Draft standard a tool to help industry reduce Campylobacter – Lab M
The firm said only more testing, agreed industry limits and putting in place effective control measures will lead to a reduction in Campylobacter levels.
However, the draft standard provides industry with a tool to help and optimise testing methodology and standardise best practice across laboratories.
Campylobacter is the UK’s leading cause of food poisoning and a year-long survey by the UK Food Standards Agency (FSA) showed 73% of chickens tested positive for the pathogen, with one in five (19%) within the highest band of contamination (>1,000 cfu/g).
Draft standard
ISO/DIS 10272-1: Microbiology of food and animal feed - Horizontal method for detection and enumeration of Campylobacter - Part 1: Detection method and ISO/DIS 10272-2 Part 2: Colony-count technique are draft standards issued in February.
They were circulated for public comment and closing date for comments was 30 April.
The responsible committee, A W/9 Microbiology, will consider all comments they received to assess if further amendments are required or if the draft standard can be approved and published as an international standard.
Ez Elmerhebi at Lab M said the key change is the older standard didn’t differentiate between different sample types; it simply stated one media and conditions for all samples.
“Through an enhanced understanding of the organism it has been possible to revise the standard to take into consideration the numbers of campylobacters present, the level of background flora and the stressed state of Campylobacter," he told FoodQualityNews.
“A simple linear model is no longer optimal and that has been adapted to define the use of different media accordingly.
“The standard is game-changing in the sense that it is more practical and better suited to what laboratories face.
”The choice of media is clearly defined, which supports standardisation across laboratories. The media and techniques included, however, are not new.”
Campylobacter media
A reliable toolkit for testing is critical and Lab M offers media for Campylobacter detection and isolation that support the three methods set out in Part 1: Detection method.
The draft standard describes the use of: Bolton Broth for samples with low background flora, such as cooked meats; Preston Broth for low Campylobacter levels in the presence of high background flora, including raw meats and raw milks; and direct mCCDA, a Campylobacter Blood-Free Selective medium, for instances where numbers of Campylobacter are high, in samples such as faeces or raw poultry meat.
Lab M’s portfolio for Campylobacter testing includes Campylobacter Blood Free Selective Medium (Modified CCDA), which supports the growth of most enteric Campylobacters, Campylobacter Enrichment Broth (Bolton Formulation) for selectively enhancing the recovery of sub-lethally damaged organisms, and Preston Broth for highly contaminated samples.
Part 2 outlines a colony-count technique to enable enumeration, which is critical when an accurate level of Campylobacter needs to be established.
This will help support industry when considering acceptance thresholds and monitoring prevalence, said Lab M.
To achieve this, part 2 incorporates decimal dilutions to obtain a colony forming unit (cfu) per gram, per mL or per cm2.
Lab M said it was already in line with the standard, as the core testing media in the draft standard are already available and are performance compliant according to ISO 11133:2014.
Exeter Broth, the preferred choice in many research institutes and some laboratories depending on sample type and workflow, will be added to the range soon, according to Lab M.
“Even though the draft standard is available, some laboratories have run their own extensive validation studies and found Exeter Broth to be suitable for their sample types,” said Elmerhebi.
“If this media is their preferred choice they are able to use it. However, if they have accreditation according to ISO 17025, they would need to demonstrate equivalence with their alternative method.”
