It has been often described that classical methods may fail in
the detection of typical V. tapetis or that, although being detected
by indirect procedures (i.e. immunofluorescence), the pathogen
could not be isolated on culture media (Castro et al., 1992, 1995).
These facts can be explained by an antagonist relationship among
the clam microbiota (Castro et al., 2002) or by the inhibitory activity
and/or overgrowth of other easy-growing bacteria, as was demonstrated
in an experimental challenge carried out by Drummond
et al. (2007), which obtained 43 positive results by PCR vs. only
three reisolations from experimentally inoculated clams. This result
highlights the difficulty for the isolation of this pathogen.