Selenium bioactive compounds produced by beneficial microbes.

Selenium (Se) is an essential trace element present as selenocysteine (SeCys) in selenoproteins, which have an important role in thyroid metabolism and the redox system in humans. Se deficiency affects between 500 and 1000 million people worldwide. Increasing Se intake can prevent from bacterial and viral infections. Se deficiency has been associated with cancer, Alzheimer, Parkinson, decreased thyroid function, and male infertility. Se intake depends on the food consumed which is directly related to the amount of Se in the soil as well as on its availability. Se is unevenly distributed on the earth's crust, being scarce in some regions and in excess in others. The easiest way to counteract the symptoms of Se deficiency is to enhance the Se status of the human diet. Se salts are the most toxic form of Se, while Se amino acids and Se-nanoparticles (SeNPs) are the least toxic and most bio-available forms. Some bacteria transform Se salts into these Se species. Generally accepted as safe selenized microorganisms can be directly used in the manufacture of selenized fermented and/or probiotic foods. On the other hand, plant growth-promoting bacteria and/or the SeNPs produced by them can be used to promote plant growth and produce crops enriched with Se. In this chapter we discuss bacterial Se metabolism, the effect of Se on human health, the applications of SeNPs and Se-enriched bacteria, as well as their effect on food fortification. Different strategies to counteract Se deficiency by enriching foods using sustainable strategies and their possible implications for improving human health are discussed.

Filamentous morphology engineering of bacteria by iron metabolism modulation through MagR expression.

The morphology is the consequence of evolution and adaptation. Escherichia coli is rod-shaped bacillus with regular dimension of about 1.5 µm long and 0.5 µm wide. Many shape-related genes have been identified and used in morphology engineering of this bacteria. However, little is known about if specific metabolism and metal irons could modulate bacteria morphology. Here in this study, we discovered filamentous shape change of E. coli cells overexpressing pigeon MagR, a putative magnetoreceptor and extremely conserved iron-sulfur protein. Comparative transcriptomic analysis strongly suggested that the iron metabolism change and iron accumulation due to the overproduction of MagR was the key to the morphological change. This model was further validated, and filamentous morphological change was also achieved by supplement E. coli cells with iron in culture medium or by increase the iron uptake genes such as entB and fepA. Our study extended our understanding of morphology regulation of bacteria, and may also serves as a prototype of morphology engineering by modulating the iron metabolism.

Combined effect of brazilin-rich extract and lawsone methyl ether against infection-causing bacteria.

Bacterial contamination and infection widely affect the food, pharmaceutical and biomedical industries. Additionally, these bacteria developed resistance to synthetic antibiotics causing public health danger, globally. Natural plant extracts (NPE) are suitable alternatives to synthetic antibiotics to tackle antimicrobial resistance problems. Furthermore, a blend or combination of different NPEs exerts a wide spectrum of antimicrobial activity. Therefore, the combined effect of brazilin-rich extract (BRE) and lawsome methyl ether (LME) against infection-causing common bacteria were evaluated. BRE had a lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against most of the Gram-negative bacteria (Salmonella typhi, Salmonella typhimurium and Pseudomonas aeruginosa) while LME was active against most of the Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus, and Staphylococcus epidermidis). The combination of BRE and LME at 2:1 and 1:1 concentration significantly reduced the MIC value of each compound as compared to either BRE or LME concentration alone (P < 0.05). Further time-kill kinetics revealed a 3.0-3.5 log reduction in Gram-positive bacteria and a 2.5-3.0 log reduction in Gram-negative bacteria during 120 min of incubation, respectively. Therefore, a combination of BRE and LME was recommended as natural antibacterial to synthetic antibiotics for food and pharmaceutical applications.

Preparation of high-temperature and low-temperature-resistant solid microbial agent for cattle manure fermentation and effect on composting.

