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GI Microbiology Flashcards

1
Q

What are the key roles of epidemiology in gastrointestinal infections?

A

Epidemiology plays a role in the prevention and development of gastrointestinal tract infections caused by pathogenic bacteria.

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2
Q

Define ‘microbiome’.

A

The normal microbial flora residing in the gastrointestinal tract.

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3
Q

What is the significance of Bacteroides fragilis?

A

An anaerobe located in the colon, it is a common cause of intra-abdominal infections after surgery or trauma.

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4
Q

What type of bacteria is Clostridium difficile?

A

An anaerobic, spore-forming, toxigenic gram-positive bacillus.

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5
Q

What condition is associated with Clostridium difficile?

A

Antibiotic-associated diarrhea and colitis.

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6
Q

What does the presence of red or purple colonies on MacConkey agar indicate?

A

Lactose fermentation.

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7
Q

What type of DNA can bacteria exchange via conjugation?

A

Plasmid DNA.

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8
Q

What is a localized epidemic?

A

A disease outbreak affecting a small group of people within a confined area.

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9
Q

What is a nationwide epidemic?

A

A disease outbreak affecting a sizeable number of people in several different cities or regions of a country.

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10
Q

What is the definition of a pandemic?

A

An outbreak affecting several different countries worldwide within a relatively short span of time.

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11
Q

What does ‘endemic’ mean?

A

When an infectious agent becomes well established within a community with expected incidence/prevalence.

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12
Q

List classic agents of diarrhea.

A
  • E. coli (many types)
  • Salmonella (many types)
  • Cholera
  • Shigella
  • Staphylococcus aureus
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13
Q

What is Enteropathogenic E. coli (EPEC) known for?

A

Causing serious infantile diarrhea, particularly in the developing world.

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14
Q

What are the toxins produced by Enterotoxigenic E. coli (ETEC)?

A

Labile toxin (LT) and stable toxin (ST).

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15
Q

What is a unique feature of Enteroinvasive E. coli (EIEC)?

A

It causes dysentery similar to Shigella and invades intestinal mucosal cells.

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16
Q

What serious condition is caused by Enterohemorrhagic E. coli (EHEC)?

A

Hemolytic uremic syndrome (HUS).

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17
Q

What is the most common strain of Enterohemorrhagic E. coli?

A

Serotype H7:0157.

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18
Q

What caused the E. coli 0104:H4 epidemic?

A

Contaminated sprouts derived from fecally contaminated fenugreek seeds.

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19
Q

What was unusual about the E. coli 0104:H4 epidemic?

A

Atypical age range and long incubation period.

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20
Q

Fill in the blank: The major pathogenic E. coli bacteria are known as _______.

A

[EPEC, ETEC, EIEC, EHEC, EAEC]

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21
Q

True or False: ETEC is considered a serious condition.

A

False.

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22
Q

What does it mean for an organism to stain gram negative?

A

The bacteria has a thin peptidoglycan wall

Gram-negative bacteria have a thinner peptidoglycan layer compared to gram-positive bacteria, which allows them to take up the red counterstain during the Gram staining process.

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23
Q

List some examples of pathogenic Gram-negative bacilli associated with gastrointestinal infections.

A
  • Shigella
  • Salmonella (S. enterica serovar typhi, S. enterica serovar paratyphi, non-typhoidal strains)
  • Yersinia enterocolitica
  • Campylobacter jejuni
  • Helicobacter pylori
  • Vibrio (V. cholerae, V. parahemolyticus, V. vulnificus)

These bacteria are known to cause various gastrointestinal diseases and infections.

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24
Q

What is the mechanism of infectivity for Shigella?

A

Shigella invades the M cells of peyer’s patches and evades phagocytosis

Shigella uses the host’s actin cytoskeleton to move from cell to cell, facilitating its spread.

