Replacement Of Antibiotics Research Articles

Phytobiotic effects of Guinea grass supplementation on production and health performances of coloured-broilers

Growing concerns about antibiotic resistance in the livestock industry have prompted researchers to explore alternative solutions. This study investigated the effects of Megathyrsus maximus as a phytobiotic supplement on the production performance and health of Sasso broilers raised in tropical environments. 216 Sasso mixed-sex broiler chicks were randomly assigned to six treatment groups (six replicates per treatment): Treatment 1 (T1) as a negative control (no antibiotics), Treatment 2 (T2) as a positive control (100 mg/kg oxytetracycline), and Treatments 3–6 received 1.25, 2.50, 3.75, and 5.00 g/kg of M. maximus grass meal on top the basal diet, respectively, without antibiotics. At day 56, broilers in T6 had the highest final body weight (1.87 kg) and superior FCR of 1.93. Nutrient digestibility was optimised at higher doses of M. maximus, with the highest CP (67.68%) and EE (74.50%) digestibility in the T6 group (p < 0.001). Megathyrsus maximus also improved intestinal morphology, with higher VH:CD in all segments. However, microbial counts and carcase characteristics remained largely unaffected, though meat quality was significantly improved in terms of reduced drip loss and shear force at supplementation levels of 5.00 g/kg. Blood biomarkers analysis and decreased liver enzyme activity in the M. maximus groups, particularly in T6, suggests lowered inflammation and enhanced liver function. This study concludes that M. maximus supplementation, particularly at the highest inclusion level (T6) shows potential as an effective antibiotic replacement in tropical poultry production.

Growth Performance, Digestive Enzymes Activities and Gut Microbiota of Malaysian Mahseer, Tor tambroides Fingerlings Affected by Various Probiotics Concentrations

The most valued freshwater fish in Malaysia is the Malaysian mahseer, Tor tambroides, also known as Empurau. Due to the extended growing period, innovative feeding management is required to maintain fish health. This study looked at the effect of Lacto-sacc, a feed additive and antibiotic replacement made up of Lactobacillus acidophilus, Saccharomyces cerevisiae and Enterococcus faecium, on T. tambroides fingerlings’ growth performance, digestive enzyme activities and gut microbiota. A total of 600 fingerlings, each weighing 6.53 g ± 0.17 g, were allocated into twelve 650 L tanks, with 50 fingerlings per tank. Over a period of 20 weeks, the fish were fed four different diets: 0% Lacto-sacc as control (A), 0.5% Lacto-sacc (B), 1.0% Lacto-sacc (C), and 1.25% Lacto-sacc (D), with each diet replicated in three tanks. Although statistic revealed no significant differences in growth performance among treatment group (p&gt;0.05), but it is noteworthy that fingerlings of T. tambroides were fed a diet containing 0.5% Lacto-sacc exhibited a trend toward improved growth performance with value higher SGR, along with elevated lipase and protease activities than other groups. Fusobacteria, Proteobacteria, Bacteroidetes, Firmicutes were the top four phyla in the gut microbiota of T. tambroides, accounting for more than 95%, with Fusobacteria dominating at around 70% of the gut microbiota. Cetobacterium, ZOR0006, Brevinema, and Aeromonas were the most common genera detected. T. tambroides fed a 0.5% Lacto-sacc (B) diet had lower Fusobacteria abundance while increasing other dominating bacteria compared to other treatments. Although there is no significant difference in gut microbiota, the gut microbiota of T. tambroides fed probiotics was more consistently disturbed and diversified, indicating less species dominance. The addition of Lacto-sacc, particularly at a concentration of 0.5%, appeared to enhance growth performance and increase the activity of digestive enzymes compared to the diet without Lacto-sacc, although the results were not statistically significant.

A BODIPY derivative for PDT/PTT synergistic treatment of bacterial infections

Phototherapeutic antimicrobials, including photodynamic and photothermal antimicrobials, are considered effective alternatives for antibiotic strategy due to their broad-spectrum antibacterial activity and low risk of resistance. Here, a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivative containing triphenylamine groups was co-assembled with Pluronic F-127 (F-127) to form nanoparticles (BICF NPs). BICF NPs have excellent photodynamic and photothermal properties and are demonstrated to be effective in inhibiting and disrupting bacterial biofilms, thereby promoting the healing of subcutaneous abscesses. This work provides a new avenue for antibiotic replacement therapy.

