Listeria

Listeria

Listeria is genus of gram positive rod shaped bacteria of which the specie, Listeria monocytogenes causes listeriosis. There are six other non-pathogenic species – L. grayi, L. inocua, L. ivanovii, L. seeligeri and L. welshimeri, which are non-pathogenic. Listeriosis is a disease that causes severe illness that has a mortality rate of 20%. Listeria monocytogenes is found in the gut of ruminants and can be divided into 16 serovars on the basis of somatic and flagellar antigens. It is a facultative anaerobic and a very hardy bacteria which can survive drying and freezing. Listeria monocytogenes expresses beta hemolysin which causes haemoglobin to rupture.

Occurrence of Listeria

This bacteria is found commonly in uncooked meats and vegetables, in milk cold foods, ice creams and ready to eat meats like hot dogs. To prevent infection of ready to eat foods, factories that produce them are advised to continuously monitor the environment and production equipment for Listeria to prevent its establishment in the plant.

Conventional Method - Biolife Italiana

Arasains in Indonesia supplies Biolife culture media which can be used to cultivate and identify Listeria spp. and L. monocytogenes. Listeria monocytogenes grows on the Mueller Hinton agar. Identification is enhanced if the agar has sheep blood as a small zone of haemolysis can be seen around the colonies. Haemolysis differentiates Listeria from coryneform bacteria. The method of analysis requires 24-48 hours of pre-enrichment followed by other tests.

Lateral Flow – RapidChek® Listeria spp. & Listeria monocytogenes

The RapidChek® Listeria test system offers a single-step enrichment media to enable fast, accurate and simple Listeria detection within 40 hours. The simple preparation of enrichment media without autoclaving offers fast and flexible test planning. RapidChek® Listeria is AOAC approved for use in a variety of foods and environmental samples.

The RapidChek® Listeria monocytogenes test system is one of the first one-step immunological AOAC-certified testing system for Listeria monocytogenes. The proprietary RapidChek® Listeria NextDay™ enrichment media, also used in the Listeria NextDay™ systems, offers a short enrichment time. RapidChek® Listeria monocytogenes is AOAC approved for use on various environmental surfaces (stainless steel and plastic) and food samples (hot dogs, frozen breaded chicken, frozen cooked shrimp, cured ham, and ice cream).


 Benefit:

  • Fast & simple procedure 
  • Reliable results
  • Easy resource management
  • Approved by AOAC RI

Lateral Flow - VIP® Gold Listeria

Biocontrol Indonesia supplies VIP® Gold, a lateral flow device to detect all 6 species of Listeria including L. mono, thus providing a good indication of product and surface quality. This is a labour-saving single step enrichment protocol for all sample types. The VIP® Gold is an AOAC approved method.


 Benefit:

  • Fast presumptive screening and easy detection after enrichment steps
  • Direct application of enrichment sample
  • Single result format
  • No skills and no automation required
  • Robust housing format for better handling

ELISA - Transia™ Plate Listeria

Biocontrol Indonesia also supply Transia™ plate for the detection of Listeria spp. or only Listeria monocytogenes. This is a sandwich ELISA technology that is used with a 96 well microtiter plate. For large volume testing the process can be automated using the Gemini Analyzer. This test has AFNOR and NORD Val approvals. For Listeria spp. there is only a single enrichment step whilst for L. mono there is a first enrichment step in Demi Fraser broth of 20 hrs at 30°C and a second enrichment in Fraser broth for 24 hrs at 37°C. The time for ELISA test is 2 hr and 40 min.


 Benefit:

  • Accurate and reliable
  • High throughput efficiency – 96 well microtiter plate format 
  • Increase Productivity with Automation

PCR Technology – SureFast® Listeria Screening PLUS & Listeria monocytogenes PLUS

R-Biopharm Indonesia produced the SureFast® Listeria Screening PLUS. It is a real-time PCR for the direct, qualitative detection of a specific DNA sequence of Listeria. Each reaction contains an internal amplification control (IAC).

SureFast® Listeria monocytogenes PLUS is a real-time PCR for the direct, qualitative detection of DNA sequences of the Listeria monocytogenes virulence-associated gene prfA. Each reaction contains an internal amplification control (IAC).


 Benefit:

  • Qualitative detection
  • Of common foodborne pathogens with qPCR
  • Simple and straightforward
  • Increased efficiency – multiplex kits

PCR technology – Assurance® GDS Listeria

Merck Biocontrol Indonesia provides a PCR platform, Assurance GDS, for detection of Listeria spp. and L. mono. This method has three levels for the isolation of bacteria. Enrichment is a single step with time to results in 24 hrs.


 Benefit:

  • Improves accuracy by capturing and concentrating target pathogens
  • Superior proprietary reagents
  • Multiplexing DNA amplification
  • Faster cycling with evenly heat transfer

For more question about the product please contact our expertise

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Frequently Asked Questions

  • What is the advantage of using Eliza technology for Listeria?

    Identification of the bacteria is easier and more specific. There is no need to look for haemolysis.

  • Which factories usually test for listeria?

    Factories that produces food that are chilled or frozen usually test for Listeria eg: seafood processing factories, ice cream factory and frozen meat like sausages.

  • What is the advantage of using Assurance GDS?

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