Naturvetenskap och tillämpad vetenskap

Detta är ett tillägg till SS-EN ISO 18744:2016.

This document specifies a method for the enumeration of culturable microorganisms in water by counting the colonies on a low-nutrient agar culture medium after incubation at 22 °C for 7 d. The method is intended to measure the operational efficiency of the treatment process of public drinking water supplies, including the water in distribution systems and containers. The method is particularly suitable to monitor water for human consumption which is low in nutrients and is distributed in temperatures below 20 °C. The method can be applied to all types of water, including pool and spa waters. NOTE 1 The low-nutrient agar in use in this document usually gives higher colony counts from water samples than nutrient-rich formulations of culture media typically used for enumeration of culturable microorganisms. NOTE 2 The method is also applicable for waters of very low nutrient content such as de-ionised, distilled or reverse osmosis waters. NOTE 3 This document describes the use of R2A medium. There are other formulations available, e.g. R3A medium that might be suitable for certain applications but go beyond the scope of this document.

This document specifies the general requirements and provides guidance for the development and application of loop-mediated isothermal amplification (LAMP) to detect microorganisms and associated genetic markers (e.g. antimicrobial resistance genes, virulence genes) in the food chain. This document is applicable to all LAMP methods, platforms, items from food chain and laboratories. The use of LAMP for quantification is out of scope for this document.

Validation and verification of LAMP methods as either alternative or reference methods are not covered in this document. Both validation and verification of microbiological methods are discussed in detail in the ISO 16140 series and ISO 17468.

General requirements for isothermal methods including LAMP for molecular biomarker analysis are covered by ISO 22942-1, and general requirements and definitions for polymerase chain reaction (PCR) for the detection and quantification of microorganisms in the food chain are covered by ISO 22174. This document has been established for microorganisms in the food chain and is applicable to:

— products intended for human consumption;

— products for feeding animals;

— environmental samples in the area of food and feed production and handling;

— samples from the primary production stage for the above items.