amount of histamine (Table 1). Detection of BA-producing bacteria
by conventional culture technique is often tedious and unreliable.
Early and accurate detection of BA-producing bacteria is important
for preventing BA accumulation in food. On the other hand, it is
more important to find a good correlation between histamine production
and presence of hdcA gene. To reveal this relation all isolates
were scanned using a set of primers (hdc3F and hdc4R).
Only 13 isolates tested positive for hdcA gene (Fig. 3), while PCR
bands were not detected for some isolates producing histamine.
Histamine production was seen large-scale (Figs. 1 and 2) and similar
variation was seen in positive PCR colonies production. The
present molecular studies showed poor correlation between histamine
production and presence of hdcA gene. So histamine production
was not controlled by only hdcA gene. Some other gene(s)
could take part in histamine production