7. GI infections -3

Question 1

A 19 year old woman comes to her doctor complaining of dry mouth, difficulty swallowing, vomiting and weight loss. During examination it is noted that there are flat ulcers along her esophagus. A biopsy is taken showing infection causes by a enveloped dsDNA virus. What is the most the infectious agent?

A.Candida spp
B.CMV
C. H. pylori 
D. HSV-1
E.Coxsackievirus B 

RFA

Answer 1

ANS. B. CMV- is a enveloped dsDNA virus and makes flat ulcers in the esophagus

A. Candida spp- would cause similar symptoms but is a fungus and would make “cottage cheese” like lesions.

C H. pylori- is causes stomach ulcer and duodenal ulcers and is a gram negative bacteria

D. HSV-1 is a enveloped dsDNA virus but makes multiple small discrete superficial ulcers

E. Coxsackievirus B- is a positive RNA virus( Picorno family) and is associated with myocarditis, pericarditis and Pancreatitis

Question 2

A 29 year old man complains of nausea and heart burt. He usually feel epigastric pain 1-2 hours after food. What is the virulence factor in the mostly likely infectious organisms that raises the man’s risk of cancer?

A.Baba
B. Urease 
C.Saba
D.Cag A+
E. VacA

RFA

Answer 2

Ans. D. Cag A+-The infection agent in question is H. pylori. Cag A+ causes signaling alternations on host cell physiology. transitions epithelial cell to mesenchymal cell phenotype

• Increases ulcer risk
• increases cancer risk

A. Baba- adhesion

B. Urease- allows H. Pylori to survive in stomach acid

C. Saba-adhesion

E. VacA- forms anion selection channels in bacuole memberanes causing swelling. Also insterts into mitochondrial membranes killing mitochonrida.

Question 3

A 65 year old woman presents with esophagitis. 2 months ago she underwent a kidney transplant. Virology shows a large, enveloped ds DNA virus. What is the causative organism? (MG)

A. CMV
B. HSV-1
C. HSV-2
D. Adenovirus
E. Candida

Answer 3

A. CMV

Candida is a not a virus but can also cause esophagitis.

HSV-1 can cause esophagitis and is also a large, envoloped ds DNA virus but is not associated with solid organ transplants like CMV is.

Question 4

A 40 year old male presents with epigastric burning 3 hours after eating and pain that wakes him up at night which is relieved by eating or taking antacids. Stool sample shows melena. A breath test is urease positive. What is another feature of the causative organism? (MG)

A. PAS positive
B. Gram positive
C. Non-motile
D. Anaerobic
E. Catalase positive

Answer 4

E. Catalast positive

Organism is Helicobacter pylori

Dx is duodenal ulcer