We used microbiology and molecular biology techniques to screen out high-temperature and low-temperature-resistant saprobiotics for compost and prepared a compound fermentation bacteria agent to rapidly ferment cattle manure into high-quality organic fertilizer in low-temperature season. Conventional composting and high-throughput techniques were used to analyze the changes of physical and chemical indexes and biodiversity in the process of composting, from which high and low-temperature-resistant strains were obtained, and high-temperature and low-temperature-resistant solid composite bactericides were prepared and added to composting to verify the effects of composite bactericides on composting. The conventional composting cycle took 22 days, and the diversity of microflora increased first and then decreased. Composting temperature and microbial population were the key factors for the success or failure of composting. Two strains of high-temperature-resistant bacteria and six strains of low-temperature-resistant bacteria were screened out, and they were efficient in degrading starch, cellulose, and protein. The high-temperature and low-temperature-resistant solid bacterial agent was successfully prepared with adjuvant. The preparation could make the compost temperature rise quickly at low temperature, the high temperature lasted for a long time, the water content, C/N, and organic matter fell quickly, the contents of total phosphorus and total potassium were increased, and the seed germination index was significantly improved. Improve the composting effect. The solid composite bacterial agent can shorten the composting time at low temperature and improve the composting efficiency and quality.

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

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

Wastewater treatment from a science faculty during the COVID-19 pandemic by using ammonium-oxidising and heterotrophic bacteria.

During and after the pandemic caused by the SARS-CoV-2 virus, the use of personal care products and disinfectants increased in universities worldwide. Among these, quaternary ammonium-based products stand out; these compounds and their intermediates caused substantial changes in the chemical composition of the wastewater produced by these institutions. For this reason, improvements and environmentally sustainable biological alternatives were introduced in the existing treatment systems so that these institutions could continue their research and teaching activities. For this reason, the objective of this study was to develop an improved culture medium to cultivate ammonium oxidising bacteria (AOB) to increase the biomass and use them in the treatment of wastewater produced in a faculty of sciences in Bogotá, D.C., Colombia. A Plackett Burman Experimental Design (PBED) and growth curves served for oligotrophic culture medium, and production conditions improved for the AOB. Finally, these bacteria were used with total heterotrophic bacteria (THB) for wastewater treatment in a pilot plant. Modification of base ammonium broth and culture conditions (6607 mg L-1 of (NH4)2SO4, 84 mg L-1 CaCO3, 40 mg L-1 MgSO4·7H2O, 40 mg L-1 CaCl2·2H2O and 200 mg L-1 KH2PO4, 10% (w/v) inoculum, no copper addition, pH 7.0 ± 0.2, 200 r.p.m., 30 days) favoured the growth of Nitrosomonas europea, Nitrosococcus oceani, and Nitrosospira multiformis with values of 8.23 ± 1.9, 7.56 ± 0.7 and 4.2 ± 0.4 Log10 CFU mL-1, respectively. NO2- production was 0.396 ± 0.0264, 0.247 ± 0.013 and 0.185 ± 0.003 mg L-1 for Nitrosomonas europea, Nitrosococcus oceani and Nitrosospira multiformis. After the 5-day wastewater treatment (WW) by co-inoculating the three studied bacteria in the wastewater (with their self-microorganisms), the concentrations of AOB and THB were 5.92 and 9.3 Log10 CFU mL-1, respectively. These values were related to the oxidative decrease of Chemical Oxygen Demand (COD), (39.5 mg L-1), Ammonium ion (NH4+), (6.5 mg L-1) Nitrite (NO2-), (2.0 mg L-1) and Nitrate (NO3-), (1.5 mg L-1), respectively in the five days of treatment. It was concluded, with the improvement of a culture medium and production conditions for three AOB through biotechnological strategies at the laboratory scale, being a promising alternative to bio-augment of the biomass of the studied bacteria under controlled conditions that allow the aerobic removal of COD and nitrogen cycle intermediates present in the studied wastewater. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03961-4.

Economic Burden of Acute Gastroenteritis among Members of Integrated Healthcare Delivery System, United States, 2014-2016.

We conducted a large surveillance study among members of an integrated healthcare delivery system in Pacific Northwest of the United States to estimate medical costs attributable to medically attended acute gastroenteritis (MAAGE) on the day care was sought and during 30-day follow-up. We used multivariable regression to compare costs of MAAGE and non-MAAGE cases matched on age, gender, and index time. Differences accounted for confounders, including race, ethnicity, and history of chronic underlying conditions. Analyses included 73,140 MAAGE episodes from adults and 18,617 from children who were Kaiser Permanente Northwest members during 2014-2016. Total costs were higher for MAAGE cases relative to non-MAAGE comparators as were costs on the day care was sought and costs during follow-up. Costs of MAAGE are substantial relative to the cost of usual-care medical services, and much of the burden accrues during short-term follow-up.

