Characterization of a symbiotic beverage based on water-soluble soybean extract fermented by Lactiplantibacillus plantarum ATCC 8014.

The health benefits of functional foods are associated with consumer interest and have supported the growth of the market for these types of foods, with emphasis on the development of new formulations based on plant extracts. Therefore, the present study aimed to characterize a symbiotic preparation based on water-soluble soy extract, supplemented with inulin and xylitol and fermented by Lactiplantibacillus plantarum ATCC 8014. Regarding nutritional issues, the symbiotic formulation can be considered a source of fiber (2 g/100 mL) and proteins (2.6 g/100 mL), and it also has a low-fat content and low caloric value. This formulation, in terms of microbiological aspects, remained adequate to legal standards after storage for 60 days under refrigeration and also presented an adequate quantity of the aforementioned probiotic strain, corresponding to 9.11 Log CFU.mL-1. These viable L. plantarum cells proved to be resistant to simulated human gastrointestinal tract conditions, reaching the intestine at high cell concentrations of 7.95 Log CFU.mL-1 after 60 days of refrigeration. Regarding sensory evaluation, the formulation showed good acceptance, presenting an average overall impression score of 6.98, 5.98, and 5.16, for control samples stored for 30 and 60 days under refrigeration, respectively. These results demonstrate that water-soluble soy extract is a suitable matrix for fermentation involving L. plantarum ATCC 8014, supporting and providing data on the first steps towards the development of a symbiotic functional food, targeting consumers who have restrictions regarding the consumption of products of animal origin, diabetics, and individuals under calorie restrictions.

Recombinant probiotic Lactococcus lactis delivering P62 mitigates moderate colitis in mice.

Introduction and objective: p62 is a human multifunctional adaptor protein involved in key cellular processes such as tissue homeostasis, inflammation, and cancer. It acts as a negative regulator of inflammasome complexes. It may thus be considered a good candidate for therapeutic use in inflammatory bowel diseases (IBD), such as colitis. Probiotics, including recombinant probiotic strains producing or delivering therapeutic biomolecules to the host mucosal surfaces, could help prevent and mitigate chronic intestinal inflammation. The objective of the present study was to combine the intrinsic immunomodulatory properties of the probiotic Lactococcus lactis NCDO2118 with its ability to deliver health-promoting molecules to enhance its protective and preventive effects in the context of ulcerative colitis (UC). Material and methods: This study was realized in vivo in which mice were supplemented with the recombinant strain. The intestinal barrier function was analyzed by monitoring permeability, secretory IgA total levels, mucin expression, and tight junction genes. Its integrity was evaluated by histological analyses. Regarding inflammation, colonic cytokine levels, myeloperoxidase (MPO), and expression of key genes were monitored. The intestinal microbiota composition was investigated using 16S rRNA Gene Sequencing. Results and discussion: No protective effect of L. lactis NCDO2118 pExu:p62 was observed regarding mice clinical parameters compared to the L. lactis NCDO2118 pExu: empty. However, the recombinant strain, expressing p62, increased the goblet cell counts, upregulated Muc2 gene expression in the colon, and downregulated pro-inflammatory cytokines Tnf and Ifng when compared to L. lactis NCDO2118 pExu: empty and inflamed groups. This recombinant strain also decreased colonic MPO activity. No difference in the intestinal microbiota was observed between all treatments. Altogether, our results show that recombinant L. lactis NCDO2118 delivering p62 protein protected the intestinal mucosa and mitigated inflammatory damages caused by dextran sodium sulfate (DSS). We thus suggest that p62 may constitute part of a therapeutic approach targeting inflammation.

Gut Microbiome Changes Occurring with Norovirus Infection and Recovery in Infants Enrolled in a Longitudinal Birth Cohort in Leon, Nicaragua.

