PDAT: Infectious Disease Midterm Exam I PDF - 2018

This is not a real exam. This is a creative adaptation to the material presented in class, and the questions suspected to be on the exam. By using this resource, you acknowledge that I may be completely misleading you or saving your life. More than likely, it is a healthy balance. PATHOPHYS...

This is not a real exam. This is a creative adaptation to the material presented in class, and the questions suspected to be on the exam. By using this resource, you acknowledge that I may be completely misleading you or saving your life. More than likely, it is a healthy balance. PATHOPHYSIOLOGY, DRUG ACTION, & THERAPEUTICS (PDAT): INFECTIOUS DISEASE Midterm Exam I, February 16, 2018, 9:30-10:20 AM Rules and Instructions Time There are 30 questions and the maximum number of points for this exam is 150. You have approximately 50 minutes to complete the test. On average, this gives you 1.66666666666666666666666666667 minutes per question. There is an additional page following the 30 questions that provides the suggested answers to this representative exam. Please be sure to reach each question carefully, as it may indicate there are multiple potential answers. Directions This exam contains both multiple-choice type questions, as well as NAPLEX-style questions. Make sure to read the entire question and answer to the best of your ability. 1. Examine your booklet exam for completeness; it should contain 6 testing pages and 1 answer sheet 2. Mark the correct answers on the booklet - this will be your record to keep 3. Review your answers 4. Check to see if you were correct by viewing the last page. 5. After taking the test, if you disagree with an answer you can submit a regrade request to [email protected]. Regrades should be submitted with evidence from lecture and an explanation, I look forward to being corrected if I am wrong as it will help me as well! Good Luck! D Po 1. Select the situation that most correctly applies to the symbiotic relationships between hosts and microbes as discussed in class: a. The nutritional suggestion to avoid Red Meats is based on the harmful metabolites produced by bacteria when metabolizing choline. b. An exogenous perturbation, Rifaximin is an antibiotic that inhibits RNA polymerase, specifically leading to inflammation and the elimination of beneficial bacteria. This perturbation is an example of Host- Microbial Dysbiosis. c. One example of Host-Microbial Mutualism is the synthesis of short-chain fatty acids such as butyrate, by bacteria. Butyrate is the primary energy source for human colonocytes. d. In an experiment involving gnotobiotic mice, it was shown that maturation of the immune system and related cells is independent from gut microbiota. 2. Clostridium difficile is a gram-positive, spore-forming bacteria that leads to 30,000 deaths annually. In most cases, the infection is manageable with antibiotics. Which of the following about C. diff infections (CDI) is false? a. The most significant preventative therapy conferring protection against C diff is to have a robust microbiome. b. The recurrence of CDI is most frequently associated with decreased microbial diversity and offending medications such as PPIs c. Eliminating the overuse of narrow spectrum antibiotics is an example of a CDI modifiable risk factor. d. Procedures involving the introduction of healthy donor fecal suspensions into the GI tract of a CDI patient is a valid and highly efficacious treatment option. 3. More than one answer may be correct. Concerning prebiotics and probiotics, select all of the following that are true? a. Probiotics are live microorganisms, such as non-pasteurized yogurt, that have health benefits when consumed. b. The term prebiotic refers to non-digestible carbohydrates that stimulate the metabolism of healthy gut microbiota. c. Hempel et al is a large meta-analysis that showed prebiotics as adjunct/concurrent therapy to antibiotic regimens reduce the risk of antibiotic-associated diarrhea (AAD) by 58%. d. One requirement of a prebiotic is that it must resist mammalian metabolism/absorption in the upper gastrointestinal tract. 