FDA guidance urges food firm Salmonella test caution

US food safety authorities have urged food manufacturers, processors, packager and distributors to “be aware” of the potential for false results when testing for Salmonella species (Salmonella spp.).

The Food and Drug Administration (FDA) revised document, Guidance for Industry: Testing for Salmonella Species in Human Foods and Direct-Human-Contact Animal Foods, has pressed for caution when testing for Salmonella in human foods and direct-human-contact animal foods.

The document, which provides guidance on human foods or direct-human-contact animals foods intended for distribution to consumers, institutions or food processors, addresses testing procedures for Salmonella species and the interpretation of test results where the presence of this pathogen may result in injury.

It does not apply to egg producers and others already covered the FDA’s final rule, the Prevention of Salmonella Enteritidis in Shell Eggs during Production, Storage, and Transportation, the FDA added.

Cultural methods

The guidance urges firms to follow the cultural method measures advised in the FDA’s Bacteriological Analytical Manual (BAM) or a validated non-BAM method when conducting tests for Salmonella spp.

Using cultural methods can yield one of three results: a presumptive positive result, a confirmed positive result or a negative result.

“Consider any confirmed positive result to be valid…. There are a number of explanations why a food that is contaminated with Salmonella spp. may initially yield a confirmed positive result for Salmonella spp. in one test and subsequently yield a negative result for Salmonella spp. in one or more additional tests.”

The FDA document also included direction in relation to the control of tested foods.

“Maintain control of a food that is being tested for the presence of Salmonella spp., pending the final outcome of that testing, to ensure that the food could be reconditioned, destroyed, or diverted," it said.

“For the purpose of this guidance, FDA considers that a firm maintains control of a food if the food has not been transferred to another person.”

Draft guidance

The 8 March 2012 dated FDA guidance, which represents the FDA’s current thinking on testing procedures surround Salmonella species, follows a 2011 draft that was open to comment.

“In the Federal Register of March 23 2011, FDA made available a draft guidance entitled Testing for Salmonella Species in Human Foods and Direct-Human-Contact Animal Foods and gave interested parties an opportunity to submit comments by June 21 2011. The Agency reviewed and evaluated these comments and has modified the guidance where appropriate,” said the FDA 2012 document.

Notice of the March 2012 guidance was published in the US Federal Register. Comments on the document have been welcomed.