ERP Micro December 2019

B astin et al . : J ournal of AOAC I nternational V ol . 102, N o . 5, 2019  1609

Table 2017.09S. Comparative results for the confirmation and identification of Campylobacter (inclusivity)

Modified Charcoal Cefoperazone Deoxycholate

RAPID’ Campylobacter Agar

Columbia Blood Agar

Campy Cefex Agar

Ref. Columbia Blood Agar a

N  b X  c Percent PA d

Target

Collaborator

N X Percent PA

Percent PA

Percent PA N X Percent PA

N X

N X

1 2 3 4 5 6 7 8 9

16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16

1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00

16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00

Campylobacter species

10 e 10 1.00 14 f 14 1.00 14 f 14 1.00 16 16 1.00

16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 14 g 14 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 14 g 14 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00

16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00

10 11 12 13 14 15 16 17

15 h 15 1.00 16 16 1.00 15 h 15 1.00 16 16 1.00

16 16 1.00 16 16 1.00 16 16 1.00 16 16 1.00

nt i nt

NA j

nt nt

16 16 1.00

NA 16 16 1.00

a  Reference method only confirmed to the genus level. b N = Number of correct identifications. c X = Total number of isolates tested. d  PA = Positive agreement.

e  Six isolates note tested using entire workflow because participant not able to continue with testing. f  Two isolates not tested using entire workflow because participant was not able to continue testing.

g  No growth observed for two isolates. h  No growth observed for one isolate. i   nt = Data not being used for mCCDA. j   NA = Not applicable.

avoid generating bubbles. Let stand at room temperature (20–25°C) for 5 min. Repeat pipetting 20 times. Centrifuge for 2 min at maximum speed (15871–21130 × g , equivalent to 13000–15000 rpm for an Eppendorf tube centrifuged with a 5424R rotor). Aliquot 5 μL into microcentrifuge tubes (screw caps recommended) and store at –20°C or below for up to 5 months; do not refreeze once thawed. ( c )  Preparation of 70% formic acid .—Transfer 70 μL formic acid to 30 μL HPLC grade water. ( d )  Preparation of HCCA matrix .—Add 250 μL standard solvent. Mix on a vortex mixer for 1 min or until dissolved. Once reconstituted, store in the dark at room temperature (20–25°C) up to 1 week. Check for crystal formation on the bottom of the tube each day before use and mix on a vortex mixer for a minimum of 1 min if needed or until dissolved. D. Cleaning Target Plate: Reusable Polished Stainless-Steel Target Plates Only When using reusable polished stainless-steel target plates, two procedures can be followed to guarantee an appropriate and

C. General Preparation ( a )  Isolation of organisms for testing .—Organisms for testing must be isolated on one of the recommended media. Please refer to the MALDI Biotyper System Quick Guide for Food Testing (No. 1855438) for a list of recommended isolation media ( Salmonella species: XLD, BGA, RSA, BSA, ASAP, or any nonselective agars; Cronobacter species: ESIA, CCI, or any nonselective agars; and Campylobacter species: CBA, mCCDA, RCA, CCA, CFA, or any nonselective agars). Organisms for testing must be subcultured as necessary to ensure purity. Testing should be conducted on a culture that has been grown for 24–48 h in appropriate temperature conditions. Use only a single isolated colony (or colonies to obtain sufficient biological material) when performing identification on the MALDI Biotyper System. Note: Unknown cultures cannot be refrigerated prior to identification, and spotted target overlaid with HCCA Matrix must be analyzed within 24 h. ( b )  Preparation of BTS .—Add 50 μL standard solvent to BTS tube. Dissolve by gently pipetting up and down 20 times;