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846900.9856Probiogenomic analysis of Lactiplantibacillus plantarum SPS109: A potential GABA-producing and cholesterol-lowering probiotic strain. Lactiplantibacillus plantarum SPS109, an isolated strain of lactic acid bacteria (LAB) from fermented foods, showed remarkable potential as a probiotic with dual capabilities in γ-aminobutyric acid (GABA) production and cholesterol reduction. This study employs genomic and comparative analyses to search into the strain's genetic profile, safety features, and probiotic attributes. The safety assessment reveals the absence of virulence factors and antimicrobial resistance genes, while the genome uncovers bacteriocin-related elements, including sactipeptides and a cluster for putative plantaricins, strengthening its ability to combat diverse pathogens. Pangenome analysis revealed unique bacteriocin-related genes, specifically lcnD and bcrA, distinguishing SPS109 from four other L. plantarum strains producing GABA. In addition, genomic study emphasizes SPS109 strain distinctive features, two GABA-related genes responsible for GABA production and a bile tolerance gene (cbh) crucial for cholesterol reduction. Additionally, the analysis highlights several genes of potential probiotic properties, including stress tolerance, vitamin production, and antioxidant activity. In summary, L. plantarum SPS109 emerges as a promising probiotic candidate with versatile applications in the food and beverage industries, supported by its unique genomic features and safety profile.202439044985
601610.9853Investigating human-derived lactic acid bacteria for alcohol resistance. BACKGROUND: Excessive alcohol consumption has been consistently linked to serious adverse health effects, particularly affecting the liver. One natural defense against the detrimental impacts of alcohol is provided by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH), which detoxify harmful alcohol metabolites. Recent studies have shown that certain probiotic strains, notably Lactobacillus spp., possess alcohol resistance and can produce these critical enzymes. Incorporating these probiotics into alcoholic beverages represents a pioneering approach that can potentially mitigate the negative health effects of alcohol while meeting evolving consumer preferences for functional and health-centric products. RESULTS: Five lactic acid bacteria (LAB) isolates were identified: Lactobacillus paracasei Alc1, Lacticaseibacillus rhamnosus AA, Pediococcus acidilactici Alc3, Lactobacillus paracasei Alc4, and Pediococcus acidilactici Alc5. Assessment of their alcohol tolerance, safety, adhesion ability, and immunomodulatory effects identified L. rhamnosus AA as the most promising alcohol-tolerant probiotic strain. This strain also showed high production of ADH and ALDH. Whole genome sequencing analysis revealed that the L. rhamnosus AA genome contained both the adh (encoding for ADH) and the adhE (encoding for ALDH) genes. CONCLUSIONS: L. rhamnosus AA, a novel probiotic candidate, showed notable alcohol resistance and the capability to produce enzymes essential for alcohol metabolism. This strain is a highly promising candidate for integration into commercial alcoholic beverages upon completion of comprehensive safety and functionality evaluations.202438659044
605320.9844Probiotic properties of lactic acid bacteria isolated from water-buffalo mozzarella cheese. This study evaluated the probiotic properties (stability at different pH values and bile salt concentration, auto-aggregation and co-aggregation, survival in the presence of antibiotics and commercial drugs, study of β-galactosidase production, evaluation of the presence of genes encoding MapA and Mub adhesion proteins and EF-Tu elongation factor, and the presence of genes encoding virulence factor) of four LAB strains (Lactobacillus casei SJRP35, Leuconostoc citreum SJRP44, Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and Leuconostoc mesenteroides subsp. mesenteroides SJRP58) which produced antimicrobial substances (antimicrobial peptides). The strains survived the simulated GIT modeled in MRS broth, whole and skim milk. In addition, auto-aggregation and the cell surface hydrophobicity of all strains were high, and various degrees of co-aggregation were observed with indicator strains. All strains presented low resistance to several antibiotics and survived in the presence of commercial drugs. Only the strain SJRP44 did not produce the β-galactosidase enzyme. Moreover, the strain SJRP57 did not show the presence of any genes encoding virulence factors; however, the strain SJRP35 presented vancomycin resistance and adhesion of collagen genes, the strain SJRP44 harbored the ornithine decarboxylase gene and the strain SJRP58 generated positive results for aggregation substance and histidine decarboxylase genes. In conclusion, the strain SJRP57 was considered the best candidate as probiotic cultures for further in vivo studies and functional food products development.201425117002
