Enterococcus faecium M7AN10 probiótico em matriz alimentar para cães / Enterococcus faecium M7AN10 probiotic in food matrix for dogs / Enterococcus faecium M7AN10 probiótico en matriz alimentaria para perros

Probióticos são capazes de melhorar o equilíbrio da microbiota intestinal, trazendo benefícios ao hospedeiro. Atualmente no mercado há poucas opções de alimentos, com probióticos em sua composição, destinados a cães e gatos. Portanto, o objetivo deste trabalho foi desenvolver uma matriz alimentar canina (ração úmida) com o probiótico Enterococcus faecium M7AN10. Para tal, avaliou-se a inocuidade, atividade enzimática, atividade antimicrobiana, potencial probiótico e a viabilidade do microrganismo em matriz alimentar canina. O isolado foi considerado inócuo, pois apresentou ausência de atividade hemolítica e de gelatinase, além de ser suscetível a diversos antimicrobianos. E. faecium M7AN10 apresentou atividade proteolítica e capacidade de produção de exoplissacarídeo. Em relação a atividade antimicrobiana pelo método da estria radial, o isolado inibiu Acinetobacter sp. 1, Corynebacterium sp. 4, Micrococcus luteus 33, Micrococcus luteus 43, Micrococcus sp. 3, Micrococcus sp. 20, Micrococcus sp. 36. Além disso, E. faecium M7AN10 apresentou capacidade de autoagregação de 33,50% e resistiu de forma constante quando submetido ao trato gastrointestinal in vitro em conjunto com Lacticaseibacillus rhamnosus LB 1.5 e Lacticaseibacillus paracasei LB 6.4. O cultivo misto manteve-se viável em matriz alimentar canina durante o período de oito dias. Com base nesses resultados, o isolado E. faecium M7AN10 foi considerada uma bactéria candidata a probiótico que pode vir a ser usada como aditivo em alimento para cães.

Probiotics are capable of improving the balance of the intestinal microbiota, bringing benefits to the host. Currently, on the market, there are few food options with probiotics in their composition intended for dogs and cats. Therefore, this research aimed to develop a canine food matrix (wet food) with the probiotic Enterococcus faecium M7AN10. To this end, the harmlessness, enzymatic activity, antimicrobial activity, probiotic potential, and viability of the microorganism in the canine food matrix were evaluated. The isolate was considered harmless, as it showed no hemolytic and gelatinase activity and was susceptible to several antimicrobials. E. faecium M7AN10 showed proteolytic activity and exopolysaccharide production capacity. Regarding antimicrobial activity using the radial stria method, the isolate inhibited Acinetobacter sp. 1, Corynebacterium sp. 4, Micrococcus luteus 33, Micrococcus luteus 43, Micrococcus sp. 3, Micrococcus sp. 20, Micrococcus sp. 36. Furthermore, E. faecium M7AN10 showed a self-aggregation capacity of 33.50% and resisted consistently when subjected to the gastrointestinal tract in vitro together with Lacticaseibacillus rhamnosus LB 1.5 and Lacticaseibacillus paracasei LB 6.4. The mixed culture remained viable in a canine food matrix over eight days. Based on these results, the isolate E. faecium M7AN10 was considered a candidate bacterium for a probiotic that could be used as an additive in dog food.

