question

1. What are the characteristics of the Influenza virus?

answer

1. Enveloped, with segmented, single-stranded, negative-sense RNA genomes

question

2. What part of the influenza virus must fuse with the host cell membrane to transfer the virus?

answer

2. Envelope

question

3. What is the basis for emergence of new pandemic strains?

answer

3. segmented genome allows reassortment

question

4. What 3 proteins are located on the influenza envelope?

answer

4. Hemagglutinin, Neuraminidase, M2

question

5. Which proteins on the flu virus are targets for neutralizing antibodies?

answer

5. Hemagglutinin, Neuraminidase

question

6. Which protein is essential for the infectivity of the flu virus?

answer

6. M2

question

7. What is the replication scheme for the flu virus?

answer

7. 1. Entry through receptor mediated endocytosis 2. Low pH of endosome required for infectivity 3. Replication in nucleus

question

8. Does the flu virus need a symport to release the virus into the host cell?

answer

8. No, low pH of endosome opens M2 channel and releases virus

question

9. Why does the flu virus have to replicate in the nucleus?

answer

9. mRNA spliced, requires capped mRNAs from host (cap-stealing)

question

10. How can Influenza A, B, and C be distinguished ?

answer

10. Antigenic Differences between their nucleocapsid (NP) and Matrix (M) proteins

question

11. What influenza infects Humans only?

answer

11. Influenza B

question

12. What species can the Influenza A virus infect?

answer

12. humans, pigs, horses, avian species, aquatic mammals

question

13. Which flu virus can infect humans and pigs?

answer

13. Influenza C

question

14. How many distinct RNA segments does Flu A and B have?

answer

14. 8

question

15. Why does Flu C on contain 7 RNA segments?

answer

15. 2 segments are found on the same protein

question

16. Influenza A is subdivided into subtypes and designated by 5 things, whats the only part you need to know about?

answer

16. The antigenic description of the HA and NA molecules (EX. H3N2, H1N1)

question

17. What part of the body is Influenza isolated to?

answer

17. Respiratory Tract, Upper and Lower

question

18. How is Flu mainly spread?

answer

18. Aerosol droplets (coughing, sneezing)

question

19. After infection of Flu virus when do virus titer peak?

answer

19. 48 hours

question

20. How long does it take for a person to stop shedding the Flu virus after infection?

answer

20. 6-8 days

question

21. What does influenza induce in the body that contributes to recovery?

answer

21. interferon (IFN)

question

22. Where is the antibody response found in the body?

answer

22. Both Serum and Secretory

question

23. What is the incubation period for the Flu virus?

answer

23. Short 24hrs, can be up to 4-5 days

question

24. What are the initial symptoms of the Flu?

answer

24. Headache, chills, and dry cough

question

25. What follows the initial symptoms of the Flu?

answer

25. high fever, myalgias, malaise, anorexia

question

26. After the fever resolves from the flu how long can cough and weakness persist?

answer

26. 1-2 weeks

question

27. How do the symptoms of the flu differ in children and adults?

answer

27. Children have higher fever – can result in convulsions, higer incidence of vomiting and abdominal pain

question

28. What are some complications of Influenza if the virus is not cleared?

answer

28. Primary viral Pneumonia, Combined viral-bacterial pneumonia, Bacterial pneumonia, Reye’s syndrome

question

29. What population is at high risk of developing Primary Viral pneumonia after the flu?

answer

29. Elderly, Patients with cardiopulmonary disease

question

30. How soon after onset of illness can influenza progress to Primary viral pneumonia?

answer

30. 6-24 hrs

question

31. If an elderly patient presents with Flu and shortly after develops tachypnea, tachycardia, cyanosis, high fever and hypotension, What are you worried about and how can you treat him?

answer

31. Primary viral pneumonia, Supportive treatment and Antivirals, monitor for bacterial superinfection

question

32. What is a more likely complication of flu then primary viral pneumonia?

answer

32. Combined viral-bacterial pneumonia

question

33. How is viral-bacterial pneumonia distinguished from primary viral pneumonia?

answer

33. onset is usually delayed in viral-bacterial pneumonia

question

34. A patient develops shaking chills, pleuritic chest pain, and productive cough, 4 days after improving from the flu, what’s wrong?