23730.9843CsbD, a Novel Group B Streptococcal Stress Response Factor That Contributes to Bacterial Resistance against Environmental Bile Salts. Group B Streptococcus (GBS) can cause many serious infections and result in severe symptoms depending on the infected organs. To survive and initiate infection from the gastrointestinal tract, GBS must resist physiochemical factors, such as bile salts, a potent antibacterial compound in the intestine. We found that GBS isolated from diverse sources all possess the capability to defend bile salts and permit survival. By constructing the GBS A909 transposon mutant library (A909(Tn)), we identified several candidate genes that might participate in the bile salt resistance of GBS. The rodA and csbD genes were validated as relevant to bile salt resistance. The rodA gene was anticipated to be related to peptidoglycan synthesis and influence the bile salt resistance of GBS by cell wall construction. Notably, we found that the csbD gene worked as a bile salt resistance response factor and influenced several ABC transporter genes, specifically at the later growth period of GBS under bile salt stress. We further detected the marked intracellular bile salt accumulation in ΔcsbD by hydrophilic interaction chromatography-liquid chromatography/mass spectrometry (HILIC-LC/MS). Collectively, we showed a novel GBS stress response factor, csbD, contributes to bacterial survival in bile salts by sensing bile salt stress and subsequently induces transcription of transporter genes to excrete bile salts. IMPORTANCE GBS, a conditional pathogenetic colonizer of the human intestinal flora, can cause severe infectious diseases in immunocompromised patients. Therefore, it is critical to understand the factors that contribute to the resistance to bile salts, which are abundant in the intestine but harmful to bacteria. We identified rodA and csbD genes involved in bile salt resistance using a transposon insertion site sequencing (TIS-seq) based screen. The rodA gene products might be involved in peptidoglycan synthesis as important contributors to stress resistance including bile salts. However, the csbD gene conferred bile salt resistance by promoting transporter genes transcription at the later growth period of GBS in response to bile salts. These findings developed a better understanding of the stress response factor csbD on the bile salt resistance of GBS.202337195202
72340.9839Ail and PagC-related proteins in the entomopathogenic bacteria of Photorhabdus genus. Among pathogenic Enterobacteriaceae, the proteins of the Ail/OmpX/PagC family form a steadily growing family of outer membrane proteins with diverse biological properties, potentially involved in virulence such as human serum resistance, adhesion and entry into eukaryotic culture cells. We studied the proteins Ail/OmpX/PagC in the bacterial Photorhabdus genus. The Photorhabdus bacteria form symbiotic complexes with nematodes of Heterorhabditis species, associations which are pathogenic to insect larvae. Our phylogenetic analysis indicated that in Photorhabdus asymbiotica and Photorhabdus luminescens only Ail and PagC proteins are encoded. The genomic analysis revealed that the Photorhabdus ail and pagC genes were present in a unique copy, except two ail paralogs from P. luminescens. These genes, referred to as ail1Pl and ail2Pl, probably resulted from a recent tandem duplication. Surprisingly, only ail1Pl expression was directly controlled by PhoPQ and low external Mg2+ conditions. In P. luminescens, the magnesium-sensing two-component regulatory system PhoPQ regulates the outer membrane barrier and is required for pathogenicity against insects. In order to characterize Ail functions in Photorhabdus, we showed that only ail2Pl and pagCPl had the ability, when expressed into Escherichia coli, to confer resistance to complement in human serum. However no effect in resistance to antimicrobial peptides was found. Thus, the role of Ail and PagC proteins in Photorhabdus life cycle is discussed.201425333642