Noroviruses are associated with one fifth of diarrheal illnesses globally and are not yet preventable with vaccines. Little is known about the effects of norovirus infection on infant gut microbiome health, which has a demonstrated role in protecting hosts from pathogens and a possible role in oral vaccine performance. In this study, we characterized infant gut microbiome changes occurring with norovirus-associated acute gastroenteritis (AGE) and the extent of recovery. Metagenomic sequencing was performed on the stools of five infants participating in a longitudinal birth cohort study conducted in León, Nicaragua. Taxonomic and functional diversities of gut microbiomes were profiled at time points before, during, and after norovirus infection. Initially, the gut microbiomes resembled those of breastfeeding infants, rich in probiotic species. When disturbed by AGE, Gammaproteobacteria dominated, particularly Pseudomonas species. Alpha diversity increased but the genes involved in carbohydrate metabolism and glycan biosynthesis decreased. After the symptoms subsided, the gut microbiomes rebounded with their taxonomic and functional communities resembling those of the pre-infection microbiomes. In this study, during disruptive norovirus-associated AGE, the gut microbiome was temporarily altered, returning to a pre-infection composition a median of 58 days later. Our study provides new insights for developing probiotic treatments and furthering our understanding of the role that episodes of AGE have in shaping the infant gut microbiome, their long-term outcomes, and implications for oral vaccine effectiveness.

Comparison of probiotic Lactobacillus strains isolated from dairy and Iranian traditional food products with those from human source on intestinal microbiota using BALB/C mice model.

This study compares the probiotic Lactobacillus strains isolated from dairy and Iranian traditional food products with those from human sources on intestinal microbiota using BALB/C mice model. First, Lactiplantibacillus plantarum (M11), Limosilactobacillus fermentum (19SH), Lactobacillus acidophilus (AC2), and Lactobacillus gasseri (52b) strains, isolated from either Iranian traditionally fermented products or human (healthy woman vaginal secretions), identified with molecular methods and selected based on the surface hydrophobicity, auto- and co-aggregation, were investigated for their probiotic properties and compared with their standard probiotic strains in vitro. The native strains and their mixtures (MIX) were then orally fed to five groups of female inbred BALB/C mice over the course of 38 days by gavage at 0.5 and 4 McFarland, respectively, equal to 1.5 × 108 and 1 × 109 cfu/ml. Feeding paused for 6 days to test the bacteria's adhesion in vivo. According to the findings, the probiotic Lactobacillus strain isolated from human source (52b) exhibited the best in vitro and in vivo adhesion ability. Probiotic Lactobacillus strains isolated from Iranian traditional food products (19SH and AC2) had the most co-aggregation with Listeria monocytogenes (ATTC 7644), Salmonella enterica subsp. enterica (ATCC 13,076), and Escherichia coli (NCTC 12,900 O157:H7) in vitro. These strains produced the most profound decreasing effect on the mice intestinal microbiota and pathogens in vivo. The difference in the strains and their probiotic potential is related to the sources from which they are isolated as well as their cell walls. The results suggest that (19SH and 52b strains) are the best candidates to investigate the cell wall and its effect on the host immune system.

Survival of commercial probiotic strains and their effect on dark chocolate synbiotic snack with raspberry content during the storage and after simulated digestion

BACKGROUND: A key challenge for manufacturers of pro-health food containing active probiotic microorganisms is to develop a product with attractive sensory features along with maintenance of declared number of microorganisms during storage and transfer by alimentary tract. RESULTS: The highest concentration of polyphenols was observed in snacks without an additive of probiotics as well as those with an additive of L. rhamnosus and B. animalis bacteria and concentration of these compounds increased by 9.5% during six months of storage. None of the products distinguished itself in the sensorial assessment although each was assessed positively. The number of microorganisms was stable and comparatively high during six months of storage at a room temperature and in cooling conditions (108 cfu/g). In the digestion model, an influence of aggressive digestion conditions was examined in the alimentary tract on the number of microorganisms, which allowed to arrange strains from the most resistant (S. boulardii) to the most sensitive (B. breve). It must be noted that currently on the market there is no available snack containing probiotic yeast as well as there is no literature data on works on such formulation of food. CONCLUSIONS: In the newly developed snack made of chocolate, in which sugar has been replaced with maltitol, a raw material was added in the form of raspberry, prebiotic in the form of inulin and a strain of probiotic bacteria, including the unprecedented so far S. boulardii, which stands a high chance to occupy a good place on the market of functional food.

