Microbio - CHAPTER 20 REVIEW PDF

CHAPTER 20 1. What diseases are associated w/ Neisseria? (Slide 5) a. Gonorrhea and meningitis 2. What are the characteristics of these diseases? a. Gonorrhea: secrete protease that cleaves secretory immunoglobulin A (IgA) i. Survive within neutrophils...

CHAPTER 20 1. What diseases are associated w/ Neisseria? (Slide 5) a. Gonorrhea and meningitis 2. What are the characteristics of these diseases? a. Gonorrhea: secrete protease that cleaves secretory immunoglobulin A (IgA) i. Survive within neutrophils ii. Antigenic variability iii. Opa proteins bind to T cell receptors, preventing activation and immunological memory b. Meningitis: normal microbiota of the upper respiratory tract 3. What is the morphology of Neisseria? (6) a. Diplococcus 4. Gonorrhea – transmission, treatment, eOect on infants (7-11)] a. Transmission: sexual encounters b. Treatment: complicated due to resistant strains; broad-spectrum intramuscular cephalosporins c. EOect on infants: ophthalmia neonatorum – infant blindness due to a gonorrheal infection of the eyes 5. Who is aOected by Neisseria Meningitidis? a. Individuals under the age of 20 6. Prevention? a. Vaccination protects against serogroups A, C, Y, and W but not B due to similarities with neurons 7. What are the 3 most common causes of gram-negative Hospital acquired infections in the US? (20) a. Escherichia b. Proteus c. Pseudomonas 8. Are most of these organisms true pathogens or opportunistic? (22) a. Enteric bacteria are the most common gram-negative pathogens of humans, mostly opportunistic 9. What are some of the tests for identifying these? (24) a. 10. What do the O and H refer to when looking at strains of E. coli? (25) a. O polysaccharide on surface b. H antigen on flagella c. Antigens used for identification (Escherichia coli O157:H7) 11. What are the virulence factors that are common to these? (25) a. Capsules, fimbrae, adhesisns, exotoxins, siderophores, hemolysins, type III secretion system injects material into host cells 12. What is MacConkey good for? Is it a diOerential media? (28) a. For gram negatives; good for seeing growth b. It is diOerential and selective growth 13. What is a coliform? Are they all pathogens? Why do we care about them? (31) a. Coliform (indicator organisms): rapidly ferment lactose; normal microbiota but may be opportunistic pathogens b. Coliforms in water indicate impure water and poor sewage treatment 14. Are all E. coli pathogens? What is so special about O157:H7? (33) a. Not all E. coli are pathogens, they are part of the normal microbiota of the intestine b. O157:H7 – most prevalent pathogenic E. coli; Shiga-like toxin 15. What are some gram – true pathogens? (35) a. Salmonella, Shigella, and Yersinia 16. Most common causes of Salmonella? (36) a. Most human infections due to consuming food contaminated with animal feces b. Poultry and eggs 17. What organism is associated with Typhoid fever? (39) a. Salmonella 18. How serious is Shigella? How is it transmitted? And treated? (42, 44) a. Severe form of dysentery – pus and bloody stool b. Associated with poor hygiene and sewage treatment c. People ingest bacteria present on their own contaminated hands or in contaminated food; person-to-person spread is possible d. Treated with fluid and electrolyte replacement 19. Two types of disease caused by Yersinia? Which is worse? (45) a. Bubonic plague (50% death untreated) and pneumonic plague (near 100% fatality) 20. How would you typically catch this disease? (45) a. Y. pestis b. Xenopsylla cheopis (rat flea) after biofilm blockage c. Uses type III secretion system to inject apoptosis protein in macrophages and neurophils 21. What diseases do Pasteurellacea cause? Symptoms? Who is usually aOected? (49- 52) a. Haemophilus influenzae b. Symptoms: stiO neck, light sensitivity, and seizures c. Common cause of meningitis prior to vaccination (3-28 months old) 22. What disease does Bordetella cause? How is it contacted, prevented? (54-57) a. Causes pertussis (whooping cough) – B. pertussis  b. Contracted by inhalation: bacteria inhaled in aerosols multiply in ciliated cells c. Prevented by DTaP vaccine 23. What is the reservoir for Pseudomonas? True pathogen or opportunist? Treatment? (60) a. Reservoir: ubiquitous in soil, decaying organic matter, and moist environments b. Opportunistic infections in immunocompromised patients (can colonize almost any organ or system, burn victims) c. Treatment: diOicult due to drug resistance 24. What is unique/unusual about risk factors for Prevotella? (64) a. Vegetarians; associated with a healthy diet high in plants b. Sinus and ear infections c. Almost all periodontal infections d. Gynecological infections e. Brain abscesses f. Abdominal infections g. Treat by surgical removal of infected tissue and carbapenem