4. Inappropriate antibiotic therapy includes risks such as increased vulnerability to additional infectious diseases and the development of resistance. Which clinical findings immediately support the initiation of antibiotic therapy? a. A specific lab result that positively identifies the viral agent responsible b. An obvious bacterial infection that requires urgent treatment c. Labs indicating fever, severely low WBC count, and elevated ESR d. A left-shift e. Elevated Procalcitonin levels 5. Which of the following is true about hospital-acquired infections? a. They are gram(-) bacilli resistant to penicillin, ampicillin, and erythromycin b. Severe nosocomial (hospital-originated) infections by E. coli necessitate initial use of monotherapy c. The sterile hospital environment is host to less harmful infectious agents compared to community dwellings d. A patient’s prior antibiotic use in the hospital is helpful for identifying what has worked in the past 6. KJ is a 45yo Asian American M presenting to the ICU with a black lesion on his forearm, complaining of severe pain, and passing in and out of consciousness. Of the following choices, what is the most appropriate first step to take? a. Previous medical history (1 week ago) indicates the patient was treated for MRSA. The patient should be treated empirically for MRSA, using an antibiotic with a different mechanism of action than previously used. b. Consult the Antibiogram for the most appropriate and effective treatment for MRSA c. Collect cultures from the patient d. Ignore the previous medical history, and treat with the best antibiotic for the presumptive diagnosis e. Since the patient will likely be staying a while, find the most plush pillow in the equipment closet 7. Select the incorrect matching of an infection and its suspected organism a. A patient with an infection involving an inflamed trachea should be treated as a medical emergency with empiric therapy targeted at H. infuenzae b. A patient diagnosed with Hospital Acquired Pneumonia (HAP) is more serious than the community- acquired relative, because the suspected organism is the often resistant M catarrhalis. c. Due to the severity of the infection, a patient diagnosed with Meningitis should receive age-based empiric therapy, because the suspected organism varies by age group. d. Ameobiasis is a protozoan disease frequently associated with travelers or campers, affected by the pathogenic amoeba Entamoeba histolytica. e. A patient diagnosed with Osteomyelitis (an infection of the bone), should be treated for the common skin microflora inhabitant, S. aureus, until cultures or medical history suggest otherwise. 8. The term “Anatomical Sterile Sites” refers to: a. A site where, if bacteria are found, requires immediate treatment. b. Sites on the body such as Bones, the Upper Respiratory Tract, and the Cardiovascular System. c. When infected, it is immediately considered a “True infection” d. The Central Nervous System and the Urinary Tract are examples of Anatomical Sterile Sites. e. All of the above 9. You are a pharmacy resident on call. A 16yo F comes to the ICU complaining of dysuria. A nurse hands you a sample gathered from the patient’s urinary tract. You quickly run a gram stain test and look into the microscope. You see pink/red rod-shaped cells. What is the presumed diagnosis and spectrum of treatment? a. The patient has LUPUS and needs epinephrine STAT b. The likely bug is S. pneumoniae and should be treated with Gram(+) spectrum antibiotics. c. The likely bug is an Enterobacteraciae and should be treated with Gram(+) spectrum antibiotics d. The likely bug is E. coli and should be treated with Gram(-) spectrum antibiotics e. The likely bug is S. epidermidis and should be treated with Gram(-) spectrum antibiotics 10. Evaluating the “Common Cold” and Influenza, which of the following is incorrect? a. Inappropriate treatment with antibiotics may negatively impact the microbiome, taking as long as 1 to 2 years to reconstitute. b. Discriminating between symptoms: i. Common Cold: A stuffy nose is common, the fever and cough are usually mild. ii. Flu: A stuffy nose is rare, the fever and cough are usually severe c. Both the ‘common cold’ and the ‘flu’ are the result of a viral infection d. There is no curative treatment to the common cold, current remedies include a “tincture of time” e. All answers A-D are correct. 11. More than one answer may be correct. In class, we discussed several epidemiological terms. Read each of the following prompts and select those that are accurate depictions of the key word a. An inapparent infection is active and has the ability to be transmitted, whereas a latent infection is less likely to be transmitted and is inactive until sufficient perturbation of the immune system. b. The rate of infection following exposure of a small population (such as a school) to the index case is termed the secondary attack rate. c. A pandemic disease refers to a world-wild epidemic. An epidemic disease is one that is constantly present in a population. And an endemic disease is one acquired by many hosts in a given area in a short time. “The flu has become endemic!” d. Whereas prevalence refers to the number of people who newly develop a case during a particular time period, incidence calculates the total number of cases (new and old) during a given time period. e. Herd immunity is the resistance of a community to the invasion and spread of an infectious agent because of resistance inherent to a high proportion of individual members of the group. 