answer

34. Influenza followed by bacterial pneumonia

question

35. What are the most common culprits of bacterial pneumonia after the Flu?

answer

35. S. pneumonia, S. Aureus, H. influenza

question

36. What are some atypical causes of bacterial pneumonia?

answer

36. M. pneumonia, Chlamydia pneumonia

question

37. What syndrome is characteristic of noninflammatory cerebral edema and fatty infiltration of the liver?

answer

37. Reye’s syndrome

question

38. What does Reye’s syndrome result in, how is this tested?

answer

38. severe hepatic dysfunction, elevated serum transaminase and ammonia levels

question

39. What type of Antigenic variation results from minor point mutations in a single HA gene?

answer

39. Antigenic drift

question

40. How does antigenic shift change the Influenza virus?

answer

40. major antigenic changes that result from replacement of either the HA or NA gene segment (Ex. H1 aH3)

question

41. What type of antigenic variation is responsible for most of the major influenza pandemics?

answer

41. Antigenic Shift

question

42. What is the definition of a pandemic strain?

answer

42. New subtype with no existing human immunity, highly pathogenic, transmitted easily between humans

question

43. What type of tests are available to detect influenza A and B?

answer

43. immunoassay-based nasopharyngeal swabs

question

44. How are inactivated vaccines made and how are they administered?

answer

44. purified virus grown in eggs, whole virus or subvirion, inactivated with formalin or ?-propiolactone, Administered IM

question

45. T/F The inactivated vaccine protects against influenza infection.

answer

45. F – Does not protect against infection but induces resistance to illness

question

46. Who is approved for the Live vaccine FluMist?

answer

46. Healthy kids 2-17, Health Adults 18-49

question

47. This year who does the CDC recommend get the Flu vaccine?

answer

47. EVERYONE – Universal Influenza Vaccination

question

48. Who is the influenza vaccine recommended for?

answer

48. Pregnant women in 2nd-3rd trimester during flu season, Healthy kids 6mo-5yrs, People 50+yrs, Any age with Chronic medical conditions, Nursing home residents and providers, People who care for those at high risk, Children/Teens with long-term aspirin therapy

question

49. How do Amantadine and Rimantadine work as antiviral agents?

answer

49. Inhibits the M2 ion channel of influenza A

question

50. Who are amantadine and Rimantadine used for?

answer

50. individuals at high risk, people with egg allergies that can’t receive flu vaccine

question

51. T/F Resistance to Aniviral Agents can develop.

answer

51. T – results from single amino acid substitutions in the transmembrane domain of the M2 channel; H3N2 and H1N1 are resistant

