Lactic acid bacteria isolated from young calves--characterization and potential as probiotics

Isolation of lactic acid bacteria from the reproductive tract of mares as potentially beneficial strains to prevent equine endometritis

Endometritis, the inflammation of the endometrium, is the leading cause of subfertility in mares, and therefore responsible for major economic losses in the horse industry worldwide. It is generally treated with uterine lavages combined with ecbolic agents and local or systemic antibiotics. However, since antibiotic overuse has been associated with antimicrobial resistance in mares with persistent endometritis, new prevention and treatment alternatives are needed. One such alternative could be the use of probiotic lactic acid bacteria (LAB) isolated from the host. Thanks to their species specificity, resident microbiota may restore ecological equilibrium within the host, and therefore, help prevent infections and improve physiological functions. In the present study, 257 bacterial strains were isolated from 77 healthy mares, and 88.76% (n = 228) of them were phenotypically classified as LAB. Within this group, 65.79% were able to inhibit at least one strain from each of the genera that most commonly cause equine endometritis (Streptococcus equi subsp. zooepidemicus, Escherichia coli, and Staphylococcus spp.). Five strains (RCE11, RCE20, RCE91, RCE99, and RCE167) were selected on the basis of their beneficial properties: ability to autoaggregate and adhere to equine epithelial cells, high inhibition of and co-aggregation with all the bacteria isolated from clinical cases of endometritis evaluated, and negative co-inhibition between one another. All five were finally identified as Enterococcus spp., namely E. faecium (two strains), E. hirae (two strains), and E. gallinarum (one strain). Further studies will assess their safety and biotechnological potential for the design of a multi-strain probiotic formula to prevent equine endometritis.

Non-encapsulated, encapsulated, and lyophilized probiotic Limosilactobacillus reuteri SW23 influenced the growth and gut health in calves

The present study was conducted to assess the impact of non-encapsulated, air-dried microencapsulated, and lyophilized microencapsulated probiotics in indigenous cattle calves (Bos indicus). Twenty-four (5-7 days old) indigenous cattle calves were selected and assigned into four groups, with six calves in each as follows: control (CON), fed milk and basal diet alone, and treatment groups supplemented with non-encapsulated (NEC), air-dried microencapsulated (AEC) and lyophilized microencapsulated (LEC) probiotic L. reuteri SW23 at 108 CFU/head/day in skim milk as a carrier provided for 60 days. The animals were divided into four groups, adopting a complete randomized design, and the effects were considered significant at p ≤ 0.05. Probiotics supplementation increased (p < 0.05) body weight gain (kg), average daily gain, and structural growth measurements in calves of all treatment groups. Dry matter intake (g/d), feed conversion efficiency, and fecal counts of Lactobacilli and Bifidobacteria were also increased in the treatment groups compared to CON. The fecal consistency index was highest in CON (0.70 ± 0.03), followed by NEC (0.68 ± 0.01), AEC (0.66 ± 0.02), and LEC (0.65 ± 0.02). Fecal pH and ammonia levels were reduced (p < 0.05) in the probiotic-fed groups compared to CON, with a concomitant increase in fecal lactate, acetate, and propionate levels. In addition, cell-mediated and humoral immunity were significantly increased in supplemented groups as compared to CON. Thus, it can be concluded that supplementation of the probiotics in microencapsulated/non-encapsulated forms to neonatal calves had a variety of positive effects on their health, including better performance, improved gut health, and a lower fecal consistency index. Moreover, among all supplemented groups, the lyophilized microencapsulated group outperformed air-dried microencapsulated and non-microencapsulated groups in terms of ADG, DMI, and gut health.

Characterization of Autochthonous Lactic Acid Bacteria Isolated from a Traditional Ethiopian Beverage, Tella

This study aimed to isolate lactic acid bacteria (LAB) from a traditional Ethiopian fermented product, Tella, and evaluate their functional properties. Of forty-three isolates, seven LAB were screened and identified as Pediococcus pentosaceus, Latilactobacillus curvatus, Leuconostoc mesenteroides, and Lactiplantibacillus plantarum species. The isolates were tested for their alcohol tolerance, acid and bile resistance, auto-aggregation, co-aggregation, hydrophobicity, antibacterial activity, and antibiotic susceptibility. LAB isolates, specifically P. pentosaceus TAA01, L. mesenteroides TDB22, and L. plantarum TDM41, showed a higher degree of alcohol tolerance in 8% and 10% (w/v) ethanol concentrations. Additionally, these three isolates displayed survival rates >85% in both acidic pH and bile environments. Among the isolates, L. plantarum TDM41 demonstrated the highest auto-aggregation, co-aggregation, and hydrophobicity with (44.9 ± 1.7)%, (41.4 ± 0.2)%, and (52.1 ± 0.1)% values, respectively. The cell-free supernatant of the isolates exhibited antibacterial activity against foodborne pathogens of Escherichia coli, Salmonella Enteritidis, and Staphylococcus aureus. Each isolate exhibited various levels of resistance and susceptibility to seven antibiotics and resistance was observed against four of the antibiotics tested. After performing a principal component analysis, Pediococcus pentosaceus TAA01, L. mesenteroides TDB22, and L. plantarum TDM41 were selected as the most promising ethanol-tolerant probiotic isolates.

Antioxidant Effects and Probiotic Properties of Latilactobacillus sakei MS103 Isolated from Sweet Pickled Garlic

Fermented vegetable-based foods, renowned for their unique flavors and human health benefits, contain probiotic organisms with reported in vitro antioxidative effects. This study investigates the probiotic properties of Latilactobacillus sakei MS103 (L. sakei MS103) and its antioxidant activities using an in vitro oxidative stress model based on the hydrogen peroxide (H2O2)-induced oxidative damage of RAW 264.7 cells. L. sakei MS103 exhibited tolerance to extreme conditions (bile salts, low pH, lysozyme, H2O2), antibiotic sensitivity, and auto-aggregation ability. Moreover, L. sakei MS103 co-aggregated with pathogenic Porphyromonas gingivalis cells, inhibited P. gingivalis-induced biofilm formation, and exhibited robust hydrophobic and electrostatic properties that enabled it to strongly bind to gingival epithelial cells and HT-29 cells for enhanced antioxidant effects. Additionally, L. sakei MS103 exhibited other antioxidant properties, including ion-chelating capability and the ability to effectively scavenge superoxide anion free radicals, hydroxyl, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid, and 2,2-diphenyl-1-picrylhydrazyl. Furthermore, the addition of live or heat-killed L. sakei MS103 cells to H2O2-exposed RAW 264.7 cells alleviated oxidative stress, as reflected by reduced malondialdehyde levels, increased glutathione levels, and the up-regulated expression of four antioxidant-related genes (gshR2, gshR4, Gpx, and npx). These findings highlight L. sakei MS103 as a potential probiotic capable of inhibiting activities of P. gingivalis pathogenic bacteria and mitigating oxidative stress.