High-throughput sequencing-based analysis of the composition and diversity of the endophyte community in roots of Stellera chamaejasme.

Stellera chamaejasme (S. chamaejasme) is an important medicinal plant with heat-clearing, detoxifying, swelling and anti-inflammatory effects. At the same time, it is also one of the iconic plants of natural grassland degradation in northwest China, playing a key role in the invasion process. Plant endophytes live in healthy plant tissues and can synthesize substances needed for plant growth, induce disease resistance in host plants, and enhance plant resistance to environmental stress. Therefore, studying the root endophytes of S. chamaejasme is of great significance for mining beneficial microbial resources and biological prevention and control of S. chamaejasme. This study used Illumina MiSeq high-throughput sequencing technology to analyze the composition and diversity of endophytes in the roots of S. chamaejasme in different alpine grasslands (BGC, NMC and XGYZ) in Tibet. Research results show that the main phylum of endophytic fungi in the roots of S. chamaejasme in different regions is Ascomycota, and the main phyla of endophytic bacteria are Actinobacteria, Proteobacteria and Firmicutes (Bacteroidota). Overall, the endophyte diversity of the NMC samples was significantly higher than that of the other two sample sites. Principal coordinate analysis (PCoA) and permutational multivariate analysis of variance (PERMANOVA) results showed significant differences in the composition of endophytic bacterial and fungal communities among BGC, NMC and XGYZ samples. Co-occurrence network analysis of endophytes showed that there were positive correlations between fungi and some negative correlations between bacteria, and the co-occurrence network of bacteria was more complex than that of fungi. In short, this study provides a vital reference for further exploring and utilizing the endophyte resources of S. chamaejasme and an in-depth understanding of the ecological functions of S. chamaejasme endophytes.

Comprehensive bioremediation effect of phosphorus-mineralized bacterium Enterobacter sp. PMB-5 on cadmium contaminated soil-crop system.

Phosphate-mineralizing bacteria (PMBs) have been widely studied by inducing phosphate heavy metal precipitation, but current researches neglect to study their effects on soil-microbe-crop systems on cadmium (Cd) contaminated. Based on this, a strain PMB, Enterobacter sp. PMB-5, was inoculated into Cd contaminated pots to detect soil characteristics, Cd occurrence forms, soil biological activities, plant physiological and biochemical indicators. The results showed that the inoculation of strain PMB-5 significantly increased the available phosphorus content (85.97%-138.64%), Cd-residual fraction (11.04%-29.73%), soil enzyme activities (31.94%-304.63%), plant biomass (6.10%-59.81%), while decreased the state of Cd-HOAc (11.50%-31.17%) and plant bioconcentration factor (23.76%-44.24%). These findings indicated that strain PMB-5 could perform the function of phosphorus solubilization to realize the immobilization of Cd in the complex soil environment. Moreover, SEM-EDS, FTIR, XPS, and XRD analysis revealed that strain PMB-5 does not significantly alter the soil morphology, structure, elemental distribution, and chemical composition, which suggested that remediation of Cd contamination using strain PMB-5 would not further burden the soil. This research implies that PMB-5 could be a safe and effective bioinoculant for remediating Cd-contaminated soils, contributing to the sustainable management of soil health in contaminated environments.

Characterizing arginine, ornithine, and putrescine pathways in enteric pathobionts.

Arginine-ornithine metabolism plays a crucial role in bacterial homeostasis, as evidenced by numerous studies. However, the utilization of arginine and the downstream products of its metabolism remain undefined in various gut bacteria. To bridge this knowledge gap, we employed genomic screening to pinpoint relevant metabolic targets. We also devised a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics method to measure the levels of arginine, its upstream precursors, and downstream products in cell-free conditioned media from enteric pathobionts, including Escherichia coli, Klebsiella aerogenes, K. pneumoniae, Pseudomonas fluorescens, Acinetobacter baumannii, Streptococcus agalactiae, Staphylococcus epidermidis, S. aureus, and Enterococcus faecalis. Our findings revealed that all selected bacterial strains consumed glutamine, glutamate, and arginine, and produced citrulline, ornithine, and GABA in our chemically defined medium. Additionally, E. coli, K. pneumoniae, K. aerogenes, and P. fluorescens were found to convert arginine to agmatine and produce putrescine. Interestingly, arginine supplementation promoted biofilm formation in K. pneumoniae, while ornithine supplementation enhanced biofilm formation in S. epidermidis. These findings offer a comprehensive insight into arginine-ornithine metabolism in enteric pathobionts.