12. The goal of epidemiology is to control or stop epidemics. A major distinguishing characteristic compared to other studies is that epidemiology deals with groups of people, rather than individuals. Which of the following is not an application of epidemiology in the building of a healthy community? a. To intermittently survey community members to detect changes in the prescribing patterns of antibiotics b. To plan feasible remedies and ensure successful installment with follow-up monitoring c. To investigate outbreaks and analyze its causes d. To monitor the efficacy of a community’s vaccination program e. To provide a community diagnosis 13. Harnessing the 5 D’s of Antimicrobial Stewardship, our objectives when treating an infection are: a. Minimize costs and discharging the patient with empiric therapy b. To give low-dose antibiotics to elderly patients c. To cure infection and minimize complications d. Acquire specimens immediately following initiation of empiric therapy e. To improve creatinine clearance and develop antibiograms 14. More than one response may be selected. Which of the following will not help support our diagnosis or treatment of a patient? a. Interviewing the patient and being told “it really hurts when I urinate” b. Using intramuscular therapy to decrease pain associated with injection c. Discovering the patient was treated for MRSA last weekend after bowling practice d. Make the decision to switch from IV à PO therapy as [WBC] increases e. Using an Antibiogram to select appropriate therapy while awaiting culture results 15. Which of the following is a potential reason for receiving an unsatisfactory response during treatment of an infection? a. The patient has a large abscess that tests positive for infective agents b. The IV fell out of the patients arm and is sitting on the floor c. When culture susceptibility results come back, it is determined that the bacterium is resistant to your previously administered empiric therapy. d. The patient has a severe infection and a bacteriostatic antibiotic is being used e. All of the Above 16. Antibiotics inhibit protein translation by interacting with the functional centers of the ribosome. Identify the correct description of the mechanism of action employed by macrolide antibiotics a. Interaction with residues within the nascent peptide channel near the catalytic center producing partial obstruction and protein-specific inhibition. b. Interaction with residues of the catalytic center within the large ribosomal subunit preventing peptide bond formation c. Occupation of the A site of the small ribosomal subunit producing steric clash with incoming aminoacyl- tRNA. d. Interaction with mismatched and distorted RNA sequences in the small ribosomal subunit, blocking the accuracy detection system 17. Which of the following is incorrect about the mechanism of action of Linezolid, an oxazolidinone a. Inhibition of peptide bond formation when the amino acid residue Ala is penultimate b. Homology between the human ribosome and bacterial ribosome at the side of linezolid action leads to inhibition of mitochondrial translation c. Due to its specific inhibition on the translation of essential proteins, Linezolid therapy may quickly precipitate host complications such as myelosuppression d. Clash with incoming aminoacyl-tRNA will prevent polymerization e. Indicated for gram (+) including MRSA 18. Why is the bacterial ribosome a favored target for antibiotic therapy? a. The ribosome is responsible for the translation of proteins essential to the cell b. The genes encoding for the ribosomal subunits are conserved in the prokaryotic domain c. The ribosome is an intracellular organelle only found in bacteria d. The genes encoding for the ribosomal subunits have a high copy number and are redundant e. The ribosome is capable of single spontaneous resistance mutations that decrease the bacterium’s viability 19. More than one response may be selected. Select the true statements concerning antibiotic resistance a. The cfr gene is often present on transposons and plasmids, associated with other resistance genes b. The cfr-mediated A2503 methylation confers resistance to Phenicols, Lincosamides, Oxazolidinones, Pleuromutilins, and Streptogramin A (PHLOPS) c. The cfr-mediated A2503 methylation occurs at the nascent peptide exit tunnel d. The Erm-mediated A2058 methylation confers resistance to macrolides, Lincosamides, and Streptogramin B (MLSB) e. The Erm-mediated A2058 methylation occurs at the overlapping sites in the peptidyl transferase center 20. Which antibiotic class that we discussed best matches this