Identification and evaluation of probiotic potential of Bifidobacterium breve AHC3 isolated from chicken intestines and its effect on necrotizing enterocolitis (NEC) in newborn SD rats

Necrotizing enterocolitis (NEC) is a severe intestinal disease of the newborn infants, associated with high morbidity and mortality. It has been reported that Bifidobacterium could protect the intestinal barrier function and reduce the risk of NEC. This study aimed to evaluate the probiotic potential of Bifidobacterium strains isolated from the chicken intestines and its effect on necrotizing enterocolitis in newborn SD rats. Out of 32 isolates, B. breve AHC3 not only exhibited excellent probiotic potential, including tolerance to artificial simulated gastric conditions, adhesion to HT-29 cells, antioxidant capacity and antibacterial activity, but also possessed reliable safety. Additionally, NEC model was established to further investigate the effect of B. breve AHC3 on necrotizing enterocolitis in newborn SD rats. It was illustrated that administration of B. breve AHC3 significantly not only reduced the incidence of NEC (from 81.25% to 34.38%) (P< 0.05), but also alleviated the severity of ileal injury (P< 0.05). Compared with NEC model, B. breve AHC3 could significantly decrease the level of proinflammatory factor TNF-α (P< 0.05) and increase the level of antiinflammatory factor IL-10 (P< 0.05) in the ileum of NEC rats. Through the intervention of B. breve AHC3, the gray value of inducible nitric oxide synthase (iNOS) in intestinal tissue of NEC rats was significantly reduced (P< 0.05). It was indicated that B. breve AHC3 exhibited prominent probiotic potential and reliable safety. In the neonatal SD rat model of NEC, B. breve AHC3 had an available protective effect on the intestinal injury of NEC, which might be related to reducing the inflammatory reaction in the ileum and inhibiting the expression of iNOS in intestinal tissue cells. B. breve AHC3 could be used as a potential treatment for human NEC.

Screening and characterization of Sahiwal cattle calves-origin lactic acid bacteria based on desired probiotic attributes for potential application

Probiotics are living microorganisms that confer health benefits to host when administered in adequate amounts. To develop novel host-specific probiotic for their application as feed additive, the present study was undertaken to isolate and characterize probiotic strains of indigenous cattle-calves origin. A total of 55 colonies were isolated from 12 healthy calves, with 34 of the isolates being Gram-positive, catalase-negative and vancomycin-resistant. Furthermore, eleven isolates showed tolerance to acid (pH 2.0) and thirteen isolates tolerated bile salts (0.3%). Seven common acid and bile tolerance strains were further investigated for other probiotic attributes and displayed higher (p< 0.05) auto-aggregation and cell surface hydrophobicity values. Moreover, all seven isolates had potent antibacterial activity against pathobiont E. coli as well as significant co-aggregation capacity and enzyme activity. In vitro biosafety assessment revealed that all seven isolates were non-hemolytic, negative for mucin degradation and susceptible to most of the antibiotics. Based on the obtained findings, heatmap and principal component analysis identified four highly effective probiotic candidates confirmed by 16S rDNA sequencing as Limosilactobacillus reuteri SW23, Limosilactobacillus reuteri SW26, Limosilactobacillus reuteri SW27 and Enterococcus faecium SW28, respectively. Further studies on biosafety aspect are warranted for the application of these strains in animal as potential probiotics.HIGHLIGHTSL. reuteri SW23, L. reuteri SW26, L. reuteri SW28 and Enterococcus faecium SW28 were successfully isolated and identified from indigenous calves' feces.These microbes were characterized for potential probiotics attributes.Heatmap analysis and principal component analysis (PCA) was used along with probiotic attributes to select highly effective probiotic candidates.

Lactobacillus (Limosilactobacillus) reuteri: a probiotic candidate to reduce neonatal diarrhea in calves

Background

Diarrhea in newborn calves is considered life-threatening and results in large economic losses in dairy farms. Lactobacilli generally play an important role in intestinal health, and Lactobacillus (Limosilactobacillus; L.) reuteri is the dominant Lactobacillus species in the feces of healthy calves during the first week of life. In calves with diarrhea on day 2 postpartum, lactobacilli are significantly reduced even up to 24 h before the onset of clinical signs. Since the probability of occurrence of diarrheal disease decreases as the L. reuteri count in the feces increases, oral administration of this species might have a protective effect against diarrhea.

Objective

These studies were designed to demonstrate whether oral administration of preselected L. reuteri isolates can reduce the incidence of diarrhea in newborn calves on dairy farms.

Microorganisms

46 L. reuteri isolates from 2-day-old healthy calves were available from a previous study.

Animals

170 newborn calves of Simmental breed of 10 dairy farms in Bavaria (Germany), were included in the study; of 166 animals the data could be evaluated.

Methods

Microbiological (antibiotic sensitivity test, acid and bile salt stability test, antimicrobial activity of the supernatants), molecular biological (PCR, RAPD-PCR) and toxicological methods (MTT test) were used to select and to characterize suitable L. reuteri isolates. The administration of a suspension of two selected L. reuteri isolates (6-8 × 108 colony forming units per day) to calves was performed from day 2 to day 5 after birth in a double-blinded placebo-controlled study. Clinical monitoring of the calves continued until the 14th day of life.

Results

Out of 46 L. reuteri isolates, only 2 met the set criteria and were used in the feeding trial. In the placebo group, 44 of 83 calves developed diarrhea within the first 2 weeks of life, whereas in the L. reuteri group this was only the case in 31 of 83 animals (p < 0.05).

Conclusion

L. reuteri appears to be of particular importance for the intestinal health of newborn calves. The diarrhea protective effect could be even more pronounced if an improved administration regimen is developed in terms of start, frequency, and duration.

Biofilm formation by agave epiphytic lactic acid bacteria fed with agave fructans

The aim of this work was to find out if biofilms can be made by lactic acid bacteria (LAB) isolated from agave plants using agave fructans as sole carbohydrate substrates or if it was necessary to use fructose as a breakdown product of such polymers. This is part of a research project geared to develop industrial lactic acid production from agave fructans, an abundant raw material in Mexico's agave plantations. Present results showed that nine strains of LAB isolated from Agave salmiana and belonging to genus Lacticaseibacillus and Enterococcus produced exopolysaccharides directly from agave fructans to a greater extent than with fructose. The best polysaccharide productions in planktonic cultures were Lacticaseibacillus paracasei strains DG2, DG3, DG4 and DG8. Furthermore, all nine LAB strains produced biofilms on polystyrene microplates, much better with agave fructans than with fructose. In most strains, biofilm formation was favored at pH from 6.0 to 6.5, except for strains DG7 and DG9 where pH 5.5 was optimal. Biofilm formation required between 3 and 5 days of incubation in all Lacticaseibacillus paracasei strains, whereas Enterococcus faecium required a little less of 3 days. Present results support the straight use of agave fructans to develop LAB biofilms using agave epiphytic bacteria. This finding simplifies upstream processing of agave fructans to be used for future lactic acid fermentation in LAB biofilm reactors.

Understanding Age-Related Longitudinal Dynamics in Abundance and Diversity of Dominant Culturable Gut Lactic Acid Bacteria in Pastured Goats

Understanding gut lactic acid bacteria (LAB) in healthy hosts is an important first step in selecting potential probiotic species. To understand the dynamics of LAB in healthy goats, a cohort of thirty-seven healthy new-born goat kids was studied over a ten-month period. Total LAB was quantified using SYBR green qPCR. Seven hundred LAB isolates were characterized using microscopy, M13 RAPD genotyping and 16S rDNA sequencing. The highest and lowest LAB counts were detected at one week and ten months of age, respectively. Diverse LAB species were detected, whose identity and prevalence varied with age. The main isolates belonged to Limosilactobacillus reuteri, Limosilactibacillus fermentum, Lactobacillus johnsonni, Ligilactobacillus murinus, Ligilactobacillus salivarius, Limosilactobacillus mucosae, Lactiplantibacillus plantarum, Ligilactobacillus agilis, Lactobacillus acidophilus/amyolovolus, Pediococcus spp. and Enterococcus spp. Uniquely, L. reuteri and Pediococcus spp. were most common in pre- and peri-weaned goats, while Lactobacillus mucosae and Enterococcus spp. were predominant in goats one month and older. Based on RAPD genotyping, L. reuteri had the highest genotypic diversity, with age being a factor on the genotypes detected. This data may be relevant in the selection of age-specific probiotics for goats. The findings may also have broader implications by highlighting age as a factor for consideration in probiotic bacteria selection in other animal hosts.