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25
Fill in the blank: Shigella produces _______ toxin, which cleaves part of the 60s ribosome.
Shiga ## Footnote Shiga toxin is responsible for disrupting protein synthesis in host cells.
26
What clinical picture is associated with Shigella infection?
Abdominal cramps, tenesmus, pus and blood in stool ## Footnote Symptoms typically appear about 3 days after ingestion of the bacteria.
27
What is the main reservoir for Salmonella typhi?
Humans ## Footnote Unlike non-typhoidal strains, Salmonella typhi does not have an animal reservoir.
28
How is Salmonella typically transmitted?
Eating contaminated food products, especially poultry, eggs, and dairy ## Footnote Fecal-oral transmission is the most common route, especially in cases involving food handlers.
29
What is the virulence factor of Salmonella?
Type III secretion system ## Footnote This system helps Salmonella inject virulence factors into host cells, facilitating infection.
30
What is the clinical presentation of Salmonella gastroenteritis?
Nausea, vomiting, cramps, diarrhea ## Footnote Symptoms usually develop 6-48 hours after consumption of contaminated food.
31
What is a distinguishing feature of Yersinia enterocolitica?
It mimics appendicitis ## Footnote Infection can lead to fever, leukocytosis, and right lower quadrant pain.
32
True or False: Campylobacter jejuni is motile.
True ## Footnote Campylobacter jejuni is known for its motility and characteristic comma or S-shaped appearance.
33
What are the detection methods for Helicobacter pylori?
* Urea breath test * Endoscopy biopsies * Stool antigen test ## Footnote These tests help confirm the presence of H. pylori in patients with gastrointestinal symptoms.
34
What is the main source of infection for Vibrio cholerae?
Water and shellfish ## Footnote Poor sanitation and fecal-oral transmission are common routes for cholera infection.
35
Fill in the blank: The cholera toxin activates _______ cyclase, leading to increased cAMP.
adenylate ## Footnote This mechanism results in hypersecretion of water and electrolytes into the intestinal lumen.
36
What is the typical incubation period for typhoid fever caused by Salmonella typhi?
10-14 days ## Footnote Symptoms include fever, headache, myalgia, malaise, and the appearance of rose spots.
37
What is a common complication of hemolytic uremic syndrome associated with Shiga toxin?
Acute renal failure ## Footnote This syndrome also presents with thrombocytopenia and hemolytic anemia.
38
What organisms are known to cause systemic disease after leaving the gastrointestinal tract?
* Salmonella typhi * Shigella ## Footnote Both of these bacteria can cause infections that affect other systems in the body.
39
What are the key roles that epidemiology plays in gastrointestinal infections?
Epidemiology helps in the prevention and understanding the development of gastrointestinal tract infections, particularly those caused by viruses. ## Footnote It provides insights into the spread and control of infections.
40
List the common viral pathogens that cause gastrointestinal tract infections.
* Norovirus * Rotavirus * Adenoviruses * Astroviruses * Cytomegalovirus ## Footnote These pathogens are significant in the context of viral gastroenteritis.
41
What types of gastrointestinal infections are classified as non-inflammatory?
* Food toxemia * Viral gastroenteritis * Bacterial gastroenteritis (non-inflammatory forms) ## Footnote These classifications help in understanding the nature of the infections.
42
What are the manifestations of G.I. tract infection-related illnesses?
* Nausea & Vomiting * Diarrhea (watery) * Abdominal pain / cramping * Fever (+/-) * Headache * Dysentery (bloody diarrhea) ## Footnote These symptoms can help in diagnosing the type of gastrointestinal infection.
43
True or False: Norovirus is a common cause of viral gastroenteritis in young children.
True ## Footnote It is particularly concerning due to its severe effects in this age group.
44
What is the primary transmission route for Norovirus?
