Rapid test for Salmonella Risk in food factories

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ISO 6579-1:2017

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AOAC® PTM^SM Certification Download certificate

NEMIS technologies Salmonella Risk test

Salmonella contamination is a major food safety risk in food production environments, but actually detecting salmonella in your facility can be challenging. Enter the N-Light™ Salmonella Risk Test from NEMIS Technologies. Not only does this test detect Salmonella spp., it also detects a small range of closely-related bacteria that share genetic and metabolic markers. That means you get a more accurate assessment of the true contamination risk in your facility.

The NEMIS N-Light™ Salmonella Risk Test utilises our proprietary Aquaspark™ platform which is built on pioneering phage technology to quickly detect even small amounts of live bacteria. Unlike traditional lab tests that take days to get results, the NEMIS N-Light™ Salmonella Risk Test produces actionable results in as little as 24 hours. Fast, accurate, easy-to-use. The future of food systems testing is here.

Salmonella spp. detection – status quo

Salmonella infections pose a significant health risk, often linked to contaminated food products, making the control of food production crucial. The microbial environment in food production is extensive and intricate, with certain bacterial groups like Enterobacteriaceae and Salmonella spp. often at the centre of food safety concerns. Although Salmonella spp. is rarely found in factory settings, appearing in only 2 to 8 out of every 1000 routinely tested samples, total Enterobacteriaceae (TEB) counts can be much higher.

Unfortunately, no clear data links TEB counts to Salmonella spp. in environmental samples, which has been a significant challenge for researchers and industry experts. The EU Scientific Panel highlighted this issue and concluded that it is currently impossible to establish a direct correlation between Enterobacteriaceae and Salmonella spp.

AYOPI Groups
are at the highest risk

CDC estimates that Salmonella causes approximately 1.2 million illnesses and 450 deaths yearly in the US.

Pregnant women and newborns

Adults aged 65 and older

People with weakened immune systems

N-Light™ Salmonella Risk
Indicator test

N-Light™ Salmonella Risk is not designed to detect only Salmonella spp. Instead, it also targets a small selection of closely related bacteria (such as Citrobacter, Klebsiella and Enterobacter) that share specific metabolic and genetic markers.

Positive N-Light™ Salmonella Risk does not mean finding exclusively Salmonella spp. Instead, it highlights an elevated likelihood of contamination, allowing for timely interventions and corrective actions to ensure food production safety.

1 Identification of sampling sites and zones with N-Light™ Salmonella Risk
2 Positive result
3 Citrobacter,
Enterobacter,
Klebsiella,
Salmonella spp.

N-Light™ Salmonella Risk  tube contains a unique, innovative technology

The Biosafety Cap for safe
on-site enrichment

Pioneering phage
technology

Patented AquaSpark™
platform for detection of live bacteria

See our technology
in action

Consider your sampling needs:
N-Light™ MaxiSampler vs N-Light™ swab

Patent pending

By choosing the right tool for each surface type and size, you can meet regulatory guidelines effectively while maximizing sampling efficiency and accuracy.

N-Light™ MaxiSampler

Patent pending

Designed for Large Surface Coverage Excels in sampling larger, flat surfaces such as floors, walls, and countertops. Provides broader detection of potential contamination across sizable zones.
Guideline Endorsed for Broader Surveillance Environmental monitoring guidelines often endorse sponges for larger, straightforward areas to capture a comprehensive view of contamination risks.
Surface Area With a typical range up to 0.3 m² (like a 30×30 cm area), N-Light™ MaxiSampler maximizes sampling on expansive surfaces, offering robust environmental surveillance.

N-Light™ swab

Ideal for Hard-to-Reach Areas Swabs are perfect for narrow or intricate surfaces such as equipment joints, cracks, and small parts that might otherwise be missed.
Recommended by Guidelines for Small Surface Sampling Many guidelines, such as those from the FDA and ISO, suggest swabs for sampling limited areas or surfaces with complex geometries.
Surface Area Typically covers around 0.1m² (like a 10×10 cm area), making swabs ideal for focused or spot sampling on high-touch or high-risk zones.

