Micro December 2018

Inoculating Organisms

Inoculum and stabilizing conditions

Matrix

Non- E. coli coliform Enterobacter cloacae NBRC 13535 Enterobacter gergoviae QL 123009-1 Enterobacter gergoviae ATCC 33028

E. coli

2 Weeks at 20-25°C Lyophilized culture 16-24 h at 20-25°C Unstressed culture 16-24 h at 20-25°C Unstressed culture

E. coli 3M REC11

Soybean Meal

E. coli 3M REC1

Stainless Steel

E. coli QL 16160-10

Sealed Concrete

a ATCC: American Type Culture Collection, Manassas, VA. b QL: Q Laboratories Culture Collection, Cincinnati, OH. c 3M: 3M Food Safety, St. Paul, MN. d Not applicable. e NBRC: NITE Biological Resource Center, Tokyo, Japan.

Table 11: Inoculum heat stress results Matrix

Inoculating Organism Klebsiella oxytoca ATCC a 51817

Agar TSA b VRB c

CFU/g

Percent Injury

6.4 x 10 9 2.2 x 10 9 3.5 x 10 9 8.8 x 10 8 7.2 x 10 9 3.0 x 10 9 4.6 x 10 9 1.5 x 10 9 5.2 x 10 9 1.5 x 10 9 2.4 x 10 9 7.8 x 10 9

65.63%

Pasteurized Whole Milk

TSA

E. coli QL d 16154-3

74.86%

VRB with MUG e

TSA VRB TSA TSA VRB TSA

Klebsiella pneumoniae QL 11007-7

58.33%

Butter

E. coli QL 16160-18

67.39%

VRB with MUG

Klebsiella oxytoca ATCC 700324

71.15%

Pasteurized Carrot Juice

E. coli QL 16160-9

69.17%

VRB with MUG

a ATCC: American Type Culture Collection, Manassas, VA. b TSA: Trypticase Soy Agar. c VRB: Violet Red Bile Agar. d QL: Q Laboratories Culture Collection, Cincinnati, OH. e VRB with MUG: Violet Red Bile Agar with 4-methyl-umbelliferyl- β -D-glucuronide.

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