Hsp65-Producing Lactococcocus lactis Prevents Antigen-Induced Arthritis in Mice.

Oral tolerance is the physiological process that enables the immune system to differentiate between harmless dietary and microbiota antigens from pathogen derived antigens. It develops at the mucosal surfaces and can result in local and systemic regulatory and anti-inflammatory effects. Translation of these benefits to the clinical practice faces limitations involving specificity and doses of antigen as well as regimens of feeding. To circumvent these problems, we developed a recombinant Hsp65 delivered by the acid lactic bacteria Lactococcus lactis NCDO 2118 directy in the intestinal mucosa. Hsp65 is a ubiquitous protein overexpressed in inflamed tissues and capable of inducing immunoregulatory mechanisms. L. lactis has probiotic properties and is commonly and safely used in dairy products. In this study, we showed that continuous delivery of HSP65 in the gut mucosa by L. lactis is a potent tolerogenic stimulus inducing regulatory CD4+LAP+ T cells that prevented collagen-induced and methylated bovine serum albumin-induced arthritis in mice. Clinical and histological signs of arthritis were inhibited as well as levels of inflammatory cytokines such as IL-17 and IFN-γ, serum titers of anti-collagen antibodies and rheumatoid factor. Oral administration of L. lactis induced alterations in microbiota composition toward an increased abundance of anaerobic bacteria such as Bifidobacterium and Lactobacillus. Tolerance to HSP65 and arthritis prevention induced by the recombinant L. lactis was associated with increase in IL-10 production by B cells and it was dependent on LAP+ T cells, IL-10 and TLR2 signaling. Therefore, HSP65-producing treatment induced effective tolerance and prevented arthritis development suggesting it can be used as a therapeutic tool for autoimmune diseases.

What Differentiates Probiotic from Pathogenic Bacteria? The Genetic Mobility of Enterococcus faecium Offers New Molecular Insights.

Enterococcus faecium is a lactic acid bacterium with applications in food engineering and nutrigenomics, including as starter cultures in fermented foods. To differentiate the E. faecium probiotic from pathogenic bacteria, physiological analyses are often used but they do not guarantee that a bacterial strain is not pathogenic. We report here new findings and an approach based on comparison of the genetic mobility of (1) probiotic, (2) pathogenic, and (3) nonpathogenic and non-probiotic strains, so as to differentiate probiotics, and inform their safe use. The region of the 16S ribosomal DNA (rDNA) genes of different E. faecium strains native to Pernambuco-Brazil was used with the GenBank query sequence. Complete genomes were selected and divided into three groups as noted above to identify the mobile genetic elements (MGEs) (transposase, integrase, conjugative transposon protein and phage) and antibiotic resistance genes (ARGs), and to undertake pan-genome analysis and multiple genome alignment. Differences in the number of MGEs were found in ARGs, in the presence and absence of the genes that differentiate E. faecium probiotics and pathogenic bacteria genetically. Our data suggest that genetic mobility appears to be informative in differentiating between probiotic and pathogenic strains. While the present findings are not necessarily applicable to all probiotics, they offer novel molecular insights to guide future research in nutrigenomics, clinical medicine, and food engineering on new ways to differentiate pathogenic from probiotic bacteria.

Technological strategies ensuring the safe arrival of beneficial microorganisms to the gut: From food processing and storage to their passage through the gastrointestinal tract.

The development of functional foods containing probiotics has experienced a great boom in the last years, reflected by the increasing number of novel products available at the market, as well as by the well-documented extensive research, going beyond the traditional fermented dairy foods. However, to safe arrive to their target, the gut, microorganisms contained in food products have to overcome different barriers, both technological and physiological. Food processing might cause different types of damages on beneficial bacteria, which finally lead to a decrease of viability. In addition, once ingested, and before arriving to the gut, microorganisms are exposed to other food constituents, low pH and digestive juices, all of them constituting detrimental environments that can decrease their viability. For this reason, this review offers an updated state of the art on the microorganisms' response to the factors affecting their survival during drying techniques, storage and rehydration. Current strategies to overcome detrimental processing effects on bacterial viability are also reviewed, as well as the effect of food matrices on bacterial protection during food manufacturing and storage. The effect of probiotic microorganisms on the gut, and in particular on the intestinal microbiota is an issue of increasing interest in the last decades, and thus, special emphasis was put it on.

