Screening of New Potential Probiotics Strains against Photobacterium damselae Subsp. piscicida for Marine Aquaculture

Abstract

On intensive fish farms, 10% of the population dies exclusively from pathogens, and Photobacterium damselae subsp. Piscicida (Ph. damselae subsp. Piscicida), the bacteria causing pasteurellosis in marine aquaculture, is one of the major pathogens involved. The objective of this study was to obtain new probiotic strains against pasteurellosis in order to limit the use of chemotherapy, avoiding the environmental repercussions generated by the abusive use of these products. In this study, 122 strains were isolated from the gills and intestines of different marine fish species and were later evaluated in vitro to demonstrate the production of antagonistic effects, the production of antibacterial substances, adhesion and growth to mucus, resistance to bile and resistance to pH gradients, as well as its harmlessness and the dynamic of expression of immune-related genes by real-time PCR after administration of the potential probiotic in the fish diet. Only 1/122 strains showed excellent results to be considered as a potential probiotic strain and continue its characterization against Ph. damselae subsp. piscicida to determine its protective effect and elucidating in future studies its use as a possible probiotic strain for marine aquaculture.

Probiotic properties of Bacillus strains isolated from the gastrointestinal tract against pathogenic Vibriosis

“…In the current investigation, all selected stains were found to be susceptible to tested antibiotics demanded by EFSA. This result may ensure the inability and scarcity to transfer antibiotic resistance genes to gut bacteria, thus assuring their safety for aquaculture application (Gutieŕrez Falcoń et al, 2021). Regarding hydrolic enzymes and virulence factors, S17 did not show haemolytic activity (g-haemolytic), gelatinase production, and bile salt deconjugation.…”

“…Upon ingestion in GIT, probiotic strains have to attach to the border of microvilli or to the mucus to prevent the colon sweep. Cell adhesion is a complex process which involves contact between the membrane of bacterial cell and surface (Mbozo et al, 2017;Dutta et al, 2018;Rungsirivanich et al, 2020;Gutieŕrez Falcoń et al, 2021). In fact, many factors including electrostatic interactions, hydrophobicity, steric forces, components of the surface, pH of the milieu, and viscosity are involved (Balcaźar et al, 2008;Muñoz-Atienza et al, 2014;Chauhan and Singh, 2019).…”

Therapeutic Potential of Marine Probiotics: A Survey on the Anticancer and Antibacterial Effects of Pseudoalteromonas spp.

“…They also engage in the blockage of the pathogen's ability to utilize certain nutrients, prevention of their attachment to the host environment, distortion of the enzymatic activities of the pathogens, enhancement of the quality of water, stimulation of the immune system, and improvement of host nutrition. Marine probiotics are a promising source of novel bioactive compounds with anticancer, antibacterial, immunomodulatory, antioxidant, anti-inflammatory, and antiviral properties, as have been implicated in several studies [27,[32][33][34][35][36][37][38][39].…”

Administration of probiotics affects Artemia franciscana metanauplii intestinal ultrastructure and offers resistance against a Photobacterium damselae ssp. piscicida induced oxidative stress response

“…An effective and environmentally friendly approach to prevent fish diseases is the administration of probiotic bacteria with beneficial effects on the growth and pathogen resistance of the host organism as well as positive effects in water quality [12] , [13] , [14] . Probiotics are defined as “microbial supplements that affect beneficially the host animal by improving its health when consumed in adequate amounts” [ 15 , 16 ].…”

“…Probiotics are defined as “microbial supplements that affect beneficially the host animal by improving its health when consumed in adequate amounts” [ 15 , 16 ]. In aquaculture the employed probiotics include lactic acid bacteria (LAB) and strains of the genus Bacillus [17] , Vibrio and Pseudomonas [ 12 , [18] , [19] , [20] ]. Efficient delivery of probiotics to the target organism is performed using Artemia, the live fish and shrimp larvae food, as their vehicle [ 21 , 22 ].…”