4071 Isolation of Salmonella, Lab Final

Salmonella Family

Enterobacteriaceae

Salmonella Gram Stain

Gram-negative rod

Salmonella Spore Characteristics

non-spore-forming

Salmonella Motility

predominantly motile enterobacteria

Salmonella Origin

Animal origin; undercooked meat, poultry, dairy, eggs

Salmonella antigens

O and H

O Antigen

somatic antigen

H Antigen

flagellar antigen

Universal pre-enrichment (Salmonella)

Encourages recovery and division of injured cells before selective stress

Selective enrichment (Salmonella)

Suppresses coliforms and other microorganisms

Selective media for Salmonella

XLD, HE, BS agar (black-centered colonies)

Salmonella Biochemical Tests

TSI and LIA

Salmonella TSI result

Red slant with yellow butt (may have black center)

Salmonella LIA result

Purple slant with yellow butt (may have black center)

Salmonella detection limit

Theoretically 1 organism per 25 g sample (0.04 CFU/g)

Lab Technique- Salmonella Pre-enrichment

25 g of chicken skin + 225 mL of UPB broth (Universal pre-enrichment - Day 1)

Lab Technique- What temp and for how long was UPB Broth incubated for

35°C 24h

Lab Technique- After incubation of UBP, what enrichments were used for selection

SC and RV Broth

Lab Technique- How much broth from UBP was transferred into selective enrichment

Transfer 1 mL of UPB broth to 9 mL of SC and RV

Lab Technique- How long and at what temp were selective enrichment for Salmonella testing incubated at

SC broth at 35˚C for 24 h and RV broth at 42˚C for 24 h

The limit of detection for qualitative microbiological methods is theoretically _ organism per analytical portion of a sample (or 0.04 CFU per g in the typical 25-g portion)

1