Isolation and risk assessment of Geotrichum spp. in the white shrimp (Litopenaeus vannamei Boone, 1931) from culture ponds

• Ochoa, José Luis ^[1] ; Ochoa-Alvarez, Norma ^[1] ; Guzmán-Murillo, Maria Antonia ^[1] ; Hernandez, Sergio ^[2] ; Ascencio, Felipe ^[1]
  1. [1] Centro de Investigaciones Biologicas del Noroeste
  2. [2] Centro Interdisciplinario de Ciencias Marinas (IPN)
• Localización: Latin American Journal of Aquatic Research, ISSN-e 0718-560X, ISSN 0716-1069, Vol. 43, Nº. 4, 2015, págs. 755-765
• Idioma: inglés
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• Resumen

  • The present study was done in order to identify the fungus invading some of the supralittoral ponds used for shrimp aquaculture in the CIBNOR facilities in La Paz, Baja California Sur (BCS), México during the summer season. From the walls and bottoms of the ponds, two strains of Geotrichum spp. were isolated and morphologically identified. Fungal adhesion towards hemocytes and primary cultures of various white 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 postlarvae (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 this fungus provokes great mortality of post-larvae. Hence, Geotrichum spp. could be considered an opportunistic pathogen that might represent a serious health risk to shrimp in culture.