Learn more

Simple, Effective, Testing process

1. Sample

2. Transfer

3. Incubate

24 h / 37 °C

4. Activate

5 min

5. Measure

10 s

Recommended products:

N-Light™ L.monocytogenes Learn more

N-Light™ Listeria spp. Learn more

N-Light™ E.coli Learn more

N-Light™ ATP Learn more

N-Light™ MaxiSampler: Revolutionizing Surface Sampling Learn more

N-Light™ Salmonella Risk

NEMIS product REF 00014

Product description

N-Light™ Salmonella Risk is a qualitative test method for rapid evaluation of the contamination risk for the foodborne bacterial pathogen Salmonella and a small selection of closely related bacteria that share specific metabolic and genetic markers. The test method is suitable for use in food processing areas and equipment as part of an environmental monitoring program. Final test results are available 24h after sampling.

Storage conditions: 2-8 °C / 36-46 °F, DO NOT FREEZE

Transport conditions: ambient (short duration only)

HS tariff number: 38221900

Country of origin: CH

Each test consists of the following components:

N-Light™ Biosafety Tube, filled with N-Light™ Salmonella Risk Enrichment Broth, 2 ml
N-Light™ Dispensing Closure, containing the Salmonella Risk AquaSpark®/Lysis tablet, 1 pc. / 15 mg
N-Light™ Salmonella Risk Starter Tablet, 1 pc. / 45 mg, separately packaged in the Starter Tablet Dispenser

Technical specifications

NEMIS tests each production batch against the specifications listed below.

General characteristics	Specification
Broth general appearance	Yellowish, clear waterlike solution
Broth visible turbidity	No particles
Broth optical density (A600nm)	< 0.10
Broth Volume	1.80 – 2.20 ml
Broth pH value	7.20 – 7.60
Functionality test (Background)	< 10 000 RLU (NEMIS Luminometer)
Quantity of AquaSpark®, selective agents and lysis agents	Internal specification

Microbial performance	Specification
Sterility control	No growth, 7 days @ 37 °C
Salmonella javiana N2427-08	Positive result
Salmonella typhimurium ATCC 14028	Positive result
Klebsiella pneumoniae ATCC 13882	Negative result
Citrobacter freundii CF#11	Negative result
Cronobacter dublinensis DSM 18797	Negative result
E. coli ATCC 11303	Negative result
Enterobacter cloaceae ATCC 23373	Negative result

Certificates of analysis are available on request.

Packaging specifications

General characteristics	Primary packaging (test tube)	Secondary packaging (product box)	Tertiary packaging (distributor box)
Amount	1 test	50 tests (1 x 50)	300 tests (6 x 50)
Starter Tablet Dispenser	Not included*	Included	Included
N-Light™ Tablet Dispenser Tool	Not included**	Not included**	Not included**
Bar code / GTIN	See below	7649994979249	7649994979256
Length	1.9 cm	29.0 cm	40.5 cm
Width	1.9 cm	11.5 cm	30.8 cm
Height	11.1 cm	12.1 cm	26.2 cm
Net weight	0.010 kg	0.650 kg	4.250 kg
Total plastic amount	0.008 kg	0.390 kg	2.340 kg
Non-reusable plastic amount — in the product — in the packaging	0.008 kg 0.000 kg	0.389 kg 0.001 kg	2.334 kg 0.006 kg

* – each product box contains 50 tests and one separate Starter Tablet Dispenser containing 50 Starter Tablets. The dispenser is packaged in a sealed aluminum pouch and labeled with a separate lot number.

** – the reusable N-Light™ Tablet Dispenser Tool is not included and needs to be ordered separately (NEMIS product REF 00018).