In vitro investigation on lactic acid bacteria isolatedfrom Yak faeces for potential probiotics

In order to evaluate the potential and safety of lactic acid bacteria (LAB) isolated from faeces samples of Ganan yak as probiotic for prevention and/or treatment of yak diarrhea, four strains of LAB including Latilactobacillus curvatus (FY1), Weissella cibaria (FY2), Limosilactobacillus mucosae (FY3), and Lactiplantibacillus pentosus (FY4) were isolated and identified in this study. Cell surface characteristics (hydrophobicity and cell aggregation), acid resistance and bile tolerance, compatibility, antibacterial activity and in vitro cell adhesion tests were also carried out to evaluate the probiotic potential of LAB. The results showed that the four isolates had certain acid tolerance, bile salt tolerance, hydrophobicity and cell aggregation, all of which contribute to the survival and colonization of LAB in the gastrointestinal tract. There is no compatibility between the four strains, so they can be combined into a mixed probiotic formula. Antimicrobial tests showed that the four strains were antagonistic to Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. Moreover, the in vitro safety of the four isolates were determined through hemolytic analysis, gelatinase activity, and antibacterial susceptibility experiments. The results suggest that all the four strains were considered as safe because they had no hemolytic activity, no gelatinase activity and were sensitive to most antibacterial agents. Moreover, the acute oral toxicity test of LAB had no adverse effect on body weight gain, food utilization and organ indices in Kunming mice. In conclusion, the four LAB isolated from yak feces have considerable potential to prevent and/or treat yak bacterial disease-related diarrhea.

Dendrobium officinale Xianhu 2 polysaccharide helps forming a healthy gut microbiota and improving host immune system: An in vitro and in vivo study

Dendrobium officinale is widely consumed owing to its numerous beneficial effects. We aimed to characterize polysaccharides of Dendrobium officinale (DOP) from the stems of Dendrobium officinale Xianhu 2 and clarify whether it benefit the intestinal microbiota and the immune system. The DOP weighed 291 kDa and comprised mannose, glucose, galactose, and rhamnose at 59.31:33.31:1.00:0.51 M ratio. In in vitro/vivo studies, DOP significantly increased benign intestinal microbe proportion (Lactobacillus, etc.), but reduced harmful bacteria (Escherichia_Shigella) (P < 0.05), and significantly increased butyric acid production (P < 0.05). Concentrations of 2 g/L DOP for in vitro fermentation and 100 mg/kg body weight for the mouse model were effective. In mice, DOP significantly reduced CRP, CD3, CD4, and TNF-α levels and increased C4 levels (P < 0.05). DOP might influence the immune system indirectly through regulation of the gut microbiota. Its possible regulation mechanism was that DOP reduced CD4+ Th cells proliferation so that reduced the secretion of TNF-α.

Characterization of autochthonous lactobacilli from goat dairy products with probiotic potential for metabolic diseases

The present study aimed to design functional fermented goat milk with probiotic potential for metabolic diseases. Thereby, autochthonous lactobacilli from goat dairy products that target improving the inflammatory, lipid, and glycemic profile were characterized. We designed fermented goat milk using Lactobacillus delbrueckii subsp. indicus CRL1447 as starter strain, supplemented with different probiotic consortia formed by Limosilactobacillus fermentum CRL1446, Lactiplantibacillus paraplantarum CRL1449, and CRL1472 strains. These lactobacilli were selected for their positive effects on inhibition of α-glucosidase, bile salts hydrolase activity, cholesterol assimilation, and decreased triglyceride percentage in Caenorhabditis elegans. Furthermore, the lactobacilli oral administration to obese mice caused a significant decrease in body weight gain and ameliorated hyperglycemia and hyperlipemia. These results reveal the potential of this goat dairy product as a functional food to prevent obesity and related pathologies. Goat milk-derived products stand out for their marketing potential. Hence, fermented goat milk incorporating novel probiotics represents a group of food products with broad prospects by their promising nutritive and therapeutic properties for metabolic diseases. The goat dairy product designed in this study could be used in the prevention of dyslipidemia and hyperglycemia in obese people.

•

New probiotic consortium (CRL1449, CRL1472, and ​CRL1446) was selected.

•

The probiotic consortium showed in vitro immuno and adipomodulatory properties.

•

Lactobacillus delbrueckii subsp. indicus CRL1447 was selected as a starter culture for fermented milk elaboration.

•

Manufacturing of a functional fermented goat milk with a new probiotic consortium.

Leuconostoc mesenteroides LVBH107 Antibacterial Activity against Porphyromonas gingivalis and Anti-Inflammatory Activity against P. gingivalis Lipopolysaccharide-Stimulated RAW 264.7 Cells

Probiotics, active microorganisms benefiting human health, currently serve as nutritional supplements and clinical treatments. Periodontitis, a chronic infectious oral disease caused by Porphyromonas gingivalis (P. gingivalis), activates the host immune response to release numerous proinflammatory cytokines. Here, we aimed to clarify Leuconostoc mesenterica (L. mesenteroides) LVBH107 probiotic effects based on the inhibition of P.gingivalis activities while also evaluating the effectiveness of an in vitro P.gingivalis lipopolysaccharide-stimulated RAW 264.7 cell-based inflammation mode. L. mesenteroides LVBH107 survived at acid, bile salts, lysozyme, and hydrogen peroxide conditions, auto-aggregated and co-aggregated with P. gingivalis, exhibited strong hydrophobicity and electrostatic action, and strongly adhered to gingival epithelial and HT-29 cells (thus exhibiting oral tissue adherence and colonization abilities). Moreover, L.mesenteroides LVBH107 exhibited sensitivity to antibiotics erythromycin, doxycycline, minocycline, ampicillin, and others (thus indicating it lacked antibiotic resistance plasmids), effectively inhibited P.gingivalis biofilm formation and inflammation (in vitro inflammation model), reduced the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) and inflammatory mediators (NO and PGE₂), and decreased the expression levels of inflammation related genes. Thus, L.mesenterica LVBH107 holds promise as a probiotic that can inhibit P.gingivalis biofilm formation and exert anti-inflammatory activity to maintain oral health.

Impact of Probiotics on Dairy Production Efficiency

There has been growing interest on probiotics to enhance weight gain and disease resistance in young calves and to improve the milk yield in lactating animals by reducing the negative energy balance during the peak lactation period. While it has been well established that probiotics modulate the microbial community composition in the gastrointestinal tract, and a probiotic-mediated homeostasis in the rumen could improve feed conversation competence, volatile fatty acid production and nitrogen flow that enhances the milk composition as well as milk production, detailed changes on the molecular and metabolic level prompted by probiotic feed additives are still not understood. Moreover, as living biotherapeutic agents, probiotics have the potential to directly change the gene expression profile of animals by activating the signalling cascade in the host cells. Various direct and indirect components of probiotic approaches to improve the productivity of dairy animals are discussed in this review.