Ingestion of contaminated food and water, with person-to-person transmission also occurring. ## Footnote This highlights the importance of hygiene in preventing outbreaks.
45
What is the main cause of severe diarrhea in young children infected with Rotavirus?
Severe, sometimes life-threatening diarrhea leading to dehydration. ## Footnote Rotavirus infections can be particularly dangerous in developing countries.
46
Fill in the blank: The first Rotavirus vaccine was called _______.
Rotashield ## Footnote This vaccine was withdrawn due to serious side effects.
47
What are the key functions of Rotavirus gene products?
* VP1: polymerase * VP3: mRNA capping * VP7: facilitates attachment to host cells * NSP4: acts as an enterotoxin ## Footnote These proteins play critical roles in the virus's life cycle and pathogenicity.
48
What is the second most frequent cause of non-bacterial gastroenteritis in infants?
Adenoviruses ## Footnote This highlights the importance of viral pathogens in pediatric gastroenteritis.
49
What is a common symptom in patients with Cytomegalovirus colitis?
* Diarrhea * Weight loss * Anorexia * Fever ## Footnote These symptoms indicate severe gastrointestinal distress in immunocompromised patients.
50
What is the significance of the Norovirus outbreak on cruise ships?
It highlights the risk of viral gastroenteritis in confined spaces with high population density. ## Footnote These outbreaks often involve hundreds of cases in a short period.
51
True or False: Rotavirus infections primarily occur during the summer months.
False ## Footnote Rotavirus infections have a seasonal incidence during wintertime months.
52
What are the common diagnostic methods for Rotavirus?
Antigen detection and supportive therapy such as fluid replacement. ## Footnote These methods are crucial for managing the illness.
53
What viral gastroenteritis condition is often referred to as 'stomach flu'?
Norovirus infection ## Footnote This term is commonly used but can be misleading as it is not caused by the influenza virus.
54
Which demographic is most affected by Rotavirus?
Young children, especially those under 3 years of age. ## Footnote The severity of the infection can lead to hospitalization and serious complications.
55
What is the primary mode of transmission for Entamoeba histolytica?
Ingestion of cysts in contaminated water, fecal-oral
56
What are the common clinical features of Entamoeba histolytica infection?
* Most asymptomatic * Bloody diarrhea * Liver abscess * RUQ pain * Anchovy paste exudate
57
How is an amoebic liver abscess identified in imaging?
Abscess/abnormality appears as a dark area
58
What are the diagnostic methods for Entamoeba histolytica?
* Trophozoites or cysts in stool * Histology: flask-shaped lesions * Serology
59
What is the first-line treatment for Entamoeba histolytica?
* Metronidazole * Iodoquinol
60
Describe the characteristics of the trophozoite of Entamoeba histolytica.
Trophozoite has 1 nucleus & has ingested several RBCs of the host
61
What is the primary mode of transmission for Giardia lamblia?
Ingestion of cysts in contaminated water
62
What are the risk factors associated with Giardia lamblia infection?
* Camping * Hiking * Poor sanitation * IgA deficiencies
63
What are the common clinical features of Giardia lamblia infection?
* Bloating * Cramps * Flatulence * Foul smelling, fatty diarrhea
64
What are the diagnostic methods for Giardia lamblia?
* Trophozoite or cysts in stool * Serology
65
What is the first-line treatment for Giardia lamblia?
Metronidazole
66
What is the transmission method for Cryptosporidium?
Ingestion of oocysts in contaminated water, fecal-oral ## Footnote Cryptosporidium is commonly transmitted through contaminated water sources.
67
What are the risk factors associated with Cryptosporidium infection?
Immunosuppression, HIV/AIDS ## Footnote Individuals with weakened immune systems are at higher risk for severe infections.
68
What are the clinical features of Cryptosporidium in immunocompetent individuals?
Self-limited watery diarrhea ## Footnote The infection usually resolves on its own in healthy individuals.
69
What are the clinical features of Cryptosporidium in immunocompromised individuals?