Novel milk-juice beverage with fermented sheep milk and strawberry (Fragaria × ananassa): Nutritional and functional characterization.

This study was aimed at developing a new functional fermented beverage manufactured with semi-skimmed sheep milk and strawberry pulp (Fragaria × ananassa Duch.) and commercial prebiotic ingredients. We also compared the performance of the yogurt starter cultures and a Lactobacillus plantarum strain (CECT_8328) with potential probiotic properties. We assessed the nutritional profile, bioactivity compounds, viability of lactic acid bacteria during storage, and survival of L. plantarum after in vitro simulated digestion during the storage period. The lactic acid bacteria were viable throughout the storage period, but only L. plantarum maintained good viability after simulated digestion. Nevertheless, neither inulin nor potato starch increased bacterial viability. The fermented semi-skimmed sheep milk strawberry beverages we developed are good sources of minerals and proteins.

Resveratrol protects Lactobacillus reuteri against H2O2- induced oxidative stress and stimulates antioxidant defenses through upregulation of the dhaT gene.

Understanding of the mechanisms implicated in the protective role of probiotic bacteria is of the utmost scientific interest. This study provides original insight into the genetic and molecular basis of the responses of Lactobacillus reuteri PL503 against hydrogen peroxide (H2O2)-induced oxidative stress. Six experimental groups were considered depending on the addition and concentration of H2O2 and resveratrol: 1. CONTROL (L. reuteri in MRS broth); 2. H2O2 (L. reuteri in MRS broth + 0.5 mM H2O2); 3. LRES (L. reuteri in MRS broth + 20 µM resveratrol); 4. HRES (L. reuteri in MRS broth + 100 µM resveratrol); 5. H2O2-LRES (L. reuteri in MRS broth + 0.5 mM H2O2 + 20 µM resveratrol); 6. H2O2-HRES (L. reuteri in MRS broth + 0.5 mM H2O2 + 100 µM resveratrol). Three replicates were incubated at 37 °C for 24 h in microaerophilic conditions sampled at 12, 16, 20 and 24 h. The NADH-dependent-oxidoreductase encoded by the dhaT gene is a plausible candidate to be strongly implicated in the antioxidant response of L. reuteri. Resveratrol (100 µM) is found to protect L. reuteri against protein carbonylation plausibly through various mechanisms including direct scavenging of reactive oxygen species (ROS), upregulation of the dhaT gene and promoting the synthesis of sulfur containing compounds. The hypothesis formulated on the ability of L. reuteri to detoxify H2O2 and its underlying mechanism needs to be clarified. Furthermore, the consequences of protein carbonylation as a reflection of oxidative damage to bacteria and its role in the responses of bacteria to oxidative stress need to be further investigated.

Antimicrobial activity of bacteriocin-like inhibitory substance produced by Pediococcus pentosaceus: from shake flasks to bioreactor.

Bacteriocins are peptides produced by various species of bacteria, especially lactic acid bacteria (LAB), which have a large spectrum of action against spoilage bacteria and foodborne pathogens. However, when not entirely characterized, they are alternatively called bacteriocin-like inhibitory substances (BLIS). Pediococcus pentosaceus ATCC 43200 grew and produced BLIS optimally when cultivated anaerobically in bioreactor for 24 h at 30 °C and 200 rpm in De Man, Rogosa and Sharp (MRS) medium supplemented with 1.5% peptone. Under such optimal conditions, the cell mass concentration (3.41 g/L) was 66% higher, the generation time (1.28 h) 38% shorter and the BLIS activity against different indicator strains significantly higher than in MRS medium without any supplement taken as a control, and the exponential phase started 4 h before. The agar diffusion method showed BLIS inhibition halos against LAB strains with diameter in the range 11.0-19.5 mm and specific areas between 377.1 and 2654.6 mm2/mL, while BLIS activity against Listeria strains was better quantified by the liquid medium assay that showed, for the fermented broth without any dilution, 100 and 50% inhibition of Listeria innocua and Listeria seeligeri growth, respectively. These results highlight the potential of P. pentosaceus BLIS as a natural antimicrobial for application in the food industry.