608150.9839In vitro probiotic characteristics and whole-genome sequence analysis of lactic acid bacteria isolated from monkey faeces. This study aimed to isolate lactic acid bacteria from monkey faeces and evaluate their safety and probiotic properties through a combination of in vitro assays and complete genomic sequencing. The results revealed that two Limosilactobacillus reuteri strains (LDHa and LSHe) exhibited promising probiotic attributes: no hemolytic activity, remarkable antibacterial activity against intestinal pathogens, high bile salt tolerance (77.46% survival rate for LDHa at 0.3% bile salt concentration), excellent gastrointestinal resistance (survival rate > 40%), and favorable surface characteristics (63.92-66.00% auto-aggregation; 91.33-93.80% hydrophobicity). The whole genome sequencing results revealed that strain LDHa has a total length of 2,031,794 bp with a GC content of 39.02% and contains (Strompfová et al. 2014) coding genes. The LSHe strain has a total length of 2,031,507 bp with a GC content of 39.02% and contains 1954 coding genes. Genomic analysis revealed that both strains possess four CRISPR sequences and one secondary metabolic gene cluster, with functional annotations from the EGGNOG, KEGG, and CAZy databases demonstrating genome stability; the absence of horizontally transferable antibiotic resistance genes; the enrichment of metabolic pathway-related genes, and probiotic-associated functional potential including antimicrobial, anti-inflammatory, immunomodulatory, and antitumor activities. This study demonstrated that L. reuteri LDHa and LSHe exhibit favorable safety profiles and probiotic potential at both physiological and genomic levels, positioning them as promising candidates for probiotic formulations in captive primate populations.202540852645
602660.9839Probiotic Characteristics and Whole Genome Analysis of Lactiplantibacillus plantarum PM8 from Giant Panda (Ailuropoda melanoleuca) Milk. Milk is a rich source of probiotics, particularly lactic acid bacteria (LAB), which have been shown to promote gut health, support the immune system, enhance digestion, and prevent pathogen colonization. This study aimed to isolate and identify LAB strains from giant panda (Ailuropoda melanoleuca) milk, evaluate their probiotic properties, and analyze the genomic characteristics of a promising strain. Thirteen LAB strains were isolated from 12 samples of giant panda milk. Among all LAB strains, Lactiplantibacillus plantarum PM8 (PM8) demonstrated probiotic properties and safety features. It exhibited strong growth performance, high antipathogenic activity against four pathogens, and strong survival rates under simulated gastrointestinal conditions. PM8 also showed excellent adhesion capabilities to Caco-2 cells. Additionally, safety assessment revealed no hemolysin production and minimal antibiotic resistance, making it a promising candidate for probiotic applications. The genome of PM8 consists of 3,227,035 bp with a GC content of 44.60% and contains 3171 coding sequences, including 113 carbohydrate-active enzyme genes and genes related to exopolysaccharides synthesis, vitamin B biosynthesis, adhesion, antioxidant activity, and bile salt hydrolysis. Notably, it contains genes involved in nonribosomally synthesized secondary metabolite and bacteriocin production. The genomic safety analysis confirmed that PM8 lacks the capacity to transmit bacterial antimicrobial resistance and is non-pathogenic to both humans and animals. These findings suggest that PM8 holds considerable potential for enhancing gut health and supporting the development of safe probiotic products.202539900880
602570.9837Phenotypic and Genomic Insights into Schleiferilactobacillus harbinensis WU01, a Candidate Probiotic with Broad-Spectrum Antimicrobial Activity Against ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter) Pathogens. The increasing prevalence of multidrug-resistant (MDR) pathogens, particularly ESKAPE bacteria, necessitates alternative antimicrobial strategies. Probiotics, particularly lactic acid bacteria, protect against pathogenic infections. This study aimed to characterize Schleiferilactobacillus harbinensis WU01, isolated from fermented palm sap, and evaluate its probiotic potential and antimicrobial activity. Its probiotic characteristics were assessed based on low-pH and bile tolerance, auto-aggregation, hydrophobicity, and adhesion to Caco-2 cells. Antimicrobial activity against ESKAPE pathogens was evaluated using the agar well diffusion assay. Whole-genome sequencing (WGS) and in silico analysis were performed to identify bacteriocin-related genes, virulence factors, and antibiotic-resistance genes. WU01 exhibited a strong tolerance to gastrointestinal conditions, with high survival rates under acidic and bile-salt environments. S. harbinensis WU01 demonstrated significant auto-aggregation, high hydrophobicity, and strong adhesion to Caco-2 cells. Antimicrobial assays revealed inhibitory activity against MDR ESKAPE pathogens, which correlated with the presence of bacteriocin-related genes, including those homologous to Carnocin_CP52. Molecular dynamics (MDs) simulations confirmed the interaction of Carnocin_CP52 with bacterial membranes, suggesting a mechanism for pathogen disruption. WGS confirmed the absence of virulence and antimicrobial-resistance genes, confirming its safety for probiotic applications. These findings suggest that S. harbinensis WU01 possesses probiotic properties and antimicrobial activity against ESKAPE pathogens. The combined results highlight its potential application in functional foods and therapeutic interventions.202540238333