Susceptibility of Legionella gormanii Membrane-Derived Phospholipids to the Peptide Action of Antimicrobial LL-37-Langmuir Monolayer Studies.

LL-37 is the only member of the cathelicidin-type host defense peptide family in humans. It exhibits broad-spectrum bactericidal activity, which represents a distinctive advantage for future therapeutic targets. The presence of choline in the growth medium for bacteria changes the composition and physicochemical properties of their membranes, which affects LL-37's activity as an antimicrobial agent. In this study, the effect of the LL-37 peptide on the phospholipid monolayers at the liquid-air interface imitating the membranes of Legionella gormanii bacteria was determined. The Langmuir monolayer technique was employed to prepare model membranes composed of individual classes of phospholipids-phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), cardiolipin (CL)-isolated from L. gormanii bacteria supplemented or non-supplemented with exogenous choline. Compression isotherms were obtained for the monolayers with or without the addition of the peptide to the subphase. Then, penetration tests were carried out for the phospholipid monolayers compressed to a surface pressure of 30 mN/m, followed by the insertion of the peptide into the subphase. Changes in the mean molecular area were observed over time. Our findings demonstrate the diversified effect of LL-37 on the phospholipid monolayers, depending on the bacteria growth conditions. The substantial changes in membrane properties due to its interactions with LL-37 enable us to propose a feasible mechanism of peptide action at a molecular level. This can be associated with the stable incorporation of the peptide inside the monolayer or with the disruption of the membrane leading to the removal (desorption) of molecules into the subphase. Understanding the role of antimicrobial peptides is crucial for the design and development of new strategies and routes for combating resistance to conventional antibiotics.

[Characteristics of Epiphytic Bacterial Community on Submerged Macrophytes in Water Environment Supplemented with Reclaimed Water].

Biofilms attached to submerged macrophytes play an important role in improving the water quality of the water environment supplemented with reclaimed water. In order to explore the effects of reclaimed water quality and submerged macrophyte species on the characteristics of an epiphytic bacterial community, different types of submerged macrophytes were selected as research objects in this study. 16S rRNA high-throughput sequencing technology was used on the epiphytic bacteria and the surrounding environmental samples to analyze the bacterial community structure and functional genes. The results showed that approximately 20%-35% of the nitrogen and phosphorus nutrients were absorbed and utilized in the water environment supplemented with reclaimed water. However, the COD, turbidity, and chroma of the downstream water were significantly increased. The bacterial community of the biofilms attached to submerged macrophytes was significantly different from that in the surrounding environment (soil, sediment, and water body) and in the activated sludge that was treated by reclaimed water. In terms of bacterial community diversity, the richness and diversity were significantly lower than those of soil and sediment but higher than those of plankton bacteria in water. In terms of bacterial community composition, dominant genera and corresponding abundances were also different from those of other samples. The main dominant bacterial genera were Sphingomonas, Aeromonas, Pseudomonas, and Acinetobacter, accounting for 7%-40%, respectively. Both macrophyte species and the quality of reclaimed water (BOD5, TN, NH4+-N, and TP) could affect the bacterial community. However, the effect of water quality of the bacterial community was greater than that of macrophytes species. Additionally, the quality of reclaimed water also affected the abundance of functional genes in the bacterial community, and the relative abundance of nitrogen and phosphorus cycling functional genes was higher in areas with higher nitrogen and phosphorus concentrations.

Achromobacter seleniivolatilans sp. nov. and Buttiauxella selenatireducens sp. nov., isolated from the rhizosphere of selenium hyperaccumulator Cardamine hupingshanesis.

