PROBIOTIC POTENTIAL OF Bacillus cereus AGAINST Vibrio spp. IN POST-LARVAE SHRIMPS

Abstract

-Bacillus spp. have been used against diseases caused by bacteria that affect cultured shrimp, providing beneficial effects on the host shrimps by altering their microbial community, and improving zootechnical indexes. The objective of this work was to evaluate the effects of a diet supplemented with Bacillus cereus-a bacterium with probiotic potential-on post-larvae Litopenaeus vannamei shrimps grown in laboratory. The experiment lasted for fifteen days and consisted of six treatments-control (T 1 ), probiotic (T 2 ), Vibrio parahaemolyticus (VP) (T 3 ), probiotic and VP (T 4 ), V. alginolyticus (VA) (T 5 ), and probiotic and VA (T 6 ). The survival rate, weight gain, colonization capacity of the probiotic bacteria, pathogen count, and histopathological lesions were evaluated. There was no significant difference (p≥0.05) in survival between treatments. The groups with pathogens and without probiotics presented lower weight gain. The result of the Bacillus cereus count in the treatments T 2 , T 4 and T 6 were significantly different (p<0.05), the probiotic bacteria were more aggressive in competing for space and nutrients when compared to V. parahaemolyticus than when compared to V. alginolyticus. Animals fed with the probiotic presented lower counts of these pathogens than those fed without the probiotic (p<0.05). No histopathological lesions were found in the organs and tissues of the shrimps. Bacillus cereus showed a high colonizing capacity in post-larvae shrimps, causing a significant reduction of pathogens, probably by secreting antimicrobial substances and the competitive exclusion, which justifies their use as probiotic bacteria.Keywords: Litopenaeus vannamei. Antimicrobial. Bacillus cereus. Vibriosis. AVALIAÇÃO DE POTENCIAL PROBIÓTICO FRENTE À INFECÇÃO EXPERIMENTAL POR VÍBRIOS EM PÓS-LARVAS DE CAMARÃO MARINHORESUMO -Bacillus spp. têm sido utilizados contra bacterioses que acometem camarão marinho cultivado, proporcionando efeito benéfico sobre o hospedeiro, alterando a comunidade microbiana intestinal e melhorando índices zootécnicos. O objetivo deste trabalho foi avaliar os efeitos de uma dieta suplementada com Bacillus cereus, bactéria com potencial probiótico em pós-larvas de Litopenaeus vannamei cultivados em laboratório. O experimento teve duração de quinze dias e consistiu de seis tratamentos: T 1 controle; T 2 somente com probiótico; T 3 com Vibrio parahaemolyticus (VP); T 4 com probiótico e com VP; T 5 com V. alginolyticus (VA); e T 6 com probiótico e com VA. Foram avaliados a sobrevivência, o ganho de peso, a capacidade de colonização das bactérias probióticas, contagem de patógenos e lesões histopatológicas. Não foi verificada diferença significativa (P≥0,05) entre os tratamentos na sobrevivência. Os grupos desafiados com patógenos e sem uso de probióticos foram os que apresentaram menor ganho de peso. Na contagem de Bacillus cereus, houve diferença significativa (P<0,05) entre os tratamentos T 2, T 4 e T 6 , observando-se que o probiótico competiu melhor por espaço e nutrientes quand...

Marine sponge-associated bacteria as biocontrol agents of vibriosis on whiteleg shrimp caused by Vibrio parahaemolyticus

“…These isolate probably synthesis different anti-Vibrio compounds which give different effects on shrimp survival rate, as well as indicating a high diversity of anti-Vibrio compounds produced by these sponge-associated bacteria. Supporting this result, the shrimp fed with probiotics Bacillus cereus exhibited a higher survival rate (51.48 ± 16.51%) compared to untreated shrimps (53.01 ± 8.48%), as reported by Vidal et al (2018). Another study also reported that spongeassociated bacteria could enhance shrimps survival rate ranging 70-90%, higher than the positive control which is only inoculated with V. harveyi (38.3±2.9%) (Rini et al 2017).…”

Vibriosis Outbreaks in Aquaculture: Addressing Environmental and Public Health Concerns and Preventive Therapies Using Gilthead Seabream Farming as a Model System

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“…Their use in aquaculture systems such as the BFT and aquamimicry also improves the zootechnical process of the system (De Melo et al, 2015). Probiotics are living microorganisms that are added to the aquaculture environment through food or water to exert beneficial effects on the host health and its growth performance by modulating the guts' microflora (Balcázar et al, 2006;Merrifield et al, 2010;Dawood et al, 2016Dawood et al, , 2018Vidal et al, 2018). The use of probiotics in aquaculture is a suitable alternative to therapeutics for controlling occurrences of infectious diseases and they can contribute to improve water quality (Liu et al, 2010;Jahangiri and Esteban, 2018;Biswas et al, 2019;Nathanailides et al, 2021).…”

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