Enterobacteriaciae

Characteristics

Spores

Motility

Peritrichous flagella

Non-motile

Shigella

Klebsiella

Metabolism

Catalase

Cytochrome Oxidase

Nitrate to Nitrites (Red.)

Hydrogen sulfide (H2S)

Fermentation

glucose

lactose w/ acid

Pathogenic

Frank

Salmonella

Shigella

acid-resistant

Infective dose = ~200 cells

Opportunistic

E. Coli

Klebsiella

Aerobic Gram-Negative Rods

Escherichia

Clinical

GI-tis

Adherence

EPEC

Nursery outbreaks

"Attaching and effacing lesion"

EAggEC

Prolonged water diarrhea

Adherence main virulence factor

Have pili

ETEC

LT

increased cAMP

decreased NaCl absorption

Traveler's Diarrhea

ST

increased cGMP

Colonization pili

attach to microvilli of small intestine epithelium

EHEC

Fast food hamburgers

Verotoxin (Shiga-like toxin)

Bloody diarrhea

Sequela = Hemolytic uremis syndrome (HUS)

Young children

Acute renal failure

Thrombocytopenia

Hemolytic anemia

EIEC

shigella-like

destroy colonic epithelium

intracellular parasites following endocytosis by epithelia

Invasive

do no penetrate epithelium layer

septicemia unlikely

Extra-intestinal

UTI

Neonatal

Meningitis

K1 Antigen

Majority CNS infections

Septicemia

Characteristics

most predominant facultative anaerobic normal flora member of GI

indicates fecal contamination of food and water

Lactose

Indole

Shigella

Clinical

Bacillary dysentery

1-4 incubation period

Blood, mucus in stool

Epidemiology

Primates the only host

Fecal-to-oral

Species

S. dysenteriae

Shiga

Inhibits protein synthesis

S. flexneri

S. boydii

S. sonnei

Motile

Fermentation

No gas

Invasive

do not penetrate epithelium layer

septicemia unlikely

Salmonella

Clinical

GI-itis

Widal

Treatment

Fluid Replacement

Antibiotics

Would prolong the carrier state

Septicemia

S. choleraesius

Enteric fever (typhoid)

7-14 days

Enter intestinal lymphatics

Can survive inside PMNs

S. typhi

Treatment

Cam

Amp

Trimethoprim-sulfamethoxazole

Species

S. typhi

S. choleraesuis

swine

S. enteritidis

1500 serotypes

Turkeys / Chickens

Motile

Metabolism

Fermentation

Lactose

Subtopic

Hydrogen sulfide

Penetration

through epithelial tight junctions

septicemia likely

Klebsiella

Clinical

Pneumonia

3% in young adults

UTI

2nd leading cause

Lactose

Characteristics

Motile

Capsule

Mucoid

Virulence factor

Inhibits phagocytosis

Yersinia

Clinical

GI-itis

Bubonic Plague

Zoonotic infection

Species

Y. pestis

Bubonic plague

Y. enterocolitica

GI-itis

Rare in U.S.

Y. pseudotuberculosis

Pseudo appendicitis

Inflammation in the lymph nodes

Other

Enterobacter

Serratia

Citrobacter

Proteus

Morganella

Providencia