MICROBIOLOGY done by producing high quality spectra and carrying out comparative analysis to observe any differences between the spectra of each isolate. Figure 2 shows two E.coli isolates analysed at the laboratory that have clear differences and so therefore, are not the same strain of E.coli. Figure 1. A MALDI-TOF MS spectrum.
spectra for each sample and then doing a comparison between the data generated for each isolate. This process is known as MALDI-TOF MS Strain Typing. STRAIN TYPING MALDI-TOF MS strain typing can be effectively used to screen batches of isolates, ruling out links between them and indicating whether samples could be the same. Utilising this cost-effective technique can reduce the number of samples needing further, more expensive analysis, or even removing the need for this further analysis completely. This is
Figure 2. MALDI-TOF MS spectra of two E.coli isolates.
Strain typing plays a similar role to that of ribotyping in beyond species analysis and has been seen experimentally to have a similar level of sensitivity to this, both in our internal studies and in the scientific literature.
In practice, strain typing is generally used for Listeria isolates in the food micro setting, though it can also be used to get resolution beyond species for a range of other food related organisms, including E.coli. There are some organisms that this testing does not apply to due to their microbiology, such as Salmonella species, as it is not possible to distinguish accurately between the various sub species of this genus. In this specific instance however, other bespoke solutions for these organisms can be found, such as Salmonella Check & Trace serotyping system utilised by ALS in the UK, a system designed specifically to distinguish between isolates of Salmonella enterica. For ALS, the removal of the need to subcontract beyond species analysis has enabled this testing to be carried out more rapidly than previously used techniques and deliver results to clients more quickly, in a timeframe that can have an impact on key decisions.
NEW PRODUCT
Herald launches high quality salad container range Herald has launched a selection of premium, eco-friendly, disposable, brown craft salad bowls aimed at specialist food stores and the best delicatessens. The quality disposables manufacturer and supplier is specifically targeting highend, independent stores; notably, those who are keen to offer the highest quality packaging to complement their produce. The bowls, which are available in a selection of sizes, including 500cc, 750cc and 1000cc, come with PET lids and are designed to enhance the product offering, presenting the contents in the most optimum light. The same size containers are available in a rectangle shape, with paper lids, for hot food, complementing the salad bowls and allowing for a wider choice of offering. Managing director of Herald, Yogesh Patel said: “Just because food has been prepared to take away and eat at home, work or on the go, doesn’t mean that the bar should be set lower in terms of quality and customer experience. “We expect the majority of the take up for these containers to come from high-end delicatessens and takeaways simply because they are charging premium prices for top products and their customers expect that level of quality to extend to the packaging. Our aim, as a supplier, is to provide products that match all needs and expectations.” Call 0208 507 7900 or email sales@heraldplastic.com to order a copy of the catalogue. www.sandwich.org.uk I 49
