7 pages, 1 figure.-- PMID: 16960050 [PubMed].-- Copyright © American Dairy Science Association, 2006.Biogenic amines are toxic substances that appear in foods and beverages as a result of AA decarboxylation. The enzyme histidine decarboxylase catalyzes the decarboxylation of histidine to histamine, the biogenic amine most frequently involved in food poisoning. The aim of the present work was to develop a real-time quantitative PCR assay for the direct detection and quantification of histamine-producing strains in milk and cheese. A set of primers was designed, based on the histidine decarboxylase gene sequence of different gram-positive bacteria. The results show the proposed procedure to be a rapid (total processing time < 2 h), specific and highly sensitive technique for detecting potential histamine-producing strains. Chromatographic methods (HPLC) verified the capacity of real-time quantitative PCR to correctly quantify histamine accumulation.This work was supported by European Union research grant no. QRLT-2002-02388. D. M. Linares was the recipient of a fellowship from the Spanish Ministry of Education and Science. M. Fernández, B. del Río, and M. C. Martín are beneficiaries of I3P CSIC contracts financed by the European Social Fund.Peer reviewed