question

52. How do Neuraminidase inhibitors work as antiviral agents?

answer

52. inhibit virus release, limiting spread

question

53. What are 2 types of Neuraminidase inhibitors?

answer

53. Relenza (zanamivir), Tamiflu (oseltamivir phosphate)

question

54. When do Neuraminidase inhibitors need to be administered to be most effective?

answer

54. within 48 hrs of symptoms developing

question

55. What is different about the Paramyxoviruses compared to the Influenza viruses?

answer

55. Paramyxoviruses are nonsegmented

question

56. What are the characteristics of a paramyovirus?

answer

56. Consist of 2 Subfamilies, containing 5 genera, Enveloped, Nonsegmented, negative stranded RNAviruses

question

57. Where do paramyxoviruses replicate?

answer

57. Cytoplasm

question

58. What is an important characteristic of paramyxoviruses that can cause syncytia formation?

answer

58. They fuse at the cell surface

question

59. What respiratory pathogen is important in infants and children?

answer

59. Human parainfluenza viruses (hPIV)

question

60. What are the major causes of croup?

answer

60. hPIV 1, 2, and 3

question

61. What are the major causes of pneumonia and bronchiolitis?

answer

61. hPIV3

question

62. What is hPIV4 linked to?

answer

62. mild upper respiratory illnesses

question

63. Where do PIVs initially infect?

answer

63. mucous membranes of nose and throat

question

64. What can severe hPIV3 infections result in?

answer

64. bronchopneumonia, bronchiolitis, bronchitis

question

65. What are the typical symptoms of hPIV infection in children?

answer

65. cough, hoarseness and fever

question

66. If a childs cough becomes brassy, “seal-like” or barking and stridor ensues, what has developed?

answer

66. Croup

question

67. What other viral infection can cause the same hPIV Croup symptoms?

answer

67. Influenza A

question

68. Chlamydia trachomatis can cause similar symptoms to what virus?

answer

68. hPIVs

question

69. What pathogens can cause bronchitis similar to hPIVs?

answer

69. Streptococcus pneumonia, Mycoplasma pneumonia

question

70. Can symptoms of adenovirus, rhinovirus, or coronavirus be distinguished from mild cases of hPIV infection?

answer

70. No

question

71. When are hPIV 1 and 2 infections most common?

answer

71. Fall

question

72. If croup develops in the winter months what is usually the culprit?

answer

72. influenza or RSV

question

73. How are hPIVs transmitted?

answer

73. direct contact, large droplet spread

question

74. T/F Reinfection with the same serotype of PIV is uncommon.

answer

74. F – common and can occur relatively quickly

question

75. T/F There are no vaccines or antivirals used for hPIVs.

answer

75. T

question

76. What is responsible for many lower respiratory tract infections in children?

answer

76. Human metapneumovirus (hMPV)

question

77. What is the MOST important cause of viral lower respiratory tract disease in infants and children worldwide?

answer

77. Respiratory Syncytial Virus (RSV)

question

78. Where does RSV initially infect?

answer

78. nasopharynx

question

79. If RSV spreads to the lower respiratory tract, how long does it take and what are the symptoms?

answer

79. 1-3 days, cough and low-grade fever develop

question

80. T/F RSV can cause permanent lung damage and the development of asthma.

answer

80. T

question

81. Where can RSV antigens be found?

answer

81. both epithelium and in exfoliated epithelia cells plugging the airways

question

82. T/F RSV is uncommon in adults.

answer

82. F – common in normal adults; symptoms – rhinorrhea, cough, headache, fatigue, fever

question

83. What patients are at high risk for RSV

answer

83. premature infants, children with chronic lung disease, Premature infants ;1yr at start of RSV season

question

84. How is RSV spread?

answer

84. Large droplet or Fomite contamination

question

85. What the heck is a Fomite?

answer

85. any inanimate object or substance capable of carrying infectious organisms (ex. bedding, cloth, stethoscope)

question

86. What is the treatment for RSV infection?

answer

86. mostly supportive, ensure adequate oxygenation, hydration, and nutrition

question

87. What is Synagis (palivizumab) and who is it use for?

answer

87. recombinant monoclonal antibody that neutralizes RSV, used for high risk infants

question

88. What family is Rhinovirus part of?

answer

88. Picornaviridae

question

89. How many serotypes do Rhinoviruses have?

answer

89. ;100

question

90. What characteristics does the Rhinoviruses have?

answer

90. Small, non-enveloped, positive-strand RNA virus

question

91. What is the distinguishing feature of the mRNA of Rhinovirus?

answer

91. 5’VPg

question

92. What differentiates Rhinoviruses from other picornaviruses?

answer

92. Inactivated by pH 6.0 or lower

question

93. Why is Rhinovirus difficult to grow in culture?

answer

93. requires reduced temperature (33C) for optimal growth

question

94. What does Rhinovirus bind to get into the host cell?

answer

94. iCAM-1

question

95. How does Rhinovirus exploit the host cell?

answer

95. IFN and TNF-? upregulate iCAMs, Rhinovirus binds iCAMs

question

96. Once the Rhinovirus enters the cell what is the first event that takes place?

answer

96. Translation of a polyprotein

question

97. How are Rhinovirus viral proteins released from the polyprotein?

answer

97. following specific cleavage events by the virally encoded proteases

question

98. How is translation of picornavirus genomes initiated?

answer

98. cap-independent mechanism

question

99. What is the IRES (internal ribosome entry site)?

answer

99. Sequence near the 5’ end of picornavirus genome that initiates translation

question

100. How is translation of picornavirus genomes linked to host cell translation?

answer

100. Linked to mechanism by which host cell translation is inhibited.

question

101. What are the characteristics of a Coronavirus?

answer

101. Large, Enveloped, positive-stranded RNA virus, Genome capped at 5’ end, has 3’poly A+ tail

question

102. What RNA virus has the largest Genome?

answer

102. Coronavirus

question

103. How is the polymerase polyprotein of the coronavirus translated?

answer

103. 1. cis-cleavage of viral polymerase which synthesizes a (-)sense antigenome, 2. antigenome is template for synthesis of sub-genomic mRNA