Lot and serial number of the test

Each test has a unique number printed on the tube label. The human readable format is LLLLLLL-XXXXX. Additionally, this number is encoded without the hyphen in a linear barcode of type Code 128:

LLLLLLL: 7-digit lot number
XXXXX: 5-digit consecutive number

N-Light™ Salmonella Risk
Required materials

N-Light™ Salmonella Risk test tubes (incl. dispenser containing starter tablets)
NEMIS Bench-top Luminometer
NEMIS Dry Block Heater
Kitchen Timer
Optional: N-Light™ Tablet Dispenser Tool (REF 00018)
Optional: N-Light™ Activation Tool (REF 00008)
N-Light™ sampling devices containing compatible moistening solution
- N-Light™ sterile dry swabs BP with separate PBS buffer (REF 00026)
- N-Light™ sterile dry swabs BP with separate neutralizer (REF 00037)
- N-Light™ sterile MaxiSamplers with separate BPW buffer (REF 00062)
- N-Light™ sterile MaxiSamplers with separate neutralizer (REF 00064)

N-Light™ Salmonella Risk AOAC certificate N-Light™ Salmonella Risk Brochure N-Light™ Salmonella Risk Instructions for Use

Training

At NEMIS, your success is our priority. Our experts are here to guide you with comprehensive training resources, including instructional videos, to help your team confidently and accurately perform procedures. For on-demand training requests, please contact us at techsupport@nemistech.com.

FAQ

The N-Light™ Salmonella Risk test is a qualitative test for rapidly detecting the foodborne bacterial pathogen Salmonella spp. and closely related bacteria. It is intended for use in food processing areas and equipment as part of an environmental monitoring program. Being intuitive, rapid, cost-effective, and lab-free, it offers an affordable solution to enhance testing and empower your quality management process. Given the low prevalence of Salmonella spp. on environmental surfaces, N-Light™ Salmonella Risk not only detect Salmonella spp. but also a small selection of closely related bacteria. Certain strains of Klebsiella, Citrobacter and Enterobacter share the metabolic marker alpha- galactosidase activity with Salmonella spp. Based on NEMIS’ research, we suggest that the persistent presence of alpha-galactosidase-positive bacteria growing in our selective broth can be used as an indicator of the risk of the presence of Salmonella spp.

The low prevalence of Salmonella spp. on environmental surfaces makes its detection difficult. Therefore, the use of specific tests for Salmonella spp. usually gives a meagre rate of positive results, giving quality managers a false sense of security. The N-Light™ Salmonella Risk test allows quality managers to be in control, taking prompt preventive and corrective actions when the risk of the presence of Salmonella spp. is detected.

N-Light™ Salmonella Risk is not an Enterobacteriaceae test as the combined selectivity of the AquaSpark™ detection molecule and the selectivity of the enrichment broth (phages and antibiotics) inhibits the growth of most Enterobacteriaceae strains phylogenetically distant from Salmonella spp. Please read the Salmonella Risk supporting document for more information

AquaSpark™ enzyme substrates are dioxetane derivatives bearing a chemical structure that specifically reacts with a target enzyme. After the reaction with the enzyme, light is emitted in chemiluminescence. Being fully synthetic molecules, the platform offers a wide choice array of compounds that allow rapid detection of enzymatic activities, amongst other applications.

RLU stands for Relative Light Units and is the unit of measure used in the NEMIS luminometer. RLU values are proportional to the amount of AquaSpark™ light emission triggered by the specific enzyme. For each NEMIS test, a certain threshold for presumptive positive and presumptive negative results has been defined. In the case of the N-Light™ Salmonella Risk test, when the signal is above 20'000 RLU, the enzyme alpha-galactosidase has been detected, indicating that there is a risk of the presence of Salmonella spp.

The test combines two core technologies: NEMIS bacteriophages (selective enrichment) and AquaSpark™, an ultrasensitive chemiluminescent molecule that reacts with the alpha-D-galactosidase enzyme produced by almost all Salmonella spp. and some other Enterobacteriaceae. In practice, the user follows a simple protocol:

Collect the sample using a swab.
Transfer it to the enrichment tube.
Break and leave the swab inside the tube.
Add the antibiotic tablet.
Incubate it for 24 hours.
Release the AquaSpark™ tablet into the tube.
Incubate the activated tube at 37 ˚C for 3-4 minutes
Measure results

If there is a risk of having Salmonella spp. that have grown in the selective broth, bacteria will initiate a reaction that generates light which the Luminometer measures, thus yielding a presumptive positive result.

