Enteric bacteria 1 and 2 Flashcards Preview

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Flashcards in Enteric bacteria 1 and 2 Deck (15):

All foodborn enterobacteriaceae are; normally they cannot;
______ subversion

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


Diarrhea may be

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)


What can cause complications with foodborne enterobacteriaceae?

Dehydration and electrolyte loss


Virulence factors often;
common virulence factors are

carried on plasmids (easy transfer);
fimbriae/pili for attachment, T3SS for immune evasion and/or host cell invasion, toxins


Pathogenic E coli come in;
E coli the only pathogen here likely to

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


Highest risk of infection in

children; highest risk of mortality in neonates and elderly


Risk of HUS from

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


Risk of reactive arthritis/Reiter's syndrome from

Shigella, Salmonella, Yersinia


Antimicrobial susceptibility tests required for

optimal antibiotic choice (resistance common)


Exposure minimized to foodborne enterobacteriaceae by

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


Noninfectious bacterial-toxigenic food poisoning follows when;
Foods left at room temp grow

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


1. Listeria is a

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

College Basketball To Go


2. Listeria is

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


Listeriosis causes; treat with

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


Non-enterobacteriaceae causes

gastroenteritis in previously-healthy; rehydrate and report