Isolation and risk assessment of Geotrichum spp. at American white shrimp (Litopenaeus vannamei) from culture ponds

Jose-Luis Ochoa, Norma Ochoa-Alvarez, Maria Antonia Guzmán-Murillo, Sergio Hernández, Felipe Ascencio


DOI: https://doi.org/10.3856/vol43-issue4-fulltext-14

Abstract


  Our work was carried out in order to identify the molds invading some of the ponds used for shrimp aquaculture in the supralittoral zone of CIBNOR in La Paz, Baja California Sur (BCS), México during the summer season. From the walls and bottoms of the containers, two strains of Geotrichum spp. were isolated and morphologically identified. Fungal adhesion towards hemocytes and primary cultures of various shrimp (Litopeneaus vannamei) tissues (gill, tegument, and gut) was analyzed to determine infectivity. Extracellular protease, lipase, and amylase activity were evaluated as virulence factors. Survival of shrimp post-larvae (PL8) exposed to fungal culture supernatant or to their filaments was also investigated. The results showed that shrimp tegument cells and hemocytes were very susceptible to Geotrichum spp. invasion, and that these fungi provoke considerable mortality of  post-larvae. Hence, Geotrichum spp. could be considered an opportunistic pathogen that might represent a serious health risk to shrimp in culture.   

Ochoa J, Ochoa-Alvarez N, Guzmán-Murillo M, Hernández S, Ascencio F. Isolation and risk assessment of Geotrichum spp. at American white shrimp (Litopenaeus vannamei) from culture ponds. Lat. Am. J. Aquat. Res.. 2017;43(4). Available from: doi:10.3856/vol43-issue4-fulltext-14 [Accessed 22 Jan. 2019].
Ochoa, J., Ochoa-Alvarez, N., Guzmán-Murillo, M., Hernández, S., & Ascencio, F. (2017). Isolation and risk assessment of Geotrichum spp. at American white shrimp (Litopenaeus vannamei) from culture ponds. Latin American Journal of Aquatic Research, 43(4). doi:http://dx.doi.org/10.3856/vol43-issue4-fulltext-14