The lasso peptide produced by Bacillus licheniformis MCC 2514 demonstrates efficacy in treating in-vivoSalmonella Typhimurium infection

Salmonella, a significant pathogen transmitted through food, presents a substantial threat to public health. The issue of antibiotic misuse is causing a quest for alternative replacements. An antimicrobial peptide, predicted as lasso peptide 2514 (LP-2514), derived from the probiotic bacteria Bacillus licheniformis MCC 2514, has demonstrated effectiveness against various foodborne pathogens including Salmonella. This study aims to assess the efficacy of this peptide in vivo. Mice infected with Salmonella Typhimurium received daily oral administration of LP-2514 (30 mg/kg/day) for 2 weeks until the symptoms subsided. After the treatment, biochemical and histopathological parameters were examined. LP-2514 treated mice demonstrated reduced infection, as evidenced by a 5-fold decrease in aspartate aminotransferase concentration and a 10-fold decrease in alanine aminotransferase concentration in plasma. Nitric oxide generation was decreased by 61.23 %, C-reactive protein by 75.9 %, and numerous antioxidant enzymes were elevated to suppress the infection. Increased expression of the anti-inflammatory marker Interleukin-10 (IL-10) by 43-fold was observed in treated mice, while untreated mice displayed elevated expression of pro-inflammatory cytokines indicating the severity of infection. Hence, LP-2514 successfully alleviated the disease symptoms caused by S. Typhimurium, thus exhibiting as a potential replacement for antibiotics or food-grade preservatives.

Electrosynthesis of Anisotropic Biogenic Silver Nanoparticles as A Promising Antibacterial Agent Using Stachytarpheta Jamaicensis Leaf Extract

Antibiotic-resistant bacteria provide a great opportunity to use silver nanoparticles (AgNPs) as potential antibiotic replacements. This work utilized Stachytarpheta jamaicensis leaf extract (SJLE)-mediated electrosynthesis of biogenic AgNPs. By using two silver rods and SJLE as the electrolysis medium, biogenic AgNP is produced through electrosynthesis. The properties of the formed AgNPs and SJLE phytochemical composition were examined. The disc diffusion method was utilized to evaluate AgNPs' antibacterial efficacy against Escherichia coli and Staphylococcus aureus. The high amount of phenolics, flavonoids, and tannins in SLJE provides biomolecules rich in -OH and carbonyl groups, allowing SLJE to have antimicrobial effects as well as act as a capping agent and bioreductor during electrosynthesis. The presence of functional groups from various phytochemicals leads to the formation of anisotropic AgNP crystals with a size of 38.22 ± 13.06 nm and high purity (95.75 ± 0.43%). Antibacterial activity tests against E. coli and S. aureus show that anisotropic biogenic AgNPs outperformed spherical AgNPs, probably due to the angular AgNPs' ease of penetration into bacterial cell walls. The characteristics of the AgNPs developed induced outstanding antibacterial efficacy against E. coli and S. aureus. Thus, SLJE-based electrosynthesis provides a synergistic synthetic design of AgNPs as antibacterial agents with several potential long-term advantages, including high purity, fast synthesis, low cost, absence of hazardous ingredients, and simplicity in scaling up.

IN VITRO ASSESSMENT OF GRAIN OF PARADISE ADDITIVE AS ANTIMCROBIAL GROWTH PROMOTER: EFFECT IN RUMINANT DIET

This research was carried out to assess the replacement of conventional antibiotics (tetracycline) with a spice such as Grain of Paradise (Aframomum melegueta) as a growth promoter in ruminant production. The results of proximate, fibre and phytochemical analyses of the spice revealed the presence of appreciable quantities of tannins, saponins, phenols, oxalates, alkaloids etc. The in vitro studies using inoculum from cattle showed that at 24th, 30th and 33rd hour of incubation, similar but lowest gas production was observed in substrate containing 2% tetracycline (17.00, 21.33 and 22.67 mL/200mg) and 2% spice (18.00, 21.67 and 23.00 mL/200mg) respectively, than other treatments. Percentage methane/total gas produced by 1% spice additive (18.89 mL/200mg) is similar (p&gt;0.05) to 2% spice additive (19.44 mL/200mg), but lower (p&lt;0,05) than in 2% tetracycline additive (35.36 mL/200mg). Ammonia nitrogen produced by substrate containing 3% spice additive had lowest value (13.61mL/0.80 mg/dL). Inclusion of spice at various levels has no effect on total Volatile Fatty Acids (VFA) and individual VFA production. In conclusion, spice such as Grain of Paradise (Aframomum melegueta), can therefore be used as a growth promoter feed additive to replace tetracycline at 2% inclusion and to reduce the effect of enteric methane production by ruminant animals. This might solve the problem of residual effects of antimicrobials in meat produced by ruminant animals for human consumption.