question

104. What is unique about the coronavirus mRNA synthesis mechanism?

answer

104. “leader-primed” – results in nested set of overlapping mRNAs with common 3’ end

question

105. What allows for a high frequency of recombination in the coronavirus?

answer

105. “Leader-primed” – polymerase “hopping”

question

106. What percentage of Upper respiratory infections does coronavirus cause in humans?

answer

106. 15-20%

question

107. What “severe atypical pneumonia” was caused by a coronavirus in 2003?

answer

107. SARS

question

108. T/F coronaviruses cause a significant amount of GI problems?

answer

108. T

question

109. What do Rhinovirus and coronavirus infections do to the nasal mucosa?

answer

109. Cause shedding of the ciliated epithelium

question

110. Why are conventional vaccinations not feasible for coronaviruses and rhinoviruses?

answer

110. Large # of serotypes for rhinoviruses, high frequency of recombination for coronaviruses

question

111. What is Structure of Adenovirus?

answer

111. Linear, double-stranded DNA genome, 36 kilobase pairs, No envelope

question

112. What does Adenovirus cause infection in?

answer

112. Respiratory, Eye, GI

question

113. What is Adenovirus stable against?

answer

113. detergents, low pH

question

114. How many serotypes of Adenoviruse are known to infect humans?

answer

114. 49

question

115. Where does replication and assembly of Adenovirus occur?

answer

115. Nucleus

question

116. How is adenovirus spread?

answer

116. Respiratory or fecal-oral route

question

117. What Bug is associated with pharyngoconjunctival fever in children?

answer

117. Adenovirus

question

118. Conjunctivitis that feels like “sand in the eye” is caused by what bug?

answer

118. Adenovirus

question

119. What is the main pathogenic species of Pseudomonads?

answer

119. P. aeruginosa

question

120. What bug is widely distributed in nature and is highly resistant to antibiotics and can rapidly evolveresistance?

answer

120. Pseudomonads

question

121. What characteristics do Pseudomonas have?

answer

121. Gram Negative, motile, aerobic rods, Produce Soluble Pigments

question

122. What allows pseudomonas to grow just about anywhere?

answer

122. Obligate aerobes – can us CO2, atmospheric ammonia, nitrogen sources

question

123. An organism that grows at 42C is diagnostic for what bug?

answer

123. Pseudomonas

question

124. What do cultures of Pseudomonas smell like?

answer

124. Grapes

question

125. What type of pigmented siderophores do pseudomonas produce and what color are they?

answer

125. Pyocyanin – Blue, Pyoverdin – fluorescent yellow pigment

question

126. What do some strains of pseudomonads produce that is induced in the CF lung?

answer

126. Alginate

question

127. What does an overproduction of alginate result in?

answer

127. mucoid phenotype

question

128. Who do pseudomonads cause a problem for?

answer

128. immune suppressed people

question

129. What type of toxin do pseudomonads produce?

answer

129. Exotoxin A

question

130. How does Exotoxin A effect the cell?

answer

130. causes necrosis by blocking protein synthesis

question

131. What 2 toxins have an identical mechanism of blocking protein synthesis, but are produced by different bugs?

answer

131. Exotoxin A and diphtheria

question

132. What bug is associated with Swimmers ear frequently?

answer

132. Pseudomonas

question

133. What type of rash can you get if you are on a medical conference and you shave your legs before going into a hot tub that doesn’t have enough chemicals? what bug caused it?

