Sketchy Microbiology: Salmonella (Salmonella Enteritis, Salmonella Typhi)

The salmon dinner — Salmonella

According to lecture there is a NEW classification. What is it?

There are 2 species;

1. Salmonella Enterica

2. Salmonella Bongori

However, most pathogens are from Salmonella Enterica species. Including S. Enterica, S. Serovar, S. Typhi.

What is common about all Salmonella?

1. Gram Negative Rod

2. Motile

3. Non-lactose Fermenting

4. Resistant to bile salts

5. H2S Producing

According to lecture a single change in antigen (H1) causes different diseases. What is the 2 groups?

1. Group B — found in S. Paratyphi → enteric fever

2. Group i — found in S. Typhi → gastroenteritis

Hint: Red Hue

Red Color — Gram Negative

(Non-lactose Fermenter, White on MacConkey’s Agar)

Tail Flopping around — Motile

Black Plate — H2S Positive

(All motile enteric colonies stain black on hektoen agar)

Lemon — Acid Labile

(need high does to cause an infection. Patients w/ proton pump inhibitor are more susceptible to infection)

Glass Dome — Capsule

(Positive for citrate utilization turns indicator blue due to alkaline pH)

Bird Cages w/ MΦ — Facultative Intracellular

(Invades through colon through the macrophages to get into the colon)

Hint: Which one is represented by the chicken

Chicken — Salmonella Enteritis

Chicken — Salmonella Enteritis most commonly acquired from Poultry, Eggs, Swine.

• 24 - 72h incubation period

(Food-borne outbreak)

Candle — Salmonella Enteritis causes inflammatory diarrhea, and Gastroenteritis

Turkey Baster — Salmonella Enteritis contains Type 3 secretion system; detects eukaryotic cells that will increase infectivity

What is the clinical progression of S. Enteritis?

Ingestion of S. Enteritis → Absorbed into epithelial cells of small intestine → Baceria penetrate cells and migrate to lamina propria of ileocecal region → multiply in lymphatic follicle → hypertrophy and hyperplasia → inflammatory response → prostaglandin release → cAMP stimulated → loose stool / diarrhea

Seagull — Salmonella Typhi

SeaGULL = GALL bladder reservoir of carriers

What do we knw about S. Typhi

• Strictly a human host

• Causes Typhoid Fever

• S. Paratyphi A,B,C cause Enteric Fever

• Fecal-Oral Transmission

• 10-14 day incubation

Chef Apron — think “Typhoid Mary”

(She knew she has Typhoid and continued cooking consciously infecting people; charged with second degree murder)

Hint: Spots

Red spots on apron — 25% of Enteric Fever patients get red spots on their stomach due to infection

Fish Bones — Salmonella Typhi is #1 cause of osteomyelitis in adults with sickle cell

Sickle — Sickle Cell Disease

Bird Shit — S. Typhi can cause "pea soup" diarrhea

Flower on table — S. Typhi is treated with fluoroquinolone, or a cephalosporin (ceftriaxone)

Syringe — S. Typhi has a Live, Attenuated

Vaccine

What is the clinical progression of Enteric Fever (Typhoid Fever)?

S. Typhi is ingested → Passes through ileocecal epithelial cells → Intraluminal multiplication → Macrophages engulf it (but its still viable) → Intracellular multiplication in Liver, Spleen, Bone Marrow → Necrosis, Hemorrhage, Perforation of Intestinal wall → re-enters bowels → gastrointestinal symptoms