Influence of annealing temperature on the structure, morphology, optical property and antibacterial response of phytochemicals-assisted synthesized zinc oxide nanoparticles

Abstract Antibiotic overuse has caused a variety of bacterial pathogens to develop new resistance mechanisms. As a result, discovering an appropriate replacement for the standard antibiotics has become an immediate concern. The present work demonstrates a facile, eco-friendly and economical method for the synthesis of hexagonal wurtzite zinc oxide nanoparticles (ω-ZONPs) using the ethanolic extract of triphala. Gas chromatography–mass spectrometry analysis of the triphala extract proved the presence of certain secondary metabolites, which aids in the formation of ω-ZONPs. The influence of annealing temperature on the antibacterial action of as-synthesized ω-ZONPs was studied for three different annealing temperatures. X-ray diffraction, dynamic light scattering, field emission electron microscopy and energy dispersive X-ray spectroscopy analyses were used to examine the impact of annealing temperature on the structure, particle size and morphology of ω-ZONPs. Fourier transform infrared spectra revealed the change in intensity of the characteristic peaks in ω-ZONPs with different annealing temperatures. From UV–Visible diffuse reflectance spectroscopy, variation in the band gap of ω-ZONPs with increasing annealing temperature was detected. Kirby Bauer disc diffusion was adopted to examine the antibacterial potential of ω-ZONPs against bacterial strains such as Staphylococcus aureus, Enterococcus faecium, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ω-ZONPs annealed at 200 °C inhibited the growth of three bacterial pathogens, E. coli, B. subtilis and P. aeruginosa and exhibited effective antibacterial activity in comparison with ω-ZONPs annealed at relatively high temperatures. Thus, the antibacterial potential of ω-ZONPs could be further explored as disease controlling agents and such prototypes could be made available for commercial mass production.

Characterization of spray-dried plasma-induced immune response in Salmonella-challenged broiler chicks

Spray-dried plasma (SDP) is a functional feed additive that has been established to improve performance and health of livestock. Understanding the effect of SDP in immune response modulation is essential to optimize its use for controlling Salmonella Enteritidis (SE) infection in chickens. This study was conducted to determine the levels of expression of selected cytokine genes in the ileum and cecal tonsil of SE-challenged broiler chicks. In a floor-pen housing, 320 broilers chicks were randomly assigned to 6 treatment groups: CX (unmedicated corn-soybean meal (SBM) basal without SDP), MX (unmedicated corn-SBM basal with antibiotic bacitracin methylene disalicylate (BMD) added at 0.055g/kg diet), PCX (unmedicated corn-SBM basal with SDP added at 30g/kg diet). Treatments SE, MSE, and PSE consisted of chicks inoculated with 7.46 × 108 CFU SE /mL at 1 d of age and given diets similar to CX, MX, and PCX, respectively. Samples of cecal tonsils and ileum were collected on d 3, 7 and 14 post infection for qRT-PCR analysis to determine the expression levels of interleukin (IL)-1β, interferon-γ (IFN-γ), IL-13, IL-17, IL-6, and transforming growth factor (TGF)-β genes. In the ceca tonsils, expression of IFN-γ was not affected by the interaction of Day and Treatment (P > 0.05). The level of the anti-inflammatory cytokine IL-13 was lower in MX and PCX on d 7 whereas high levels were expressed (P < 0.05) in MSE and PSE. In the ileum, expression of IL-17 and IFN-γ was significantly lower (P < 0.05) in PSE and MSE, but only PSE expressed lower IL-6 comparable to unchallenged treatments. On d 28 postchallenge, concentrations of anti-SE IgY and IL-6 protein were higher (P < 0.05) in the SE-challenged treatments compared to the unchallenged treatments. Overall, these results suggest that dietary SDP showed similar potency to BMD in modulating intestinal cytokine response against intestinal SE colonization in broiler chicks and therefore can be considered suitable alternative replacement for antibiotics in broiler production.