answer

133. Hot Tub Folliculitis, Pseudomonas

question

134. How are pseudomonas infections treated?

answer

134. Combined therapy to limit resistance

question

135. What are the characteristics of Acinetobacter?

answer

135. Ubiquitous aerobic gram negative coccobacillus

question

136. How does Acinetobacter infect?

answer

136. compromised patients – low pathogenic potential

question

137. What strain of Acinetobacter is most common?

answer

137. A. baumanii

question

138. What bug has recently been a major problem in the Burn Wards of Memphis?

answer

138. A. baumanii

question

139. What pathogen is A. baumanii easily mistaken for?

answer

139. N. meningiditis

question

140. How is A. baumanii differentiated from Neisseria?

answer

140. oxidase negative

question

141. Why is antimicrobial testing necessary to guide therapy of Actinobyces?

answer

141. Extremely resistant to antibiotics

question

142. What bug shows biopolar metachromic granules?

answer

142. B. pertussis

question

143. What bug is a small gram negative coccobacillus that looks like H. influenza?

answer

143. B. pertussis

question

144. Why do you have to let the lab know before you culture someone you suspect as having whooping cough?

answer

144. requires an enriched and selective medium for primary isolation – Bordet-Gengou medium

question

145. How is B. pertussis transmitted?

answer

145. droplet inoculation

question

146. What does B. pertussis produce a lot of that causes irritation, inflammation, and cough?

answer

146. AB exotoxins

question

147. Does B. pertussis invade the ciliated epithelium?

answer

147. No, multiples on epithelia without invasion

question

148. What controls the virulence gene expression of B. pertussis?

answer

148. bvgA/bvgS two component regulatory system

question

149. What is the enzymatic action that is specific for the Pertussis toxin?

answer

149. Interfere with PMN, monocyt, and macrophage function, Lymphocytosis, Sensitization to histamine, Hypoglycemia

question

150. How does the BvgS/A system regulate virulence factors?

answer

150. BvgS senses a stimulus, phosphate from a donor transferred to BvgS eventually goes to BvgA which Activates transcription of several genes.

question

151. How Does Pertussis A toxin interfere with normal function?

answer

151. Conversion of ATP to cAMP cannot be stopped because the Gi protein that normally inhibits adenylate cyclase is inhibited by A toxin.

question

152. How long is the incubation period for B. Pertussis?

answer

152. 1-2 weeks

question

153. When are patients most infections with B. Pertussis?

answer

153. Catarrhal stage

question

154. How is the paroxysmal stage of B. pertussis characterized?

answer

154. coughing fits – with whoop inhalation, lasts about 2 weeks, high white blood cell count

question

155. How is B. pertussis diagnosed?

answer

155. primary by clinical features, Nasopharyngeal swap

question

156. Whats the drug of choice for B. pertussis?

answer

156. Erythromycin

question

157. How is B. pertussis prevented?

answer

157. DTap immunization

question

158. What bug is a Gram positive Rod that appear in clumps resembling Chinese letters?

answer

158. C. diphtheriae

question

159. Where is C. diphtheriae found?

answer

159. Human reservoir – not found anywhere else in nature

question

160. T/F Production of diphtheria toxin only occurs in cells that have been transduced with a phage that carries the toxin genes.

answer

160. T

question

161. What is the expression of the Diphtheria toxin dependent on?

answer

161. iron – Low concentrations increase toxin production, High concentrations repress production

question

162. What type of toxin is the Diphtheria toxin?

answer

162. AB toxin (like pseudomonas)

question

163. What tissues are most affected by Diphtheria toxin?

answer

163. myocardium and peripheral nerves

question

164. What does the A subunit of Diphtheria toxin inhibit?

answer

164. polypeptide elongation in the presence of NAd by inactivation of EF-2

question

165. What is the characteristic pathology of Diptheria toxin?

answer

165. pseudomembrane over tonsils, pharynx, and larynx

question

166. What bug can cause the characteristic “bull neck”?

answer

166. C. Diptheria

question

167. What is the mainstay of therapy for Diphtheria?

answer

167. Antitoxin – immediately

question

168. What is the characteristic stain of Mycobacteria?

answer

168. Acid fast stain positive

question

169. What is unique about the M. Tuberculosis envelope?

answer

169. Mycolic Acid, Cord Factor, Wax-D

question

170. What properties are associated with the high concentrations of lipids in the cell wall of M. tuberculosis?

answer

170. Impermeability to stains and dyes, Resistance to antibiotics, acidic and alkaline compounds, osmotic lysis, lethal oxidations, desiccation