Assessment of probiotic efficacy and anticancer activities of Lactiplantibacillus plantarum ESSG1 (MZ683194.1) and Lactiplantibacillus pentosus ESSG2 (MZ683195.1) isolated from dairy products

Resistance to antibiotics is on the rise, and its indiscriminate usage has resulted in human and animal management constraints. In the research for an innovative treatment to diminish antimicrobial resistance, lactic acid bacteria (LAB) throw light on diminishing this problem in public health. As a result, this paper looked at the efficacy of LAB isolates and their active metabolites to combat pathogens, reduce antibiotic use in clinical settings, and explore the anticancer potential of 8 strains of LAB isolated from dairy products. Antifungal and antibacterial potential of LAB isolates against selected crop pathogenic fungi and food pathogenic bacteria had been estimated. Results revealed that all isolates exert antioxidant efficacy relating to DPPH, NO scavenging ability, reducing power, superoxide anion, hydroxyl radical, and anti-lipid peroxidation potential. Additionally, 12B isolate exert the highest anticancer upshot with IC₅₀ values of 43.98 ± 0.4; 36.7 ± 0.6, 43.1 ± 0.8, and 35.1 ± 0.3 μg/ml, versus Caco-2, MCF-7, HepG-2, and PC3 cell lines respectively, whereas 13B isolate significantly had the highest selectivity index between peripheral blood mononuclear cells (PBMCs) and the tested human cancer cell lines compared to 5-fluorouracil. 13B was the most apoptosis-dependent death inducer for all human cancer cell lines besides exerting the lowest percentage of apoptosis against PBMCs suggesting its safety against PBMCs. The most promising strains 12B and 13B were identified by 16S rRNA sequencing as Lactiplantibacillus plantarum ESSG1 (MZ683194.1) and Lactiplantibacillus pentosus ESSG2 (MZ683195.1). LAB and their extracts are superb substitutive, safe, and efficient antimicrobial, antioxidant, and antitumor curative agents.

New sources of lactic acid bacteria with potential antibacterial properties

In the face of the growing demand for functional food, the search for new sources of lactic acid bacteria (LAB) becomes a priority. In our research, we used multiplied culture conditions followed by identification via the matrix-assisted laser desorption ionization-time of flight mass spectrometry for seeking LAB strains in plant- and animal-derived sources. Furthermore, the selected LAB isolates were examined for their proteolytic activity as well as antimicrobial action against different bacterial pathogens. The applied method appeared to be useful tool for searching LAB strains within different types of the biological matrices. The best source of the LABs was from calf. Comparing properties of the two selected LABs, those isolated from calf demonstrated the greatest proteolytic and antibacterial properties suggesting that gastrointestinal microbiota are the most valuable LAB source. Nevertheless, second selected strain derived from pickled cucumber juice may be also treated as a promising source of potential probiotic strains.

Evaluation of the Probiotic Potential of Lactobacillus delbrueckii ssp. indicus WDS-7 Isolated from Chinese Traditional Fermented Buffalo Milk In Vitro

The present study aimed to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from Chinese traditional fermented buffalo milk. Out of 22 isolates, 11 were putatively identified as LAB preliminarily. A total of six LAB strains displayed strong adhesion to HT-29 cells and all these strains showed preferable tolerance to artificially simulated gastrointestinal juices. WDS-4, WDS-7, and WDS-18 exhibited excellent antioxidant capacities, including DPPH radical, ABTS⁺ radical, and superoxide anion scavenging activities. Compared with the other two LAB strains, WDS-7 had a stronger inhibition effect on four pathogens. Based on the 16S rRNA gene sequencing and phylogenetic analysis, WDS-7 was identified as Lactobacillus delbrueckii ssp. indicus and selected to assess the potential and safety of probiotics further. The results revealed that WDS-7 strain had a strong capacity for acid production and good thermal stability. WDS-7 strain also possessed bile salt hydrolase (BSH) activity. Compared to LGG, WDS-7 was a greater biofilm producer on the plastic surface and exhibited a better EPS production ability (1.94 mg/ml as a glucose equivalent). WDS-7 was proved to be sensitive in the majority of tested antibiotics and absence of hemolytic activity. Moreover, no production of biogenic amines and β-glucuronidase was observed in WDS-7. The findings of this work indicated that L. delbrueckii ssp. indicus WDS-7 fulfilled the probiotic criteria in vitro and could be exploited for further evaluation in vivo.

Development of Next-Generation Probiotics by Investigating the Interrelationships between Gastrointestinal Microbiota and Diarrhea in Preruminant Holstein Calves

Simple Summary

The present study investigated the relationship between gastrointestinal microbiota and diarrhea in preruminant calves by using immune-related markers and further isolating specific bacterial strains, enriched in clinically healthy individuals, for potential next-generation probiotics. The gathering of microbiomic data strongly indicated the possible beneficial effects of Bifidobacterium longum subsp. longum. With further screening and isolating with immunomodulatory and antagonistic effects, two Bifidobacterium longum subsp. longum strains might be expected to emerge as next-generation probiotics. The finding here might provide a solution for preventing gastrointestinal disorders for preruminant calves without sustained periods of administration through inhibiting the infectious bacteria, immunomodulatory effect and possible modulating microbiota.

Abstract

(1) Background: We aimed to isolate and identify potential next-generation probiotics (NGP) by investigating the interrelationships between gastrointestinal microbiota and diarrhea in preruminant Holstein calves. (2) Material and methods: Twenty preruminant Holstein calves were divided into healthy and diarrheic groups after the combination outcomes of veterinary diagnosis and fecal scores. The fecal microbiome, plasma cytokines, plasma immunoglobulin (Ig) G and haptoglobin were analyzed. The potential probiotic bacteria were identified by comparing the microbiota difference between healthy and diarrheic calves and correlation analysis with fecal scores and inflammatory markers. The identified bacteria were also isolated for further evaluation for antimicrobial activities and immunoregulatory effects. (3) Results: Microbiota analysis suggested that Ruminococcaceae_UCG_014, Bifidobacterium and Pseudoflavonifractor positively correlated with bovine IgG and negatively correlated with fecal score; inflammatory factors, bovine HP, and IL-8 were classified as beneficial bacteria contributing to the health of the calves. The alternation of gut microbial composition also induced changes in the functional gene enrichment of gut microbiota in calves. The gathering of microbiomic data strongly indicated the possible beneficial effects of Bifidobacterium longum subsp. longum, expected to develop as NGP. After isolation and evaluation of the potential functionality in vitro, two specific bifidobacterial strains demonstrated antimicrobial activities and immunoregulatory effects. (4) Conclusions: The results provide a new probiotic searching approach for preventing gastrointestinal disorders in preruminant calves. Further animal study is necessary to verify the results.

Search of antimicrobial lactic acid bacteria from Salmonella-negative dogs

Background

Salmonellosis is one of the most important food-borne zoonotic disease affecting both animals and humans. The objective of the present study was to identify gastrointestinal (GI) lactic acid bacteria (LAB) of canine-origin from Salmonella-negative dogs’ faeces able to inhibit monophasic Salmonella Typhimurium previously isolated from dogs’ faeces, in order to be used as a potential probiotic in pet nutrition.

Results

Accordingly, 37 LAB were isolated from Salmonella-negative dogs’ faeces and tested against monophasic S. Typhimurium using the spot on lawn method out of which 7 strains showed an inhibition halo higher than 2.5 cm. These 7 strains were also tested with the co-culture method and one showed the greatest inhibition value (p < 0.05). Subsequently, the isolate was identified through 16S rRNA sequencing and sequence homology and designated as Ligilactobacillus salivarius (L. salivarius). LAB from Salmonella-positive dogs were also identified and none was the selected strain. Finally, to identify the mechanism of inhibition of L. salivarius, the supernatant was analyzed, and a dose response effect was observed.

Conclusions

It is concluded that the canine-origin L. salivarius, could possess some in vitro functional attributes of a candidate probiotic and could prevent monophasic S. Typhimurium colonization or inhibit its activity if the infection occurs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03070-x.

First characterization of the probiotic potential of lactic acid bacteria isolated from Costa Rican pineapple silages

Background

Agro-industrial waste from tropical environments could be an important source of lactic acid bacteria (LAB) with probiotic potential.