602880.9837Isolation, Characterization, and Comparative Genomics of the Novel Potential Probiotics from Canine Feces. Lactic acid bacteria (LAB) are commonly used as probiotics; however, not all LAB strains have the same beneficial effects. To successfully use LAB as probiotics in canines, LAB species should originate from the canine intestinal tract as they display host specificity. The objective of this study was to investigate the phenotypic and genomic traits of potential probiotic LAB isolated from canine fecal samples. Twenty LAB samples were evaluated for their potential probiotic characteristics including resistance to low pH, bile salts, hydrophobicity, auto-aggregation, co-aggregation, adhesion to epithelia or mucosa, and production of inhibitory compounds. Additionally, we evaluated their safety and other beneficial effects on canine health, such as DPPH free radical scavenging, and β-galactosidase. Four strains demonstrated potential probiotic characteristics and were selected: Enterococcus hirae Pom4, Limosilactobacillus fermentum Pom5, Pediococcus pentosaceus Chi8, and Ligilactobacillus animalis FB2. Safety evaluations showed that all strains lacked hemolytic activity, could not produce biogenic amines, and did not carry any pathogenic genes. In addition, L. fermentum Pom5 and P. pentosaceus Chi8 displayed susceptibility to all antibiotics and concordant with the absence of antibiotic resistance genes. Based on their phenotypic and genomic characteristics, L. fermentum Pom5 and P. pentosaceus Chi8 were identified as potential probiotic candidates for canines.202337484003
604290.9835Limosilactobacillus fermentum ING8, a Potential Multifunctional Non-Starter Strain with Relevant Technological Properties and Antimicrobial Activity. Lactic acid bacteria (LAB) have gained particular attention among different exopolysaccharide-producing microorganisms due to their safety status and effects on human health and food production. Exopolysaccharide-producing LAB play a crucial role in different ways, such as improving texture, mouthfeel, controlling viscosity, and for low-calorie food production. In this study, we isolated a multifunctional strain with good exopolysaccharide production properties. Limosilactobacillus fermentum ING8 was isolated from an Indian traditional fermented milk (Dahi) and evaluated for its safety, enzymatic activity, NaCl resistance and temperature tolerance, milk coagulation, and storage stability. Finally, the complete genome of this strain was sequenced and subjected to safety in silico evaluation and genomic analysis. The results revealed that L. fermentum ING8 possesses relevant technological properties, such as exopolysaccharide production, antimicrobial activity, and galactose utilization. Besides, this strain showed very high stability to storage conditions at refrigeration temperature. In addition, the genomic analysis did not evidence any possible deleterious elements, such as acquired antibiotic resistance genes, virulence genes, or hemolysis-related genes. However, all structural genes related to the galactose operon and EPS production were detected. Therefore, L. fermentum ING8 can be considered a promising multifunctional bacterium to be proposed as non-starter in different types of dairy productions.202235267336
332100.9835Analysis and Reconstitution of the Menaquinone Biosynthesis Pathway in Lactiplantibacillus plantarum and Lentilactibacillus buchneri. In Lactococcus lactis and some other lactic acid bacteria, respiratory metabolism has been reported upon supplementation with only heme, leading to enhanced biomass formation, reduced acidification, resistance to oxygen, and improved long-term storage. Genes encoding a complete respiratory chain with all components were found in genomes of L. lactis and Leuconostoc mesenteroides, but menaquinone biosynthesis was found to be incomplete in Lactobacillaceae (except L. mesenteroides). Lactiplantibacillus plantarum has only two genes (menA, menG) encoding enzymes in the biosynthetic pathway (out of eight), and Lentilactobacillus buchneri has only four (menA, menB, menE, and menG). We constructed knock-out strains of L. lactis defective in menA, menB, menE, and menG (encoding the last steps in the pathway) and complemented these by expression of the extant genes from Lactipl. plantarum and Lent. buchneri to verify their functionality. Three of the Lactipl. plantarum biosynthesis genes, lpmenA1, lpmenG1, and lpmenG2, as well as lbmenB and lbmenG from Lent. buchneri, reconstituted menaquinone production and respiratory growth in the deficient L. lactis strains when supplemented with heme. We then reconstituted the incomplete menaquinone biosynthesis pathway in Lactipl. plantarum by expressing six genes from L. lactis homologous to the missing genes in a synthetic operon with two inducible promoters. Higher biomass formation was observed in Lactipl. plantarum carrying this operon, with an OD(600) increase from 3.0 to 5.0 upon induction.202134361912