question

171. When do Tubercles form with tuberculosis infection?

answer

171. Primary Disease

question

172. What are calcified tubercles seen called?

answer

172. Ghon complexes

question

173. In the absence of CMI, how can TB progress?

answer

173. Miliary TB

question

174. What test for TB indicates infection but does not indicate disease?

answer

174. PPD

question

175. How long do cultures of TB need to be kept to rule out disease?

answer

175. 1-2 months

question

176. What is the treatment plan for TB?

answer

176. Combined therapy - Isoniazid, Rigampin, pyrazinamide, and ethambutol or streptomycin, 6-9 months, patients are non-infectious within 2 weeks but not cured

question

177. What is Cord Factor for?

answer

177. virulence factor that functions to inhibit PMN migration

question

178. What are the characteristics of Actinomyces?

answer

178. Club-shaped, gram + rods that form Branched filaments.

question

179. What do the microcolonies of actinomyces in pus look like?

answer

179. sulfur granules

question

180. What is the reservoir of Actinomyces?

answer

180. Human oral and GI

question

181. What is Actinomyces israelii nearly always associated with?

answer

181. Trauma and compromised immunity (surgery, tooth extraction, IUDs)

question

182. What Disease is characterized by “lumpy jaw”?

answer

182. Cervicofacial actinomycosis

question

183. What is the treatment for Actinomyces?

answer

183. Prolonged Penicillin

question

184. Where is Nocardia found?

answer

184. Soil

question

185. What does Nocardia resemble?

answer

185. Aerobic weakly gram positive branching rods that look like fungi

question

186. What kind of acid stain do Nocardia have?

answer

186. weakly acid fast

question

187. T/F Nocardiosis are Penicillian resistant.

answer

187. T – use Trimethylprim-sulfamethoxazole

question

188. Does Atypical Pneumonia always include fever?

answer

188. No – may or may not, radiological evidence may distinguish

question

189. How does growth of Chylamydia occur?

answer

189. biphasic developmental cycle

question

190. What is a significant cause of community acquired pneumonia?

answer

190. Chlamydia pneumonia

question

191. What are the characteristics of Chlamydia?

answer

191. Gram-negative spherical bacteria that are obligate intracellular parasites

question

192. What is the developmental cycle of Chlamydiae?

answer

192. Elementary Bodies attach and enter cell, Primary Differentiation, Cell division, Rapid multiplication, Effector secretions, Secondary differentiation, EB released and Reinfect

question

193. What bug is associated with chronic atherosclerotic disease?

answer

193. Chlamydia Pneumoniae

question

194. What are the 3 predominant bacterial causes of Atypical Pneumonia?

answer

194. Chlamydia, Mycoplasma, Legionella

question

195. What is the smallest free-living organism?

answer

195. Mycoplasma

question

196. T/F Mycoplasma lack a cell wall.

answer

196. T

question

197. What are the symptoms of Mycoplasma pneumoniae, and who do they typically occur in?

answer

197. Mild respiratory infection, sore throat and pharyngitis, occur in 1-5 YO

question

198. How does mycoplasma activate inflammatory cytokines?

answer

198. lipoproteins interact with alveolar macrophage Toll-like receptors

question

199. T/F Mycoplasma will not show up in a blood test.

answer

199. F – Positive blood test after 10 days of infection

question

200. What is used to Treat M. pneumonia?

answer

200. 2nd Generation – Macrolides, Tetracyclines, Fluoroquinolones

question

201. What are the characteristics of Legionella?

answer

201. Aerobic Gram Negative Rod, facultative intracellular bacteria

question

202. What is Legionnaires Disease?

answer

202. more severe pneumonia form of L. pneumophila infection

question

203. What temperatures are Legionella dormant, have ideal growth, and survive but don’t multiple?

answer

203. Dormant ;20C, Ideal Growth Rate 20-50C, Survive but don’t multiple ;50C

question

204. Where does L. pneumophila replicate?

answer

204. alveolar macrophages after inhalation

question

205. How does L. pneumophila avoid phagosome-lysosome fusion?

answer

205. creating a specialized vacuole that resembles the endoplasmic reticulum of the host

question

206. Who does L. pneumophila most often infect?

answer

206. middle age to older patients, smokers, chronic lung disease patients and immunocompromised

question

207. How is L. pneumophila treated?

answer

207. Macrolides, fluoroquinolones

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