Los probióticos son capaces de mejorar el equilibrio de la microbiota intestinal, aportando beneficios al huésped. Actualmente en el mercado existen pocas opciones de alimentos con probióticos en su composición, destinados a perros y gatos. Por lo tanto, el objetivo de este trabajo fue desarrollar una matriz alimentaria canina (comida húmeda) con el probiótico Enterococcus faecium M7AN10. Para ello se evaluó la inocuidad, actividad enzimática, actividad antimicrobiana, potencial probiótico y viabilidad del microorganismo en matriz alimentaria canina. El aislado fue considerado inofensivo, ya que no mostró actividad hemolítica ni gelatinasa, además de ser susceptible a varios antimicrobianos. E. faecium M7AN10 mostró actividad proteolítica y capacidad de producción de exoplisacáridos. En cuanto a la actividad antimicrobiana mediante el método de las estrías radiales, el aislado inhibió a Acinetobacter sp. 1, Corynebacterium sp. 4, Micrococcus luteus 33, Micrococcus luteus 43, Micrococcus sp. 3, Micrococcus sp. 20, Micrococcus sp. 36. Además, E. faecium M7AN10 mostró una capacidad de autoagregación del 33,50% y resistió consistentemente cuando se sometió al tracto gastrointestinal in vitro junto con Lacticaseibacillus rhamnosus LB 1.5 y Lacticaseibacillus paracasei LB 6.4. El cultivo mixto permaneció viable en una matriz de alimento canino durante un período de ocho días. Con base en estos resultados, el aislado E. faecium M7AN10 se consideró una bacteria candidata para un probiótico que podría usarse como aditivo en la comida para perros.

Influence of the food matrix on dual-species biofilm of Listeria monocytogenes and Pseudomonas fluorescens

In the food industry, the formation of biofilms results in serious microbial recontamination problem. This work aimed to study Listeria sp. obtained from sliced products and food handling surfaces, for the preparation of food of animal origin to be consumed cold. Listeria monocytogenes, Listeria innocua and Listeria seeligeri were detected. In the evaluation of antibiotic susceptibility, the isolates were sensitive to ampicillin and penicillin, which were the main antibiotics used in treatment. The isolates showed the ability to form biofilm in microplate, in stainless steel and polypropylene surfaces, with a variation of sessile cells between 4.29±0.23 and 7.03±0.01 log10 CFU cm-2 in TSBYE. This ability was also observed in food matrix composed of UHT whole milk in mono-species cultivation and in associated cultivation of L. monocytogenes with Pseudomonas fluorescens. The application of sanitizers peracetic acid and sodium hypochlorite revealed efficiency in the eradication of adhered cells and biofilms formed in stainless steel surfaces. Therefore, Listeria sp. showed to be persistent and able to form biofilm in mono-species cultivation or associated with P. fluorescens, under different conditions. Taking these aspects into account, the need for proper hygiene in the food production process is highlighted in order to avoid risks to the consumers health.(AU)

Characterization of Lactic Acid Bacteria in Raw Buffalo Milk: a Screening for Novel Probiotic Candidates and Their Transcriptional Response to Acid Stress.

Lactic acid bacteria (LAB) are important microorganisms for the food industry due to their functional activity, as starters and potential probiotic strains. With that in mind, we explored the LAB diversity in raw buffalo milk, screening for novel potential probiotic strains. A total of 11 strains were identified by combination of MALDI-TOF and partial 16S rDNA sequencing and selected as potential probiotic candidates. Bacteria innocuity assessment was performed by determining antimicrobial susceptibility and the presence of virulence factors. Antagonism activity against Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes and Staphylococcus aureus was assessed, as well as milk proteolytic activity and exopolysaccharides production. Seven strains were identified as innocuous and two of them, Lactobacillus rhamnosus LB1.5 and Lactobacillus paracasei LB6.4 were selected for further probiotic potential analyses. Both strains demonstrated adhesion ability to Caco-2 cells, coaggregated with S. aureus and E. coli and maintained cell viability after gastrointestinal simulation in vitro, suggesting their probiotic potential. Furthermore, the transcriptional response of Lact. rhamnosus LB1.5 and Lact. paracasei LB6.4 to in vitro acid stress was assessed by RT-qPCR targeting seven genes related to adhesion, aggregation, stress tolerance, DNA repair and central metabolism. The association between the transcriptional responses and the maintenance of cell viability after gastrointestinal simulation highlights the genetic ability as probiotic of the two selected strains. Finally, we have concluded that Lact. rhamnosus LB1.5 and Lact. paracasei LB6.4 are important probiotic candidates to further in vivo studies.