Effect of Candidate Probiotic Yeast Kodamaea ohmeri and Candida parapsilosis on Growth Performance and Resistance of Whiteleg Shrimp (Litopenaeus vannamei) against Vibrio parahaemolyticus Infection

Abstract

Graphical Abstract Highlight Research Potential probiotic yeast non-Saccharomyces for the aquaculture sector has been explored. To the best of our knowledge, this is the first study to evaluate the potential of ohmeri as a candidate probiotic yeast in whiteleg shrimp under V. parahaemolyticus challenge. Effect of yeasts ohmeri and C. parapsilosis as growth promoters and immunostimulants against V. parahaemolyticus infection in whiteleg shrimp has been revealed. K. ohmeri and C. parapsilosis improved growth performance and influenced hemocyte-related immune parameters in whiteleg shrimp following V. parahaemolyticus challenge.   Abstract Disease in shrimp aquaculture has been a serious problem that leads to reduced productivity and significant economic losses, one of which is caused by Vibrio parahaemolyticus. This pathogen causes acute hepatopancreatic necrosis disease (AHPND), resulting in high mortality in shrimp farming operations. The use of antibiotics for bacterial disease management in aquaculture has raised concerns regarding antimicrobial resistance and environmental impacts. In response, some countries have implemented restrictions or regulatory measures on the use of specific antimicrobial compounds in aquaculture.  Probiotics have become one of the preferred alternatives because of their effectiveness in preventing disease and their environmentally safe. This study evaluated the effects of administering the yeast probiotics candidate Kodamaea ohmeri and Candida parapsilosis on the growth performance and resistance of whiteleg shrimp challenged with V.parahaemolyticus. A total of 240 whiteleg shrimp (1.14±0.10 g, weight) were distributed into 12 glass aquaria (40×30×30cm, stocking density 1 individual/L), with three aquaria assigned to each treatment. The experiment used a completely randomized design with four treatments: positive control (PC), negative control (NC), K. ohmeri probiotic candidate (KO), and C. parapsilosis probiotic candidate (CP), each with three replicates. The candidate probiotics were administered at a dose of 106 CFU/mL every morning for 30 days, after which a challenge test was conducted by immersion in V. parahaemolyticus RifR at a density of 105 CFU/mL for 7 days, except for the negative control. The results showed that administration of the candidate probiotic K. ohmeri resulted in significantly better growth performance (p<0.05) and a greater reduction in total vibrio count and total V.parahaemolyticus RifR count than other treatment. In addition, K. ohmeri produced significant increase in total hemocyte count, differential hemocyte count, and survival rate than the other treatments (p<0.05) after the challenge period. In conclusion, the candidate probiotic yeast K. ohmeri significantly improved growth performance and increased survival of whiteleg shrimp following V. parahaemolyticus infection under the experimental aquarium conditions tested.