Antithrombotic Activity of Milk Protein Hydrolysates by Lactic Acid Bacteria Isolated from Commercial Fermented Milks

ABSTRACT In the last decade, thrombosis has been one of the pathologies with high incidence creating great concern in Health Institutes all around the world. Considering this, the aim of this research was to determine the antithrombotic activity of peptides released during lactic fermentation. Reconstituted skim milk powder was fermented by Lactobacillus casei Shirota and Lactobacillus johnsonii LA1 isolated from commercial fermented milks. The hydrolysis degree and proteolytic profile were analyzed by trinitrobenzenesulfonic acid spectrophotometry method and by peptide polyacrylamide electrophoresis gel separation. The milk fermented by Lactobacillus casei Shirota exhibited a higher concentration of free amino groups than that fermented by Lactobacillus johnsonii LA1. Additionally, in both fermentation systems peptides with molecular weights lower than 1.4 kDa were observed. The highest inhibition of thrombin (31.67±2.35%) was observed in milk fermented by Lactobacillus johnsonii LA1 at 10 hours of fermentation. Finally, no relationship was found between the antithrombotic capacity and the proteolytic profile.

Effect of sodium reduction and flavor enhancer addition on probiotic Prato cheese processing.

The effect of partial substitution of NaCl with KCl and the flavor enhancers addition (arginine, yeast extract and oregano extract) on Probiotic Prato cheese processing with (L. casei 01, 7logCFU/mL) was investigated. Microbiological (lactic acid bacteria and probiotic counts), physicochemical (proximate composition, pH, proteolysis), bioactivity (antioxidant and angiotensin I-converting enzyme inhibitory activity), rheological (uniaxial compression and creep tests), water mobility (time domain low field magnetic resonance), microstructure (scanning electron microscopy) and sensory evaluation (consumer test) were performed. Sodium reduction and flavor enhancers addition did not constitute an obstacle to the survival of lactic and probiotic bacteria. Proximate composition, antioxidant and angiotensin I-converting enzyme inhibitory activity, and the rheological parameters were affected by the addition of flavor enhancer. No change in the fatty acid profile of cheeses was observed while good performance in the consumer test was obtained by the addition of yeast extract and oregano extract. Prato cheese can be an adequate carrier of probiotics and the addition of different flavor enhancers can contribute developing this functional product in the cheese industry.

Sheep Milk: Physicochemical Characteristics and Relevance for Functional Food Development.

Sheep milk has a high nutritional value and high concentrations of proteins, fats, minerals, and vitamins, as compared to the milks of other domestic species. The physicochemical and nutritional characteristics of sheep milk can be advantageous for the manufacture of products containing prebiotic ingredients and/or probiotic bacteria, which are major categories in the functional food market. Following this technological trend, this review will address the characteristics and advantages of sheep milk as a potentially functional food, as well as the development of sheep milk dairy products containing prebiotics and/or probiotics.

Assessment of antioxidant activity, lipid profile, general biochemical and immune system responses of Wistar rats fed with dairy dessert containing Lactobacillus acidophilus La-5.

