LECTURE - Intro to Enterics

Question 1

the members of Enterobacteriaceae

Answer 1

• all gram neg rods
• most flagellated
• Escherichia, salmonella, Shigella (belongs within E. coli species), Yersinia

Question 2

Other enteric organisms not related to Enterobacteriaceae

Answer 2

Campylobacter jejuni, Helicobacter pylori, Vibrio cholerae

Question 3

large intestine microbiome

Answer 3

Bacteroides, Bifidobacterium, Peptococcus, Peptostreptococcus (mainly anaerobic!)
- E. coli (facultative anaerobe) outnumbered 1000 to 10 000:1

Question 4

three major presentations in a GI infection

Answer 4

• small bowel diarrhea (watery diarrhea)
• large bowel diarrhea (dysentery)
• penetrating disease (enteric fever syndrome)

Question 5

serotypes of E. coli

Answer 5

over 160 based on:

• O antigens (LPS)
• H antigens (flagella)
• K antigens (capsular polysaccharide)

Question 6

E. coli now grouped into these

Answer 6

pathotypes (pathogenic types) or virotypes based on genetics (ETEC, EPEC, EHEC, etc.)

Question 7

infection vs. intoxication

Answer 7

Infection: occurs when live bacterial cells are ingested. These bacterial cells can then grow in the digestive tract and cause symptoms. An example of a bacterial infection is Salmonella infection. Intoxication: occurs from eating a food that contains a toxin produced by bacteria

Question 7

infection vs. intoxication

Answer 7

Infection: occurs when live bacterial cells are ingested. These bacterial cells can then grow in the digestive tract and cause symptoms. An example of a bacterial infection is Salmonella infection. Intoxication: occurs from eating a food that contains a toxin produced by bacteria

Question 8

Vi

Answer 8

capsule or microcapsule for S. Typhi

Question 9

K

Answer 9

capsule or microcapsule for E. coli

Question 10

variable part of LPS in gram negs

Answer 10

capsule antigens

Question 11

What is one way to distinguish among members of the Enterobacteriaceae?

Answer 11

biochemical criteria

Question 12

Crypt cells

Answer 12

secrete mucus (thick and thin patches - varies depending on person’s general health) ; coating that microorganisms have to deal with in order to establish themselves in the small intestine

Question 13

this defines serotypes within species

Answer 13

antigenic characteristics

Question 14

most common presentation of GI infection

Answer 14

small bowel disease ( watery diarrhea)

Question 15

Penetrating disease

Answer 15

don’t spend much time in GI; invade enterocytes then spread through bloodstreeam

Question 16

Enteric Fever Syndrome (penetrating disease) organisms

Answer 16

S. Typhi

• proper sewage treatments compromised (earthquakes, wars, etc.)
• Yersinia

Question 17

most organisms in this area of the GI

Answer 17

transverse colon