Methods

Twelve LAB isolates were isolated from pineapple silages. The species identification was carried out considering 16S rRNA and pheS genes. Experiments to evaluate the probiotic potential of the isolates included survival under simulated gastrointestinal environment, in vitro antagonistic activity (against Salmonella spp. and Listeria monocytogenes), auto-aggregation assays, antibiotic susceptibility, presence of plasmids, adhesiveness to epithelial cells, and antagonistic activity against Salmonella in HeLa cells.

Results

Lacticaseibacillus paracasei, Lentilactobacillus parafarraginis, Limosilactobacillus fermentum, and Weissella ghanensis were identified. Survival of one of the isolates was 90% or higher after exposure to acidic conditions (pH: 2), six isolates showed at least 61% survival after exposure to bile salts. The three most promising isolates, based on survivability tests, showed a strong antagonistic effect against Salmonella. However, only L. paracasei_6714 showed a strong Listeria inhibition pattern; this isolate showed a good auto-aggregation ability, was resistant to some of the tested antibiotics but was not found to harbor plasmids; it also showed a high capacity for adhesion to epithelial cells and prevented the invasion of Salmonella in HeLa cells. After further in vivo evaluations, L. paracasei_6714 may be considered a probiotic candidate for food industry applications and may have promising performance in acidic products due to its origin.

Probiotic Characterization of Indigenous Kocuria flava Y4 Strain Isolated from Dioscorea villosa Leaves

This aim of the study was to isolate and screen potential probiotics from Dioscorea villosa leaves. The potential isolate Y4 was obtained from the Dioscorea villosa leaves, and its ability to grow in a medium containing high NaCl concentrations (2-10%) indicated its negative hemolytic activity. Furthermore, Y4 demonstrated inhibitory activity against human pathogens, such as Klebsiella pneumonia, Staphylococcus aureus, Citrobacter koseri, and Vibrio cholerae, as well as towards a plant pathogen isolate OR-2 (obtained from Citrus sinensis). Some biologically important functional groups of Y4 metabolites, such as sulfoxide; aliphatic ether; 1, 2, 3-trisubstituted, tertiary alcohol: vinyl ether; aromatic amine; carboxylic acid; nitro compound; alkene mono-substituted; and alcohol, were identified through FTIR analysis. The 16S rRNA sequencing and subsequent phylogenetic tree analysis indicated that Y4 and OR-2 are the closest neighbors to Kocuria flava (GenBank accession no. MT773277) and Pantoea dispersa (GenBank accession no. MT766308), respectively. The potential isolate Y4 was found to exhibit adhesion, auto-aggregation, co-aggregation, and weak biofilm activity. It also exhibited a high level of antimicrobial activity and antibiotic susceptibility. The safety of K. flava Y4 isolate, which is proposed to be a probiotic, was evaluated through acute oral toxicity test and biogenic amine production test. Moreover, the preservation potential of isolate Y4 was assessed through application on fruits under different temperatures. Thus, our results confirmed that Kocuria flava Y4 is a prospective probiotic and could also be used for the preservation of fruits.

Potential prebiotic properties of exopolysaccharides produced by a novel Lactobacillus strain, Lactobacillus pentosus YY-112

Exopolysaccharides (EPSs) derived from Lactobacilli have important physiological effects and are commonly used as new prebiotics. We identified and studied a new Lactobacillus strain, YY-112, isolated from waxberry (Myrica rubra). This strain, identified as Lactobacillus pentosus, tolerates acids, bile salts, and artificial digestive fluids. The EPS derived from this strain weighed 5.9 × 10⁴ Da and contained glucose, mannose, glucosamine, galactose, and rhamnose at 62.69 : 85.85 : 2.46 : 2.92 : 1.00 molar ratios. We found that the EPS from this strain increased the ratio of Bacteroidetes to Firmicutes and decreased the relative abundance of Proteobacteria, especially Escherichia-Shigella, when added to a simulated gastrointestinal system in vitro. After analysing the short-chain fatty acids, we found that this EPS promoted the production of acetic acid, propionic acid, and butyric acid, and reduced the ratio of acetic acid to propionic acid. We conclude that Lactobacillus pentosus YY-112 is a potential probiotic strain with EPS that is beneficial for the intestinal microbiota and short-chain fatty acid production.

Properties of a New Probiotic Candidate and Lactobacterin-TK2 Against Diarrhea in Calves

Calf diarrhea is an important problem that can result in death and which leads to economic losses. Probiotics in the gastrointestinal tract can be effective for the prevention of diarrhea. In this study, some strains were isolated from traditional fermented dairy products (Shubat and Kumiss) and the feces of Holstein calves and heifers. Some probiotic properties were determined using a total of 124 isolates and Lactobacterin-TK². Most of the isolates and Lactobacterin-TK² were adversely affected by pH 2.0; however, they maintained their viability at pH 4.0 and 0.3% bile salt. The most effective antifungals on yeast strains were nystatin, voriconazole, and ketoconazole; however, they were resistant to itraconazole and amphotericin B. The majority of LAB strains and Lactobacterin-TK² were susceptible to penicillin and tetracycline, whereas they were resistant to trimethoprim-sulfamethoxazole. Bacillus spp. strains were susceptible to enrofloxacin, trimethoprim-sulfamethoxazole, and gentamicin but resistant to penicillin. Also, 71% of lactobacilli have high hydrophobicity, whereas other strains have low hydrophobicity or had no hydrophobicity. Antagonistic properties of some selected strains against pathogenic bacteria were examined. All of the LABs inhibited at least one pathogen. The inhibitory effect of yeast strains on pathogens could not be determined. Then, five of the LAB strains were genotypically identified as Enterococcus faecium, one as Lactobacillus casei, and the yeast strains were identified as Saccharomyces cerevisiae and Clavispora lusitaniae. L. casei K2 and S. cerevisiae S430b were selected as superior strains. These strains are capable of being used as a new probiotic candidate following in vivo trials.

Probiotics-Live Biotherapeutics: a Story of Success, Limitations, and Future Prospects-Not Only for Humans

In livestock production, lactic acid bacteria (LAB) represent the most widespread microorganisms used as probiotics. For such critical use, these bacteria must be correctly identified and characterized to ensure their safety and efficiency. Recently, probiotics have become highly recognized as supplements for humans and in particular for animals because of their beneficial outcome on health improvement and well-being maintenance. Various factors, encompassing dietary and management constraints, have been demonstrated to tremendously influence the structure, composition, and activities of gut microbial communities in farm animals. Previous investigations reported the potential of probiotics in animal diets and nutrition. But a high rate of inconsistency in the efficiency of probiotics has been reported. This may be due, in a major part, to the dynamics of the gastrointestinal microbial communities. Under stressing surroundings, the direct-fed microbials may play a key role as the salient limiting factor of the severity of the dysbiosis caused by disruption of the normal intestinal balance. Probiotics are live microorganisms, which confer health benefits on the host by positively modifying the intestinal microflora. Thus, the aim of this review is to summarize and to highlight the positive influence of probiotics and potential probiotic microbe supplementation in animal feed with mention of several limitations.