The treatment of chronic wounds using bacteriophages

Introduction and aim of study: Chronic wounds are increasingly challenging global healthcare. These wounds, which take over 3 months to heal, are complicated by untreated infections and the formation of biofilm, hindering healing and antibiotic effectiveness. To tackle these issues, new treatments like bacteriophage therapy are being explored. Bacteriophages, viruses that target bacteria, offer promise in overcoming antibiotic resistance. However, their use presents challenges that need to be addressed. Material and methods: Our review is based on the analysis of materials collected in Pubmed, Elsevier and other scientific articles using keywords: “chronic wound”, “chronic wounds infection”, “biofilms”, “MDR”, “bacteriophage”, “phage therapy”. Conclusions: The rise of chronic wounds due to resistant infections poses a significant challenge for patients and healthcare systems. Multidrug-resistant bacteria, often forming biofilm, evade current treatments, urging the search for alternatives. Phage therapy, showing efficacy against various stubborn infections, including those from surgery or diabetes, gains attention. Advanced delivery systems enhance targeted treatment, while phage cocktails improve effectiveness, especially against multiple resistant strains. Safety is generally observed, but larger trials are needed. Though not a replacement for antibiotics, phage therapy offers hope, needing robust clinical validation. While challenges exist, its societal, commercial, and economic benefits suggest a promising future beyond clinical use.

Update of the cooling protocol for antibiotic-free storage of boar semen at 5°C improves sperm quality and maintains low bacterial counts.

Preserving boar semen at 5°C instead of the conventional storage temperature of 17°C would enable a reduction of antibiotic use in pig insemination. To protect the chilling-sensitive boar spermatozoa, holding the extended semen at a higher temperature before cooling could be beneficial and facilitate the implementation of the innovative preservation concept in practice, provided that bacterial growth is kept at a low level. The aim of this study was to introduce a holding time (HT) at 17°C before cooling and to examine the effect on sperm quality and bacterial growth compared to the original cooling protocol for antibiotic-free 5°C semen storage. A series of experiments with semen doses from eight boars extended in Androstar® Premium without conventional antibiotics revealed that sperm kinematics and the integrity of sperm plasma membranes and acrosomes were improved with HT between 16 and 24 h followed by delayed cooling with 0.04°C/min when compared to the original protocol for semen preservation at 5°C (p < 0.05). Both a shorter HT of 6 h and a faster cooling rate of 0.07°C/min reduced sperm quality (p < 0.05). The HT for 24 h did not compromise the inhibitory effect on bacterial growth during long-term semen storage at 5°C, not even in semen doses spiked with Serratia marcescens. In conclusion, semen storage at 5°C with the modified cooling protocol improved sperm quality and is antimicrobially efficient. It thus presents a ready-to-use tool for a reduction or replacement of antibiotics in pig insemination.

Antibacterial Action of Zn2+ Ions Driven by the In Vivo Formed ZnO Nanoparticles.

Antibacterial formulations based on zinc oxide nanoparticles (ZnO NPs) are widely used for antibiotic replacement in veterinary medicine and animal nutrition. However, the undesired environmental impact of ZnO NPs triggers a search for alternative, environmentally safer solutions. Here, we show that Zn2+ in its ionic form is a more eco-friendly antibacterial, and its biocidal action rivals that of ZnO NPs (<100 nm size), with a minimal biocidal concentration being 41(82) μg mL-1 vs 5 μg mL-1 of ZnO NPs, as determined for 103(106) CFU mL-1 E. coli. We demonstrate that the biocidal activity of Zn2+ ions is primarily associated with their uptake by E. coli and spontaneous in vivo transformation into insoluble ZnO nanocomposites at an internal bacterial pH of 7.7. Formed in vivo nanocomposite then damages E. coli membrane and intracellular components from the inside, by forming insoluble biocomposites, whose formation can also trigger ZnO characteristic reactions damaging the cells (e.g., by generation of high-potential reactive oxygen species). Our study defines a special route in which Zn2+ metal ions induce the death of bacterial cells, which might be common to other metal ions capable of forming semiconductor oxides and insoluble hydroxides at a slightly alkaline intracellular pH of some bacteria.

The effects of Artemisia annua nutritional supplementation at varying concentrations on broiler growth, economic yield, and gene expression levels of certain antioxidant, inflammatory, and immune genes.

