MARINE STRAIN LACTOBACILLUS PENTOSUS H16 PROTECTS ARTEMIA FRANCISCANA FROM VIBRIO ALGINOLYTICUS PATHOGENIC EFFECTS

MARISA GARCÉS; CYNTHIA SEQUEIROS; MELANIA FERNÁNDEZ; NELDA LILA OLIVERA

Mar del Plata

Congreso; X Congreso Argentino de Microbiología General SAMIGE; 2014

SAMIGE

Diseases caused by Vibrio spp. are commonly implicated in episodes of mortality in mariculture,particularly at the larval phases. In aquaculture, bacterial diseases have habitually been controlled using antibiotics. This practice may lead to the emergence of multiresistant strains, causing serious sanitary concerns. Currently, probiotics have been considered to prevent bacterial infections. Probiotics are microorganisms or their products that when administered via the feed or to the rearing water improve the host condition by providing both a nutritional benefit and protection against pathogens. In a previous work, we demostrated in vitro probiotic properties of Lactobacillus pentosus H16 which included production of antimicrobial compounds against the fish pathogen Vibrio alginolyticus, high adhesion to fish mucus and the capability to inhibit V. alginolyticus adhesion to fish mucus. Furthermore, H16 successfully bioencapsulated in Artemia franciscana nauplii. The aim of this study was to assess in vivo H16 probiotic capability. Two challenge experiments using A. franciscana nauplii infected with V. alginolyticus were performed. Bacteria-free nauplii were distributed at a density of 100 nauplii per vessel containing 100 ml of sterile seawater. In both experiments, 3 uninfected units were used as controls. In the first experiment, each treatment included 3 vessels containing bacteria-free nauplii and 1) H16 (4.6 E+05 CFU/ml), 2) V. alginolyticus (5.3 E+05 CFU/ml), and 3) H16 and V. alginolyticus simultaneously co-inoculated at those concentrations. After 48h of incubation, the nauplii survival rate was recorded. The second experiment was similar to the first except that in 3) H16 was inoculated at the beginning of the experiment and V. alginolyticus after 24h of incubation. After 72h of incubation, the nauplii survival rate was recorded. Our results showed that H16 protects the nauplii against Vibrio infection only when it was administrated previously to V. alginolyticus inoculation. Probably, an early addition of H16 allowed the colonization of Artemia nauplii, and consequently the inhibition of V. alginolyticus. The probiotic properties of L.pentosus H16, its capability of outcompete with V. alginolyticus in vivo and its successful bioencapsulation in a live carrier such as Artemia for administration to marine fish and crustacean larvaes, make this strain an interesting alternative for the prevention of vibriosis in mariculture.