In vitro evaluation of lactic acid bacteria with probiotic activity isolated from local pickled leaf mustard from Wuwei in Anhui as substitutes for chemical synthetic additives

The extensive abuse of chemical synthetic additives has raised increased attention to food safety. As substitutes, probiotics play an important role in human health as they balance the intestinal microbes in host. This study was aimed to isolate and evaluate the potential probiotic activities of lactic acid bacteria (LAB) from a local pickled leaf mustard (PLM) from Wuwei city in Anhui province through in vitro experiments. A total of 17 LAB strains were obtained as probiotics. All the isolates were sensitive to chloramphenicol, tetracycline, erythromycin, and doxycycline but exhibited resistance to antibiotics (e.g., streptomycin, kanamycin, gentamicin, and vancomycin). Out of the 17 strains, 9 were sensitive to most of the antibiotics and had no cytotoxic activity on human colorectal adenocarcinoma cell line (HT-29) cells. The isolated AWP4 exhibited antibacterial activity against four indicator pathogen strains (ATCC8099: Escherichia coli, ATCC6538: Staphylococcus aureus, ATCC9120: Salmonella enteric, and BNCC192105: Shigella sonnei). Based on the phylogenetic analysis of the 16S rRNA gene, AWP4 belonged to Lactiplantibacillus plantarum. This study indicated that the Wuwei local PLM could be a potential resource to isolate beneficial LAB as probiotics. The data provide theoretical guidance for further animal experiments to estimate the probiotic effect and safety of Lpb. plantarum AWP4 in vivo.

Isolation and Genetic Identification of Endophytic Lactic Acid Bacteria From the Amazonian Açai Fruits: Probiotics Features of Selected Strains and Their Potential to Inhibit Pathogens

The açai palm (Euterpe oleracea) is native to the Amazon basin, a humid tropical forest. High levels of total mesophilic bacteria with high diversity have been consistently reported in açai fruits. As local consumers have few digestive problems, the results of the present study reveal the lactic acid bacteria (LAB) recovered from açai fruits with characteristics that suggest they are possible candidates for probiotics and antagonistic potential against pathogens for the first time. Açai fruits were sampled from five different locations in the Eastern Amazonia floodplains. Sixty-six isolates were recovered from fruits and tested for some probiotic characteristics following FAO/WHO guidelines. Approximately 65% of the isolates showed no catalase or oxidase activity, Gram-positive staining or cocci and bacilli cell morphology. Furthermore, 48% of the isolates demonstrated preliminary characteristics that suggest safety for use, as they presented no coagulase enzyme activity or gamma-hemolysis. These strains were identified as belonging to the genera Lactiplantibacillus and Pediococcus, and 32 strains also presented resistance to vancomycin, ciprofloxacin and streptomycin. In addition, 28 isolates showed a survival rate, expressed as log cycle reduction, higher than 0.9 under gastric conditions (pH 2). All strains tested positive in bile salts deconjugation tests and showed a survival rate higher than 0.8 in the presence of this salt. Regarding antimicrobial activity against pathogens, all strains were able to inhibit Salmonella Typhimurium (ATCC^® 14028^TM) and 97% were capable of inhibiting Escherichia coli (ATCC^® 25922^TM). Concerning the results of in vitro antagonistic assays, three isolates (B125, B135, and Z183 strains) were selected for antagonistic tests using açai juice contaminated with these two pathogens. All tested LAB strains were able to inhibit pathogen growth in açai juice. In summary, açai fruits are a potential source of LAB isolates to be investigated as probiotics.

Inulin Fermentation by Lactobacilli and Bifidobacteria from Dairy Calves

Prebiotics are increasingly examined for their ability to modulate the neonate gut microbiota of livestock, and products such as inulin are commonly added to milk replacer used in calving. However, the ability of specific members of the bovine neonate microbiota to respond to inulin remains to be determined, particularly among indigenous lactobacilli and bifidobacteria, beneficial genera commonly enriched by inulin. Screening of Bifidobacterium and Lactobacillus isolates obtained from fresh feces of dairy calves revealed that lactobacilli had a higher prevalence of inulin fermentation capacity (58%) than bifidobacteria (17%). Several Ligilactobacillus agilis (synonym Lactobacillus agilis) isolates exhibited vigorous growth on, and complete degradation of, inulin; however, the phenotype was strain specific. The most vigorous inulin-fermenting strain, L. agilis YZ050, readily degraded long-chain inulin not consumed by bifidobacterial isolates. Comparative genomic analysis of both L. agilis fermenter and nonfermenter strains indicated that strain YZ050 encodes an inulinase homolog, previously linked to extracellular degradation of long-chain inulin in Lacticaseibacillus paracasei, that was strongly induced during growth on inulin. Inulin catabolism by YZ050 also generates extracellular fructose, which can cross-feed other non-inulin-fermenting lactic acid bacteria isolated from the same bovine feces. The presence of specific inulin-responsive bacterial strains within calf gut microbiome provides a mechanistic rationale for enrichment of specific lactobacilli and creates a foundation for future synbiotic applications in dairy calves aimed at improving health in early life.IMPORTANCE The gut microbiome plays an important role in animal health and is increasingly recognized as a target for diet-based manipulation. Inulin is a common prebiotic routinely added to animal feeds; however, the mechanism of inulin consumption by specific beneficial taxa in livestock is ill defined. In this study, we examined Lactobacillus and Bifidobacterium isolates from calves fed inulin-containing milk replacer and characterized specific strains that robustly consume long-chain inulin. In particular, novel Ligilactobacillus agilis strain YZ050 consumed inulin via an extracellular fructosidase, resulting in complete consumption of all long-chain inulin. Inulin catabolism resulted in temporal release of extracellular fructose, which can promote growth of other non-inulin-consuming strains of lactic acid bacteria. This work provides the mechanistic insight needed to purposely modulate the calf gut microbiome via the establishment of networks of beneficial microbes linked to specific prebiotics.

Systematic review of an intervention: the use of probiotics to improve health and productivity of calves

The aims of this study were to undertake a systematic review and meta-analysis of the types of probiotic formulations that are commercially available and to critically appraise the available evidence for the effectiveness of probiotics in improving the health and productivity of calves. Relevant papers were identified to answer the question: 'In calves aged between birth to one year, is the use of probiotics associated with changes in haematological or biochemical parameters, faecal bacteria counts, average daily live weight gain, dry matter intake, or feed conversion ratio?' The search of the literature yielded 67 studies that fit the primary screening criteria. Included studies were assessed for bias and confounding using a predefined risk assessment tool adapted from the Cochrane Collaboration's tool for assessing risk of bias in randomised trials and GRADE guidelines. Meta-analysis was performed using Review Manager and R. Random sequence generation was low in more than 59 % of studies. Risk of allocation concealment and performance bias were largely unclear in over 68 % of studies. Calves fed probiotics had increased average daily live weight gains (ADG) from birth to weaning (mean difference [MD] = 83.14 g/d 95 % CI = 58.36-107.91, P < 0.001) compared with calves on a control diet. Calf age reduced the level of heterogeneity of the effect of probiotics on ADG for calves between one to three weeks of age (τ² = 73.15; I² = 4%; P = 0.40) but not for calves older than three weeks of age (τ² = 2892.91; I² = 73 %; P < 0.001). Feed conversion ratio (FCR) was lower for calves on probiotics (MD = -0.13 kg of dry matter intake (DMI) to kg of live weight (LW) gain, 95 % CI = -0.17 to -0.09, P < 0.001), and the heterogeneity of effect was large in younger aged calves (τ² = 0.05; I² = 78 %; P = 0.03). The risk of bias regarding the methodology in the included studies was high. The quality of evidence for each outcome was categorised as moderate. There is sufficient data to support the effectiveness of probiotic use in some applications such as for the improvement of performance and productivity parameters of calves. However, the evidence is weak for other potential probiotic uses in calves such as improved health and reduced risk of disease. Therefore, the existing data are inconclusive and do not support the use of probiotics as an alternative to antimicrobials to improve calf health and productivity.

Survival of Beneficial Vaginal Lactobacilli (BVL) to Different Gastrointestinal Tract Conditions

BACKGROUND

Lactobacilli are the dominant bacteria in the healthy vaginal tract, preventing the income of pathogenic microorganisms, either sexually or not transmitted. Probiotics are used to restore the vaginal microbiome by local administration. However, the ascendant colonization is proposed as a way to restore the vaginal balance, and to exert some complementary effects on the host, situation that requires that probiotic strains resist the gastrointestinal tract passage.

