Congresso Brasileiro de Microbiologia 2023

Congresso Brasileiro de Microbiologia 2023

Resumo: 345-1

345-1

CAN LACTIC ACID BACTERIA ACT AS PROBIOTIC ALTERNATIVES IN AQUACULTURE? EVALUATION OF PROBIOTIC PROPERTIES AND SAFETY OF LAB ISOLATES

Autores:

Angélica Liberalino da Silva (UFRPE - UNIVERSIDADE FEDERAL RURAL DE PERNAMBUCO, UNIVASF - UNIVERSIDADE FEDERAL DO VALE DO SÃO FRANCISCO) ; Felipe dos Santos Alencar (UNIVASF - UNIVERSIDADE FEDERAL DO VALE DO SÃO FRANCISCO) ; Renata Farias Silva Souza (UNIVASF - UNIVERSIDADE FEDERAL DO VALE DO SÃO FRANCISCO) ; Mariana Alves Andrade (UNIVASF - UNIVERSIDADE FEDERAL DO VALE DO SÃO FRANCISCO) ; Milenna Alves dos Santos (UNIVASF - UNIVERSIDADE FEDERAL DO VALE DO SÃO FRANCISCO) ; Isabelly Dálete Ferreira Ribeiro (UNIVASF - UNIVERSIDADE FEDERAL DO VALE DO SÃO FRANCISCO) ; Vasco Ariston de Carvalho Azevedo (UFMG - UNIVERSIDADE FEDERAL DE MINAS GERAIS) ; Mateus Matiuzzi da Costa (UNIVASF - UNIVERSIDADE FEDERAL DO VALE DO SÃO FRANCISCO, UFRPE - UNIVERSIDADE FEDERAL RURAL DE PERNAMBUCO)

Resumo:

Probiotics are groups of microorganisms that provide benefits to their hosts when administered in correct quantities. In aquaculture, they can be used to enhance performance, immune response, and resistance to pathogens, serving as an alternative to antimicrobial use. Therefore, this study aimed to evaluate, through in vitro and in silico tests, the probiotic properties and safety characteristics of Lactic Acid Bacteria (LAB) isolates as a potential means of controlling bacterial diseases in fish. Two isolates, Lb CNRZ327 and Lc NCDO2118, were cultured in MRS and m17 media, respectively, under specific conditions for each one. The autoaggregation assay was conducted using spectrophotometry; similarly, the coaggregation assay was performed, testing the coaggregation potential of the isolates with Edwardsiella tarda, Plesiomonas shigelloides, Aeromonas hydrophila, and Streptococcus agalactiae strains. Concurrently, hydrophobicity was determined using two solvents: xylene and n-hexane (nonpolar solvents). Additionally, hemolytic activity and DNase production were evaluated by incubating the bacteria in deoxyribonuclease agar medium for 48 hours; meanwhile, the prediction of adhesion-related genes was conducted using the SPAAN software. However, both isolates exhibited low autoaggregation capacity, reaching approximately 15% after 4 hours of incubation. In coaggregation, Lb CNRZ327 demonstrated greater capacity with A. hydrophila isolates, while Lc NCDO2118 showed lower coaggregation ability. Both isolates were considered hydrophilic, adhering poorly to the tested solvents. However, regarding bacterial adhesion potential, in silico analysis revealed the presence of adhesion related genes in both isolates. Confirming their non-pathogenicity, no hemolytic activity or DNase production was identified in the tested bacteria. Even though both exhibited low autoaggregation, possibly linked to their specific characteristics, the ability of coaggregation with Aeromonas hydrophila suggests a probiotic potential for controlling these important potentially pathogenic bacteria. It is noteworthy that despite the low hydrophobicity, strong host-cell attachment remains possible for the tested microorganisms. Moreover, in silico analysis indicated a high probability of adhesion-related genes in both isolates, while the absence of hemolytic activity and DNase production proved their safety. Therefore, these results suggest that Lc NCDO2118 and Lb CNRZ327 have probiotic potential, although further studies are necessary for better characterization and in vivo effects analysis.

Palavras-chave:

Antibiotic alternative, Fish pathogens, in silico analysis, Lactobacillus delbrueckii, Lactococcus lactis

Agência de fomento:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), e Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE)