Isolation, characterization, and assessment of lactic acid bacteria toward their selection as poultry probiotics

Harnessing Enterococcus faecium WFD-128 from yogurt fermentation: Unveiling probiotic attributes and targeted inhibition of Shigella sonnei diarrheal pathogenesis

Diarrhea is a leading cause of mortality among children under five, with few effective interventions beyond oral rehydration, antibiotics, and zinc supplementation. This study aimed to identify and evaluate the probiotic and anti-diarrheal potential of Enterococcus faecium WFD-128, isolated from fermented yogurt, through in vitro, in silico, and in vivo approaches. The bacterium showed notable antibacterial activity, with inhibition zones measuring 21 mm and 19 mm against Shigella flexneri and Shigella sonnei, respectively. Additionally, it exhibited anti-biofilm effectiveness of 82 % and 80 % against these pathogens. It exhibited resistance to Amoxicillin, intermediate sensitivity to Ampicillin and Chloramphenicol, and tolerance to bile salts over 3-48h, and to acidic pH levels ranging from 2 to 8. Gas Chromatography-Mass Spectrometry (GC-MS) identified 68 volatile compounds, of which [1,1'-Bicyclohexyl]-4-carboxylic acid, 4'-propyl-, 4-fluorophenyl ester (-8.5) and Cholest-4-en-26-oic acid, 3-oxo-, methyl ester (-7.9) showed strong binding affinities to the diarrheal protein T3SS of Shigella sonnei (PDB: 6WRY) in molecular docking studies. These compounds exhibited favorable pharmaceutical properties in ADMET analysis, further supported by molecular dynamics simulations. In vivo experiments with albino mice validated the bacterium's therapeutic potential. Histopathological analysis revealed significant recovery of diarrhea-affected organs, including the kidney, liver, intestine, and spleen, following treatment with E. faecium. This aligns with in vitro and in silico findings, demonstrating the bacterium's therapeutic effectiveness. This study highlights the promise of E. faecium as a probiotic-based treatment against bacteria-induced diarrhea, offering a strong foundation for the development of innovative anti-diarrheal therapeutics.

Characterization and genomic analysis of Lactiplantibacillus plantarum LP8 as a probiotic candidate for medical applications

This study presents the whole genome sequencing (WGS) and functional analysis of Lactiplantibacillus plantarum LP8, a promising probiotic strain, is presented in this research. The genome comprises a 3.23 Mbp circular chromosome and three plasmids including plasmid1_LP8 (58,764 bp), plasmid2_LP8 (45,003 bp), and plasmid3_LP8 (7985 bp). Functional annotation identified 3151 coding sequences (CDSs) mapped to 209 RAST subsystems, alongside biosynthesis gene clusters encoding Plantaricin J and other secondary metabolites such as RiPP-like peptides and terpenes. Safety analysis revealed no acquired antimicrobial resistance gene (AMR) or virulence genes, with only intrinsic resistance to certain antibiotics. In vitro analysis confirmed its sensitivity to antibiotics such as ampicillin, erythromycin, and tetracycline, and its hemolytic activity displayed an α-hemoly-sis pattern. These findings confirm L. plantarum LP8 as a safeand effective probiotic candidate with significant potential for antimicrobial and biotechnological applications.

Prevalence and Characterisation of Antimicrobial Resistance, Virulence Factors and Multilocus Sequence Typing (MLST) of Escherichia coli Isolated from Broiler Caeca

This study was undertaken to determine the effect of bird age and administering either Lactococcus lactis ssp. lactis 1 (LL) or Limosilactobacillus fermentum 1 (LF) in the drinking water on the prevalence of antimicrobial resistance by phenotypic test, multilocus sequence typing (MLST) and virulence genes of Escherichia coli (E. coli) isolated from broiler caeca by whole-genome sequencing (WGS) analysis. Male (Ross 308) day-old chicks (240) were reared for 28 days. Water was provided either untreated (CON) or with LL (107/mL) or LF (107/mL) via a nipple drinker on three days each week during the starter phase (days 1, 3, 5, 7, 9 and 11 d) in eight replicate pens per treatment, with initially ten chicks per pen. One chick from each pen was sacrificed when LL or LF was added to the water, and again on d 14 and 28. There was no evidence that LL and LF had any effect on the prevalence of antimicrobial resistance and virulence genes in E. coli isolates. The population density of Lactobacillus sp. and coliforms decreased with age (p < 0.001). The high resistance of E. coli to ampicillin and tetracycline was maintained throughout the life of the broilers. The prevalence of virulence genes was greatest during the starter phase but declined when birds were 28 days of age (p < 0.05). In birds < 14 d of age, E. coli MLST 457, 1640, 1485 and 155 were dominant, and these carried iucD, irp2, astA, iutA and iroN genes. When birds were 28 d of age, MLST 1286, 1112 and 973 predominated, and these carried few virulence genes. This suggests that young birds were more susceptible to putative pathogenic E. coli than older birds. Supporting the development of a healthy microbiome that might control the proliferation of potentially pathogenic E. coli is an area of future research.

Antimicrobial Activity, Genetic Diversity and Safety Assessment of Lactic Acid Bacteria Isolated from European Hakes (Merluccius merluccius, L.) Caught in the Northeast Atlantic Ocean

Background/Objectives: The overuse and misuse of antibiotics has contributed significatively to the growing problem of the emergence and spread of antibiotic resistance genes among bacteria, posing a serious global challenge to the treatment of bacterial infectious diseases. For these reasons, there is a current and growing interest in the development of effective alternative or complementary strategies to antibiotic therapy for the prevention of fish diseases, which are mainly based on the use of probiotics-in particular, those belonging to the Lactic Acid Bacteria (LAB) group. In this context, the aim of the present study was to characterise, evaluate the genetic diversity and assess the safety of candidate probiotic LAB strains for aquaculture isolated from faeces and intestines of European hakes (Merluccius merluccius, L.) caught in the Northeast Atlantic Ocean (Ireland). Methods: The direct antimicrobial activity of the LAB isolates was tested by the Stab-On-Agar method against key ichthyopathogens. Subsequently, their taxonomic classification and genetic diversity were determined by 16SrDNA sequencing and Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR), respectively. To ensure the in vitro safety of the LAB isolates, their biofilm-forming ability was assessed by a microtiter plate assay; their sensitivity to major antibiotics used in aquaculture, human and veterinary medicine by a broth microdilution method and their haemolytic and gelatinase activity by microbiological assays. Results: All LAB isolates were biofilm producers and susceptible to chloramphenicol, oxytetracycline, flumequine and amoxicillin. A total of 30 isolates (85.7%) were resistant to at least one of the tested antibiotics. None of the 35 LAB isolates showed haemolytic or proteolytic activity. Conclusions: Among the isolated strains, five LAB strains exhibiting the highest antimicrobial activity against aquaculture-relevant ichthyopathogens, taxonomically identified as Streptococcus salivarius, Enterococcus avium and Latilactobacillus sakei, were selected for further characterisation as potential probiotic candidates to promote sustainable aquaculture. To our knowledge, this is the first study to report that hake intestines and faeces represent viable ecological niches for the isolation of LAB strains with antimicrobial activity.

Impact of dietary polyphenols from shredded, steam-exploded pine on growth performance, organ indices, meat quality, and cecal microbiota of broiler chickens

The chicken's gastrointestinal tract is home to complex and diverse microbial communities that can be manipulated to enhance health and productivity. Although polyphenols have recently attracted the attention of researchers due to their potent antioxidant capabilities, their impact on the gut microbiota remains largely unexplored. Hence, in this study, we conducted a comprehensive analysis of the effects of dietary supplementation with polyphenol-rich extract from shredded, steam-exploded pine particles (PSPP) on growth, meat quality, and gut microbial dynamics in broiler chickens. Supplementation of PSPP was found to significantly improve birds' FCR until the third week of the trial but only marginally affected meat quality. Based on metataxonomic analyses of the cecal microbiotas of broilers fed increasing concentrations of PSPP, dietary PSPP modulated the composition of the cecal microbiota of the birds with a concomitant increase of Bacteroidetes and a decrease in the Firmicutes population. Similar trends were observed for the proportions of Alistipes and Faecalibacterium at the genus level. Additionally, 43 unique bacterial species were detected in the cecal microbiome of birds fed with PSPP. However, microbial diversity did not vary significantly among treatment groups. A particularly interesting finding was the specialization observed in the microbiome of birds receiving PSPP supplementation. Microbial co-occurrence network analyses revealed substantial modifications in their network structure when compared to control birds. Families like Rikenellaceae and Eubacteriaceae were notably absent, and the number of microbial interactions was drastically lower in the PSPP-fed group. Microbial taxa modeling revealed that the impact of increasing dietary PSPP levels primarily affected genus-level taxa, showing a decreasing trend. Overall, this offers compelling evidence that continuous PSPP supplementation may not only alter the composition of intestinal microbes but also have a profound effect on the interactions among different microbial species. Conversely, PSPP had minimal effects on broilers' performance and meat quality.

Probiotic Potential of Pediococcus pentosaceus M6 Isolated from Equines and Its Alleviating Effect on DSS-Induced Colitis in Mice

Colitis in equines has high morbidity and mortality rates, which severely affects the development of the equine-breeding industry. With the issuance of antibiotic bans, there is an urgent need for healthier and more effective alternatives. In recent years, probiotics have been widely used as microbial feed additives in animal husbandry, playing a crucial role in preventing and treating diarrhea and regulating host immune function. In this study, we isolated and screened a strain with rapid and stable acid production using bromocresol purple, litmus milk coloration tests, and acid production performance assessments. Based on morphological characteristics, physiological and biochemical properties, and 16S rDNA identification, the strain was identified as Pediococcus pentosaceus and named M6. The Pediococcus pentosaceus M6 exhibited stable growth and tolerance to high temperatures, acid and bile salt concentrations, and simulated gastrointestinal fluid environments. The M6 strain demonstrated good antibacterial effects against Escherichia coli, Staphylococcus aureus, and Salmonella. The M6 strain did not produce hemolysis zones on Columbia blood agar plates, indicating its high safety, and was found to be insensitive to 12 antibiotics, including cephalexin and neomycin. Additionally, intervention in mice with dextran sulfate sodium (DSS)-induced colitis alleviated weight loss and shortened colon length. To a certain extent, it regulated the expression of inflammatory cytokines and the gut microbiota within the body and reduced inflammatory cell infiltration and intestinal barrier damage. In summary, the isolated Pediococcus pentosaceus M6 strain exhibited excellent probiotic properties and could alleviate DSS-induced colitis in mice, suggesting its potential application value as a probiotic in animal husbandry.

Lactobacillus salivary LSbg3 is a Potential Food Probiotic Having Excellent Anti-pathogen Effect That Might Improve Antibiotic-Resistant Diarrhea in Dogs

Antibiotics may disrupt the intestinal microbiota balance and induce antimicrobial resistance. Although probiotics should be a priority treatment for animal diarrhea, it still has chance to be used as same/or behind as antibiotics in the clinic. Among the probiotics, Lactobacillus (Lact.) was the most frequently utilized in clinical setting since its excellent ability of safety, anti-pathogen, stress resistance, and easy colonization in intestine. In this study, we screened 24 strains of Lact. in the presence of antibiotics from clinical common antibiotic-treated feces, identified L. salivarius LSbg3 exhibiting good stress resistance, potent antibacterial activity, and exceptional intestinal adhesion capability. Its genome showed a good function of regulating intestinal nutrition while lack of transmission antibiotic-resistance genes. Additionally, in a simulated canine diarrhea with failed antibiotic treatment, LSbg3 had a good efficacy in the releasing diarrhea, balancing the microbiome and suppressing typical pathogens, positioning a potential food probiotic have excellent effect on anti-pathogen that can effectively improve antibiotic-resistant diarrhea in dogs.

Complete Genome Sequence and Probiotic Properties of Pediococcus acidilactici CLP03 Isolated from Healthy Felis catus

Probiotics are available from various sources, including the gastrointestinal tract of healthy animals. In this study, Pediococcus acidilactici was isolated for the first time from Felis catus and evaluated for its functionality. The findings revealed that P. acidilactici CLP03 exhibited inhibitory properties against pathogenic bacteria (E. coli, Salmonella, S. aureus, P. aeruginosa, and L. monocytogenes). Then, survival of strains exposed to pH 2.5, 0.3% bile salts, 0.5% bile salts, and gastrointestinal fluids was 63.97%, 98.84%, 87.95%, and 52.45%, respectively. Also, P. acidilactici CLP03 demonstrated high hydrophobicity (69.63-82.03%) and self-aggregation (73.51-81.44%), negative for hemolytic, and was susceptible to clindamycin. Finally, the scavenging rates of DPPH, ABTS, and O2- were 53.55%, 54.81%, and 85.13%, respectively, which demonstrated that the strain CLP03 has good oxidation resistance. All these characteristics contribute to the survival, colonization, and functionality of the strain in the gastrointestinal tract, indicating their excellent probiotic potential. On the other hand, animal experiments (KM mice, randomly assigned to four groups) showed that the gavage of CLP03 had no toxic effects on mice, increased the serum SOD content, and decreased the MDA and BUN contents, which revealed gavage of CLP03 significantly increased the antioxidant capacity of mice in vivo. In addition, complete genome annotation showed that P. acidilactici CLP03 had 1976 CDS genes, and the numbers of CRISPR, gene islands, and phages were 8, 3, and 6, respectively. In conclusion, P. acidilactici CLP03 could be a candidate functional cat probiotic to enhance animal health and welfare.

Effects of Lactobacillus acidophilus on production performance and immunity of broiler chickens and their mechanism

Introduction

Lactobacillus species have attracted more and more attention as a potential antibiotic substitute for human health and animal production due to their remarkable antibacterial effects. However, the underlying mechanism is unclear. This experiment's goal was to investigate the impacts of lactic acid bacteria (LAB) on the growth performance, carcass characteristics, immune function of broiler chickens and their mechanism.

Methods

One hundred and eighty 1-day-old AA broilers were used and randomly allocated into 3 treatment groups with 6 replicates of 10 chickens per replicate. The 3 treatment groups were control group (CK), L. acidophilus added group (LAB-E, 1.0 × 108 CFU/kg) for the first 7 days; L. acidophilus added group (LAB-A, 1.0 × 108 CFU/kg) for the whole experimental period. Broilers had free access to water and feed.

Results

The results showed that addition of L. acidophilus for the whole experimental period significantly decreased ADFI, FCR and the abdominal fat percentage of broilers (p < 0.05), tended to increase the levels of IgG in broiler serum (p = 0.093). The LAB-A group had higher HDL-C content and IL-2, IL-4 content, and lower level of LPS in broiler serum compared to the controls (p < 0.05).

Discussion

In conclusion, L. acidophilus improved feed efficiency and immune function of broilers by controlling nutrient metabolism and inflammation responses of broilers. L. acidophilus can be used as a potential substitute for antibiotics in broiler production.

Probiotic characteristics and whole genome sequencing of Pediococcus pentosaceus SNF15 and its protective effect on mice diarrhea induced by Escherichia coli K99

Escherichia coli (E. col iK99) is one of the primary pathogens that cause infectious calf diarrhea, resulting in mortality and causing economic losses. Probiotics have been widely researched for their positive impact on inhibiting the growth of pathogenic bacteria and enhancing immunity and gut health as alternatives to antibiotics. This study isolated one probiotic from healthy calf feces: Pediococcus pentosaceus SNF15 (P. pentosaceus SNF15). In vitro assessments included growth character and acid-producing ability, bile salt and artificial gastroenteric fluid tolerance, Caco-2 adhesion, hemolysis screening, and antibiotic susceptibility. Whole-genome sequencing identified immunomodulatory, antimicrobial, and metabolic genes. A murine model evaluated probiotic efficacy against E. coli K99, outcomes included clinical indices (fecal score, weight), histopathology (H&E), inflammatarty factor (qRT-PCR and ELISA), tight junction proteins and mucin (immunohistochemistry detection). Finally, 16S rRNA sequencing was performed to compare the composition and relative abundance of the gut microbiota among the different groups. P. pentosaceus SNF15 demonstrated excellent growth performance and acid production capacity, bile salt and artificial gastroenteric fluid resistance, Caco-2 cells adhesion and safety (γ-hemolysis, antibiotic sensitivity) Genomic analysis revealed to immune, anti-inflammatory, antagonistic pathogens, and carbohydrate utilization, including secondary bile acid, nicotinate and nicotinamide. The animal tests showed that the P. pentosaceus SNF15 treatment protects against E. coli K99 infection, as evidenced by clinical symptoms, including weight loss, fecal score, liver atrophy, and spleen enlargement occurred histological damage. Compared with the CN group, the supplementation of P. pentosaceus SNF15 strains ameliorated the damage of jejunum and the content of tight junction proteins occludin, claudin, ZO-1, and MUC2 and decreased the levels of IL-6, IL-1β, and TNF-α in jejunum. The 16S rDNA sequence results showed that infection with Escherichia coli K99 led to an imbalance in gut microbiota; the proportion of Firmicutes and Bacteroidetes decreased, and Proteobacteria increased. P. pentosaceus SNF15 helps improve intestinal microbial composition and prevents this trend. P. pentosaceus SNF15 supplementation can prevent and treat the clinical symptoms, intestinal epithelial mucosal integrity, intestinal permeability, and immune-related cytokines and regulate the intestinal microbiota in E. coli K99-infected mice. This research revealed that P. pentosaceus SNF15 possesses desirable probiotic characteristics and could be used as a potential probiotic to remit neonatal calf diarrhea, caused by E. coli K99 infection.

Probiotic Potential of Enterococcus lactis GL3 Strain Isolated from Honeybee (Apis mellifera L.) Larvae: Insights into Its Antimicrobial Activity Against Paenibacillus larvae

This study aimed to address the need for effective probiotics and antibacterial agents to combat American foulbrood disease in honeybees, caused by Paenibacillus larvae. In the context of declining honeybee populations due to pathogens, we isolated eight lactic acid bacteria (LAB) strains from honeybee larvae (Apis mellifera L.) and evaluated their probiotic potential and inhibitory effects against P. larvae. Methods included probiotic property assessments, such as acid and bile salt resistance, hydrophobicity, auto-aggregation, co-aggregation with P. larvae, antioxidant capacities, osmotolerance to 50% sucrose, and antibiotic susceptibility. Results indicated that the GL3 strain exhibited superior probiotic attributes and potent inhibitory effects on P. larvae. Whole-genome sequencing revealed GL3 to be an Enterococcus lactis strain with genetic features tailored to the honeybee larval gut environment. Pangenome analysis highlighted genetic diversity among E. lactis strains, while molecular docking analysis identified aborycin, a lasso peptide produced by GL3, as a promising inhibitor of bacterial cell wall synthesis. These findings suggested that GL3 was a promising probiotic candidate and antibacterial agent for honeybee health management, warranting further investigation into its in vivo efficacy and potential applications in beekeeping practices.

Developing Gut-Healthy Strains for Pets: Probiotic Potential and Genomic Insights of Canine-Derived Lactobacillus acidophilus GLA09

Probiotics are widely used to improve pet health and welfare due to their significant biological activity and health benefits. Lactobacillus acidophilus GLA09 was derived from the intestinal tract of healthy beagles. The safety and suitability evaluation of GLA09 was completed through a combination of whole genome sequence and phenotypic analyses, including tests for the inhibition of harmful bacteria, acid resistance, bile salt tolerance, adhesion, and amine-producing substance content. The findings revealed that GLA09 has good gastrointestinal tolerance, inhibits the growth of pathogenic bacteria, and does not produce toxic biogenic amines. The genome of GLA09 comprises one chromosome and one plasmid, with a genome size of 2.10 M and a Guanine + Cytosine content of 38.71%. It encodes a total of 2208 genes, including 10 prophages, and 1 CRISPR sequence. Moreover, 56 carbohydrate-encoding genes were identified in the CAZy database, along with 11 genes for cold and heat stress tolerance, 5 genes for bile salt tolerance, 12 genes for acid tolerance, and 14 predicted antioxidant genes. Furthermore, GLA09 has one lincosamide resistance gene, but there is no risk of transfer. GLA09 harbors a cluster of Helveticin J and Enterolysin A genes linked to antimicrobial activity. Genomic analysis validated the probiotic attributes of GLA09, indicating its potential utility as a significant probiotic in the pet food industry. In summary, L. acidophilus GLA09 has the potential to be used as a probiotic in pet food and can effectively combat intestinal health in pets.

Antibacterial Activity, Probiotic Potential, and Biocontrol Efficacy of Two Lactic Acid Bacteria Against Penicillium expansum on Fresh Grapes

Lactic acid bacteria are commonly present in various sources and possess significant probiotic properties. They can inhibit pathogenic bacteria and fungi simultaneously, making them promising candidates as bio-preservatives. This study investigated two potential probiotic strains: Lactiplantibacillus plantarum LR5-2 (isolated from fermented meat products) and Lacticaseibacillus rhamnosus SQ63 (isolated from infant feces). The study evaluated their aggregation ability, anti-pathogenic activity, safety, and tolerance to gastrointestinal conditions, phenol, and bile salts. Additionally, their biological control potential against Penicillium expansum on fresh grapes was assessed. The results demonstrated that both strains exhibited high survival rates under extreme gastrointestinal conditions, enhanced Auto-aggregation, co-aggregation, and hydrophobicity. They displayed strong antioxidant activity and significant antibacterial effects against 11 pathogenic fungi and foodborne pathogens. Biosafety testing revealed that both strains are sensitive to most antibiotics, do not produce biogenic amines, and exhibit no hemolytic or DNase activity. In grapes, L. plantarum LR5-2 and L. rhamnosus SQ63 significantly reduced the incidence and disease index of P. expansum infection. In conclusion, the characterization analysis and bio-preservation experiments revealed that LR5-2 and SQ63 have strong potential as probiotics and bio-preservatives.

Effects of Enterococcus faecalis Supplementation on Growth Performance, Hepatic Lipid Metabolism, and mRNA Expression of Lipid Metabolism Genes and Intestinal Flora in Geese

The effects of Enterococcus faecalis (E. faecalis) at a concentration of 1.0 × 108 CFU/mL on growth performance, hepatic lipid metabolism, and mRNA expression related to lipid metabolism, intestinal morphology, and intestinal flora were investigated in geese. A total of 60 male geese, aged 30 days and of similar weight, were randomly assigned to 2 groups. Each group was divided into six replicates, with five geese per replicate. During the 45-day experiment, the control group received a basal diet, while the experimental group was provided with the same basal diet supplemented with E. faecalis in drinking water at a concentration of 1.0 × 108 CFU/mL. E. faecalis significantly increased the half-eviscerated weight of geese and improved ileal intestinal morphology (p < 0.05). Serum triglyceride (TG) levels were significantly reduced on day 5, while serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels were significantly decreased on day 25 (p < 0.05). By day 45, serum TG and free fatty acid (FFA) levels were also significantly reduced (p < 0.05). Additionally, E. faecalis significantly increased the HDL/LDL ratio and serum high-density lipoprotein cholesterol (HDL-C) levels (p < 0.05). Serum insulin levels were significantly elevated on day 25, and glucagon-like peptide-1 (GLP-1) levels were significantly increased on day 45 (p < 0.05). On day 25 of the trial, hepatic TG levels, FFA levels, and Oil Red O-stained areas in the liver were significantly reduced (p < 0.05), accompanied by significantly decreased mRNA expression of hepatic acetyl-CoA carboxylase (ACCA) (p < 0.05). Conversely, the mRNA expression levels of fatty acid synthase (FASN), farnesoid X receptor (FXR), sterol regulatory element-binding protein 1 (SREBP-1), and peroxisome proliferator-activated receptor-α (PPARα) were significantly elevated (p < 0.05). A 16S rRNA diversity analysis of ileal contents on day 25 revealed significant differences in intestinal flora composition between the control and E. faecalis groups. The 16S rRNA data demonstrated a strong correlation between microbial communities and lipid-related physiological and biochemical indicators (p < 0.05). In conclusion, E. faecalis supplementation promoted fatty acid oxidation, reduced blood lipid levels, alleviated hepatic lipid accumulation, and improved ileal morphology and intestinal flora diversity, thereby enhancing growth performance and lipid metabolism in geese. These findings suggest that E. faecalis is a promising probiotic candidate for development as a feed additive.

Tropical fruit-derived Lactiplantibacillus as potential probiotic and antifungal agents against Fusarium oxysporum

Fifty-five lactic acid bacteria (LAB) were isolated from seven selected tropical fruits, with Solanum nigrum exhibiting the highest LAB prevalence and Couroupita guianenis and Musa fruits showing the lowest counts. Two strains isolated from Ficus racemosa demonstrated significant antifungal activity against Fusarium oxysporum. 16S rDNA sequencing identified these strains as Lactiplantibacillus plantarum MYSVCF3 and Lpb. argentoratensis MYSVCF5. The isolates displayed adaptability to a broad range of environmental conditions, including temperatures of 10-45 °C, pH 2-6, and salt up to 7%. The strains tolerated simulated gastrointestinal conditions of acid (pH-2), phenol (0.6%), and bile (0.3%) suggesting potential probiotic attributes. Lpb. argentoratensis MYSVCF5 inhibited F. oxysporum, two ESKAPE group bacteria (P. aeruginosa, S. aureus) plus S. paratyphi and E. coli. The cell-free supernatant (CFS) of Lpb. argentoratensis MYSVCF5 reduced the growth of fungal biomass by 94% and completely inhibited conidial germination, retaining activity even after extended cold storage. LC-MS/MS analysis identified organic acids in the CFS, with citric acid as the most abundant at 34.9 (± 0.3) µg/mL, followed by lactic (8.3 µg/mL) and malic acids (5.2 µg/mL). This study isolated a novel LAB, a potential candidate having probiotics and antifungal properties for application in food and agriculture.

Bacteriocin-Producing Staphylococci and Mammaliicocci Strains for Agro-Food and Public Health Applications with Relevance of Micrococcin P1

Antimicrobial-producing strains and their bacteriocins hold great promise for the control of bacterial diseases, being an attractive alternative to antibiotics. Thus, the aim of this study was to evaluate the inhibitory activity of 15 bacteriocin-producing staphylococci and mammaliicocci (BP-S/M) strains and their pre-purified extracts with butanol (BT) against a collection of 27 harmful or zoonotic strains (including Gram-positive/-negative bacteria and molds) with relevance in the public health and agro-food fields. These indicators (excluding Gram-negative strains) were grouped into seven categories based on their potential application areas: dairy livestock mastitis, avian pathogen zoonoses, swine zoonoses, food safety, aquaculture, wine making, and mushroom cultivation. In addition, cross-immunity assays between the BP-S/M strains were carried out to identify potential strain combinations to enhance their activity against pathogens. Finally, the hemolytic and gelatinase activities were tested in the BP-S/M strains. A strong inhibitory capacity of the BP-S/M strains was verified against relevant Gram-positive indicators, such as methicillin-resistant Staphylococcus aureus, Listeria monocytogenes, and Clostridium perfringens, among others, while no activity was detected against Gram-negative ones. Interestingly, several BT extracts inhibited the two mold indicators included in this study as representants of mushroom pathogens. The Micrococcin P1 producer Staphylococcus hominis C5835 (>60% of indicators were intensively inhibited by all the methods) can be proposed as a potential candidate for the control of bacterial diseases in the aforementioned categories alone or in combination with other BP-S/M strains (mainly with Staphylococcus warneri X2969). In this regard, five potential combinations of BP-S/M strains that enhanced their activity against specific pathogens were detected.

Probiotic Characterization of Lactic Acid Bacteria from Donkey Feces in China

Probiotics are beneficial to humans and animals and often used for regulating immunity, intestinal microbiota balance, and animal growth performance. Donkey husbandry has boomed in China in recent years and there is an urgent need for probiotics effective for improving donkey health. However, studies on potential probiotic strains isolated from donkeys are scarce. This project aimed to screen LAB strains from donkey feces, detect their antimicrobial activity and evaluate their probiotic characteristics in vitro. Thirteen LAB isolates showed different degrees of antimicrobial activity against four indicator bacteria: three common pathogens (Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium) and one pathogen restricted to equines (Salmonella. abortus equi), eight of which could inhibit all four pathogens. Seven isolates showed higher tolerance to low pH and bile salts, with >50% and >60% survival rates, respectively. Five of them had more than 50% survival rate to artificial gastric and intestinal fluids. Only three isolates possessed good properties, with >40% auto-aggregation, >40% hydrophobicity, and high co-aggregation with the indicator pathogens. An L9 isolate, identified as Ligilactobacillus salivarius, was sensitive to most antibiotics tested. Overall, these results indicate that the L. salivarius L9 isolate meets the requirements of the probiotics selection criteria in vitro and can potentially be developed as a probiotic for donkeys.

Lactobacillus agilis SNF7 Presents Excellent Antibacteria and Anti-Inflammation Properties in Mouse Diarrhea Induced by Escherichia coli

Escherichia coli (E. coli) is a common pathogen that causes diarrhea in newborns and animals. Antibiotics are typically used to treat bacterial diarrhea, a global intestinal health issue. Probiotics have gained interest as a potential substitute for antibiotics in the management of E. coli-induced diarrhea and present novel therapeutic options. In this study, the probiotic properties of Lactobacillus agilis SNF7 (L. agilis SNF7) isolated from feces were investigated, and whole genome sequencing was performed to evaluate the properties of the strain. Furthermore, we investigated the protective effects of L. agilis SNF7 in a mouse model of E. coli K99 infection. L. agilis SNF7 exhibits a high survival rate in artificial gastroenteric fluid and bile salt environments, along with an antagonistic effect against E. coli O111:K58 (B4), Staphylococcus aureus (S. aureus), and E. coli K99. Multiple genes with probiotic properties, including bacteriostasis, anti-inflammation, antioxidant, CAZyme, and the utilization of carbohydrate compounds, were identified in genome. L. agilis SNF7 prevented the gut barrier from being damaged by E. coli K99, reducing the clinical manifestations of the infection. Furthermore, L. agilis SNF7 reduced the expression of inflammatory cytokines (IL-6, IL-1β, and TNF-α) by inhibiting the phosphorylation of proteins linked to the NF-κB and MAPK signaling pathways. L. agilis SNF7 improved the intestinal microbial barrier, controlled the balance of the intestinal microecology, and reduced the entry of harmful microbes into the intestine. By controlling gut flora and reducing the inflammatory response, L. agilis SNF7 may be able to prevent and treat E. coli K99 infections. The application of L. agilis SNF7 in the creation of probiotic formulations to stop intestinal illnesses brought on by E. coli infections is clarified by this work.

Unlocking Probiotic Potential: Genomic Insights into Weissella paramesenteroides UFTM 2.6.1

Weissella, a genus of lactic acid bacteria, has diverse beneficial attributes including probiotic activity and biotechnological applications. Therefore, the investigation of the Weissella genus has garnered growing interest. In this study, we sequenced the complete genome of Weissella paramesenteroides UFTM 2.6.1 isolated from unpasteurized cow's milk from the Triângulo Mineiro region and performed probiogenomic analyses. Taxonomic characterization confirmed the identity of W. paramesenteroides. The genome comprises 1926 protein-coding genes, mainly related to cell metabolism, information storage and processing, and cellular processes and signaling. Ninety-nine unique genes associated with probiotic functions were identified in the genome of W. paramesenteroides UFTM 2.6.1, including genes involved in stress response, bacterial persistence in the gastrointestinal tract, and biosynthesis of vitamins. In silico analysis of bacteriocin-related genes identified Pediocin, and subsequent in vitro testing confirmed that W. paramesenteroides UFTM 2.6.1 exhibits antimicrobial activity against Listeria spp. Genomic characterization revealed the presence of the replicon pLCK4 and four prophage regions, one of which was intact. Moreover, no CRISPR-Cas array or associated Cas proteins were found, along with an absence of resistance and virulence genes, suggesting a safety aspect of the evaluated strain. Pan-genome analysis unveiled 204 exclusive genes in the genome of W. paramesenteroides UFTM 2.6.1, which includes metabolism and stress-associated genes. In general, the results indicate probiotic potential of W. paramesenteroides UFTM 2.6.1. Further studies are required to ensure the safety and beneficial effects of this bacterium in vivo, aiming for future applications in the food industry and animal and human medicine.

Isolation and in vitro investigation on lactic acid bacteria for potential probiotic properties from cat feces

Background

Probiotics, which are beneficial to the host, have been shown to benefit the health of cats. Lactic acid bacteria (LAB) are commonly used probiotics, but most strains used for cats are not derived from cats, leading to reduced efficacy and poor adaptation to cats. The objective was to identify LAB with promising probiotic potential specific to cats.

Method

LABs were isolated from fecal samples of 20 healthy cats. Gram staining and the survival rate in the simulated gastrointestinal tract were used for preliminary screening. Candidate strains were identified by 16S rDNA sequencing, and further evaluated for adhesion ability, growth characteristics, antibacterial activity, antioxidant capacity, and safety.

Results

24 Gram-positive isolates were identified, with 10 (F1-F10) showing robust viability in the simulated gastroenteric fluid. These 10 strains exhibited excellent adhesion to Caco-2 cells and strong auto-agglutination properties. They also possessed the capacity to antagonize and aggregate pathogens (Staphylococcus aureus ATCC 25923, Salmonella Braenderup H9812, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa PAO1), Moreover, all strains demonstrated tolerance to H2O2 concentrations ranging from 0.5-2 mmol/L and the ability to scavenge 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, indicating a certain level of antioxidant activity. Safety tests showed no hemolytic activity, and all but F6 were highly sensitive to antibiotics, with over 62.5% sensitivity to 16 antibiotics. Remarkably, F4 (Lactobacillus reuteri) and F10 (Lactobacillus brevis) exhibited exceptional viability in the simulated gastrointestinal tract, coupled with robust growth potential, enhanced adhesion efficiency, significant antibacterial and antioxidant properties.

Conclusion

Our findings revealed that F4 (Lactobacillus reuteri) and F10 (Lactobacillus brevis) hold promising potential as probiotics. This research lays a solid scientific foundation for the selection and application of probiotics tailored specifically for cats.

The potential Impact of bacterial probiotics on ruminal greenhouse gases production in vitro of dietary Delonix regia seeds in rams and steers

This study aimed to evaluate the influence of probiotic bacteria (Pediococcus acidilactici BX-B122 and Bacillus coagulans BX-B118) on methane, carbon monoxide, and hydrogen sulfide, and fermentation profile of dietary Delonix regia seeds in ruminant. Ruminal contents from slaughtered rams and steers were used as inoculum for in vitro fermentation system. The total gas, methane, carbon monoxide, and hydrogen sulfide volume, as well as pH and dry matter degradability, were quantified in three fermentation cycles. Probiotic bacteria reduced the production of methane and hydrogen sulfide, while also increasing (P < 0.05) dry matter biodegradability, short-chain fatty acids, and metabolizable energy in both rams and steers. Delonix regia seeds at 6, 12, and 18% reduced total gas production. Higher production of methane and carbon monoxide was observed in rams compared to steers. Interestingly, no impact (P > 0.05) on the pH of the ruminal contents was found in Delonix regia seeds alone or in combination with probiotics. However, higher (P < 0.05) methane conversion efficiency (i.e., ratios of methane: short-chain fatty acids, methane: metabolizable energy, and methane: organic matter) was observed in experimental diets with Delonix regia seeds compared to diets containing both Delonix regia seeds and probiotic bacteria. In conclusion, dietary inclusion of 6, 12, and 18% of Delonix regia seeds with probiotic bacteria (Pediococcus acidilactici BX-B122 and Bacillus coagulans BX-B118) can mitigate the production of methane and hydrogen sulfide, while also increasing dry matter biodegradability, short-chain fatty acids, and metabolizable energy both ruminant animals.

Bacteriocin Mining in Lactiplantibacillus pentosus PCZ4 with Broad-Spectrum Antibacterial Activity and Its Biopreservative Effects on Snakehead Fish

Some lactic acid bacteria (LAB) produce antibacterial substances such as bacteriocins, making them promising candidates for food preservation. In our study, Lactiplantibacillus pentosus PCZ4-a strain with broad-spectrum antibacterial activity-was isolated from traditional fermented kimchi in Sichuan. Whole-genome sequencing of PCZ4 revealed one chromosome and three plasmids. Through BAGEL4 mining, classes IIa and IIb bacteriocin plantaricin S were identified. Additionally, two new antibacterial peptides, Bac1109 and Bac2485, were predicted from scratch by limiting open reading frames. Furthermore, during refrigerated storage of snakehead fish, PCZ4 crude extract reduced the total bacterial count, slowed the increase in TVB-N and pH values, improved the sensory quality of the snakehead, and extended its shelf life by 2 days. Meanwhile, PCZ4 effectively inhibited the growth of artificially contaminated Aeromonas hydrophila in snakehead fish. These findings indicate that Lp. pentosus PCZ4 can produce multiple antibacterial substances with strong potential for food preservation applications.

Evaluation of Probiotic Potential and Functional Properties of Lactobacillus Strains Isolated from Dhan, Traditional Algerian Goat Milk Butter

Goat milk butter, locally known as "Dhan", from the Sfisfa region of Algeria, holds significant cultural and economic value. This study investigates the probiotic properties of lactic acid bacteria (LAB) present in Dhan, focusing particularly on Lactobacillus strains. Molecular identification using 16S rRNA revealed a dominance of Levilactobacillus brevis and Lactiplantibacillus plantarum, forming a substantial part of the bacterial profile. Three LAB isolates (DC01-A, DC04, and DC06) were selected from fresh samples, and rigorous analyses were performed to evaluate their probiotic properties. Safety assessments confirmed the absence of gelatinase, DNase, and haemolytic activities in all isolates. The isolates demonstrated high tolerance to bile salts and acidic conditions, along with the ability to survive simulated gastrointestinal digestion. Notably, strain DC06 exhibited exceptional survival at low pH (1.5) and high bile salt concentrations (0.15-0.3%). All isolates showed substantial growth in MRS medium with 2% phenol, although growth was significantly decreased at 5% phenol. Furthermore, our strains exhibited high adhesion rates to various solvents, demonstrating their potential for strong interaction with cell membranes. Specifically, adhesion to chloroform was observed at 98.26% for DC01-A, 99.30% for DC04, and 99.20% for DC06. With xylene, the adhesion rates were 75.94% for DC01-A, 61.13% for DC04, and 76.52% for DC06. The LAB strains demonstrated impressive growth in ethanol concentrations up to 12%, but their tolerance did not exceed this concentration. They also exhibited robust growth across temperatures from 10 °C to 37 °C, with strains DC04 and DC06 able to proliferate at 45 °C, though none survived at 50 °C. Additionally, the isolates showed significant resistance to oxidative stress induced by hydrogen peroxide (H2O2) and displayed medium to high autolytic activity, with rates of 50.86%, 37.53%, and 33.42% for DC01-A, DC04, and DC06, respectively. The cell-free supernatant derived from strain DC04 exhibited significant antimicrobial activity against the tested pathogens, while strain DC06 demonstrated moderate antioxidant activity with the highest DPPH scavenging rate at 68.56%, compared to the probiotic reference strain LGG at 61.28%. These collective findings not only suggest the probiotic viability of LAB strains found in Dhan but also highlight the importance of traditional food practises in contributing to health and nutrition. Consequently, this study supports the potential of traditional Dhan butter as a functional food and encourages further exploration of its health benefits.

Functional and molecular characterization of millet associated probiotic bacteria

The lactic acid bacteria are one of the sustainable ways of food production. As the native lactic acid bacteria (LAB) easily manipulate the substrate, helps in production of health essential probiotics with enhancing the bioavailability of the substrate. Here also, in present study, the native LAB isolates isolated from the millets and characterize them for the functional analysis for the human health association. In the present study, fermented millet-associated lactic acid bacteria were screened and characterized for their probiotic potential, safety evaluation and antimicrobial activity. A total of 33 isolates were purified as lactic acid bacteria based on colony shape and biochemical assays. However, only 13 isolates were found to be catalase-negative. Among the 13 isolates, 5 isolates exhibited optimum growth at 6.5% and 9.5% of salt concentrations, pH of 4.5 to 8.5 and 17 °C to 40 °C of the temperature. The probiotic properties of the five isolates exhibited that the survival rates in acid and bile salt concentration ranged from 56.2 to 73.7% and 55.3 to 70.3%, respectively. Similarly, the surface hydrophobicity of the isolates was 41-75%. Antibiotic assay revealed that all five isolates were resistant to Amoxicillin, Cloxacillin, and Penicillin-V. Interestingly, all the isolates except ME26 displayed susceptibility towards Penicillin (2 units) and Tetracycline (10 µg). Further, the four isolates (ME25, ME26, ME9, and ME2) had more antifungal activity against Aspergillus flavus. However, only three, except ME1 and ME2, showed maximum antibacterial activity and produced more antimicrobial compounds compared to reference strain L. plantarum Pb3. The potential probiotic isolates were identified as Weisella cibaria ME9, Weisella cibaria ME26, and Weisella confusa ME25.