Two Gram-stain-negative bacterial strains, R39T and R73T, were isolated from the rhizosphere soil of the selenium hyperaccumulator Cardamine hupingshanesis in China. Strain R39T transformed selenite into elemental and volatile selenium, whereas strain R73T transformed both selenate and selenite into elemental selenium. Phylogenetic and phylogenomic analyses indicated that strain R39T belonged to the genus Achromobacter, while strain R73T belonged to the genus Buttiauxella. Strain R39T (genome size, 6.68 Mb; G+C content, 61.6 mol%) showed the closest relationship to Achromobacter marplatensis LMG 26219T and Achromobacter kerstersii LMG 3441T, with average nucleotide identity (ANI) values of 83.6 and 83.4 %, respectively. Strain R73T (genome size, 5.22 Mb; G+C content, 50.3 mol%) was most closely related to Buttiauxella ferragutiae ATCC 51602T with an ANI value of 86.4 %. Furthermore, strain A111 from the GenBank database was found to cluster with strain R73T within the genus Buttiauxella through phylogenomic analyses. The ANI and digital DNA-DNA hybridization values between strains R73T and A111 were 97.5 and 80.0% respectively, indicating that they belong to the same species. Phenotypic characteristics also differentiated strain R39T and strain R73T from their closely related species. Based on the polyphasic analyses, strain R39T and strain R73T represent novel species of the genera Achromobacter and Buttiauxella, respectively, for which the names Achromobacter seleniivolatilans sp. nov. (type strain R39T=GDMCC 1.3843T=JCM 36009T) and Buttiauxella selenatireducens sp. nov. (type strain R73T=GDMCC 1.3636T=JCM 35850T) are proposed.

[Research progress of traditional Chinese medicines as quorum sensing inhibitors in collaboration with antibiotics to inhibit drug-resistant bacteria].

Quorum sensing system regulates the expression of genes related to bacterial growth, metabolism and other behaviors by sensing bacterial density, and controls the unified action of the entire bacterial population. This mechanism can ensure the normal secretion of bacterial metabolites and the stability of the biofilm microenvironment, providing protection for the formation of biofilms and the normal growth and reproduction of bacteria. Traditional Chinese medicine, capable of quorum sensing inhibition, can inhibit the formation of bacterial biofilms, reduce bacterial resistance, and enhance the anti-infection ability of antibiotics when combined with antibiotics. In recent years, the combination of traditional Chinese and Western medicine in the treatment of drug-resistant bacterial infections has become a research hotspot. Starting with the associations between quorum sensing, biofilm and drug-resistant bacteria, this paper reviews the relevant studies about the combined application of traditional Chinese medicines as quorum sensing inhibitors with antibiotics in the treatment of drug-resistant bacteria. This review is expected to provide ideas for the development of new clinical treatment methods and novel anti-infection drugs.

Plant-based compositions for the treatment of local and topical bacterial infections: a patent review.

Aim: To examine recent patents related to plants with antimicrobial effects. Methods: Our investigation was carried out using the Espacenet database, searching patents related to International Patent Classification (IPC) codes A61P31/04, and A61K36/00 between 2008 and 2023. Results: The study began with 360 patents, of which 15 were found to be duplicates; 144 were not related to the research topic and six were not available. Then, 48 patents were related to other administration routes. The final selection was 47 patents related to local administration compositions. The potential for these herbal compositions to be marketed as over-the-counter medicines was evident. Conclusion: Developing new plant-origin anti-infective agents could provide promising solutions for combating resistant infections and offer accessible treatment options.

[Box: see text].

Cellulolytic Bacillus cereus produces a variety of short-chain fatty acids and has potential as a probiotic.

