Evaluation of different culture media for the isolation and growth of the fastidious Vibrio tapetis, the causative agent of brown ring disease

Thirteen culture media were evaluated at two temperatures for the growth and isolation of Vibrio tapetis. The bacterium showed similar growth dynamics at 15 °C or 25 °C, being faster at 15 °C regardless the general media employed. Best growth of V. tapetis was obtained on Agar Seawater (ASWT) (1.7 × 106 cfu/ml), Mannitol Marine Agar (MMA) (2.6 × 106 cfu/ml), and Mannitol Trypticase Soy Agar (MTSA-1) (1.9 × 106 cfu/ml), being slightly lower on Marine Agar (MA) (5.0 × 105 cfu/ml). Growth was poor on TCBS and nule in the other media containing bile salts, indicating their inhibitory effect on the V. tapetis growth. Recovery of V. tapetis from mixed Vibrio populations, differing in acid production from sucrose and mannitol, was only possible using the selective medium MMA at both temperatures. The use of ASWT or MA at 15 °C for the routinary growth of V. tapetis, and MMA for isolation of V. tapetis from bivalve samples is recommended.

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► We evaluate the efficacy of 13 different media for growth and isolation of V. tapetis.
► Best growth of V. tapetis is obtained on MA and ASWT at 15 °C.
► Only MMA allows discrimination of typical V. tapetis strains from mixed populations.
► Bile salts inhibit the growth of the pathogen on selective media.