Dynamic hydrazone crosslinked salecan/chondroitin sulfate hydrogel platform as a promising wound healing Strategy: A comparative study on antibiotic and probiotic delivery

Natural polysaccharide-based active-ingredient carriers have been a source of great concern for a long time. In order to explore potential antibiotics and probiotics carriers, a novel injectable chondroitin sulfate/salecan (CS) hydrogel was constructed by forming dynamic hydrazone bonds. Scanning electron microscope (SEM), proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR), bacteriostatic test, and rheological experiments were used to investigate the chemical structure, inherent morphology, and enzymatic corruption of the hydrogel in vitro. The resulting hydrogels exhibited ideal probiotics loading capacity, drug release behavior, excellent antimicrobial activity and variable properties. Crucially, owing to its exceptional biocompatibility and reversible crosslinking network, this hydrogel can function as a three-dimensional extracellular matrix for cells, enabling cells to maintain high vitality and proliferation, and promote wound healing. The aforementioned findings indicated that this novel hydrogel can be a promising candidate as an active-ingredient carrier and scaffold material for tissue engineering.

Efficiency of freeze- and spray-dried microbial preparation as active dried starter culture in kombucha fermentation

BACKGROUND

Kombucha is a widely consumed fermented beverage produced by fermenting sweet tea with a symbiotic culture of bacteria and yeast (SCOBY). The dynamic nature of microbial communities in SCOBY may pose challenges to production scale-up due to unpredictable variations in microbial composition. Using identified starter strains is a novel strategy to control microorganism composition, thereby ensuring uniform fermentation quality across diverse batches. However, challenges persist in the cultivation and maintenance of these microbial strains. This study examined the potential of microencapsulated kombucha fermentation starter cultures, specifically Komagataeibacter saccharivorans, Levilactobacillus brevis and Saccharomyces cerevisiae, through spray-drying and freeze-drying.

RESULTS

Maltodextrin and gum arabic-maltodextrin were employed as carrier agents. Our results revealed that both spray-dried and freeze-dried samples adhered to physicochemical criteria, with low moisture content (2.18-7.75%) and relatively high solubility (65.75-87.03%) which are appropriate for food application. Freeze-drying demonstrated greater effectiveness in preserving bacterial strain viability (88.30-90.21%) compared to spray drying (74.92-78.66%). Additionally, the freeze-dried starter strains demonstrated similar efficacy in facilitating kombucha fermentation, compared to the SCOBY group. The observations included pH reduction, acetic acid production, α-amylase inhibition and elevated total polyphenol and flavonoid content. Moreover, the biological activity, including antioxidant potential and in vitro tyrosinase inhibition activity, was enhanced in the same pattern. The freeze-dried strains exhibited consistent kombucha fermentation capabilities over a three-month preservation, regardless of storage temperature at 30 or 4 °C.

CONCLUSION

These findings highlight the suitability of freeze-dried starter cultures for kombucha production, enable microbial composition control, mitigate contamination risks and ensure consistent product quality. © 2024 Society of Chemical Industry.

Beneficial effects of duck-derived lactic acid bacteria on growth performance and meat quality through modulation of gut histomorphology and intestinal microflora in Muscovy ducks

Duck-derived lactic acid bacteria (DDL) are a crucial beneficial bacterium in the intestines, contributing significantly to the health of ducks. However, the mechanism by which these DDL improves the growth performance and meat quality of Muscovy duck is not clear. In this study, A total of 800 male Muscovy ducks, initially weighing 50.15 ± 5.37 g, were randomly allocated into 4 groups, each with 4 replicates, consisting of 50 ducks per replicate. The control group consumed deep well water, while the experimental groups were given water supplemented with 1%, 3%, and 5% DDL (1.59×108 CFU/mL). The study duration was 70 d. The results revealed that Muscovy ducks drinks with the DDL significant reduced the feed conversion ratio (FCR) (P < 0.05) and increased the sweetness and richness of duck meat, among which the 5% drinking group has the most significant difference. Further study finding, the DDL significantly increased the height of villi, the ratio of villi height/crypt depth (V/C) on jejunum and colon, and the ratio of acidic mucus, neutral mucus, and glycogen to tissue area in both the duodenum and ileum of Muscovy ducks, and significantly decreased the tunel positive cells. Moreover, DDL significantly enhanced the abundance of genus beneficial bacterium (Bacillus, lentilactobacillus, Bacterodies, Lactobacillus) on duodenum and ileum. Additionally, drink with the DDL elevated the level of IgG in blood and the immune indices of the thymus and the fabricius bursa (P<0.05). Meanwhile, the meat composition analysis demonstrated that Muscovy duck drinks with the DDL raised the level of the saturated fatty acid rate(C12:0), and polyunsaturated fatty acid (C18:2 n-6 and C20:5 n-3,), and the monounsaturated (C18:1 n-7, and C18:1 n-9). Furthermore, correlation analysis finding that the growth performance of Muscovy ducks was positively correlated with the height of villi, the ratio of villi height/crypt depth (V/C), the abundance of genus beneficial bacterium. And the meat quality of Muscovy ducks has positively correlated with genus beneficial bacterium in intestinal, glutamic acid, saturated fatty acid rate and polyunsaturated fatty acid. This finding suggest DDL is an effective strategy to improve the growth performance and meat quality of Muscovy ducks by gut histomorphology and intestinal microflora.

Bacillus amyloliquefaciens TL promotes gut health of broilers by the contribution of bacterial extracellular polysaccharides through its anti-inflammatory potential

The focal point of probiotic efficacy and a crucial factor influencing poultry cultivation lies in the level of intestinal inflammation. In conventional farming processes, the reduction of intestinal inflammation generally proves advantageous for poultry growth. This study investigated the impact of Bacillus amyloliquefaciens TL (B.A.-TL) on inflammatory factor expression at both tissue and cellular levels, alongside an exploration of main active secondary metabolites. The results demonstrated that broiler feeding with a basal diet containing 4 × 109 CFU/kg B.A.-TL markedly enhanced chicken growth performance, concomitant with a significant decrease in the expression of genes encoding inflammatory cytokines (e.g., CCL4, CCR5, XCL1, IL-1β, IL-6, IL-8, LITAF, and LYZ) in jejunum and ileum tissues. The extracellular polysaccharides of B.A.-TL (EPS-TL) exhibited notable suppression of elevated inflammatory cytokine expression induced by Escherichia coli O55 lipopolysaccharides (LPS) in chicken macrophage-like cells (HD11) and primary chicken embryonic small intestinal epithelial cells (PCIECs). Moreover, EPS-TL demonstrated inhibitory effect on NF-κB signaling pathway activation. These findings suggested that the metabolic product of B.A.-TL (i.e., EPS-TL) could partly mitigate the enhanced expression of inflammatory factors induced by LPS stimulation, indicating its potential as a key component contributing to the anti-inflammatory effects of B.A.-TL.

Evaluating the Probiotic Profile, Antioxidant Properties, and Safety of Indigenous Lactobacillus spp. Inhabiting Fermented Green Tender Coconut Water

This study isolated and characterized four indigenous lactic acid bacterial strains from naturally fermented green tender coconut water: Lactiplantibacillus plantarum CWJ3, Lacticaseibacillus casei CWM15, Lacticaseibacillus paracasei CWKu14, and Lacticaseibacillus rhamnosus CWKu-12. Notably, among the isolates, Lact. plantarum CWJ3 showed exceptional acid tolerance, with the highest survival rate of 37.34% at pH 2.0 after 1 h, indicating its higher resistance against acidic gastric conditions. However, all strains exhibited robust resistance to bile salts, phenols, and NaCl, with survival rates exceeding 80% at given concentrations. Their optimal growth at 37 °C and survival at 20 °C and 45 °C underscored adaptability to diverse environmental conditions. Additionally, all strains showed sustainable survival rates in artificial saliva and simulated gastrointestinal juices, with Lact. plantarum CWJ3 exhibiting significantly higher survival rate (70.66%) in simulated gastric juice compared to other strains. Adherence properties were particularly noteworthy, especially in Lact. rhamnosus CWKu-12, which demonstrated the highest hydrophobicity, coaggregation with pathogens and autoaggregation, among the strains. The production of exopolysaccharides, particularly by Lact. plantarum CWJ3, enhanced their potential for gut colonization and biofilm formation. Various in vitro antioxidative assays using spectrophotometric methods revealed the significant activity of Lact. plantarum CWJ3, while antimicrobial testing highlighted its efficacy against selected foodborne pathogens. Safety assessments confirmed the absence of biogenic amine production, hemolytic, DNase, and gelatinase activities, as well as the ability to hydrolase the bile salt. Furthermore, these non-dairy probiotics exhibited characteristics comparable to dairy derived probiotics, demonstrating their potential suitability in developing novel probiotic-rich foods and functional products.

Potential Probiotic Properties and Complete Genome Analysis of Limosilactobacillus reuteri LRA7 from Dogs

This study aimed to isolate and screen canine-derived probiotics with excellent probiotic properties. Strain characterization was conducted using a combination of in vitro and in vivo probiotic characterization and safety assessments, as well as complete genome analysis. The results showed that Limosilactobacillus reuteri LRA7 exhibited excellent bacteriostatic and antioxidant activities. The survival rate at pH 2.5 was 79.98%, and the viable counts after exposure to gastrointestinal fluid and 0.5% bile salts were 7.77 log CFU/mL and 5.29 log CFU/mL, respectively. The bacterium also exhibited high hydrophobicity, self-coagulation, and high temperature tolerance, was negative for hemolysis, and was sensitive to clindamycin. In vivo studies in mice showed that the serum superoxide dismutase activity level was 53.69 U/mL higher in the MR group of mice compared to that of the control group, the malondialdehyde content was 0.53 nmol/mL lower in the HR group, and the highest jejunal V/C value was 4.11 ± 1.05 in the HR group (p < 0.05). The L. reuteri LRA7 gene is 2.021 megabases in size, contains one chromosome and one plasmid, and is annotated with 1978 functional genes. In conclusion, L. reuteri LRA7 has good probiotic potential and is safe. It can be used as an ideal probiotic candidate strain of canine origin.

Effect of dietary supplementation of two fiber sources differing on fermentability and hydration capacity on performance, nutrient digestibility and cecal fermentation in broilers from 1 to 42 d of age

A total of 378 Cobb-500 male broilers were used to evaluate the effects of 2 fiber sources, differing in hydration capacity and fermentability, on gastrointestinal tract development, apparent ileal digestibility and performance from 1 to 42d of age. There were 9 replicates per each of the 3 dietary treatments, all in mash form: a wheat-soybean control (CON) diet, CON diet diluted with 1.5% of wood lignocellulose (LC diet) as a non-fermentable insoluble fiber with high hydration capacity; and CON diluted with 1.5% of a mixture of fibers (ISFC diet) containing both lignified insoluble fiber and a prebiotic soluble fiber fraction from fructooligosaccharides. Additionally, the fermentability of both fiber sources (LC and ISFC) was determined by in vitro using cecal inoculum from broilers fed the experimental diets. Both LC and ISFC treatments impaired by 4% feed conversion ratio only during the first 7d (P = 0.003) compared with CON group. In the grower period (21-42d), the ISFC group showed the best growth (P = 0.039), and at 42d tended to show the highest body weight (P = 0.095). This agrees well with the highest ileal dry matter (P = 0.033) and organic matter (P = 0.043) digestibility observed in ISFC group and the similar trend observed for ileal protein digestibility (P = 0.099) at 42d. Also, at 42 d, absolute and relative (% body weight) digestive tract weights (P ≤ 0.041) and empty gizzard weights (P ≤ 0.034) were greater for LC and ISFC groups compared to CON. The cecal molar proportion of valeratewas greatest in ISFC group (P = 0.039). In vitro gas production was higher for ISFC than for LC substrate when using either a diet-adapted or non-adapted cecal inoculum (P < 0.05). These results show the interest in combining IF with prebiotic highly fermentable fiber, such as fructooligosaccharides, in broilers to improve nutrient digestibility and finishing performance.

Probiotic evaluation, adherence capability and safety assessment of Lactococcus lactis strain isolated from an important herb "Murraya koenigii"

Lactic acid bacteria (LAB) isolated from medicinal herb Murraya koenigii, commonly known as curry leaf, which promotes the growth and maintenance of gut microbiota, were studied for their probiotic potential. The key objective of this research was to isolate and evaluate probiotic characteristics, test adherence capabilities, and confirm their safety. Lactococcus lactis (MKL8), isolated from Murraya koenigii, was subjected to in vitro analysis to assess its resistance to the gastric environment, ability to adhere Caco-2 cells, anti-microbial activity, hydrophobicity, auto-aggregation, and safety profiling through MTT assay and hemolytic. MKL8 exhibited growth at 0.5% phenol concentrations (> 80%) and was able to survive in conditions with high bile concentrations (> 79%) and a relatively low pH (72%-91%). It shows high tolerance to high osmotic conditions (> 73%) and simulated gastric juice (> 72%). Additionally, MKL8 demonstrated strong hydrophobicity (85%), auto-aggregation (87.3%-91.7%), and adherence to Caco-2 cells. Moreover, it had an inhibitory effect against pathogens too. By performing the hemolytic and MTT assays, the non-toxicity of MKL8 isolate was examined, and it exhibited no harmful characteristics. Considering MKL8's resistance to gastrointestinal tract conditions, high surface hydrophobicity, non-toxicity, and ability to inhibit the tested pathogens, it can be concluded that MKL8 demonstrated promising probiotic properties and has potential for use in the food industry.

Lyophilized cell-free supernatants of Limosilactobacillus fermentum T0701 exhibited antibacterial activity against Helicobacter pylori

Helicobacter pylori is a prominent gastrointestinal pathogen associated with various gastrointestinal illnesses. It presents substantial health risks due to its antibiotic resistance. Therefore, it is crucial to identify alternative treatments for H. pylori infections. Limosilactobacillus spp exhibit probiotic properties with beneficial effects in humans; however, the mechanisms by which it counteracts H. pylori infection are unknown. This study aimed to evaluate the potential of Limosilactobacillus fermentum T0701 lyophilized cell-free supernatants (LCFS) against H. pylori. The LCFS has varying antimicrobial activities, with inhibition zones of up to 10.67 mm. The minimum inhibitory concentration and minimum bacterial concentration of LCFS are 6.25-25.00 mg/mL and 6.25 mg/mL to > 50.00 mg/mL, respectively, indicating its capability to inhibit H. pylori. There is morphological damage observed in H. pylori treated with LCFS. Additionally, H. pylori adhesion to AGS cells (human gastric adenocarcinoma epithelial cells) reduces by 74.23%, highlighting the LCFS role in preventing bacterial colonization. Moreover, LCFS exhibits no cytotoxicity or morphological changes in AGS cells, and with no detected virulence or antimicrobial resistance genes, further supporting its safety profile. L. fermentum T0701 LCFS shows promise as a safe and effective non-toxic agent against H. pylori, with the potential to prevent gastric colonization.

Lactiplantibacillus plantarum surface-displayed VP6 (PoRV) protein can prevent PoRV infection in piglets

Porcine rotavirus (PoRV) poses a threat to the development of animal husbandry and human health, leading to substantial economic losses. VP6 protein is the most abundant component in virus particles and also the core structural protein of the virus. Firstly, this study developed an antibiotic-resistance-free, environmentally friendly expression vector, named asd-araC-PBAD-alr (AAPA). Then Recombinant Lactiplantibacillus plantarum (L. plantarum) strains induced by arabinose to express VP6 and VP6-pFc fusion proteins was constructed. Subsequently, This paper discovered that NC8/Δalr-pCXa-VP6-S and NC8/Δalr-pCXa-VP6-pFc-S could enhance host immunity and prevent rotavirus infection in neonatal mice and piglets. The novel recombinant L. plantarum strains constructed in this study can serve as oral vaccines to boost host immunity, offering a new strategy to prevent PoRV infection.

Enterococcus faecalis provides protection during scavenging in carrion crow ( Corvus corone)

The gut microbiota significantly influences host physiology and provides essential ecosystem services. While diet can affect the composition of the gut microbiota, the gut microbiota can also help the host adapt to specific dietary habits. The carrion crow ( Corvus corone), an urban facultative scavenger bird, hosts an abundance of pathogens due to its scavenging behavior. Despite this, carrion crows infrequently exhibit illness, a phenomenon related to their unique physiological adaptability. At present, however, the role of the gut microbiota remains incompletely understood. In this study, we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing, China. Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria (75.51%) and Firmicutes (22.37%). Significant differences were observed in the relative abundance of Enterococcus faecalis among groups, highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows. Subsequently, E. faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection. Results showed that E. faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and interleukin 6 (IL-6), prevented S. enterica colonization, and regulated the composition of gut microbiota in mice, thereby modulating the host's immune regulatory capacity. Therefore, E. faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior, offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.

The novel probiotic preparation based on Lactobacillus spp. mixture on the intestinal bacterial community structure of Cherry Valley duck

The development and utilization of probiotics have many environmental benefits when they are used to replace antibiotics in animal production. In this study, intestinal lactic acid bacteria were isolated from the intestines of Cherry Valley ducks. Probiotic lactic acid bacterial strains were screened for antibacterial activity and tolerance to produce a Lactobacillus spp. mixture. The effects of the compound on the growth performance and intestinal flora of Cherry Valley ducks were studied. Based on the results of the antibacterial activity and tolerance tests, the highly active strains Lactobacillus casei 1.2435, L. salivarius L621, and L. salivarius L4 from the intestines of Cherry Valley ducks were selected. The optimum ratio of L. casei 1.2435, L. salivarius L621, and L. salivarius L4 was 1:1:2, the amount of inoculum used was 1%, and the fermentation time was 14 h. In vivo experiments showed that compared with the control group, the relative abundances of intestinal Lactobacillus and Blautia were significantly increased in the experimental group fed the lactobacilli compound (P < 0.05); the relative abundances of Parabacteroides, [Ruminococcus]_torques_group, and Enterococcus were significantly reduced (P < 0.05), and the growth and development of the dominant intestinal flora were promoted in the Cherry Valley ducks. This study will provide more opportunities for Cherry Valley ducks to choose microecological agents for green and healthy breeding.

Screening of a potential probiotic Lactiplantibacillus plantarum NUC08 and its synergistic effects with yogurt starter

This study aims to identify lactic acid bacteria (LAB) isolates possessing physiological characteristics suitable for use as probiotics in yogurt fermentation. Following acid and bile salt tolerance tests, Lactiplantibacillus plantarum (NUC08 and NUC101), Lacticaseibacillus rhamnosus (NUC55 and NUC201), and Lacticaseibacillus paracasei (NUC159, NUC216, and NUC351) were shortlisted based on intraspecies distribution for further evaluation. Their physiological probiotic properties, including transit tolerance, adhesion, autoaggregation, surface hydrophobicity, biofilm formation, and antibacterial activity, were assessed. Principal component analysis indicated that Lactiplantibacillus plantarum NUC08 was the preferred choice among the evaluated strains. Subsequent investigations revealed that co-culturing Lactiplantibacillus plantarum NUC08 with 2 yogurt starter strains resulted in a cooperative and synergistic effect, enhancing the growth of mixed strains and increasing their tolerance to simulated gastric and intestinal conditions. Additionally, when Vibrio harveyi bioluminescent reporter strain was used, the 3 cocultured strains cooperated to induce the activity of a quorum sensing (QS) molecule autoinducer-2 (AI-2), hinting a potential connection between phenotypic traits and QS in the cocultured strains. Importantly, LAB viable counts were significantly higher in yogurt co-fermented with Lactiplantibacillus plantarum NUC08, consistently throughout the storage period. In conclusion, the study demonstrates that the probiotic strain Lactiplantibacillus plantarum NUC08 can be employed in synergy with yogurt starter strains, affirming its potential for use in the development of functional fermented dairy products.