Severe watery diarrhea ## Footnote Immunocompromised patients can experience more severe symptoms.
70
How is Cryptosporidium diagnosed?
Microscopy with acid fast staining (oocysts appear red-to-maroon in color and round) ## Footnote Acid fast staining helps identify the presence of oocysts in stool samples.
71
What is the treatment for Cryptosporidium infection?
Nitazoxanide, antiretrovirals ## Footnote Nitazoxanide is the primary treatment, especially in immunocompromised patients.
72
What is the epidemiology of Cryptosporidium?
Worldwide distribution ## Footnote Cryptosporidium is found globally, affecting various populations.
73
What organism is associated with fecal-oral transmission and causes abdominal pain and watery stools with blood and pus?
Balantidium coli ## Footnote Balantidium coli is a protozoan that can cause dysentery-like symptoms.
74
What are the clinical syndromes associated with Balantidium coli infection?
Abdominal pain, tenderness, tenesmus, nausea, anorexia, watery stools with blood and pus ## Footnote Symptoms can mimic those of E. histolytica infection.
75
How is Balantidium coli diagnosed?
Trophozoites and cysts in stool ## Footnote Trophozoites have outer cilia for motility and cysts are non-motile.
76
What are the risk factors for Microsporidia infection?
Immunosuppression ## Footnote Similar to other protozoan infections, those with weakened immune systems are more vulnerable.
77
What are the clinical features of Microsporidia infection?
Weight loss, watery diarrhea, nausea, vomiting, keratoconjunctivitis ## Footnote Symptoms can vary, and keratoconjunctivitis is a notable feature.
78
What is a debated classification of Microsporidia?
An unusual form of fungi rather than protozoan ## Footnote The classification of Microsporidia has been a subject of scientific debate.
79
How is Microsporidia diagnosed?
PCR of stool, microscopy with trichrome stain ## Footnote PCR is a sensitive method for detecting Microsporidia in stool samples.
80
What are the characteristics of the spores of Microsporidia?
Ovoid spores with bright red walls, Gram-positive ## Footnote The distinct appearance of Microsporidia spores can aid in diagnosis.
81
What is the treatment for Microsporidia infection?
Albendazole ## Footnote Albendazole is commonly used to treat infections caused by Microsporidia.
82
What are nematodes commonly known as?
Roundworms
83
In which population are nematodes most commonly found?
Children, rarely in adults
84
Where are nematodes commonly transmitted?
Day-care centers, schools, mental institutions
85
What is the primary mode of transmission for nematodes?
Fecal-oral
86
What is a clinical feature associated with Enterobius vermicularis?
Pruritis of perianal area
87
What is the diagnostic test used to identify Enterobius vermicularis eggs?
Scotch tape/cellophane test
88
What are the treatment options for Enterobius vermicularis?
* Albendazole * Mebendazole * Pyrantel pamoate
89
What is a clinical feature of Ascaris lumbricoides?
GI inflammation
90
What are the diagnostic indicators for Ascaris lumbricoides?
* Bile-tinged eggs in stool * Larvae and eosinophils in sputum
91
What are the treatment options for Ascaris lumbricoides?
* Albendazole * Mebendazole * Pyrantel pamoate
92
What is a common epidemiological factor for Ascaris lumbricoides?
Poor sanitation
93
What clinical features are associated with Trichuris trichiura?
* Abdominal pain * Distention * Bloody diarrhea
94
How are Trichuris trichiura eggs diagnosed?
Eggs in stool
95
What are the treatment options for Trichuris trichiura?
* Albendazole * Mebendazole
96
What environmental conditions are favorable for Strongyloides stercoralis?
Warm temperatures, moisture, larvae found in soil
97
What is the primary mode of transmission for Strongyloides stercoralis?
Skin penetration
98
What clinical features are associated with Strongyloides stercoralis?
* Pneumonitis/cough * Duodenitis * Skin reaction * Hyperinfection syndrome
99
What are the diagnostic methods for Strongyloides stercoralis?
* Stool larvae * Serology
100
What are the treatment options for Strongyloides stercoralis?
* Ivermectin * Albendazole * Mebendazole