Artemisia annua (AA), used as a growth promoter in poultry, lowers feed costs and enhances economic efficiency. This study aimed to assess the impact of varying AA concentrations on broiler chicken growth, gene expression, and profitability. Two hundred 1-day-old male Cobb chicks were randomly allocated into four treatment groups, each containing five replicates and 10 birds. The experimental groups consisted of G1 (basal diet), G2 (basal diet with 0.3% AA), G3 (basal diet with 0.6% AA), and G4 (basal diet with 0.9% AA). The birds had continuous access to feed and water throughout the study. The experiment lasted for 42 days. We measured the growth performance (Feed intake, Life weight), carcass traits (weight after slaughter, dressed carcass, heart, gizzard, spleen, giblet and thymus weight), liver and spleen antioxidants (CAT, GSH, SOD), and gene expression of anti-inflammatory and immune- related genes. The primary findings revealed that the addition of 0.6% AA had a positive impact (p < 0.05) on all investigated variables compared with the control and other groups. Dietary supplementation with 0.6% AA led to increased breast, giblet, skeleton, and total yield, and net return compared with the control group. Supplementation with AA exhibited antioxidant, anti-inflammatory, and immunological effects through improved levels of antioxidant superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in tissue homogenates of the liver and spleen. It also upregulated the relative messenger RNA levels of anti-inflammatory interleukin (IL)-10, SOD, CAT, and GSH-Px, whereas IL-1β and tumor necrosis factor-alpha were downregulated. The study found that AA is a promising replacement for antibiotics in poultry farming as a growth promoter for chickens. 0.6% AA in the broiler diet yielded the best results, striking a balance between superior performance and robust economic benefits.

Antimicrobial mechanism of morusin against Bacillus cereus and its potential as an antimicrobial agent

Bacillus cereus, a food-borne pathogen, threatens human health and food safety. The quest for biologically active substances from natural sources acting as antimicrobial agents for the replacement of antibiotics and chemical additives has received increasing attention. In this study, the antimicrobial mechanism of morusin against B. cereus was outlined, as well as its function as a food supplement to extend the shelf-life of skimmed milk was assessed. Our findings demonstrated that the minimum inhibitory concentration (MIC) value of morusin against B. cereus was 2.25 μg/mL, inhibiting biofilm formation and reducing intracellular ATP and membrane depolarization by disturbing the permeability of the B. cereus cytoplasmic membrane. Damage or collapse of B. cereus cell membranes produced by morusin was identified using the field gun scanning electron microscope (FEG-SEM). Transcriptomic assessment indicated that the two-component system of B. cereus (narG, narH, narI, phoP, phoR, motA) responded positively to morusin within an adverse environment. Moreover, several genes associated with cell membrane and cell wall generation (murA, murB, ddlB) and amino acid metabolism (argF, argH, BCN_RS02850) were significantly downregulated, potentially accelerating the death of B. cereus. In addition, metabolomic investigation suggested that morusin restricted pyruvate metabolism, cysteine and methionine metabolic pathways, and disturbed the intracellular amino acid metabolism of B. cereus. Ultimately, 4.5 μg/mL of morusin was determined to significantly inhibit the growth of B. cereus within skimmed milk. Overall, morusin can be utilized as a natural antimicrobial agent for regulating B. cereus contamination in skimmed milk.

Metabolic pathways and antimicrobial peptide resistance in bacteria.

Antimicrobial resistance is a pressing concern that poses a significant threat to global public health, necessitating the exploration of alternative strategies to combat drug-resistant microbial infections. Recently, antimicrobial peptides (AMPs) have gained substantial attention as possible replacements for conventional antibiotics. Because of their pharmacodynamics and killing mechanisms, AMPs display a lower risk of bacterial resistance evolution compared with most conventional antibiotics. However, bacteria display different mechanisms to resist AMPs, and the role of metabolic pathways in the resistance mechanism is not fully understood. This review examines the intricate relationship between metabolic genes and AMP resistance, focusing on the impact of metabolic pathways on various aspects of resistance. Metabolic pathways related to guanosine pentaphosphate (pppGpp) and guanosine tetraphosphate (ppGpp) [collectively (p)ppGpp], the tricarboxylic acid (TCA) cycle, haem biosynthesis, purine and pyrimidine biosynthesis, and amino acid and lipid metabolism influence in different ways metabolic adjustments, biofilm formation and energy production that could be involved in AMP resistance. By targeting metabolic pathways and their associated genes, it could be possible to enhance the efficacy of existing antimicrobial therapies and overcome the challenges exhibited by phenotypic (recalcitrance) and genetic resistance toward AMPs. Further research in this area is needed to provide valuable insights into specific mechanisms, uncover novel therapeutic targets, and aid in the fight against antimicrobial resistance.