8731110.9835Isolation of Potato Endophytes and Screening of Chaetomium globosum Antimicrobial Genes. Antimicrobial peptides (AMPs) have natural antibacterial activities that pathogens find difficult to overcome. As a result of this occurrence, AMPs can act as an important substitute against the microbial resistance. In this study, we used plate confrontation tests to screen out 20 potential endophytes from potato tubers. Among them, endophyte F5 was found to significantly inhibit the growth of five different pathogenic fungi. Following that, phylogenetic analysis revealed that the internal transcribed spacer (ITS) sequences were 99% identical to Chaetomium globosum corresponding sequences. Thereafter, the Bacillus subtilis expression system was used to create a C. globosum cDNA library in order to isolate the resistance genes. Using this approach, the resistance gene screening technology in the indicator bacteria built-in library was used to identify two antimicrobial peptides, CgR2150 and CgR3101, with broad-spectrum antibacterial activities. Furthermore, the results showed that CgR2150 and CgR3101 have excellent UV, thermal, and enzyme stabilities. Also, these two peptides can significantly inhibit the growth of various bacteria (Xanthomonas oryzae pv. oryzae, Xanthomonas oryzae pv. oryzicola, Clavibacter michiganensis, and Clavibacter fangii) and fungi (Fusarium graminearum, Rhizoctonia solani, and Botrytis cinerea). Scanning electron microscopy (SEM) observations revealed that CgR2150 and CgR3101 peptides act against bacteria by disrupting bacterial cell membranes. Moreover, hemolytic activity assay showed that neither of the two peptides exhibited significant hemolytic activity. To conclude, the antimicrobial peptides CgR2150 and CgR3101 are promising in the development of a new antibacterial agent and for application in plant production.202235563004
8314120.9832Interactions between Bacteria and Bile Salts in the Gastrointestinal and Hepatobiliary Tracts. Bile salts and bacteria have intricate relationships. The composition of the intestinal pool of bile salts is shaped by bacterial metabolism. In turn, bile salts play a role in intestinal homeostasis by controlling the size and the composition of the intestinal microbiota. As a consequence, alteration of the microbiome-bile salt homeostasis can play a role in hepatic and gastrointestinal pathological conditions. Intestinal bacteria use bile salts as environmental signals and in certain cases as nutrients and electron acceptors. However, bile salts are antibacterial compounds that disrupt bacterial membranes, denature proteins, chelate iron and calcium, cause oxidative damage to DNA, and control the expression of eukaryotic genes involved in host defense and immunity. Bacterial species adapted to the mammalian gut are able to endure the antibacterial activities of bile salts by multiple physiological adjustments that include remodeling of the cell envelope and activation of efflux systems and stress responses. Resistance to bile salts permits that certain bile-resistant pathogens can colonize the hepatobiliary tract, and an outstanding example is the chronic infection of the gall bladder by Salmonella enterica. A better understanding of the interactions between bacteria and bile salts may inspire novel therapeutic strategies for gastrointestinal and hepatobiliary diseases that involve microbiome alteration, as well as novel schemes against bacterial infections.201729043249
731130.9832Regulation of lipid A modifications by Salmonella typhimurium virulence genes phoP-phoQ. Bacterial pathogenesis requires proteins that sense host microenvironments and respond by regulating virulence gene transcription. For Salmonellae, one such regulatory system is PhoP-PhoQ, which regulates genes required for intracellular survival and resistance to cationic peptides. Analysis by mass spectrometry revealed that Salmonella typhimurium PhoP-PhoQ regulated structural modifications of lipid A, the host signaling portion of lipopolysaccharide (LPS), by the addition of aminoarabinose and 2-hydroxymyristate. Structurally modified lipid A altered LPS-mediated expression of the adhesion molecule E-selectin by endothelial cells and tumor necrosis factor-alpha expression by adherent monocytes. Thus, altered responses to environmentally induced lipid A structural modifications may represent a mechanism for bacteria to gain advantage within host tissues.19979092473