101
What are the two main types of hookworms?
Ancylostoma duodenale and Necator americanus ## Footnote Hookworms are parasitic worms that infect the intestines.
102
How are hookworms transmitted?
Skin penetration ## Footnote Hookworms enter the body through the skin, often via contaminated soil.
103
What are the clinical features associated with hookworm infection?
* Allergic reaction / rash * Pneumonitis * GI symptoms * Anemia * Malnutrition ## Footnote These symptoms arise due to the worm's feeding on blood and tissue.
104
What diagnostic method is used for hookworm identification?
Eggs in stool ## Footnote The presence of hookworm eggs in a stool sample confirms infection.
105
What are the treatments available for hookworm infections?
* Albendazole * Mebendazole * Pyrantel pamoate ## Footnote These medications are effective in treating hookworm infections.
106
Which tapeworm is associated with undercooked pork?
Taenia solium ## Footnote This tapeworm causes intestinal tapeworm infections when cysticerci are ingested.
107
What is cysticercosis?
Ingestion of eggs from Taenia solium ## Footnote Cysticercosis can lead to serious complications, including neurocysticercosis.
108
What is the treatment for cysticercosis?
* Praziquantel * Bendazoles ## Footnote These medications help to eliminate the cysticerci from the body.
109
Which tapeworm is associated with undercooked beef?
Taenia saginata ## Footnote This tapeworm is similar to Taenia solium but originates from beef.
110
What are the clinical features of Diphyllobothrium latum infection?
* Intestinal tapeworm * B12 deficiency anemia ## Footnote This fish tapeworm can cause nutritional deficiencies due to its size and feeding habits.
111
Where is Diphyllobothrium latum most prevalent?
Mediterranean region and the Middle East ## Footnote This tapeworm is commonly found in areas where raw freshwater fish is consumed.
112
What is the transmission method for Echinococcus granulosus/multilocularis?
Ingestion of eggs from dog feces ## Footnote This transmission route leads to hydatid cyst disease.
113
What are the treatment options for hydatid cyst disease?
* Bendazoles * Surgical cyst resection ## Footnote Treatment may vary based on the size and location of the cysts.
114
What clinical feature is associated with Clonorchis sinensis infection?
Pigmented gallstones leading to cholangiocarcinoma ## Footnote This fluke infection can cause severe complications related to the bile ducts.
115
What is the epidemiology of Clonorchis sinensis?
Endemic in China, Korea, Japan, and parts of Southeast Asia ## Footnote The consumption of undercooked fish contributes to its spread.
116
What is the treatment for Clonorchis sinensis infection?
Praziquantel ## Footnote This medication is effective against fluke infections.
117
which regions of the GI canal contain predominantly anaerobes in the microbial flora?
esophagus & intestines
118
what bacteria thrive in the low pH environment of the stomach?
normal flora: lactobacilli, fusobacterium abnormal: Helicobacter pylori
119
True or False: Coliforms are only found in the Ileum & colon.
True
120
describe the morphology of bacteroides fragilis.
Gram negative rod or bacillus w/ a capsule
121
B. fragilis has LPS but lack what due to the absence of a key phosphate group?
endotoxin-like activity
122
Describe the gross morphology of a CDI colon.
pseudomembranous colitis: widespread yellow, white, & grey plaques coalesce to cover the colonic mucosa
123
what toxins does C. diff. produce?
A & B: both are extremely potent cytotoxins
124
what is the main cause of CDI?
colonic microbiota dysbiosis
125
True or False: All gram + bacteria will NOT grow on MacConkey agar.
True
126
what is the definition of Phage-typing?
virus only infects a particular species of bacterium
127
Compare/Contrast community-wide vs. localized epidemic.
the former affects a somewhat larger number of people
128
cholera is endemic to what nation?
Nepal
129
True or False: An organism cannot become endemic after an epidemic has occured?
False
130
What bacterial agent of diarrhea is caused by a toxin secreted into food before it is ingested
