Enteric bacteria 1 and 2

Question 1

All foodborn enterobacteriaceae are; normally they cannot;

______ subversion

Answer 1

gram neg rods; all cause gastroenteritis;
colonize the epi of the intestinal lumen, instead subverting immunological sampling by the M cells of the Peyers Patches to access the outside (blood-exposed) intestinal surface.

Immune, could include use of macrophages as Trojan Horses leading to infection of lymphatics: local false appendicitis by Yersinia, systemic enteric fevers or post-sepsis focal disease by Salmonella

Question 2

Diarrhea may be

Answer 2

watery (noninvasive or pre-invasion, Salmonella, ETEC, Yersinia) or bloody (destructive and/or invasive, Shigella, EHEC); commone exposures from proteins, especially meat (E coli, Salmonella) and eggs (Salmonella)

Question 3

What can cause complications with foodborne enterobacteriaceae?

Answer 3

Dehydration and electrolyte loss

Question 4

Virulence factors often;

common virulence factors are

Answer 4

carried on plasmids (easy transfer);

fimbriae/pili for attachment, T3SS for immune evasion and/or host cell invasion, toxins

Question 5

Pathogenic E coli come in;

E coli the only pathogen here likely to

Answer 5

many types depending on acquired virulence factors: think enterotoxigenic, enterohemorrhagic, uropathic;
ferment lactose and will turn pink on MacConkey

Question 6

Highest risk of infection in

Answer 6

children; highest risk of mortality in neonates and elderly

Question 7

Risk of HUS from

Answer 7

Shigella and EHEC (O157:H7) when Shiga, Shiga-1, or Shiga-2 protein synthesis inhibiting toxin reaches BLOODSTREAM

Question 8

Risk of reactive arthritis/Reiter’s syndrome from

Answer 8

Shigella, Salmonella, Yersinia

Question 9

Antimicrobial susceptibility tests required for

Answer 9

optimal antibiotic choice (resistance common)

Question 10

Exposure minimized to foodborne enterobacteriaceae by

Answer 10

sewage treatment, pasteurization, water chlorination, food processing, handwashing

Question 11

Noninfectious bacterial-toxigenic food poisoning follows when;
neither;
Foods left at room temp grow

Answer 11

a pt eats a food containing preformed toxins secreted by non-GI bacteria;
S aureus, B cereus, nor C botulinum survive ingestions, but their toxins cause gastroenteritis anyway;
S a and B c, and airtight-packaged foods grow Cb (intoxication happens faster than infection and as little as 2 hrrs for S aureus food poisoning

Question 12

1. Listeria is a

Answer 12

ram pos rod, beta hemolytic, grows well in cold, temp-sens tumbling motility;
transmitted by ingestion of uncooked/undercooked, particularly refrigerated, foods or contact with farm animals

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Question 13

2. Listeria is

Answer 13

IC, and escapes from phagocytic vacuole using Listerolysin and transmits cell-cell by actin-based motility (ActA); will grow in placenta

Question 14

Listeriosis causes; treat with

Answer 14

complications of pregnancy, neonatal morbidity and mortality, sepsis, and CNS infection in immunocompromised patients;
ampicillin and gentamicin, or trimeth/sulfa

SIPN on listeriosis, who wants to play TAG

Question 15

Non-enterobacteriaceae causes

Answer 15

gastroenteritis in previously-healthy; rehydrate and report