Cellulolytic bacteria ferment dietary fiber into short-chain fatty acids, which play an important role in improving fiber utilization and maintaining intestinal health. Safe and effective cellulolytic bacteria are highly promising probiotic candidates. In this study, we isolated three strains of Bacillus cereus, which exhibited cellulolytic properties, from Kele pig feces. To assess the genetic basis of cellulose degradation by the isolates, whole-genome sequencing was used to detect functional genes associated with cellulose metabolism. Subsequently, we identified that the B. cereus CL2 strain was safe in mice by monitoring body weight changes, performing histopathologic evaluations, and determining routine blood indices. We next evaluated the biological characteristics of the CL2 strain in terms of its growth, tolerance, and antibiotic susceptibility, with a focus on its ability to produce short-chain fatty acids. Finally, the intestinal flora structure of the experimental animals was analyzed to assess the intestinal environment compatibility of the CL2 strain. In this study, we isolated a cellulolytic B. cereus CL2, which has multiple cellulolytic functional genes and favorable biological characteristics, from the feces of Kele pigs. Moreover, CL2 could produce a variety of short-chain fatty acids and does not significantly affect the diversity of the intestinal flora. In summary, the cellulolytic bacterium B. cereus CL2 is a promising strain for use as a commercial probiotic or in feed supplement. IMPORTANCE: Short-chain fatty acids are crucial constituents of the intestinal tract, playing an important and beneficial role in preserving the functional integrity of the intestinal barrier and modulating both immune responses and the structure of the intestinal flora. In the intestine, short-chain fatty acids are mainly produced by bacterial fermentation of cellulose. Therefore, we believe that safe and efficient cellulolytic bacteria have the potential to be novel probiotics. In this study, we systematically evaluated the safety and biological characteristics of the cellulolytic bacterium B. cereus CL2 and provide evidence for its use as a probiotic.

Epidemiological insights into seasonal, sex­specific and age­related distribution of bacterial pathogens in urinary tract infections.

Urinary tract infections (UTIs) are prevalent and recurrent bacterial infections that affect individuals worldwide, posing a significant burden on healthcare systems. The present study aimed to explore the epidemiology of UTIs, investigating the seasonal, gender-specific and age-related bacterial pathogen distribution to guide clinical diagnosis. Data were retrospectively collected from electronic medical records and laboratory reports of 926 UTIs diagnosed in Fuding Hospital (Fujian University of Traditional Chinese Medicine, Fuding, China). Bacterial isolates were identified using standard microbiological techniques. χ2 tests were performed to assess associations between pathogens and the seasons, sex and age groups. Significant associations were found between bacterial species and seasons. Enterococcus faecium exhibited a substantial prevalence in spring (χ2, 12.824; P=0.005), while Acinetobacter baumannii demonstrated increased prevalence in autumn (χ2, 16.404; P=0.001). Female patients showed a higher incidence of UTIs. Gram-positive bacteria were more prevalent in males, with Staphylococcus aureus showing significant male predominance (χ2, 14.607; P<0.001). E. faecium displayed an age-related increase in prevalence (χ2, 17.775; P<0.001), whereas Escherichia coli tended to be more prevalent in younger patients (χ2, 12.813; P=0.005). These findings highlight the complex nature of UTIs and offer insights for tailored diagnostic and preventive strategies, potentially enhancing healthcare outcomes.

Ethanol leaf extracts of Anogeissus leiocarpus in antioxidants and hepatotoxic effects of Escherichia coli O157:H7 infected Swiss Mice.

Introduction: Diseases caused by bacteria can be managed with medicinal plants with rightful dosage that will not affect body physiology and organs. Aim: This research aimed to evaluate the antioxidants and the effects of Anogeisus leiocarpus on liver function. Materials and methods: Ethanol leaf extracts were processed for antioxidants and hepatotoxic effects using animal models. Group one (negative control) was given access to water and regular feed, group two (positive control) was dosed with 107 CFU/ml of Escherichia coli O157:H7, and groups 3-6 were dosed with 107 E. coli O157:H7 for 3 days and treated with extract concentrations of 12, 25, 50 and 100 mg/kg bw respectively for seven days. Results: Higher ascorbic acid values in Ferric reducing antioxidant property (FRAP) and Hydroxyl radical scavenging (HRS) were recorded in the positive control (0.05 ± 0.01, 41 ± 0.05) than in the extract-treated (0.02 ± 0.14, 30 ± 0.02). Increase in DPPH (47 ± 0.1268 ± 0.05 %), Free radical scavenging property (FRAP) (0.03 ± 0.02-0.08 ± 0.14 %), and HRS (38 ± 0.14-68 ± 0.12 %) was observed in the extract. The lipid peroxidation (LPO) of the quote was 78.51 ± 2.16, GSH was 36.18 ± 3.18, and catalase was 78.42 ± 4.713. In the extract-treated, decreased values were recorded for LPO ((108.36 ± 1.12-70.19 ± 1.68 µM/g), while increased values were observed in Glutathione (GSH) (25.11 ± 2.64-33.62 ± 1.35 µM/g), and catalase (54.18 ± 2.14-60.25 ± 1.4 µM/g). The values of negative control for Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), and Alkaline phosphate (ALP) were lesser than what was received in the extract treated. Conclusion: The plant's traditional medicine usage is effective at low dosage and could be a suitable candidate for drug development which will not affect the body's physiology and organs. The subjecting of A. leiocarpus ethanol leaf extract to antioxidants assays and its effect on liver function have further proved its value in folklore medicine.

