hygiena ILC100 Environmental Surface Screening Test Instructions
- June 17, 2024
- Hygiena
Table of Contents
hygiena ILC100 Environmental Surface Screening Test
Introduction
Description and Intended Use
InSite® Listeria is a screening test for Listeria species, intended to be used
for environmental monitoring in food processing environments after cleaning. A
color change of the media from yellow/amber to grey/black is considered
presumptive positive for Listeria species.
Scientific Principle
InSite Listeria devices contain a proprietary formula of antibiotics, growth
enhancers and color-changing compounds. Antibiotics inhibit most non-Listeria
microorganisms while growth enhancers provide recovery nutrients to support
the growth of sub-lethally injured Listeria. β-glucosidase enzymes produced by
Listeria species react with indicator compounds, changing the broth from
yellow to black.
Intended User
Laboratory personnel trained in standard microbiological practices are
qualified to use InSite Listeria.
Required Materials (Not Provided)
- Dry Block Incubator (at 37 ± 1 °C) (Product No. INCUBATOR or INCUBATOR2)
- Block options for incubators:
- 35 wells for swabs for INCUBATOR2 (Product No. IB001)
- 12 wells for swabs for INCUBATOR (Product No. IB003)
- Self-sealing adhesive tape, plastic wrap, or paraffin film
Important Tips Before Starting the Test
The foam tip swab is pre-moistened; condensation may be visible inside the
swab tube—this is normal. Use an aseptic technique: Do not touch the swab or
the inside of the swab tube.
Test Procedures
-
Holding the swab tube firmly, twist and pull the top with the swab out of the swab tube. Thoroughly swab a standard 10 x 10 cm (4 x 4 in) area of interest for a typical flat surface.
Important swabbing technique tips:- a. Apply sufficient pressure to create flex in the swab shaft.
- b. Swab in a crisscross pattern vertically, horizontally, and diagonally in both directions.
- c. Rotate the swab as the sample is being collected to ensure maximum sample pickup.
- d. For irregular surfaces, ensure the swabbing technique remains consistent for each test and swab a large enough area to collect a representative sample.
-
Place the swab back in the swab tube and close the device firmly.
Tip: Seal the device to avoid accidental spillage by wrapping the joint of the swab tube and bulb with adhesive tape or self-sealing wrap. -
To activate the device, hold the swab tube firmly, and use your thumb and forefinger to break the Snap-Valve by bending the bulb forward and backward. Squeeze the bulb 3 to 4 times, expelling all the liquid into the tube.
-
Gently massage the bottom of the tube by squeezing the tube 3 times, then shake for 3 seconds. This will help release cells from the swab and displace air bubbles.
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Incubate for 24 – 48 hours at 37 ± 1 °C. Observe the color change (Figure 2) and record the result. Results cannot be considered negative until after 48 hours of incubation.
Figure 1. Workflow for the InSite Listeria Device.
Additional Information
Interpretation of Results
For representative results, refer to Figure 2:
- No change in the media color after 48 hours indicates that the sample is negative for Listeria species.
- A grey or black color change of the media is indicative of Listeria species.
Listeria-like Organisms
In high numbers, certain bacteria, such as Enterococcus spp., can produce
blackening of the media. Detection of these “Listeria-like” organisms in the
environment can indicate that improvements in cleaning and sanitation are
needed and that conditions at the sample site may be conducive to the growth
of Listeria. A higher rate of presumptive positives can be expected when
testing highly contaminated surfaces such as floors and drains.
To verify the presence of Listeria in a presumptive positive sample, Hygiena
recommends testing the incubated media from the InSite device with a more
specific method
(e.g., PCR, ELISA or lateral flow).
AOAC RI Performance Tested Methods℠ Certification
The detection of Listeria spp. (L. monocytogenes, L. innocua, L. fleischmanni,
L. welshimeri, L. weihenstephanensis, L. ivanovii and L. seeligeri) using the
InSite Listeria device has earned AOAC RI PTM Certification (License #121902)
from the AOAC Research Institute. Validation studies included swabs (4 x 4
inches) of environmental surfaces (plastic, ceramic and stainless steel).
Confirmation
Presumptive positive samples can be confirmed with Hygiena’s BAX® System PCR
or Real-Time PCR Assays for Genus Listeria or Listeria monocytogenes.
Presumptive positive samples also can be confirmed by an appropriate regional
reference method, such as:
- US FDA Bacteriological Analytical Manual (BAM)
- USDA FSIS Microbiology Laboratory Guidebook (MLG)
- Health Canada Compendium of Analytical Methods
- International Organization for Standardization (ISO)
Any confirmatory results should be handled according to appropriate regulations.
Storage and Stability
- Store at 2 to 8 °C (36 to 46 °F).
- Do not use past the expiration date on the label.
Disposal
Disinfect before disposal. InSite devices can be disinfected by autoclaving,
incinerating or bleaching (soak the unsealed device in 20% bleach for 1 hour).
Then, they can be placed in the trash. Alternatively, InSite devices may be
discarded following local disposal procedures.
Safety and Precautions
- InSite devices are intended to be used on production and environmental surfaces after cleaning.
- Components of InSite devices do not pose any health risk when used correctly. Used devices should be considered biohazard and should be disposed of safely in compliance with Good Laboratory Practice and Health and Safety Regulations (see disposal instructions above).
- Listeria monocytogenes is a human pathogen. When handling samples that possibly contain L. mono, extreme care should be taken to contain the incubated samples of InSite devices. Immuno-compromised individuals and pregnant women are particularly susceptible to exposure to L. mono and should not be allowed near testing.
Hygiena Liability
As with any culture medium–based test, InSite Listeria results do not
constitute a guarantee of the quality of food, beverage products, or processes
tested with these devices. Hygiena will not be liable to the user or others
for any loss or damage, whether direct or indirect, incidental or
consequential from the use of these devices. If this product is proven to be
defective, Hygiena’s sole obligation will be to replace the product, or at its
discretion, refund the purchase price. Promptly notify Hygiena within 5 days
of discovery of any suspected defect and return the product to Hygiena;
contact Customer Service for a Returned Goods Authorization Number.
Contact Information
For more information, visit
www.hygiena.com/contact. For technical
support, visit www.hygiena.com/support.
Performance Testing Methods℠ is a service mark of AOAC International.
InSite Listeria Test, ILC100 and ILC050