Staph. Aureus
131
EPEC is a serious cause of what?
infantile diarrhea
132
what E. coli pathogen is the most common cause of "traveler's diarrhea"
Enterotoxigenic (ETEC)
133
What are the characteristics of Enteroinvasive E. coli (EIEC)
causes dysentery similar to shigella; invade intestinal mucosal cells; non-lactose fermenter; non-motile has characteristics of the shigella group of bacteria
134
What E. coli group is assoc. w/ chronic diarrhea and growth retardation?
Enteroaggregative (EAEC)
135
what E. coli group causes hemorrhagic colitis and produces Shiga-Toxin
Enterohemorrhagic (EHEC)
136
EHEC produces 2 cytotoxins that attach what organs?
colon (shigella-like toxin) kidney (HUS)
137
what is the most common E. coli strain assoc. w/ EHEC/STEC
0157:H7
138
What metabolic characteristic can be used to distinguish EHEC from other E. coli species?
EHEC do not ferment sorbitol
139
recent outbreaks of EHEC has been assoc. w/ consumption of what contaminated foods?
undercooked hamburgers & raw spinach
140
What unusual characteristics make E. coli strain 0104:H4 a unique version of an EHEC?
produces a plasmid-encoded extended spectrum beta-lactamase (an ESBL) It also contains genes from an unusual serotype of enteroaggregative E. coli
141
what is the most common shigella strain assoc. w/ infectious diarrhea in the US
S. sonnei
142
what stain of shigella is the most severve and highest mortality rate?
S. dysenteriae
143
What are the metabolic characteristics of Shigella
indole + urea + oxidase - ferments glucose non-lactose fermenter
144
Explain how individuals w/ a h/o salmonellosis can become chronic carriers of the bacteria?
S. typhi specifically: survives in the gallbladder
145
What are risk factors for salmonellosis?
PPIs pernicious anemia
146
List the 3 mechanisms of salmonella infectivity
invades M cells where the bacteria replicate in vacuoles facultative intracellular (macrophages) can spread hematogenously
147
True or False: Salmonella is an encapsulated bacteria.
True
148
how can salmonella be detected?
non-lactose fermenter oxidase negative produces H2S produces black colonies on Hektoen agar
149
what serotypes of the Salmonella enterica serovar sub species can cause typhoid fever?
typhi & paratyphi
150
True or false: the most common salmonella strain of osteomyelitis in sickle cell pts. is of the typhoidal subtype.
False
151
what is a buzz word for salmonellosis?
"Pea Soup Diarrhea"
152
Live attenuated vaccines may be implicated for travelers spending a vacation in this region of the globe for immunity against this pathogen
South central Asia Typhoidal Salmonellosis
153
what are clinical hallmarks of Typhoid fever?
rose spots; pulse temperature dissociation later manifestations: hepatosplenomegaly, intestinal hemorrhaging, perforation, septic shock
154
what bacteria can potentially cause infectious diarrhea that thrive at lower-fridge like temperatures
Listeria monocytogenes Yersinia enterocolitica
155
Yersinia is a non-motile, encapsulated bacteria. True or False?
False Yersinia can become motile at room temperatures and they are encapsulated bacteria
156
How can Yersinia be detected from other bacterial agents of infectious diarrhea
non-lactose fermenter oxidase negative looks like a "closed pin" w/ methylene blue stain
157
Unlike Y. enterocolitica which is transmitted via contaminated water, milk, or food, Y. Pestis is transmitted how and is assoc. w/ what clinical manifestations?
Y. pestis is transmitted from rats as a reservoir to fleas (vector) and into humans; daily physical contact w/ domesticated animals increases risk of transmission CMs: lymphadenopathies & DIC
158
what region of the intestine would you expect to find campylobacter enterocolitis
the Jejunum
159
what is the virulence factor of campylobacter jejuni?
LOS cell wall
160
what histological features are assoc. w/ campylobacter enterocolits?
uncerations of the mucosal surface; crypt abscesses; lymphocytic infiltration into lamina propria
161
Campylobacter is not a motile microbe. True or False?
False
162
describe the morphological features of campylobacter
comma-s-shaped spirochetes
163
