Hygiena International Ltd has further developed their highly successful ATP bioluminescence system to specifically measure bacterial contamination, giving results within a working day or shift.
The development involves their low cost but highly sensitive EnSURE hand-held luminometer, combined with their new versatile MicroSnap Total test. This system enumerates bacteria in raw, cooked and liquid foodstuffs as well as on solid surfaces such that results are available in seven hours or less. The system has been successfully launched at the IAFP (International Association of Food Protection) in Europe and USA as well as the Food Safety Management Conference (Chipping Campden, July 2012).
Picture caption: The Hygiena International EnSURE hand-held luminometer, together with samplers, which can provide bacterial counts within seven hours or within a normal day shift period.
Established laboratory-based procedures to measure bacterial contamination of foodstuffs can prove to be a lengthy and costly process. The common microbiology test for establishing total bacteria (Total Viable Count , or Aerobic Plate Counts) require laboratory incubation for 3 days in a Petri dish after which colonies are counted to give results expressed at colony forming units (CFU). The optimum number of bacterial colonies to be counted on an agar plate is 30 –300, thus several decimal dilutions are required to find the detectable range. This means that a lot of time, labour and expense is required for sample preparation and testing. The established convention assumes that one colony is desired from a single bacterium which is a gross over-simplification such that the results obtained are imprecise. Automated systems have been developed to process hundreds of samples but these have a high capital cost and those offering rapid detection systems require measurements to be made over 12 -18 hours such that results are not available until the next day.
The Hygiena MicroSnap Total bioluminogenic test system has a large dynamic range, being able to detect 10 – 10,000 bacteria without the need for serial dilutions, and every viable bacterium in the sample is measured. Accordingly the result is more precise and sample preparation is simpler, thus saving time and labour. MicroSnap requires simple, low cost equipment and being totally mobile, it can be successfully utilised in small remote locations.
MicroSnap Total can be used to test almost any sample and has been used to measure contamination in a wide variety of food types and on solid surfaces. Contamination levels of <10 cfu/g of ground beef were detected in seven hours whereas >10,000 cfu/g were identified within only 4 hours. Similar results were also obtained for a variety of ready-to-eat foods and good correlations were obtained with the plate count.
For the first time, ATP technology has been modified to be independent of ATP in the sample, such that many specific test applications can be developed, and all of which can be performed on the same, low cost, portable instrument (EnSURE).
This multiple test platform includes specific tests to measure bacterial contamination including specific indicator and pathogenic bacteria. The MicroSnap range includes tests for Total Counts, Coliforms and E. coli. Tests for Listeria species, L. monocytogenes, and Staph. aureus as well as its antibiotic resistant forms are also in development. The ZymoSnap range detects enzymes of industrial importance such as phosphatases for dairy and meat products, proteases, lipases and amylase giving results in minutes. SuperSnap is a high-sensitivity surface hygiene test giving results within 15 seconds, that is used as part of an allergen management program together with a high sensitivity protein test (AllerSnap).