ERP Micro December 2019

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

Not tested

Total

MALDI Biotyper correctly identified

Reference correctly identified as non- Listeria

Reference incorrectly identified as Listeria

MALDI Biotyper incorrectly identified

MALDI Biotyper

MALDI Biotyper Reference

Organism

Reference

15 a

14

2

1

0

48

16

16

Bacillus thuringiensis Ad2067 Staphylococcus pasteuri Ad1717 Enterococcus faecalis Ad547 Bacillus pumilus Ad733 Leuconostoc pseudomesenteroides Ad835 Enterococcus mundtii Ad1365 Staphylococcus hominis Ad849

41

16

0

0

0

23

41

16

26

16

0

0

0

38

26

16

50 16

11 15

5 1

10

0 0

13 48

51 16

16 16

0

56 b

15

1

0

0

8

56

16

44

15

1

0

0

20

44

16

15

14

1

0

0

49

15

15

Lactococcus lactis Ad425

 Total isolates

263

116 c

11

2

0

247

265 d

127 e

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  Total numbers represent isolates analyzed on the four recommended culture media: TSA/YE, O&A, OXA, and RAPID’ L. mono . e  Reference method performed from TSA/YE agar only.

addition, the use of chemicals and the need to perform certain steps in a fume hood should also be evaluated. When testing is complete, all materials and media possibly containing pathogens should be decontaminated following current industry standards for the disposal of contaminated waste (i.e., autoclave for 20 min at 120°C). Consult the Safety Data Sheet for additional information and local regulations for disposal. To reduce risks associated with environmental contamination, follow current industry standards for disposal of contaminated waste. D. General Preparation ( a ) Isolation of organisms for testing .—Organisms for testing must be isolated on one of the recommended media. Refer to the MALDI Biotyper System Quick Guide for Food Testing (No. 1855438) for a list of recommended isolation media (O&A, OXA, MOX, PALCAM, RLM, and TSA/YE). In the collaborative study, a nonselective agar (TSA/YE; Bio-Rad or equivalent), selective agar (OXA; bioMérieux or equivalent), and two chromogenic agars [O&A (Bio-Rad or equivalent) and RLM (Bio-Rad)] were used. 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 (follow specific temperature and incubation time as specified by manufacturer or reference method). Use only a single isolated colony (or colonies to get sufficient biological material) when performing identification on the MALDI Biotyper System. ( b ) Preparation of BTS.— Add 50 µL of standard solvent to BTS tube. Dissolve by gently pipetting up and down 20 times; 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 (15 871–21 130 g, equivalent to 13 000 to 15 000 rpm for Eppendorf tube centrifuged with a 5424R rotor). Aliquot 5 µL into

( 7 ) User Manual MBT Explorer Module ( 8 ) User Manual Microflex LT/SH Smart ( 9 ) User Manual Microflex

Users should read, understand, and follow all safety information in the instructions for the Bruker method. Retain safety instructions for future reference. To reduce risks associated with exposure to chemicals and biohazards, perform pathogen testing in a properly equipped laboratory under the control of trained personnel. Always follow standard laboratory safety practices, including wearing appropriate protective apparel and eye protection while handling chemicals, reagents, and contaminated samples. Avoid contact with the isolates and reagents. Dispose of isolates, chemicals, and reagents according to current industry standards. The Bruker MALDI Biotyper can detect Biosafety Level 2/3 organisms. Biological samples have the potential to transmit infectious diseases. Follow all applicable local, state/provincial, and/or national regulations on disposal of biological wastes. Wear appropriate protective equipment, which includes but is not limited to protective eyewear, face shield, clothing/laboratory coat, and gloves. All work should be conducted in properly equipped facilities utilizing the appropriate safety equipment (e.g., physical containment devices). Individuals should be trained in accordance with applicable regulatory and company/institution requirements before working with potentially infectious materials. Cleaning of the target plates should be conducted in a fume cabinet. L. monocytogenes is of particular concern for pregnant women, the aged, and the infirm. It is recommended that these concerned groups avoid handling this organism. When testing foodborne bacterial isolates, a risk assessment should be performed for any new tests to determine the safety of the protocols, and whether the procedure should be performed in a biological safety cabinet. In

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