OBJECTIVE

To determine which probiotic vaginal strains were able to resist different gastrointestinal factors (pH, bile salts, and enzymes) to advance in the design of oral formulas.

METHODS

Different protocols were applied to evaluate the growth of 24 beneficial vaginal lactic bacteria (BVL) strains at low pH and high bile salts (individually evaluated) and in combined protocols. The viability of the strains in simulated gastrointestinal tract conditions was studied to select the most resistant strains.

RESULTS

A low number of BVL was able to grow at low pH. Most of the strains did not survive at high bile salts concentration. The passage through pH first and bile salts later showed that only three strains were able to survive. In the simulated intestinal conditions, only Lactobacillus gasseri CRL1290, L. jensenii CRL1313, and L. jensenii CRL1349 decrease one or two logarithmic growth units (UFC/ml) at the end of the assay, maintaining their beneficial properties.

CONCLUSION

The behavior of BVL in the conditions assayed is not related to specific strain or metabolic group, because the resistance is strain-specific. The results highlight the importance of the screening performed in a way to select the most adequate strains to be included in the oral designed formula for the restoration of the vaginal tract microbiome.

Fermented soymilk and soy and cow milk mixture, supplemented with orange peel fiber or Tremella flava fermented powder as prebiotics for high exopolysaccharide-producing Lactobacillus pentosus SLC 13

BACKGROUND

A high exopolysaccharide-producing Lactobacillus pentosus SLC 13 strain was isolated from mustard pickles and showed the characteristics of a probiotic. Orange peel fiber powder (OPFP) and Tremella flava fermented powder (TFP) were shown to be potential prebiotics for L. pentosus SLC 13. The present study aimed to further develop new symbiotic fermented lactic acid beverages using SLC 13 with different proportions of cow milk and soymilk as food substrates, as well as with OPFP or TFP as prebiotics.

RESULTS

Acidification rate (soymilk groups, 3.02-4.37 mU min^-1 ; soymilk/milk mixture groups, 1.33-2.84 mU min^-1 ) and fermentation time (soymilk groups, 7.09-9.25 h; soymilk/milk mixture groups, 12.51-27.34 h) indicated that soymilk represents a suitable substrate for SLC 13-mediated fermentation. Moreover, OPFP and TFP induced a higher exopolysaccharide production of SLC 13 and a higher water holding capacity of fermented beverages. Sensory evaluations suggested that soymilk groups fermented with 10 g kg^-1 OPFP (SF-1.0P) and that with 5 g kg^-1 TFP (SF-0.5T) and also soymilk/milk mixture groups fermented with 5 g kg^-1 OPFP (HSMF-0.5P) and that with 10 g kg^-1 TFP (HSMF-1.0T) represent potential fermented drinks. Additionally, SF-1.0P and SF-0.5T products could be preserved for at least 21 days at 4 °C, with high viable cell counts (> 8.8 log₁₀ CFU mL^-1 ) and water holding capacity.

CONCLUSION

In the present study, we developed SF-1.0P and SF-0.5T products as a new symbiotic fermented lactic acid beverages. However, in the future, consumer acceptability could be improved by properly regulating the ratio of sugar to acid or seasoning. © 2019 Society of Chemical Industry.

Probiotic potential of Weissella strains isolated from horse feces

In this study, we isolated four Weissella confusa strains from the healthy horse feces to test their potential as equine probiotics. The identification and characteristics of these isolates were determined as per standard methods. Resistance and susceptibility of the isolated strains were tested to low pHs, different heat treatments, commonly used antibiotics and against the pathogenic strains of Salmonella, Pasteurella, Staphylococcus aureus, and Escherichia coli. After 3 h cultural in different pH medium, the 4 strains still had a certain amount of survival above pH 3.0. WH2 and WH4 were still viable at pH2.5. All the isolated strains showed proper growth at 60 °C while no strain survived at 80 °C. The inhibition of α-amylase, the scavenging ability of free radical DPPH· and hydroxyl free radical HO·were also investigated. The results showed that WH4 had highest inhibition rate of α-amylase activity and DPPH· free radical scavenging rate, and the inhibition rate of α-amylase activity was 24.09% and the DPPH· free radical scavenging rate was 35.78%. The inhibition rate ofα-amylase activity and DPPH· scavenging rate of free radicals in the other three strains were about 10%. The clearance rate of hydroxyl radical (HO·) in 4 strains was between 12% and 15%. The antibiotic susceptibilities varied for these four Weisella strains but all of them showed resistance against the frequently used equine antibiotics. All the four strains successfully suppressed the growth of standard strains in in vitro bacteriostasis experiment, which included Salmonella enteritidis (NTNC13349), Escherichia coli (C83902) and Staphylococcus aureus (BNCC186335). they also successfully suppressed the growth of state key laboratory isolating pathogens, which are Pasterurella multocida and Salmonella. Our findings suggest that the isolated strains of Weissella confusa can act as potential equine probiotics and should be explored further.

Molecular Identification and Probiotic Potential Characterization of Lactic Acid Bacteria Isolated from Human Vaginal Microbiota

Purpose: The increased demand for probiotics because of their health purposes provides the context for this study, which involves the molecular identification of lactic acid bacteria (LAB) obtained from the vaginal microbiota of healthy fertile women. The isolates were subjected for examination to prove their probiotic potential. In particular, the isolates were subjected to various tests, including acid/bile tolerance, antimicrobial activity, antibiotic susceptibility, Gram staining, and catalase enzyme activity assessment. Methods: Several methods were utilized for the molecular identification of the isolates, including ARDRA, (GTG)5-PCR fingerprinting, and the PCR sequencing of 16S-rDNA amplified fragments. Disc diffusion and well diffusion methods were used to assess antibiotic susceptibility and antibacterial activity of isolates. Tolerance to acid and bile was performed at pH 2.5 and 0.3% bile oxgall. Results: A total of 45 isolates of 88 separate organisms was selected. All of the isolates demonstrated an antibacterial effect on the exploited indicator microorganisms. All selected strains also maintained their viability at low-pH and high-bile salt conditions and exhibited abroad variation in their survival. Only the Enterococcus avium strain showed resistance to all 9 tested antibiotics. Based on the molecular identification and clustering, the 45 isolated bacteria were classified into three major groups of LAB: Enterococcus, Lactobacillus and Lactococcus. Conclusion: LAB are microorganisms that have a particularly important function in maintaining the health of the vaginal and gastrointestinal tract and in protecting it from infection by other pathogenic organisms. The isolates found to be a promising probiotic candidate by showed desirable characteristics. Therefore, strain DL3 can be used as natural food preservative with some more potential investigations.

Extra-Intestinal Fluoroquinolone-Resistant Escherichia coli Strains Isolated from Meat

Extra-intestinal E. coli are emerging as a global threat due to their diffusion as opportunistic pathogens and, above all, to their wide set of antibiotic resistance determinants. There are still many gaps in our knowledge of their origin and spread pathways, although food animals have been adjudicated vehicles for passing mult-drug resistant bacteria to humans. This study analyzed 46 samples of meat purchased from retail stores in Palermo in order to obtain quinolone-resistant E. coli isolates. Strains were screened for their phylogenetic groups, ST131-associated single nucleotide polymorphisms (SNPs), and then typed by ERIC-PCR. Their set of virulence factors, namely, kpsMII, papA, sfaS, focG, iutA, papC, hlyD, and afa genes, were investigated and their fluoroquinolone-resistance determinants evaluated. The data obtained show a dramatically high prevalence of multidrug resistance patterns in the Palermo area, with 28% of the isolates having virulence factor genes typical of ExPEC strains. No B2 group or ST131 strains were detected. Moreover, 20% of our isolates showed positivity to all the plasmid-mediated quinolone resistance (PMQR) determinants, showing a potential to transfer these genes among other bacteria. Therefore, these data underline the possibility that food animals and, specifically, poultry in particular may be a significant source of resistant bacterial strains, posing a potential zoonotic risk.