709140.9830Structure of the Response Regulator NsrR from Streptococcus agalactiae, Which Is Involved in Lantibiotic Resistance. Lantibiotics are antimicrobial peptides produced by Gram-positive bacteria. Interestingly, several clinically relevant and human pathogenic strains are inherently resistant towards lantibiotics. The expression of the genes responsible for lantibiotic resistance is regulated by a specific two-component system consisting of a histidine kinase and a response regulator. Here, we focused on a response regulator involved in lantibiotic resistance, NsrR from Streptococcus agalactiae, and determined the crystal structures of its N-terminal receiver domain and C-terminal DNA-binding effector domain. The C-terminal domain exhibits a fold that classifies NsrR as a member of the OmpR/PhoB subfamily of regulators. Amino acids involved in phosphorylation, dimerization, and DNA-binding were identified and demonstrated to be conserved in lantibiotic resistance regulators. Finally, a model of the full-length NsrR in the active and inactive state provides insights into protein dimerization and DNA-binding.201626930060
6030150.9830Molecular identification and probiotic potential characterization of lactic acid bacteria isolated from the pigs with superior immune responses. Lactic acid bacteria (LAB) belong to a significant group of probiotic bacteria that provide hosts with considerable health benefits. Our previous study showed that pigs with abundant LAB had more robust immune responses in a vaccination experiment. In this study, 52 isolate strains were isolated from the pigs with superior immune responses. Out of these, 14 strains with higher antibacterial efficacy were chosen. We then assessed the probiotic features of the 14 LAB strains, including such as autoaggregation, coaggregation, acid resistance, bile salt resistance, and adhesion capability, as well as safety aspects such as antibiotic resistance, hemolytic activity, and the presence or absence of virulence factors. We also compared these properties with those of an opportunistic pathogen EB1 and two commercial probiotics (cLA and cLP). The results showed that most LAB isolates exhibited higher abilities of aggregation, acid and bile salt resistance, adhesion, and antibacterial activity than the two commercial probiotics. Out of the 14 strains, only LS1 and LS9 carried virulence genes and none had hemolytic activity. We selected three LAB strains (LA6, LR6 and LJ1) with superior probiotic properties and LS9 with a virulence gene for testing their safety in vivo. Strains EB1, cLA and cLP were also included as control bacteria. The results demonstrated that mice treated LAB did not exhibit any adverse effects on weight gain, organ index, blood immune cells, and ileum morphology, except for those treated with LS9 and EB1. Moreover, the antimicrobial effect of LR6 and LA6 strains was examined in vivo. The results indicated that these strains could mitigate the inflammatory response, reduce bacterial translocation, and alleviate liver, spleen, and ileum injury caused by Salmonella typhimurium infection. In addition, the LR6 treatment group showed better outcomes than the LA6 treatment group; treatment with LR6 substantially reduced the mortality rate in mice. The study results provide evidence of the probiotic properties of the LAB isolates, in particular LR6, and suggest that oral administration of LR6 could have valuable health-promoting benefits.202438585699
6043160.9830Histamine and cholesterol lowering abilities of lactic acid bacteria isolated from artisanal Pico cheese. AIMS: This study was designed to select lactic acid bacteria with histamine- and cholesterol-reducing abilities to be used as potential probiotics. METHODS AND RESULTS: Thirty strains of lactic acid bacteria isolated from an artisanal raw milk cheese were screened for their abilities to degrade histamine, reduce cholesterol and hydrolyse bile salts. Strains were also screened for safety and probiotic traits, such as resistance to gastrointestinal conditions, adhesion to Caco-2 cells, resistance to antibiotics and presence of virulence genes. Two Lactobacillus paracasei strains presented high cholesterol- and histamine-lowering abilities, tested negative for the presence of virulence genes and showed susceptibility to most important antibiotics. These strains were also shown to possess desirable in vitro probiotic properties, revealed by tolerance to gastrointestinal conditions and high adhesion to intestinal cells. CONCLUSIONS: Among the screened strains, Lb. paracasei L3C21M6 revealed the best cholesterol and histamine reducing abilities together with desirable probiotic and safety features to be used in food applications. SIGNIFICANCE AND IMPACT OF THE STUDY: The strain L3C21M6 is a good candidate for use as a probiotic with histamine-degrading activity and cholesterol lowering effect. In addition, this strain could be use in dairy foods to prevent histamine food poisoning.202032500572