Unraveling the significance of calcium as a biofilm promotion signal for Bacillus licheniformis strains isolated from dairy products.

Bacillus licheniformis, a quick and strong biofilm former, is served as a persistent microbial contamination in the dairy industry. Its biofilm formation process is usually regulated by environmental factors including the divalent cation Ca2+. This work aims to investigate how different concentrations of Ca2+ change biofilm-related phenotypes (bacterial motility, biofilm-forming capacity, biofilm structures, and EPS production) of dairy B. licheniformis strains. The Ca2+ ions dependent regulation mechanism for B. licheniformis biofilm formation was further investigated by RNA-sequencing analysis. Results revealed that supplementation of Ca2+ increased B. licheniformis biofilm formation in a dose-dependent way, and enhanced average coverage and thickness of biofilms with complex structures were observed by confocal laser scanning microscopy. Bacterial mobility of B. licheniformis was increased by the supplementation of Ca2+ except the swarming ability at 20 mM of Ca2+. The addition of Ca2+ decreased the contents of polysaccharides but promoted proteins production in EPS, and the ratio of proteins/polysaccharides content was significantly enhanced with increasing Ca2+ concentrations. RNA-sequencing results clearly indicated the variation in regulating biofilm formation under different Ca2+ concentrations, as 939 (671 upregulated and 268 downregulated) and 951 genes (581 upregulated and 370 downregulated) in B. licheniformis BL2-11 were induced by 10 and 20 mM of Ca2+, respectively. Differential genes were annotated in various KEGG pathways, including flagellar assembly, two-component system, quorum sensing, ABC transporters, and related carbohydrate and amino acid metabolism pathways. Collectively, the results unravel the significance of Ca2+ as a biofilm-promoting signal for B. licheniformis in the dairy industry.

Effects of replacing Na selenite in laying hen feed with selenized glucose on production performance, egg quality, egg selenium content, microbial population, immunological response, antioxidant enzymes, and fatty acid composition.

This study aimed to explore the effects of selenized glucose (SeGlu) and Na selenite supplementation on various aspects of laying hens such as production performance, egg quality, egg Se concentration, microbial population, antioxidant enzymes activity, immunological response, and yolk fatty acid profile. Using a 2 × 2 factorial design, 168 laying hens at 27-wk of age were randomly divided into 4 treatment groups with 7 replications. Se source (Na selenite and SeGlu) and Se level (0.3 and 0.6 mg/kg) were used as treatments. When 0.3 mg SeGlu/kg was compared to 0.3 mg Na selenite/kg, the interaction findings revealed that 0.3 mg SeGlu/kg increased egg production percent and shell ash (P < 0.05). When compared to 0.3 mg Na selenite/kg, dietary supplementation with 0.3 and 0.6 mg SeGlu/kg resulted in an increase in albumen height, Haugh unit, and yolk color of fresh eggs (P < 0.05). SeGlu enhanced albumen height, Haugh unit, shell thickness (P < 0.01), albumen index, yolk share, specific gravity, shell ash (P < 0.05) of fresh eggs and shell thickness (P < 0.05) of stored eggs as compared to Na selenite. The interaction showed that 0.6 mg SeGlu/kg enhanced yolk Se concentration while decreasing malondialdehyde levels in fresh egg yolk (P < 0.05). SeGlu enhanced Se concentration in albumen and glutathione peroxidase activity in plasma (P < 0.05) as compared to Na selenite. 0.6 mg Se/kg increased lactic acid bacteria, antibody response to sheep red blood cells, and lowered ∑n-6 PUFA/ ∑n-3 PUFA ratio (P < 0.05). As a result, adding SeGlu to the feed of laying hens enhanced egg production, egg quality, egg Se concentration, fresh yolk lipid oxidation, and glutathione peroxidase enzyme activity.