The production of cultured black pearls from Pinctada margaritifera is a major economic sector for French Polynesia. To form a pearl, a fragment of mantle tissue is inserted to create a pearl sac around the nucleus, allowing successive layers of nacre to be secreted.

Despite the overall success of this technique, many failures still occur, mainly due to post-operative mortalities and nucleus rejection. This study aimed to evaluate the effects of an antiseptic treatment on these phenomena.

Effects of Antiseptic Treatments

The results show that the use of an antiseptic during grafting had no significant impact on mortality or nucleus rejection rates.

However, the antiseptic proved very effective at reducing bacterial load in the pearl sac. Two main bacterial strains were isolated after nucleus insertion: one similar to Vibrio harveyi and the other differing by only one phenotypic characteristic from V. alginolyticus.

Towards Improved Practices

These observations suggest that a rigorous improvement of hygiene conditions during the incision could significantly reduce bacterial contamination.

Researchers plan to continue their work to confirm whether these bacterial strains play a role in oyster mortality or nucleus rejection linked to post-operative infections.