Pseudomonas sp. M174 inhibits the fish pathogen Flavobacterium psychrophilum

Abstract

Aims: To study the antagonic affect of probiotic Pseudomonas M174 on the fish pathogen Flavobacterium psychrophilum. Methods and Results: The ability of Pseudomonas M174 to inhibit the growth of Fl. psychrophilum was examined in iron‐sufficient and ‐deficient media. Possible siderophore production was also investigated. Antagonistic activity was confirmed in disease challenge experiments using a rainbow trout (Oncorhynchus mykiss) model. Adhesion of Pseudomonas M174 to fish surfaces and its ability to stimulate innate immunity was also investigated in vivo. Pseudomonas M174 antagonized Fl. psychrophilum and produced siderophores in vitro. In challenge experiments with Fl. psychrophilum, fish fed with Pseudomonas M174 had lower levels of mortalities than the controls. It was possible to find Pseudomonas M174 in the intestinal content of these fish after feeding and bathing with the probiotic, but probiotic was obtained from the gills only after feeding. Respiratory burst activity was also found to be enhanced in the M174 fed fish. Conclusions: These results suggest that M174 is a potential probiotic against Fl. psychrophilum and has several modes of action. Significance and Impact of the Study: Probiotics are a promising alternative to the use of antibiotics in aquaculture and could be a more sustainable disease control method.

Protective Effect of Pseudomonas Fluorescens as a Probiotic in Controlling Fish Pathogens

“…Another probability, It also may stimulate the appetite and improve nutrition through vitamins production, detoxification of injurious compounds in the diet, and breakdown of indigestible components [14]. As companion, siderophore production is also a possible action used by Pseudomonas to counteract and constrain pathogens involved in plant diseases [43], in fish, rainbow trout [24] and it was concluded by that pathogens with potential low iron uptake should be more influenced with siderophore assembly of the probiotic used against them.…”

“…In particular, innate immunity has been shown to be affected by feeding fish with probiotic [15]. Non-pathogenic pseudomonas can be used for control of some bacterial pathogens [2] in vivo and in vitro antibacterial activity against Aeromonas hydrophila [16,17,18], Aeromonas salmonicida [19], Staphylococcus aureus and Aeromonas sobria [20], Saprolegnia and other fungi [21,22], Vibrio [23] and Flavobacterium psychrophilum [24].…”

Characterization of culturable bacterial flora in yolk sac larvae of Atlantic halibut (Hippoglossus hippoglossus L.) with

“…Pseudomonas is also present in normal flora and is capable of producing active compounds. This bacterial genus is present in normal probiotic bacterial flora due to their ability to adhere and colonize the surface of tissues, forming a barrier against pathogenic bacteria (Kesarcodi-Watson et al, 2008;Korkea-aho et al, 2011).…”

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“…isolated from a brackish water lagoon showed significant probiotic activity against a number of shrimp pathogenic vibrios, while its safety in a mammalian system was also found satisfactory 27 . In another study, Korkea-aho et al 26 recorded lower levels of mortalities in fish fed first with Pseudomonas M174 and subsequently challenged with Flavobacterium psychrophilum.…”