The viability and survival of Lactobacillus acidophilus La5 under in vitro simulated gastrointestinal in probiotic dairy dessert was assessed. In addition, the effects of regular consumption of the dessert (5g/day) on the lipid profile, immune system, and antioxidant/biochemical status of Wistar rats were also evaluated after 2weeks of treatment. Adequate counts of L. acidophilus La-5 were observed regards the viability and gastrointestinal conditions. The probiotic dairy dessert was efficient in reducing the LDL-cholesterol, triacylglycerol and increased the HDL-cholesterol in serum. Aspartate amino transferase, alanine aminotransferase, total protein, albumin, heat shock proteins, immune system responses, and blood-cells counts (monocyte, lymphocyte, neutrophil and leucocyte) were not affected (p>0.05) after 15days of treatment. Overall, the probiotic dairy dessert may be a viable alternative to enhance the blood lipid profile and could be used to improve the antioxidant defenses.

Commercial probiotic bacteria and prebiotic carbohydrates: a fundamental study on prebiotics uptake, antimicrobials production and inhibition of pathogens.

BACKGROUND: Probiotics and prebiotics are among the most important functional food ingredients worldwide. The proven benefits of such ingredients to human health have encouraged the development of functional foods containing both probiotics and prebiotics. In this work, the production of antimicrobial compounds coupled to the uptake of commercial prebiotics by probiotic bacteria was investigated. RESULTS: The probiotic bacteria studied were able to take up commercial prebiotic carbohydrates to the same or higher extent than that observed for lactose (control carbohydrate). The growth of probiotic bacteria was coupled to the production of antimicrobials such as short-chain fatty acids (SCFA), H2 O2 and bacteriocins. A higher production of antimicrobial compounds was recorded with Oligomate 55® compared with Regulact® and Frutafit® (3-5 and 10-115 times higher SCFA and H2 O2 production, respectively). The probiotic bacteria grown with Oligomate 55® also produced bacteriocins and other non-identified antimicrobial compounds. The antimicrobials produced by the probiotic bacteria inhibited up to 50% the growth of model pathogens such as Escherichia coli, Listeria innocua and Micrococcus luteus compared with control cultures. CONCLUSIONS: The results here obtained are useful for the adequate selection of probiotic/prebiotics pairs and therefore in the development of efficient functional foods.

Potencial de biodegradação de microcistinas por microrganismos / Biodegradation potential of microcystins by microorganisms

Para minimizar os problemas relacionados à ocorrência de cianobactéria em águas destinadas ao consumo humano há necessidade de se realizar estudos de alternativas técnicas de tratamento com destaque aos biofilmes com potencial de degradação de microcistinas (MC). O presente trabalho teve como objetivo avaliar o potencial de degradação de MC pela bactéria Sphingosinicella microcystinivorans B9, diferentes cepas de leveduras e bactérias probióticas. O teste foi efetuado com extrato de MC e diferentes quantidades de biovolume e densidade celular dos microrganismos. Os tratamentos foram mantidos a 27ºC com rotação de 100 rpm e as amostras para análise de MC e contagem dos microrganismos foram retiradas após 0 e 96 horas de contato. A bactéria B9 apresentou maior degradação de MC, chegando a 98% após 96 horas.

To minimize problems related to the occurrence of cyanobacteria in water for human consumption there is need to investigate alternative treatment techniques with emphasis on biofilms with the potential degradation of microcystins (MC). This study aimed to evaluate the potential degradation of MC by bacteria Sphingosinicella microcystinivorans B9, different strains of yeast and probiotic bacteria. The test was carried out with the extract obtained from strain Microcystis sp. In the tests biomass and cultures of microorganisms were used and the treatments were maintained at 27ºC with 100 rpm. Samples for analysis of MC and for counting the microorganisms were collected at 0 and 96 hours. The bacterium B9 presented the highest potential of degradation of MC reaching 98% after 96 hours.

Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae)

Effect of probiotic bacteria on survival and growth of Cortez oyster larvae, Crassostrea corteziensis (Bivalvia: Ostreidae). Disease control problems have major constraints in aquaculture production, and the use of probiotics in larviculture is a valid alternative to antibiotics. This study analyzed the effect of probiotic bacteria on survival and final size of Cortez oyster larvae Crassostrea corteziensis. Two different probiotic concentrations were evaluated, 1x10(4) and 1x10(5)CFU/ml of Lactic acid bacteria (strain NS61) isolated from Nodipecten subnodosus, and bacilli isolated from the white leg shrimp, Litopenaeus vannamei (Pseudomonas aeruginosa, strain YC58) and C. corteziensis (Burkholderia cepacia, strain Y021). Bacteria were added directly into culture tanks, starting the bioassays from veliger to pediveliger stages as follows: (1) Control, without probiotics; (2) lactic acid bacteria (Lb); (3) bacilli mix (Mb) in a proportion 1:1. Results showed a higher larval survival with Lb and Mb at a dose of 1x10(4)CFU/ml compared to the control group. Larvae exposed to Mb at 1x10(5)CFU/ml showed higher survival than Lb and control. Larval final size was not significantly increased with the tested probiotics, but larvae treated with Lb at 1x105CFU/ml showed less survival rate than those treated at 1x10(4)CFU/ml. This study showed the beneficial effect of these probiotics, added individually or mixed in C. corteziensis larvae culture. Rev. Biol. Trop. 59 (1): 183-191. Epub 2011 March 01.

El ostión de placer u ostra del Cortés (Crassostrea corteziensis) se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61) aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58) y de C. corteziensis (Burkholderia cepacia, cepa Y021). Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb), una mezcla de bacilos (Lb) en proporción 1:1 y un grupo control. La concentración de 1x10(4)UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5)UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5)UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4)UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.

Identificación, cuantificación y determinación del perfil de sensibilidad a antibióticos de bacterias prebióticas adicionadas a productos de consumo frecuente en Costa Rica / Identification, quantification and antimicrobial susceptibility pattern of probiotic bacteria added to common use food products in Costa Rica

En los últimos años, debido a la alta demanda de los productos adicionados con probióticos y los múltiples beneficios nutricionales y terapéuticos asociados, la investigación sobre estos microorganismos ha progresado considerablemente, se han realizado avances notables en su selección y caracterización. De manera general, diversas entidades como la Organización Mundial de la Salud (OMS) y la Organización de las Naciones Unidas para la agricultura y la alimentación (FAO) recomiendan que se declare en la etiqueta del producto, tanto la especie como la cantidad de microorganismos probióticos viables presentes. En este trabajo se analizaron seis productos adicionados con probióticos, con el fin de evaluar su concentración a lo largo de la vida útil del producto, se identificaron las cepas aisladas para corroborar la información declarada en la etiqueta y se determinó su perfil de susceptibilidad a antibióticos. Como resultado del análisis se encontró que las cepas adicionadas a los productos evaluados se mantienen en concentraciones aceptables durante los 28 días de vida útil de los productos. La identificación de las cepas aisladas no coincidió, en varios casos, con la estipulada por la etiqueta, no obstante, el método utilizado se basa en la capacidad de fermentar carbohidratos y no en pruebas genotípicas. Con respecto a los perfiles de susceptibilidad encontrados para las cepas analizadas, son necesarios estudios adicionales que establezcan la naturaleza intrínseca o adquirida de los determinantes de resistencia, y que evidencien si estos están codificados en elementos transferibles entre bacterias.

In the last years, due to the high demand of food products supplemented with probiotics and the multiple nutritional and therapeutic benefits associated with them, research on these microorganisms has advanced considerably, including their selection and characterization. As a general recommendation, several entities as World Health Organization (WHO) and United Nations Organization for Agriculture and Food recommend that the specification of the alive species contained and their number shall appear in the label of the product. In the present study, six different commercially available products, supplemented with probiotics were analyzed, in order to evaluate the concentration of microorganisms through the shelf life of the product, identify the strains isolated and determine the antibiotic susceptibility pattern of these. Results demonstrated that the strains isolated kept acceptable concentrations during the 28 days of storage. Nevertheless, the identification of these strains variated from the one reported on the label on several of the products tested. This can be due to the commercial method used for the identifications, which is based in the carbohydrate fermentation pattern and not in genotypic trials. The antimicrobials’ susceptibility patterns found show that further research shall be performed in order to establish the intrinsic or acquired nature of the resistance determinants, and if these are codified by transferable elements among bacteria.