ERP Micro December 2019

1620  B astin et al . : J ournal of AOAC I nternational V ol . 101, N o . 5, 2018

Table 2017.10F. Summary of results for the confirmation and identification of Gram-positive organisms: exclusivity

MALDI Biotyper correctly identified

Ref. correctly identified as non- Listeria

Ref. incorrectly identified as Listeria

MALDI Biotyper incorrectly identified

MALDI Biotyper not tested

MALDI Biotyper total

Ref. not tested

Organism

Ref. total

Bacillus thuringiensis Ad2067 Staphylococcus pasteuri Ad1717 Enterococcus faecalis Ad547

15 a

14

2

1

0

48

16

16

41

16

0

0

0

23

41

16

26

16

0

0

0

38

26

16

B. pumilus Ad733

50

11

5

1

0

13

51

16

Leuconostoc

16

15

1

0

0

48

16

16

pseudomesenteroides Ad835

56 b

15 15

1 1

0 0

0 0

8

56 44

16 16

E. mundtii Ad1365 S. hominis Ad849 Lactococcus lactis Ad425

44

20

15

14

1

0

0

49

15

15

116 c

265 d

127 e

11

2

0

247

Total isolates

263

a Ten of the isolates were identified to the group level and five to the species level. b One of the isolates was identified to the genus level only. c API Listeria used as the confirmatory biochemical, which only produces identifications for Listeria species. d The total numbers represent isolates analyzed on the four recommended culture medias: TSA/YE, O&A, OXA, and RAPID’L.mono. e Reference method performed from TSA/YE agar only.

Table 2017.10G. Comparative results for the confirmation and identification of Gram-positive organisms: exclusivity

Candidate Tryptic Soy Agar with Yeast

Candidate Ottaviani and Agosti Agar

Candidate Oxford Agar

Candidate Rapid ’L.mono Agar

Reference Tryptic Soy Agar with Yeast

X a N b Percent PA c

Target

Collaborator

X N Percent PA X N Percent PA X N Percent PA X N Percent PA

Gram-positive   organisms

1 2 3 4 5 6 7 8 9

8 8 8 8 8 8 8 8 8 8 7 7 8 8 8 8 8 8 8 8 8 8 8 8 6 6 8 8 8 8 8

100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

4 4 100.0 4 4 1 1 100.0 5 5 1 1 100.0 4 4 4 4 100.0 4 4 3 3 100.0 5 5 4 4 100.0 4 4 0 0 100.0 5 5 2 2 100.0 5 5 0 0 100.0 0 0 e 1 1 100.0 4 4 0 0 100.0 3 3 3 3 100.0 5 5 4 4 100.0 0 0 e 2 2 100.0 5 5 3 3 100.0 5 5 1 2 50.0 3 3

100.0 4 4 100.0 8 8 100.0 100.0 1 1 100.0 8 8 100.0

100.0 2 2 100.0 7 8

87.5

100.0 4 4 100.0 8 8 100.0

100.0 4 4 100.0 7 8

87.5

100.0 3 3 100.0 7 7 100.0 100.0 1 1 100.0 8 8 100.0

8 d

100.0 4 4 100.0 6 8

75.0

100.0 1 1 100.0 8 8 100.0 100.0 3 3 100.0 8 8 100.0

10 11 12 13 14 15 16

100.0 3 4 100.0 0 0 f

75.0

7 8

87.5

100.0 8 8 100.0

100.0 4 4 100.0 8 8 100.0

100.0 4 4 100.0 2 8

25.0

100.0 3 3 100.0 8 8 100.0 100.0 4 4 100.0 8 8 100.0

a

X=Total number of isolates tested.

b N=Number of correct identifications. c PA=Positive agreement. d Collaborator confirmed seven isolates to the species level and one to the genus level. e Collaborator did not receive OXA. f Collaborator observed no growth on all isolates.