Medical Bacteriology: Exam #3 Study Questions 1. Name 3 characteristics of the family Vibrionaceae. What general disease is associated with Vibrio vulnificus, V. parahaemolyticus? 2. What is the precise molecular mechanism of action for cholera toxin and how does it cause the disease symptoms? What is the structure of the toxin? Is cholera more likely transmitted by hand or fecal contaminated water and food? Why? What is the most critical treatment for cholera? Is there a vaccine for cholera? What is it? Describe several strategies for development of live attenuated vaccines for cholera. 3. Define: O1 agglutinable Vibrio cholerae, oral rehydration packet, dysentery (and 3 causes), hemolytic uremic syndrome (HUS), nosocomial 4. Compare and contrast: - Enterotoxigenic E. coli (ETEC), enterohemorrhagic and verotoxigenic E. coli (EHEC/VTEC), - Mechanism of action and structure of cholera toxin and E. coli labile toxin (LT) - Laboratory isolation of Shigella vs Salmonella vs Campylobacter - Disease caused by Salmonella enteritidis vs S. typhi - Kauffmann/White vs Ewing/CDC classification system for Salmonella - Bubonic and pneumonic plague - Urban and sylvatic plague (which is most important in the US?) - Cystitis vs pyelonephritis vs urosepsis (location and severity) 5. Why is Shigella more likely to spread from person to person than is cholera? Describe the pathogenesis of dysentery (local effects and effects of shiga toxin) Is there an animal reservoir for Shigella? EHEC? Salmonella typhi? S. enteritidis? Campylobacter? 6. What unique disease is associated with Helicobacter? How is it diagnosed and treated? 7. What specimen would be best for isolation of Salmonella typhi early, middle, and late in disease? Why? Where is S. typhi located in chronic carriers? How does it survive there? Why is S. typhi rare in the US, but S. enteritidis is frequent? Discuss the old and new typhoid fever vaccines. Why is the current typhoid vaccine considered a possible delivery "vehicle" for other vaccines? (in detail) 8. Describe pathogenesis and establishment of infection withYersinia pestis. Describe diagnosis of the plague: clinical and laboratory. Is there a vaccine? Who gets it? 9. Give one specific example of opportunistic infection for each of the following compromised states: - Genetic predisposition - Immunosuppression - Physical predisposition 10. What is the number one bacterial cause of urinary tract infections (UTI)? Is it exogenous or endogenous? Describe clinical and laboratory diagnosis of UTI. What media is used to isolate UTI pathogens? What is the purpose of each? Should MIC be determined if Enterobacteriaceae is isolated from UTI? Expain. 11. What general characteristics are associated with organisms in the family Pseudomonadaceae (list at least 5)? What is the role of the following Pseudomonas aeruginosa virulence factors in disease? - Alginate, Exotoxin A, proteases Describe the disease and clinical management of the following types of Pseudomonas infections: Chronic lung, burn, neoplasm patient. What general type of disease is associated with Aeromonas hydrophila? 12. Describe unique bacteriological characteristics of the genus Corynebacterium. Describe the precise mechanism of action of diphtheria toxin and how it causes the disease symptoms observed. Describe basic experiments which helped to understand the precise role of iron in regulation of diphtheria toxin gene expression. Explain the statement: "Toxin production by C. diphtheriae is a result of lysogenic conversion" Describe experiments which helped to define what the precise host cellular receptor is for diphtheria toxin. Describe the pathogenesis of diphtheria: Transmission, infection, toxin effects. What 3 media are used for primary plating from a patient suspected of having diphtheria? What is the most important treatment for diphtheria? Explain. Describe on "bioassay" for determining whether a Corynebacterium isolate is toxin positive. Why is diptheria very rare in the US? 13. Define: Metachromatic granules, diphtheroid, coryneform, pseudomembrane, CRM Facultative intracellular bacteria, miliary tubercles, partial acid fast (and the major organism with this property), 14. Discuss disease caused by Listeria in fetus, newborn, healthy adults. How does this organism survive inside of macrophages? How is Listeria transmitted to humans? 15. Name two bacterial genera which produce many antibiotics used today. 16. What type of disease is typically caused by Nocardia? Why does it stain partially acid fast? How is this organism transmitted? 17. Describe how sputum is prepared for isolation of Mycobacteria or Nocardia. 18. Is disease caused by Actinomyces endogenous or exogenous? Explain. Describe a typical infection. What are sulfur granules and what is their diagnostic significance? 