35170.9830Gluconacetobacter diazotrophicus Elicits a Sugarcane Defense Response Against a Pathogenic Bacteria Xanthomonas albilineans. A new role for the plant growth-promoting nitrogen-fixing endophytic bacteria Gluconacetobacter diazotrophicus has been identified and characterized while it is involved in the sugarcane-Xanthomonas albilineans pathogenic interactions. Living G.diazotrophicus possess and/or produce elicitor molecules which activate the sugarcane defense response resulting in the plant resistance to X. albilineans, in this particular case controlling the pathogen transmission to emerging agamic shoots. A total of 47 differentially expressed transcript derived fragments (TDFs) were identified by cDNA-AFLP. Transcripts showed significant homologies to genes of the ethylene signaling pathway (26%), proteins regulates by auxins (9%), beta-1,3 Glucanase proteins (6%) and ubiquitin genes (4%), all major signaling mechanisms. Results point toward a form of induction of systemic resistance in sugarcane-G. diazotrophicus interactions which protect the plant against X. albilineans attack.200619516988
8209180.9830Staphylococcus aureus resistance to human defensins and evasion of neutrophil killing via the novel virulence factor MprF is based on modification of membrane lipids with l-lysine. Defensins, antimicrobial peptides of the innate immune system, protect human mucosal epithelia and skin against microbial infections and are produced in large amounts by neutrophils. The bacterial pathogen Staphylococcus aureus is insensitive to defensins by virtue of an unknown resistance mechanism. We describe a novel staphylococcal gene, mprF, which determines resistance to several host defense peptides such as defensins and protegrins. An mprF mutant strain was killed considerably faster by human neutrophils and exhibited attenuated virulence in mice, indicating a key role for defensin resistance in the pathogenicity of S. aureus. Analysis of membrane lipids demonstrated that the mprF mutant no longer modifies phosphatidylglycerol with l-lysine. As this unusual modification leads to a reduced negative charge of the membrane surface, MprF-mediated peptide resistance is most likely based on repulsion of the cationic peptides. Accordingly, inactivation of mprF led to increased binding of antimicrobial peptides by the bacteria. MprF has no similarity with genes of known function, but related genes were identified in the genomes of several pathogens including Mycobacterium tuberculosis, Pseudomonas aeruginosa, and Enterococcus faecalis. MprF thus constitutes a novel virulence factor, which may be of general relevance for bacterial pathogens and represents a new target for attacking multidrug resistant bacteria.200111342591
8827190.9829Vancomycin-Induced Modulation of Gram-Positive Gut Bacteria and Metabolites Remediates Insulin Resistance in iNOS Knockout Mice. The role of oxidative and nitrosative stress has been implied in both physiology and pathophysiology of metabolic disorders. Inducible nitric oxide synthase (iNOS) has emerged as a crucial regulator of host metabolism and gut microbiota activity. The present study examines the role of the gut microbiome in determining host metabolic functions in the absence of iNOS. Insulin-resistant and dyslipidemic iNOS(-/-) mice displayed reduced microbial diversity, with a higher relative abundance of Allobaculum and Bifidobacterium, gram-positive bacteria, and altered serum metabolites along with metabolic dysregulation. Vancomycin, which largely depletes gram-positive bacteria, reversed the insulin resistance (IR), dyslipidemia, and related metabolic anomalies in iNOS(-/-) mice. Such improvements in metabolic markers were accompanied by alterations in the expression of genes involved in fatty acid synthesis in the liver and adipose tissue, lipid uptake in adipose tissue, and lipid efflux in the liver and intestine tissue. The rescue of IR in vancomycin-treated iNOS(-/-) mice was accompanied with the changes in select serum metabolites such as 10-hydroxydecanoate, indole-3-ethanol, allantoin, hippurate, sebacic acid, aminoadipate, and ophthalmate, along with improvement in phosphatidylethanolamine to phosphatidylcholine (PE/PC) ratio. In the present study, we demonstrate that vancomycin-mediated depletion of gram-positive bacteria in iNOS(-/-) mice reversed the metabolic perturbations, dyslipidemia, and insulin resistance.202135127558