ISO 6579-4:2025

This document specifies a horizontal in vitro method for the molecular identification and differentiation of the monophasic variant of Salmonella enterica subsp. enterica serovar Typhimurium (1,4,[5],12:i:-) lacking the second H phase H:1,2, starting from isolates. The method detects specific DNA sequences of an intergenic region of the first H phase flagellin cluster for identification of Salmonella enterica subsp. enterica serovar Typhimurium (further called Salmonella Typhimurium) and specific DNA sequences of genes associated with second H phase flagellar antigen expression. The method is applicable for: — differentiation of the isolate under analysis between monophasic Salmonella Typhimurium and the monophasic variant of another Salmonella non-Typhimurium serovar that has the same antigenic formula; — identification of the isolate under analysis being either monophasic Salmonella Typhimurium or (biphasic) Salmonella Typhimurium. This document is applicable for the analysis of a pure culture belonging to the genus Salmonella, isolated from: — products intended for human consumption; — products intended for animal feeding; — environmental samples in the area of food and feed production and handling; — samples from the primary production stage. This document can also be applied in other domains for identification of monophasic Salmonella Typhimurium (e.g. environmental, human health, animal health). NOTE This method has been validated in a method evaluation study and in an interlaboratory study with a large set of different strains (target and non-target strains), isolated from different sources (food products, animals, animal feed, primary production samples and humans). For detailed information on the validation, see Annex E.