description: X is clinically indicated to treat severe infections such as tuberculosis and the bubonic plague. It is a bactericidal antibiotic capable of self-promoted uptake that runs the risk of ototoxicity. a. Streptogramins b. Fluoroquinolones c. Sulfonamides d. Oxazolidinones e. Aminoglycosides 21. Which of the following is not an accurate description of sulfonamide activity? a. Sulfonamides are structural analogues of folate b. The addition of electron withdrawing groups to the sulfonamide amide group will reduce the pKa to be similar to that of PABA. c. Addition of trimethoprim, a Dihydrofolate reductase inhibitor, creates a bactericidal drug combination d. Mammals are tolerant of sulfonamide therapies in general because they obtain folate from their diet 22. The peptidoglycan structure: a. Is composed of Lipid II building blocks conjoined at the A-ala residue b. Is formed by cross-linking between stem peptide tails c. Is impermeable d. Can be targeted by fluoroquinolones 23. What is true about the penicillin structure? a. In Penicillin, the amide group of the b-lactam ring is unstable to acidic conditions b. Modifying the chemical structure of penicillin, such as adding an electron-withdrawing group as seen in Amoxicillin, will decrease the rate of acid hydrolysis c. The addition of polar groups, such as –NH2, can make b-lactams broad spectrum (- and +) d. Penicillin contains a thiazolidine ring e. All of the Above 24. Televancin is: a. A natural compound derived from ergot used to treat Postramatus stretzillus infections b. Is unable to penetrate the cell membrane and is therefore used only to treat gram(+) infections c. Inhibits subunit A of DNA Gyrase in bacteria d. Is a semi-synthetic derivative of Vancomycin with 10x the bactericidal activity e. It lacks hydrophobic side chains, and does not have a polar phosphate group. It is a circle. 25. More than one answer may be correct. Which of the following is true about second-generation quinolone drugs a. An example of a second-generation quinolone is norfloxacin b. They exhibit lower levels of toxicity and can be used long-term for extensive therapy, such as a 6-month anthrax regimen c. Accumulate to high levels in the plasma and are effective in treating infections of the lower respiratory tract. d. Target subunit A of DNA Gyrase e. Second-generation quinolones are still in development and are scheduled for release in 2022. 26. Which antibiotic is frequently used with quinolones for its synergistic activity and where does it act? a. Daptomycin, DNA Gyrase subunit A b. Polymixin, DNA Gyrase subunit B c. Lisinopril, DNA Gyrase subunit C d. Nalidixic Acid, DNA Gyrase subunit A e. Novobiocin, DNA Gyrase subunit B 27. While much still remains unknown, which of the following is a correct representation of Daptomycin’s activity? a. As a cationic licopeptide, daptomycin inhibits the uptake of vitamin D in the gut b. Cationic peptide side chains coordinated with Ca2+ interact with the negative charge of the cell wall components while another portion of the drug interacts with the lipid membrane c. Blockade of the peptidyl transferase enzyme in the catalytic center decreases translation of TPase d. A lipophilic tail permits passage of the compound across the cell membrane so that the cationic chains may inhibit ribosome activity 28. True or False: Azithromycin is bacteriostatic in all cases, AND Telithromycin is bactericidal in all cases a. True b. False 29. When bacteria are able to indirectly detect the presence of an antibiotic: a. The minimum bactericidal concentration (MBC) is effectively decreased b. Transcription regulators (TR) promote upregulation or downregulation, depending on the antibiotic mechanism c. Global regulators (GR) upregulate the production of virulence factors d. This occurs at Sub-MIC doses which may result in producing gnotobiotic offspring e. The Susceptibility Breakpoint will need to be adjusted to account for location in the body 30. Among the three statements below, choose your answer based on which statements are correct I Antibiotic use during critical development windows of adulthood may predispose future susceptibility to C. difficile infections II Passage of bacterial metabolites from mother to offspring is responsible for the development of the innate immune system III Antibiotic activity against C. scindens will promote deoxycholic acid availability to support growth of C. difficile a. I only b. I, II, and III c. I and II only d. III only e. None of the above 1. C 2. C 3. ABD 4. B 5. A 6. C 7. B 8. E 9. D Determine Urinary Tract. Determine Gram (-). Determine bacillus. Select most probable 10. E 11. ABE 12. A 13. C 14. BD 15. E 16. A 17. C 18. D 19. ABD 20. E 21. A 22. B 23. E 24. D 25. ABCD 26. E 27. B 28. B 29. C 30. C