Identification of novel probiotic lactic acid bacteria from soymilk waste using the 16s rRNA gene for potential use in poultry

Background and Aim

In-feed antibiotics have been used as antibiotic growth promoters (AGPs) to enhance the genetic potential of poultry. However, the long-term use of AGPs is known to lead to bacterial resistance and antibiotic residues in poultry meat and eggs. To address these concerns, alternatives to AGPs are needed, one of which is probiotics, which can promote the health of livestock without having any negative effects. In vitro probiotic screening was performed to determine the ability of lactic acid bacteria (LAB) isolated from soymilk waste to be used as a probiotic for livestock.

Materials and Methods

Four LAB isolates (designated F4, F6, F9, and F11) isolated from soymilk waste were used in this study. In vitro testing was performed on LAB isolates to determine their resistance to temperatures of 42°C, acidic pH, bile salts, hydrophobicity to the intestine, and ability to inhibit pathogenic bacteria. A promising isolate was identified using the 16S rRNA gene.

Result

All LAB isolates used in this study have the potential to be used as probiotics. On the basis of the results of in vitro testing, all isolates showed resistance to temperatures of 42°C and low pH (2.5) for 3 h (79.87%-94.44%) and 6 h (76.29%-83.39%), respectively. The survival rate at a bile salt concentration of 0.3% ranged from 73.24% to 90.39%, whereas the survival rate at a bile salt concentration of 0.5% ranged from 56.28% to 81.96%. All isolates showed the ability to attach and colonize the digestive tract with a hydrophobicity of 87.58%-91.88%. Inhibitory zones of LAB against pathogens ranged from 4.80-15.15 mm against Staphylococcus aureus, 8.85-14.50 mm against Salmonella enteritidis, and 6.75-22.25 mm against Escherichia coli. Although all isolates showed good ability as probiotics, isolate F4 showed the best probiotic ability. This isolate was identified as Lactobacillus casei strain T22 (JQ412731.1) using the 16S rRNA gene.

Conclusion

All isolates in this study have the potential to be used as probiotics. However, isolate F4 has the best probiotic properties and is considered to be the most promising novel probiotic for poultry.

Bacteriocins: potentials and prospects in health and agrifood systems

Bacteriocins are highly diverse, abundant, and heterogeneous antimicrobial peptides that are ribosomally synthesized by bacteria and archaea. Since their discovery about a century ago, there has been a growing interest in bacteriocin research and applications. This is mainly due to their high antimicrobial properties, narrow or broad spectrum of activity, specificity, low cytotoxicity, and stability. Though initially used to improve food quality and safety, bacteriocins are now globally exploited for innovative applications in human, animal, and food systems as sustainable alternatives to antibiotics. Bacteriocins have the potential to beneficially modulate microbiota, providing viable microbiome-based solutions for the treatment, management, and non-invasive bio-diagnosis of infectious and non-infectious diseases. The use of bacteriocins holds great promise in the modulation of food microbiomes, antimicrobial food packaging, bio-sanitizers and antibiofilm, pre/post-harvest biocontrol, functional food, growth promotion, and sustainable aquaculture. This can undoubtedly improve food security, safety, and quality globally. This review highlights the current trends in bacteriocin research, especially the increasing research outputs and funding, which we believe may proportionate the soaring global interest in bacteriocins. The use of cutting-edge technologies, such as bioengineering, can further enhance the exploitation of bacteriocins for innovative applications in human, animal, and food systems.

Bacterial Metabarcoding of Raw Palm Sap Samples from Bangladesh with Nanopore Sequencing

The traditional practice of harvesting and processing raw date palm sap is not only culturally significant but also provides an essential nutritional source in South Asia. However, the potential for bacterial or viral contamination from animals and environmental sources during its collection remains a serious and insufficiently studied risk. Implementing improved food safety measures and collection techniques could mitigate the risk of these infections. Additionally, the adoption of advanced food analytical methods offers the potential to identify pathogens and uncover the natural bacterial diversity of these products. The advancement of next-generation sequencing (NGS) technologies, particularly nanopore sequencing, offers a rapid and highly mobile solution. In this study, we employed nanopore sequencing for the bacterial metabarcoding of a set of raw date palm sap samples collected without protective coverage against animals in Bangladesh in 2021. We identified several bacterial species with importance in the natural fermentation of the product and demonstrated the feasibility of this NGS method in the surveillance of raw palm sap products. We revealed two fermentation directions dominated by either Leuconostoc species or Lactococcus species in these products at the first 6 h from harvest, along with opportunistic human pathogens in the background, represented with lower abundance. Plant pathogens, bacteria with the potential for opportunistic human infection and the sequences of the Exiguobacterium genus are also described, and their potential role is discussed. In this study, we demonstrate the potential of mobile laboratory solutions for food safety purposes in low-resource areas.

Characterization and Assessment of Native Lactic Acid Bacteria from Broiler Intestines for Potential Probiotic Properties

Probiotics are the most promising alternative to antibiotics for improving animal production and controlling pathogenic infections, while strains derived from natural hosts are considered highly desirable due to their good adaptation to the gastrointestinal tract. The aim of this study was to screen Lactobacillus with broad-spectrum antibacterial activity from broilers fed an antibiotic-free diet and evaluate their potential as poultry probiotics. A total of 44 lactic acid bacteria (LAB) strains were isolated from the intestines of healthy broilers, among which 3 strains exhibited outstanding antimicrobial activity and were subsequently identified through 16S rRNA sequencing as Enterococcus faecium L8, Lactiplantibacillus plantarum L10, and Limosilactobacillus reuteri H11. These three isolates demonstrated potent bacteriostatic activity against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella cholerae, with inhibition zones ranging from 15.67 ± 1.53 to 21.33 ± 0.58 mm. The selected LAB strains exhibited high tolerance to acid and bile salts, with L. reuteri H11 displaying the highest survival rate (ranging from 34.68% to 110.28%) after exposure to 0.3% (w/v) bile salts for 6 h or a low pH environment (pH 2, 2.5, and 3) for 3 h. Notably, L. reuteri H11 outperformed other strains in terms of hydrophobicity (84.31%), auto-aggregation (53.12%), and co-aggregation with E. coli ATCC 25922 (36.81%) and S. aureus ATCC 6538 (40.20%). In addition, the three LAB isolates were either fully or moderately susceptible to the tested antibiotics, except for strain L8, which resisted gentamycin and vancomycin. Consequently, these three LAB strains, especially L. reuteri H11, isolated from the intestines of broiler chickens, represent promising probiotic candidates that can be employed as feed additives to enhance production performance and control poultry pathogens.

Probing the microbial diversity and probiotic candidates from Pakistani foods: isolation, characterization, and functional profiling

Probiotics represent beneficial living microorganisms that confer physiological, nutritional, and functional advantages to human health, holding significant potential for development of functional foods. This research aimed to isolate, identify, and characterize potential probiotic bacterial strains sourced from fermented and non-fermented foods from Pakistan. A total of 341 bacterial strains were isolated from diverse food samples (81) collected from various regions of Pakistan. Strains were identified using 16S rRNA gene sequencing and phylogenetic analysis. The identified strains belonged to genera Bacillus, Staphylococcus, Microbacterium, Shigella, Micrococcus, Enterococcus, Sporosarcina, Paenibacillus, Limosilactobacillus, Kosakonia, Dietzia, Leclercia, Lacticaseibacillus, Levilactobacillus, Kluyvera, Providencia, Enterobacter, Neisseria, Streptococcus, Acinetobacter, Corynebacterium, Pantoea, Mammaliicoccus, Pseudomonas, Burkholderia, and Alkalihalobacillus. Selected strains were chosen for probiotic assessment, employing existing literature as a guideline. Among these selections, six strains exhibited hemolytic activity, and seven strains displayed resistance to multiple antibiotics, prompting their exclusion from subsequent evaluations. The remaining strains demonstrated auto-aggregation capacities spanning 3.39-79.7%, and displayed coaggregation capabilities with reported food-borne pathogens. Furthermore, nine strains exhibited antimicrobial properties against food-borne pathogens. The assessment encompassed diverse characteristics such as cell surface hydrophobicity, survival rates under varying conditions, cholesterol reduction ability, casein digestion capability, and antioxidant activity. Phylogenomic analysis, digital-DNA DNA hybridization (digi-DDH), and average nucleotide identity (ANI) calculations unveiled novel species potentially belonging to the genera Sporosarcina and Dietzia. Based on these findings, we advocate for the consideration of Staphylococcus cohnii subsp. cohnii NCCP-2414, Lacticaseibacillus rhamnosus NCCP-2569 and Levilactobacillus brevis NCCP-2574 as prime probiotic candidates with the potential for integration into formulation of functional foods.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-023-03903-6.

Therapeutic Potential of Bacteroides fragilis SNBF-1 as a Next-Generation Probiotic: In Vitro Efficacy in Lipid and Carbohydrate Metabolism and Antioxidant Activity

This study explores the potential of aerotolerant Bacteroides fragilis (B. fragilis) strains as next-generation probiotics (NGPs), focusing on their adaptability in the gastrointestinal environment, safety profile, and probiotic functions. From 23 healthy infant fecal samples, we successfully isolated 56 beneficial B. fragilis strains. Notably, the SNBF-1 strain demonstrated superior cholesterol removal efficiency in HepG2 cells, outshining all other strains by achieving a remarkable reduction in cholesterol by 55.38 ± 2.26%. Comprehensive genotype and phenotype analyses were conducted, including sugar utilization and antibiotic sensitivity tests, leading to the development of an optimized growth medium for SNBF-1. SNBF-1 also demonstrated robust and consistent antioxidant activity, particularly in cell-free extracts, as evidenced by an average oxygen radical absorbance capacity value of 1.061 and a 2,2-diphenyl-1-picrylhydrazyl scavenging ability of 94.53 ± 7.31%. The regulation of carbohydrate metabolism by SNBF-1 was assessed in the insulin-resistant HepG2 cell line. In enzyme inhibition assays, SNBF-1 showed significant α-amylase and α-glucosidase inhibition, with rates of 87.04 ± 2.03% and 37.82 ± 1.36%, respectively. Furthermore, the cell-free supernatant (CFS) of SNBF-1 enhanced glucose consumption and glycogen synthesis in insulin-resistant HepG2 cells, indicating improved cellular energy metabolism. This was consistent with the observation that the CFS of SNBF-1 increased the proliferation of HepG2 cells by 123.77 ± 0.82% compared to that of the control. Overall, this research significantly enhances our understanding of NGPs and their potential therapeutic applications in modulating the gut microbiome.