Results can be obtained after 24 hours of incubation at 37 °C. However, a shorter incubation time than 23 hours is not AOAC-validated and not encouraged if minimal contamination levels should be detected. On the other hand, test tubes can be incubated for up to 72 h yielding the same results.

The N-Light™ Salmonella Risk test broth contains a mixture of nutrients (for bacterial growth) combined with selective supplements (limiting the growth of non-target bacteria) such as antibiotics and a proprietary combination of bacteriophages. This combination creates an ideal culture medium for Salmonella spp. leading to superior sensitivity and specificity of the test. Its unique formulation inhibits the growth of competing bacteria and makes the test more reliable in challenging environments.

The only required equipment is the NEMIS dry block heater and the NEMIS luminometer. They can be used on-site without any laboratory infrastructure. However, performing the test in a separate room, distant from the production environment, is recommended.

Yes, the N-Light™ Salmonella Risk has been certified in the AOAC® Performance Tested Methods SM Program and validated against the reference method ISO 11290-1:2017.

Cause	FP	FN
Inappropriate storage conditions (see question XX)
Shorter incubation time
Incubate at a lower temperature than 37 °C
Incubate at a higher temperature than 37 °C
Immediate or delayed measurement of the sample after tablet release contrary to the directions in the N-Light™ Salmonella Risk Instructions for Use (IFU)
The antibiotic tablet was not released into the broth
Swabs were not left inside the tube.

Any deviation from the N-Light™ Salmonella Risk test IFU can lead to FP or FN results.

The test can detect all the pathogenic Salmonella spp. Strains. However, N-Light™ Salmonella Risk does not only detect Salmonella spp. but also a small selection of closely related bacteria that share specific metabolic markers, mainly certain strains of Klebsiella, Citrobacter and Enterobacter. Based on NEMIS’ research, we have found that the persistent presence of those strains can be used as indicators for the presence of Salmonella spp.

The test is sensitive to detect Salmonella spp. starting from single-digit bacteria in the sample. Good swabbing practice and accurate compliance with the test IFU are required.

No, it does not. The detection mechanism relies on the hydrolysis of AquaSpark™ by an enzyme (alpha-D-galactosidase) that is only expressed by viable Salmonella spp. Therefore, negative results will be obtained for dead bacteria.

Yes, VBNC bacteria may be detected. Unlike conventional plating methods, the test detects Salmonella spp. as long as they are metabolically active. Preliminary research has demonstrated that VBNC cells cleave the AquaSpark™ and can be distinguished from dead cells in an assay format in the laboratory. Further research is ongoing.

It is possible to collect samples from production lines or sites that have not been recently cleaned. Sample location and application of N-Light™ Salmonella Risk should be categorized as follows:

Clean Surfaces
The AOAC has validated the full performance of N-Light™ Salmonella Risk
Food or dirt residue exposed surfaces within the production or before cleaning
Samples taken from production lines (both during and after production) and other places in the facility that are regularly cleaned are well within the capacity of our test. Make sure not to overload the sample with food residues. Rather go into niches and cavities of machines and apply pressure on surfaces. Sampling more “dirt” is not necessarily useful as persistent Listeria on equipment or infrastructure should be detected.
Direct sampling of food or in places of high dirt / food residue concentration
Meticulous sampling is required to ensure no test tube overload. Do not directly collect food residues. Examples of high load sampling spots are uncleaned drains, smeared water tanks, or the inside of uncleaned food residue collection containers.

We recommend that sample locations with overload potential should be either avoided or alternative sampling spots in close vicinity be taken. In case of doubt, do not hesitate to reach out to techsupport@nemistech.com

Hot spots that accurately indicate potential product contamination should be preferentially sampled. Please refer to your Hazard Analysis and Critical Control Points (HACCP) plan.

Optimally, high-risk spots should be swabbed on a daily basis after each cleaning or production shift. In case of a positive result, immediate corrective action should be taken with re-cleaning and re-testing until a passing result can be measured. Lower-risk control points may be tested less frequently.