Biotech firm releases real-time PCR assay for detecting Cronobacter species in powdered infant formula

04-Apr-2016 - Last updated on 06-Apr-2016 at 08:45 GMT

A package of all the consumable components to run the SureTect real-time PCR part of the workflow Source: Thermo Fisher Scientific

It once took infant formula manufacturers up to two days to detect Cronobacter, a genus of bacteria that can cause serious illness to infants: now it only takes 18 hours using the new PCR assay invented by the biotech firm, Thermo Fisher Scientific.

The new PCR assay was created under Thermo Fisher Scientific’s SureTect brand, and it has received NF validation approval by AFNOR Certification according to the ISO 16140 methods comparison study.

SureTect Cronobacter assay workflow

SureTect Cronobacter assays have received validation certification for infant formula that is supplemented with probiotics, according to Cheryl Mooney, global marketing manager at the company.

“Not all other methods are validated for this sample type, which can be difficult to analyze due to the low pH environment produced during the enrichment stages,” she said.

In addition, Mooney added, SureTect Cronobacter assays are able to detect other pathogens, such as Salmonella species.

The EU Food Safety and Hygiene Regulations requires that, “all dried infant formula and dried dietary foods for special medical purposes intended for infants below six months placed on the market during their shelf-life must not contain Salmonella or Cronobacter.”

The new test will be used by in-house laboratories of infant formula manufacturers and contract labs serving those manufacturers, Mooney told DairyReporter.

How does Cronobacter contamination occur?

Contamination of infant formula products by Cronobacter species may occur after drying and during the subsequent processing steps, such as conveying, tipping, mixing, and blending with additional ingredients up to the point of filling and packaging, according to Mooney.

The growth of Cronobacter is also possible in the presence of water, she said. “Therefore, the environment needs to be kept as dry as possible, even during cleaning, which often utilizes vacuuming.”

Not validated compared to the USDA-MLG method

Thermos Fisher Scientific has five customers in Europe using its new testing system, and the feedback has been positive, because the tests reduced the amount of sample handling prior to performing the PCR test, Mooney said.

“We are looking to validate more sample types, including the larger sample sizes up to 300g.”

SureTect Cronobacter assay is currently available in the US, said Mooney. However, it has not been independently validated compared to the USDA-MLG (Microbiology Laboratory Guidebook) method.

In the future, Mooney added, there will be an increase in focusing on testing and monitoring the production environment, because a better environment monitoring program can lower the risk of introducing pathogens.

“[Powdered infant formula] is one of our most stringently-tested products in the market because of the sensitive nature of its customers, who are either not fully immune developed or immune-compromised in some way,” Mooney said. “Risk management is likely to be high on everyone's list of areas to improve.”