GI Infections 3

Question 1

what are three protective mechanisms in the esophagus?

Answer 1

• saliva
• cell mediated immunity
• esophageal motility

Question 2

_____ is a key virulence factor of H. Pylori that allows it to live in the acid environment of the stomach

Answer 2

urease

Question 3

describe the lesions caused by CMV

Answer 3

flat (ovoid, elongated or diamond shaped) ulcers; typically single in number

Question 4

HSV is part of the herpesviridae family. Describe the biology and what other viruses can be found in this family

Answer 4

• large enveloped dsDNA virus
• they can all establish a latent infection in the neurons
• cell mediated immunity is important for controlling the infection
• ## CMV, Varicella Zoster

Question 5

bactericides fragilis is common pathogen involved in _____

Answer 5

appendicitis

Question 6

candida causing esophagitis is associated with ______

Answer 6

immunosuppressed patients

Question 7

a baby that is delivered vaginally has a higher proportion of _______ species that is what resembles the mother’s vaginal flora

Answer 7

lactobacillus

Question 8

food borne illness (food poisoning) can be caused by ingestion of:

Answer 8

contaminated food/water containing: infectious agents and/or preformed toxins

Question 9

HSV 1 can travel to the esophagus via the _____ nerve

Answer 9

vagus

Question 10

a patient with pain on swelling, (odynophagia), nausea, vomiting and has multiple, small discrete superficial ulcers in the esophagus on endoscopy is indicative of what causal organism

Answer 10

HSV: MULTIPLE small discrete superficial ulcers

Question 11

HSV 1/2 is associated with genital lesions

Answer 11

HSV 2

HSV 1 = esophagitis

Question 12

what are three microorganisms that you can find in the stomach?

Answer 12

• candida
• H pylori
• peptostreptococcus

Question 13

when grown on media, describe the color change when growing H. Pylori

Answer 13

it will ↑ the pH: yellow → PINK

PINK COLORED media = postive for H. Pylori because becomes pINK when ph is INKreased

Question 14

why is carbon urea breath test usually better than serology?

Answer 14

serology is cheaper but it only indicates PREVIOUS exposure but carbon urea breathe test detects CURRENT ACTIVE infection

Question 15

HSV and CMV esophagitis is commonly seen in _____ and _____ patients

Answer 15

AIDS and transplant patients because they have ↓ cell mediated immunity → Reactivation of latent virus

Question 16

CMV establishes latent infections in _______

Answer 16

monocytes, granulocytes and lymphocytes

Question 17

patient with dysphagia, chest pain, nausea and vomiting shows flat ulcers on esophagus during endoscopy. what is the most likely causal pathogen?

Answer 17

CMV

Question 18

most common pathogens involved in appendicitis are _____, ____ , _____ and _____

Answer 18

E. coli, peptostreptococci, B. fragilis, Pseudomonas

Question 19

what are the common infectious causes of esophagitis

Answer 19

• candida
• CMV
• HSV

Question 20

pain that can awaken the patient at night and is relived by food/antacids are signs of _____ ulcers

Answer 20

duodenal

Question 21

virulence factors associated with H. Pylori:

Answer 21

• urease
• flagella
• Cag A strains: ↑ risk of ulcers and cancer and causes signaling alternations → impacts host cell physiology
• VacA (vacuolating toxin): causes swelling and mitochondrial death

Question 22

a baby delivered via C section will have ↑ _______ flora

Answer 22

skin: ↑ Staph, corynebacterium, propionibacterium

Question 23

H. Pylori is: 
gram \_\_\_\_ 
catalase \_\_\_\_
urease \_\_\_\_\_\_ 
motile/nonmotile

Answer 23

gram negative, catalase positive, urease positive and motile (multiple polar flagella)

• LPS is relatively NON toxic so it is persistent

Question 24

what are some risk factors of candida caused esophagitis?

Answer 24

• organ transplant
• alcoholism
• diabetes

11.2% HIV patients

Question 25

what are some risk factors for infectious esophagitis?

Answer 25

- cancer chemotherapy - transplantation - HIV - diabetes all of these things suppress the person's immune system

Question 26

what is the function of urease? how can this be used in diagnosis?

Answer 26

urease coverts urea and water to ammonia and carbon dioxide carbon urea breast test helps detect current active infection

Question 27

pancreatitis is rarely caused by infectious pathogens; what are they? (3)

Answer 27

- CMV - coxsackievirus B - mumps

Question 28

spontaneous bacterial peritonitis (SBP) is commonly seen in ________ (type of patients) and the most likely pathogens are : _____, ____ or _____

Answer 28

patients with alcoholic cirrhosis E. coli > non strep pneumoniae > Klebsiella pneumoniae