from one person to another through aerosol droplets. Whooping coughs mechanism is hooking its bacteria to the cilia, which are used to sweep away foreign objects, then the bacteria multiples and migrates to the ciliated cells of the lungs. Furthermore, the bacteria releases a toxin that paralyzes the cilia and kills cells, pneumonia could develop if the tiny air sacs in the lungs become infected. Lastly, the toxins in the lungs spread throughout the entire body. The illness begins as a mild respiratory illness, progresses to a cough, develops into paroxysms of cough (whoop) before symptoms finally wave over weeks to months (typically 6-10 weeks). Symptoms include sneezing, low fever, and a slight cough, and then within several days you begin "whooping" and not being able to take in air. Recovery looks like taking antibiotics for a set amount of time and it will reduce the severity and possibly the length of time of the cough, but after you have to let the cough and symptoms reduce on its own over time.

If researchers developed a drug that could prevent T. brucei from undergoing antigenic variation, do you think it could be successful in eradicating African Sleeping Sickness? Would the drug have to be administered at a certain point before or after infection in order to be helpful?

Yes, since trypanosome, also known as "sleeping sickness", does not enter cells, they are well exposed to antibodies of immunity. They are not fully eradicated by the immune attack due to antigenic variation that enables some of its population to be unrecognized by antibodies. Keeping their surface antigen static would, therefore, improve the eradication of trypanosomiasis. The drug would be administered after infection because the drug most likely works against the genes and biological pathways of the trypanosomes responsible for their surface antigens. This would allow the immune system to easily form antibodies against the surface antigens and there would be no fear that trypanosomes could vary their antigens, hence, evade the immune system.

Does the reappearance of Danielle's symptoms suggest another bout of C. difficile disease?

Yes, the reappearance of Danielle's symptoms suggests another bout of C.difficile disease.

Is there a vaccine for typhoid fever? Is it always effective? Why or why not?

Yes, there is a vaccine for typhoid, however, it is not always effective. This is because scientists have not been able to create a completely effective vaccine without knowing the underlying immunology of the pathogen.