how is campylobacter detected
does not grow on MacConkey agar; oxidase positive
164
what medical conditions are assoc. w/ campylobacter
reactive arthritis: HLA-B27 Guillain-Barre Syndrome (antigenic cross-reactivity w/ myelin protein)
165
True or false: helicobacter is a motile bacteria.
True
166
what is the virulence factor for helicobacter
urease-increases gastric pH via equilbrium shitt to urea and ammonium carbonate
167
how is H. pylori detected?
catalase & oxidase positive urea breath test does not ferment lactose
168
H. pylori assoc. peptic ulcers increases risk for what malignancies
gastric adenocarcinoma & MALTomas
169
what is the primary mechanism of infectivity for vibrios?
use of fimbriae to attach to ganglioside receptors in the intestinal wall
170
Rotavirus virons are replicated in which kind of intestinal cells
villous cells
171
what kind of genome comprises the Rotavirus
dsRNA encased in a capsid
172
compare & contrast the differences b/t the RotaTeq & Rotarix vaccines
RotaTeq: bovine & human serotypes 3-doseing schedule 85% efficacy Rotarix: human serotype only 3 dosing-schedule 95% efficacy
173
What rotavirus serotypes are in the RotaTeq vaccine?
G1-G4 & 1 P serotype
174
Adenoviruses prevalence increases in the winter months. True or False
False ; more commonly in summer months
175
The adenovirus genome contains what kind of nucleotides
dsDNA
176
what pt. populations have the highest prevalence of astrovirus induced diarrhea
ped. pts. in pediatric wards; elderly pts. in nursing homes
177
CMV colitis can also infect what other region of the GI canal
viral esophagitis
178
Clonorchis sinensis is a trematode. True or false?
True
179
What are the 3 Protozoan GI parasites you need to know?
entamoeba histolytica giardia lamblia cryptosporidium
180
What is a radiologic hallmark of an amoebic liver abscess
abnormal dark discoloration compared to the surrounding liver tissue
181
describe the microscopic appearance of histolytica lesions
flask-shaped
182
Cryptosporidium are acid-stain +. T or F?
True
183
What animals are the natural reservoir for balantidium coli
swine, monkeys
184
what is a unique clinical manifestation of microsporidia?
keratoconjunctivitis
185
Microsporidia have a gram - cell wall. T or F.
F they are gram + microbes
186
Isopora is almost exclusively assoc. w/ AIDs and immunocompromise. T or F
True
187
Trichuris trichiura is also known as what?
The Whipworm
188
Describe the Whipworm life cycle.
Ingested eggs hatch in the small intestine releasing larva Larva travel to the large intestine and invade the mucosa After 3 months, Mature adults migrate to the cecum where the females lay the next cycle of eggs
189
Describe the Entamoeba histolytica life cycle.
Invade and proliferative in the colon where it can remain or be absorbed into systemic circulation Excreted trophozoites quickly disintegrate
190
Giardia lamblia invade the mucosa of which region in the GI canal
duodenum
191
T or F? cryptosporidium infect and invade intestinal mucosa.
True
192
Enterobius vermicularis or pinworm infect the wall of the small intestine. T or F?
false eggs hatch in the small intestine and travel to the large intestine where they invade the mucosa
193
What is the pathogenesis of Pinworm perianal pruritis
adult females travel to the anus where they lay their eggs
194
Ascaris lumbricoides can cause what extraintestinal complication?
pneumonitis larvae can be absorbed into systemic circulation especially with bowel obstruction
195
Describe the strongyloides stercoralis lifecycle
Both larva and adults in soil skin penetration directly into systemic circulation causes extraintestinal symptoms Larva and adults then travel to oropharynx where they can be reswallowed into GI canal and cause GI hyperinfection syndrome
196
how is diphyllobothrium latum transmitted
ingestion of larvae infected raw freshwater fish
197
Cestodes are also referred to as what
tapeworms
198
trematodes are also called what?
Flukes
199
clonorchis sinesis causes what unique extraintestinal manifestation?
pigmented gallstones cholangiocarcinoma

Gastroenterology5 (6 decks)

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