Identification by means of molecular tools of the microbiota responsible for the formation of histamine accumulated in commercial cheeses in Spain

Histamine intoxication is an important food safety and public health concern. Ripened cheeses are the most common dairy products in which histamine can accumulate. formed by microbiota present cheese decarboxylation of histidine, due to action histidine decarboxylase. This study's objective was identify responsible for formation accumulated commercial cheeses. The content 39 different types marketed Spain, varying milk origin, assessed. About one third analysed contained more than 200 mg/kg histamine; two exceeded 500 histamine, consumption such be harmful or even toxic consumers. five with highest concentrations were selected in-depth molecular analysis. Firstly, bacterial yeast isolates obtained, then total genetic material from analysed, order verify putative presence hdc decarboxylase gene. In producing microorganisms, nucleotide sequences genes amplified, subjected them Sanger sequencing. four cheeses, main producer identified as Lentilactobacillus parabuchneri, whereas remaining it Tetragenococcus halophilus. gene located unstable plasmid, only that sample. Since all microorganisms this study not part species used starter cultures, improvement hygienic manufacturing practices and/or thermal treatments microbial inactivation may considered prevent accumulation during ripening.