Phytase-Producing Potential and Other Functional Attributes of Lactic Acid Bacteria Isolates for Prospective Probiotic Applications

Wide variations among multifaceted-health benefitting attributes of probiotics fueled investigations on targeting efficacious probiotics. In the current study, lactic acid bacteria (LAB) isolated from poultry gut, feces of rat, chicken, human infants, and fermented foods were characterized for desired probiotic functional properties including the phytase-producing ability which is one of the wanted characteristics for probiotics for potential applications for upgrading animal nutrition, enhancing feed conversion, and minimizing anti-nutritional properties. Among 62 LAB isolates Weissella kimchii R-3 an isolate from poultry gut exhibited substantial phytase-producing ability (1.77 U/ml) in addition to other functional probiotic characteristics viz. hydrophobicity, autoaggregation, coaggregation with bacterial pathogens, and antimicrobial activity against pathogens. Survival of W. kimchii R-3 cells (in free and calcium alginate encapsulated state) was examined sequentially in simulated gastric and intestinal juices. Encapsulated cells exhibited better survival under simulated gut conditions indicating that encapsulation conferred considerable protection against adverse gut conditions. Furthermore, simulated gastric and intestinal juices with pepsin and pancreatin showed higher survival of cells than the juices without pepsin and pancreatin. W. kimchii R-3 due to its significant functional probiotic attributes may have prospective for commercial applications in human/animal nutrition.

Probiotic properties of native Lactobacillus spp. strains for dairy calves

The use of native microorganisms with probiotic capacity is an alternative tool for the treatment and prevention of several diseases that affect animals, such as neonatal calf diarrhoea. The selection of probiotic strains within a collection is based on different in vitro and in vivo assays, which predict their potential. The aim of this study was to characterise a group of native Lactobacillus spp. strains isolated from faeces of healthy calves using an in vitro approach and to assess their ability to colonise the gastrointestinal tract (GIT) of calves. Native Lactobacillus spp. strains were evaluated on their capacity to survive low pH conditions and bile salts presence, biofilm formation and adhesion to both mucus and Caco-2 cells. Based on the in vitro characterisation, four strains (Lactobacillus johnsonii TP1.1, Lactobacillus reuteri TP1.3B, L. johnsonii TP1.6 and Lactobacillus amylovorus TP8.7) were selected to evaluate their capacity to colonise and persist in the GIT of calves. The assessment of enteric persistence involved an in vivo assay with oral administration of probiotics and quantification in faeces of the administered bacterial species with real-time quantitative PCR (qPCR). The study was conducted using 15 calves (1-month-old) which were divided into five groups of three animals, four of which were treated with four different selected strains and one was the control group. Strains TP1.3B and TP1.6 managed to persist in treated animals until ten days after the end of the administration period, indicating that they could be promising candidates for the design of probiotics for calves.

Immunobiotics for the Bovine Host: Their Interaction with Intestinal Epithelial Cells and Their Effect on Antiviral Immunity

The scientific community has reported several cases of microbes that exhibit elevated rates of antibiotic resistance in different regions of the planet. Due to this emergence of antimicrobial resistant microorganisms, the use of antibiotics as promoters of livestock animals' growth is being banned in most countries around the world. One of the challenges of agricultural immunology therefore is to find alternatives by modulating the immune system of animals in drug-independent safe food production systems. In this regard, in an effort to supplant antibiotics from bovine feeds, several alternatives were proposed including the use of immunomodulatory probiotics (immunobiotics). The purpose of this review is to provide an update of the status of the modulation of intestinal antiviral innate immunity of the bovine host by immunobiotics, and the beneficial impact of immunobiotics on viral infections, focused on intestinal epithelial cells (IECs). The results of our group, which demonstrate the capacity of immunobiotic strains to beneficially modulate Toll-like receptor 3-triggered immune responses in bovine IECs and improve the resistance to viral infections, are highlighted. This review provides comprehensive information on the innate immune response of bovine IECs against virus, which can be further investigated for the development of strategies aimed to improve defenses in the bovine host.

Effects of mannan-oligosaccharides and Lactobacillus acidophilus supplementation on growth performance, nutrient utilization and faecal characteristics in Murrah buffalo calves

A study of 120 days was undertaken to ascertain the effect of mannan-oligosaccharides (MOS) and Lactobacillus acidophilus supplementation on growth performance, nutrient utilization and faecal characteristics in Murrah buffalo calves. Twenty Murrah buffalo calves of 5-7 days old and 31 ± 2.0 kg of body weight (BW) were randomly assigned into four groups. Group I served as the control (CON) in which only basal diet (concentrate mixture and green fodder) was provided, without any supplementation. Mannan-oligosaccharides at 4 g/calf/day were supplemented as prebiotic to Group II (PRE), whereas Group III (PRO) received Lactobacillus acidophilus in the form of fermented milk as probiotic at 200 ml/calf/day having 10⁸  CFU/ml and Group IV (SYN) was supplemented with both MOS and Lactobacillus acidophilus as synbiotic at similar dose. Final BW (kg), dry matter intake, average daily gain, feed conversion efficiency and structural growth measurements were improved (p < .05) in the treatment groups compared to control. Digestibility of neutral detergent fibre was higher (p < .05) in SYN followed by PRE and PRO than control. The faecal lactobacilli and bifidobacterium population was higher (p < .05) in all the supplemented groups with a concomitant reduction in faecal coliform count as compared to control. Faecal ammonia, lactate and pH were also altered favourably (p < .05) in all the supplemented groups as compared to CON. The faecal volatile fatty acids were higher (p < .05) in PRE, PRO and SYN group than CON. The incorporation of MOS and Lactobacillus acidophilus in diet either individually or in combination as synbiotic has the potential to improve the performance and faecal characteristics in Murrah buffalo calves; however, the observed responses among the treatment groups were more evident in the synbiotic fed group compared to individual supplementation of MOS and Lactobacillus acidophilus.

Complete genome sequence of Lactobacillus pentosus SLC13, isolated from mustard pickles, a potential probiotic strain with antimicrobial activity against foodborne pathogenic microorganisms

Background

Lactobacillus pentosus SLC13 is a high exopolysaccharide (EPS)-producing strain with broad-spectrum antimicrobial activity and the ability to grow in simulated gastrointestinal conditions. SLC13 was isolated from mustard pickles in Taiwan for potential probiotic applications. To better understand the molecular base for its antimicrobial activity and high EPS production, entire genome of SLC13 was determined by PacBio SMRT sequencing.

Results

L. pentosus SLC13 contains a genome with a 3,520,510-bp chromosome and a 62,498-bp plasmid. GC content of the complete genome was 46.5% and that of plasmid pSLC13 was 41.3%. Sequences were annotated at the RAST prokaryotic genome annotation server, and the results showed that the genome contained 3172 coding sequences and 82 RNA genes. Seventy-six protein-coding sequences were identified on the plasmid pSLC13. A plantaricin gene cluster, which is responsible for bacteriosins biosynthesis and could be associated with its broad-spectrum antimicrobial activity, was identified based on comparative genomic analysis. Two gene clusters involved in EPS production were also identified.

Conclusion

This genomic sequence might contribute to a future application of this strain as probiotic in productive livestock potentially inhibiting competing and pathogenic organisms.