Antagonistic properties of Lactiplantibacillus plantarum MYSVB1 against Alternaria alternata: a putative probiotic strain isolated from the banyan tree fruit

Alternaria alternata, a notorious phytopathogenic fungus, has been documented to infect several plant species, leading to the loss of agricultural commodities and resulting in significant economic losses. Lactic acid bacteria (LAB) hold immense promise as biocontrol candidates. However, the potential of LABs derived from fruits remains largely unexplored. In this study, several LABs were isolated from tropical fruit and assessed for their probiotic and antifungal properties. A total of fifty-five LABs were successfully isolated from seven distinct fruits. Among these, seven isolates showed inhibition to growth of A. alternata. Two strains, isolated from fruits: Ficus benghalensis, and Tinospora cordifolia exhibited promising antifungal properties against A. alternata. Molecular identification confirmed their identities as Lactiplantibacillus plantarum MYSVB1 and MYSVA7, respectively. Both strains showed adaptability to a wide temperature range (10-45°C), and salt concentrations (up to 7%), with optimal growth around 37 °C and high survival rates under simulated gastrointestinal conditions. Among these two strains, Lpb. plantarum MYSVB1 demonstrated significant inhibition (p < 0.01) of the growth of A. alternata. The inhibitory effects of cell-free supernatant (CFS) were strong, with 5% crude CFS sufficient to reduce fungal growth by >70% and complete inhibition by 10% CFS. Moreover, the CFS was inhibitory for both mycelial growth and conidial germination. CFS retained its activity even after long cold storage. The chromatographic analysis identified organic acids in CFS, with succinic acid as the predominant constituent, with lactic acid, and malic acid in descending order. LAB strains isolated from tropical fruits showed promising probiotic and antifungal properties, making them potential candidates for various applications in food and agriculture.

Probiotic Potential of Bacillus amyloliquefaciens Isolated from Tibetan Yaks

The Tibetan livestock sector is now ailing from many infectious ailments brought on by harmful microorganisms. Therefore, this research aimed to assess the probiotic potential and safety of Bacillus amyloliquefaciens isolated from yaks in the Tibet area to provide upper-edge strain resources for probiotics development. The four strains isolated from the intestine of yaks had been identified as Bacillus amyloliquefaciens after the 16S rRNA sequence. The ethanol, bile salt, and acid tolerance revealed that the isolates had significant tolerance levels. The antibiotics susceptibility assay showed that the strains were sensitive to commonly used antibiotics, while the antibacterial assay prevented the isolates from outperforming five harmful bacteria in terms of antibacterial potency. Moreover, it was evident that strain BA5 had the strongest activity to scavenge hydroxyl radical and reduce power. According to the animal experiment, no apparent pathological change was observed in intestinal tissue sections. Furthermore, the strain had a positive effect on promoting the development of jejunal villi referred to its safety. Therefore, more research is required into the bacteriostatic and antioxidant capabilities of isolates in animal production.

Genomic characterization and probiotic potential of lactic acid bacteria isolated from feces of guinea pig (Cavia porcellus)

Background

Presently, there exists a growing interest in mitigating the utilization of antibiotics in response to the challenges emanating from their usage in livestock. A viable alternative strategy encompasses the introduction of live microorganisms recognized as probiotics, exerting advantageous impacts on the immune system and nutritional aspects of the host animals. Native lactic acid bacteria, inherently possessing specific properties and adaptive capabilities tailored to each animal, are deemed optimal contenders for probiotic advancement.

Aim

In the current investigation, microorganisms exhibiting probiotic potential were isolated, characterized, and identified from the fecal samples of guinea pigs (Cavia porcellus) belonging to the Peruvian breed.

Methods

The lactic acid bacteria isolated on Man, Rogosa, and Sharpe agar underwent Gram staining, catalase testing, proteolytic, amylolytic, and cellulolytic activity assays, low pH tolerance assessment, hemolytic evaluation, antagonism against Salmonella sp., determination of autoaggregation and coaggregation capacity, and genotypic characterization through sequencing of the 16S rRNA gene.

Results

A total of 33 lactic acid bacteria were isolated from the feces of 30 guinea pigs, also 10 isolates were selected based on Gram staining and catalase testing. All strains exhibited proteolytic activity, while only one demonstrated amylolytic capability, and none displayed cellulase activity. These bacteria showed higher tolerance to pH 5.0 and, to a lesser extent, to pH 4.0. Furthermore, they exhibited antagonistic activity against Salmonella sp. Only two bacteria demonstrated hemolytic activity, and were subsequently excluded from further evaluations. Subsequent assessments revealed autoaggregation capacities ranging from 4.55% to 23.19%, with a lesser degree of coaggregation with Salmonella sp. ranging from 3.53% to 8.94% for the remaining eight bacterial isolates. Based on these comprehensive tests, five bacteria with notable probiotic potential were identified by molecular assays as Leuconostoc citreum, Enterococcus gallinarum, Exiguobacterium sp., and Lactococcus lactis.

Conclusion

The identified bacteria stand out as promising probiotic candidates, deserving further assessment in Peruvian breed guinea pigs. This exploration aims to enhance production outcomes while mitigating the adverse effects induced by pathogenic microorganisms.

Antimicrobial use and resistance in food animal production: food safety and associated concerns in Sub-Saharan Africa

The use of antimicrobials in food animal (FA) production is a common practice all over the world, with even greater usage and dependence in the developing world, including Sub-Saharan Africa (SSA). However, this practice which serves obvious economic benefits to producers has raised public health concerns over the last decades, thus driving the selection and dissemination of antimicrobial resistance and adversely impacting food safety and environmental health. This review presents the current and comprehensive antimicrobial usage practices in food animal production across SSA. We further highlighted the overall regional drivers as well as the public health, environmental, and economic impact of antimicrobial use in the production of food animals. Antimicrobial use is likely to increase with even exacerbated outcomes unless cost-effective, safe, and sustainable alternatives to antibiotics, especially probiotics, prebiotics, bacteriocins, antimicrobial peptides, bacteriophages, vaccines, etc. are urgently advocated for and used in food animal production in SSA. These, in addition to the implementation of strong legislation on antimicrobial use, and improved hygiene will help mitigate the public health concerns associated with antimicrobial use in food animals and improve the well-being and safety of food animals and their products.

Lactobacillus plantarum supernatant inhibits growth of Riemerella anatipestifer and mediates intestinal antimicrobial defense in Muscovy ducks

Riemerella anatipestifer (RA) is an important pathogen of waterfowl, with multiple serotypes and a lack of cross-protection between each serotype, which leads to the continued widespread in the world and causing significant economic losses to the duck industry. Thus, prevention and inhibition of RA infection are of great concern. Previous research has established that Lactobacillus plantarum supernatant (LPS) can prevents the pathogenic bacteria infection. However, LPS whether inhibits RA and underlying mechanisms have not yet been clarified. In this study, we investigated the direct and indirect effects of LPS-ZG7 against RA infection in Muscovy ducks. The results demonstrated that LPS-ZG7 prevented RA growth in the presence of pH-neutralized, and the inhibition was relatively stable and unaffected by heat, acid-base and ultraviolet light (UV). Following flow cytometry data found that LPS-ZG7 increased RA membrane permeability and leakage of intracellular molecules. And scanning electron microscopy revealed LPS-ZG7 damaged the RA membrane integrity and leading to RA death. Furthermore, quantitative real time polymerase chain reaction (qPCR) analysis represented that LPS-ZG7 upregulated mucosal tight junction proteins occludin, claudin-1, and Zo-1 in Muscovy ducks, and increasing mucosal transport channels SGLT-1, PepT1, AQP2, AQP3, and AQP10 in duodenum, jejunum, and colon, then decreased the intestinal permeability and intestinal barrier disruption which were caused from RA. From the data, it is apparent that LPS-ZG7 enhanced intestinal mucosal integrity by rising villus height, villus height-to-crypt depth ratio and lower crypt depth. LPS-ZG7 significantly decreased intestinal epithelia cells apoptosis caused by RA invasion, and enhanced intestinal permeability and contribute to barrier dysfunction, ultimately improving intestinal health of host, indirectly leading to reduce diarrhea rate and mortality caused by RA. Overall, this study strengthens the idea that LPS-ZG7 directly inhibited the RA growth by increased RA membrane permeability and damaged the RA membrane integrity, and then indirectly enhanced intestinal mucosal integrity, improved intestinal health of host and mediated intestinal antimicrobial defense.

Isolation, identification, and molecular characterization of probiotic bacteria from locally selected Ethiopian free range chickens gastrointestinal tract

The poultry industry is facing continuous challenges with regard to increased feed costs and loss due to infectious disease. To overcome this challenge, several antibiotics have been used along with chicken feeds to promote growth. Nevertheless, the use of antibiotics as growth promoter has been banned in many countries, due to the concerns associated with potential risks of emerging and horizontal transfer of multidrug resistant genes to bacteria in animal tissues. The objective of this study was to identify and characterize potential probiotic bacteria strains from the gastrointestinal tract of free-range locally selected chickens. The bacterial isolates were screened, purified and characterized based on morphological, biochemical and molecular characteristics from 12 well-adopted free-range healthy young chickens. Low pH and bile salt tolerance, antagonistic activity, antibiotic activity, hemolysis activity, adhesion to the chicken intestine and carbohydrate fermentation tests was conducted to identify potential probiotic bacteria. Twelve bacterial isolates were screened based on their ability for their tolerance to low pH and bile salt. The isolates were identified by using 16S rRNA gene partial sequencing method. All screened isolates showed great survival percentage at low pH, that is (89.2 ± 0.75 to 97.1 ± 0.64) survived at 3 h and (83.6 ± 0.75 to 95.2 ± 0.63) at 6 h challenge at pH2. Isolate GCM112 was the least tolerant strain in 6.0% salt concentration at 12 and 24 h exposure time (82.1 ± 1.28 and 79.9 ± 1.96%) respectively. The result revealed no strain tests in this study exhibited α- and β-hemolytic activity when cultured in sheep blood agar. Most isolated strains showed best growth at 37°C temperature and up to 4% NaCl concentration. Based on the reported result from in vitro data, GCH212 and GCM412 isolates were recognized as best potential probiotic bacteria for chicken against pathogens but further studies are needed on in vivo assessment on the health benefits in the real life situation.