Food Safety and Environmental Testing

Microbiology Testing - Chromogenic media

All the major food pathogens can be screened using chromogenic media in a wide variety of food samples. The methodology can vary according to the sample matrix and frequently involves pre-enrichment for 24 hours or more. This ensures that any pathogen contamination is allowed time to resuscitate and achieve enough numbers to ensure that organisms are transferred on to the chromogenic medium when a sub sample is plated out.

What are chromogenic media?

  • Chromogenic media are microbiological growth media that contain enzyme substrates linked to a chromogen.
  • The enzyme substrates are microorganism specific. When they are not, the target organism is selected for by suppression of competing microflora.
  • The target population is characterized by enzyme systems that metabolize the substrate to release the chromogen. This results in a colour change in the medium.

What are the benefits of chromogenic media?

  • Shorter time to result when compared to reference methods for both negative screens and presumptive positives. Some chromogenic media give confirmed results within 24 hours!
  • Result interpretation is visual and, in some cases, does not require further testing.
  • Some chromogenic media offer reduced incubation times to allow late arriving samples to be set-up and still have next day results.

Implementation of alternative methods

  • CellMadeTM Laboratories selects alternative methods from trusted suppliers and only implements alternative methods that are certified according to internationally recognized certification bodies such as AFNOR or AOAC.
  • The implementation of a novel method is performed according to ISO 16140-3. The method verification report(s) and data are available under the Resources Centre of this website.

Proficiency tests

  • CellMadeTM Laboratories regularly participates in proficiency tests organized by recognized companies and institutions.
  • The results of these proficiency test(s) are available under the Resources Centre of this website.

 

Below table summarizes the available testing services using chromogenc media methods.


Services

Ref Services Description Price
MBC0001 Bacillus cereus (BRD 07/26-03/19)

Food pathogen. Direct enumeration of Bacillus cereus without confirmation in 24h +/- 3h. For a broad range of food and environmental samples. 

 On request
MBC0002 Campylobacter spp. (BRD 07/25-01/14)

Food pathogen. Specific detection of Campylobacter spp.  in 48h-72h. For a broad range of food and environmental samples. 

 On request
MBC0003 Cronobacter spp. (BRD 07/22-05/12)

Food pathogen. Direct enumeration of Campylobacter spp. in 44h+/- 4h. For a broad range of food and environmental samples. 

 On request
MBC0004 Escherichia coli (BRD 07/07-12/04)

Quality indicator. Direct enumeration of Escherichia coli and coliforms in 18h-24h. For a broad range of food and environmental samples. 

 On request
MBC0005 Enterobacteriaceae (BRD 07/24-11/13)

Quality indicator. Direct enumeration of Enterobacteriaceae in 24h +/- 2 h. For a broad range of food and environmental samples. 

 On request
MBC0006 Listeria spp. (BRD 07/12-12/06)

Food pathogen. Specific detection of Listeria spp.  in maximum 48h. For a broad range of food and environmental samples. 

 On request
MBC0007 Listeria monocytogenes (BRD 07/04-09/98)

Food pathogen. Specific detection of Listeria monocytogenes  in maximum 48h. For a broad range of food and environmental samples. 

 On request
MBC0008 Salmonella spp (BRD 07/11-12/05)

Food pathogen. Specific detection of Salmonella spp.  in maximum 48h. For a broad range of food and environmental samples. 

 On request
MBC0009 Staphylococcus aureus (BRD 07/09-02/05)

Food pathogen. Direct enumeration of coagulase-positive Staphylococci in 24h +/- 2h. For a broad range of food and environmental samples. 

 On request
MBC0010 E.coli 0157:H7 (BRD 07/14-09/07)

Food pathogen. Specific detection of E.coli 0157:H7  in maximum 48h. For a broad range of food and environmental samples. 

 On request