Isolation and typification of histamine-producing Lactobacillus vaginalis
strains from cheese
In food, the biogenic amine (BA) histamine is mainly produced by histidine decarboxylation catalysed by
microbial histidine decarboxylase. The consumption of foods containing high concentrations of histamine can
trigger adverse neurological, gastrointestinal and respiratory reactions. Indeed, histamine is one of the most
toxic of all BAs, and is often detected in high concentration in cheese. However, little is known about the
microorganisms responsible for its accumulation in this food. In the present work, 25 histamine-producing
Lactobacillus vaginalis strains were isolated from a blue-veined cheese (the first time that histamine-producing
strains of this species have been isolated from any food). The restriction profiles of their genomes were analysed
by PFGE, and seven lineages identified. The presence of the histidine decarboxylase gene (hdcA) was confirmed
by PCR. The nucleotide sequence and genetic organisation of the histamine biosynthesis gene cluster (HDC) and
its flanking regions are described for a representative strain (L. vaginalis IPLA11050).