19. What is the literal definition of the term "mycobacterium"? What does MOTT stand for? How are MOTTs transmitted to humans? Which branch of the immune system (humoral or CMI) is most helpful in controlling Mycobacterial infections? Explain. What is the significance of the M. avium-intracellularae complex? What are the Runyon classification criteria? Define: Scotochromogenic, photochromogenic. 20. Compare lung x-ray from tuberculosis with that from lobar pneumonia. Why are multiple antibiotics used to treat Mycobacterial infections? Why must antibiotics be given for 12 months? What media is used to culture M. leprae? Contrast host pathogenesis in primary and secondary/reactivation TB. 21. Define: Multiple drug resistant TB, BACTEC, BCG vaccine, Freunds complete adjuvant, muramyl dipeptide, anergy, old tuberculin, PPD 22. Compare tuberculoid and lepromatous leprosy with respect to contagion, host tissue damage, prognosis, skin test response, nerve damage, immunecomplex damage. What cell types does M. leprae infect? Since M. leprae cannot be grown in lab, how can one study the bacteriology of the organism? 23. Discuss the statement: Humans are susceptible to infection with M. tuberculosis, but resistant to disease. What percent of the world population is estimated to be infected with M. tuberculosis? Why is M. bovis no longer a major cause of TB in the US? Why is BCG not administered routinely in the US? 24. What is the significance of the following species of the genus Bacillus? B. stearothermophilus, B. thurengiensis, B. cereus, B. anthracis 25. Compare the form of anthrax disease in humans vs herbivorous animals. How is it transmitted in the US? 26. Describe the precise mechanism of action of the following toxins and how they cause the disease symptoms: Anthrax toxins (protective antigen, lethal factor, edema factor) Botulism toxin, Tetanus toxin, Clostridial alpha toxin 27. Define: Eschar, superoxide dismutase, ischemia, glovebox, anaerobe jar, GasPak, palladium, aerotolerance test, debride, passive immunization, lockjaw, antibiotic associated enterocolitis (and cause). 28. Describe 5 situations which predispose one to anaerobic infection. Is infection with Bacteroides endogenous or exogenous? Explain. If a patient has an anaerobic lung infection, what is the most likely organism? If a patient has an anerobic peritoneal abscess, what is the most likely organism? 29. Compare adult botulism and infant botulism with respect to: Infection, severity, age distribution, transmission, 30. How many serotypes of botulism toxin are there? Which cause disease in humans? What is the major treatment for botulism and tetanus? Why is serology (looking for antibodies) not used to diagnose botulism? 31. Describe one bioassay (in detail) for detection of botulism or tetanus toxin. What is the advantage of bioassays over an immunologically based test like an ELISA? 32. What is one "application" for botulism toxin? 33. Why is tetanus so rare in the US? 34. Define: histotoxic Clostridia, alpha toxin/lecithinase/phospholipase , 35. What are several methods used to treat clostridial myonecrosis? Journal Reports (2001): Katsu - If you have cloned the promoter for the Yersinia YfuABC iron transport system in front of the lacZ gene, How could you easily determine if YfuABC is regulated by Mn++ levels? Jared - What was the general strategy used to determine the role of SodC as a Mycobacterial virulence factor? John - How would you determine whether the Moraxella OmpE protein changes over time in chronically infected patients? Lee - The genome sequence of Streptococcus pneumoniae has been recently determined. If you know the sequence of one choline-binding protein, how would you "mine" the genome to determine if the organism can produce other choline-binding proteins? Nicole - Describe a laboratory strategy for testing whether an exotoxin inhibits protein synthesis. Shelley - Researchers are working on a vaccine to give to mothers that will protect newborns from group B Streptococcus meningitis. Explain the rationale behind developing a protein-polysaccharide conjugate, rather than polysaccharide, vaccine to give to expectant mothers to protect the newborn. Zach - Antibodies to Acinetobacter which cross react with neural proteins was suggested as a contributing factor to bovine spongiform encephalopathy (BSE). Why were IgA, rather than IgG and IgM, antibody levels tested in the cattle? From Mycology 1. Define: dermatophyte (what are the 3 genera?), germ tube, dimorphic fungi, ergosterol, azoles, amphotericin B, mycetismus, anthropophilic, zoophilic, Saboraud media, conidia 2. How are fungi isolated and identified in lab? Describe tranmission and general disease for the following fungi: Dermatophytes, Sporothrix, Coccidioides, Histoplasma, Candida, Cryptococcus