Graphene Quantum Dots Nanoantibiotic-Sensitized TiO2- x Heterojunctions for Sonodynamic-Nanocatalytic Therapy of Multidrug-Resistant Bacterial Infections.

The exploration of sonodynamic therapy (SDT) as a possible replacement for antibiotics by creating reactive oxygen species (ROS) is suggested as a non-drug-resistant theranostic method. However, the low-efficiency ROS generation and complex tumor microenvironment which can deplete ROS and promote tumor growth will cause the compromised antibacterial efficacy of SDT. Herein, through an oxygen vacancy engineering strategy, TiO2- x microspheres with an abundance of Ti3+ are synthesized using a straightforward reductant co-assembly approach. The narrow bandgaps and Ti3+/Ti4+-mediated multiple-enzyme catalytic activities of the obtained TiO2- x microspheres make them suitable for use as sonosensitizers and nanozymes. When graphene quantum dot (GQD) nanoantibiotics are deposited on TiO2- x microspheres, the resulting GQD/TiO2- x shows an increased production of ROS, which can be ascribed to the accelerated separation of electron-hole pairs, as well as the peroxidase-like catalytic activity mediated by Ti3+, and the depletion of glutathione mediated by Ti4+. Moreover, the catalytic activities of TiO2- x microspheres are amplified by the heterojunctions-accelerated carrier transfer. In addition, GQDs can inhibit Topo I, displaying strong antibacterial activity and further enhancing the antibacterial activity. Collectively, the combination of GQD/TiO2- x-mediated SDT/NCT with nanoantibiotics can result in a synergistic effect, allowing for multimodal antibacterial treatment that effectively promotes wound healing.

Macleaya cordata extract exhibits some potential as a surrogate antibiotic by improving gastrointestinal epithelial status and humoral response in goats

Macleaya cordata extract (MCE) is a potential replacement for antibiotics. In the current study, effects of MCE on the gastrointestinal health and humoral responses of host animals were explored. A total of 30 weanling goats with similar body weight of 9.15 ± 1.36 kg were randomly allocated into three groups (n = 10 per group): control group (CON group, fed with a basal diet), antibiotic group (Abx group, fed with the basal diet supplemented with 0.18 g/d vancomycin and 0.36 g/d neomycin), and MCE group (fed with the basal diet supplemented with 5 g/d MCE), for three weeks. Results showed that antibiotic addition decreased the height and area of rumen papillae, ruminal mucosa Toll-like receptor 8 (TLR8), interleukin-8 (IL-8) and interleukin-1β (IL-1β) gene relative expression levels and microbial diversity, altered the volatile fatty acid (VFA) profile in the rumen, and increased monocytes amount and CD4+ T cells percentage in the peripheral blood (P < 0.05) compared to CON group. MCE addition increased the average daily gain, ileal villus height, villus height/crypt depth, and immunoglobulin M (IgM) content in the peripheral blood (P < 0.05) compared to the CON. Additionally, MCE addition decreased the proportion of isobutyric acid in the chyme of the ileum (P = 0.005) compared to the CON group. These results suggest that antibiotic supplementation may suppress the epithelial state and microbial diversity and fermentation in goats, but stimulate cellular response to maintain the growth performance of goats. MCE administration improved the epithelial state and humoral response to promote the growth performance in goats.

Mentha piperita powder enhances the biological response, growth performance, disease resistance, and survival of Oreochromis niloticus infected with Vibrio alginolyticus

Recently, medical plants have been widely used as replacements for antibiotics in disease treatment. Because of its multiple medicinal uses, peppermint (Mentha piperita, MP) is a common herbal remedy. In the present study, MP powder was used as a feed additive to assess growth performance; hematological; biochemical and immune parameters; intestinal histology; and interleukin 1β (IL-1β) gene expression, as well as protection against Vibrio alginolyticus infection in Oreochromis niloticus. O. niloticus (n = 120, 25.66 ± 0.16 g) were fed diets containing 0 (CTR), 2, 3, or 4% MP for 60 days. The results revealed that the inclusion of 2% MP significantly improved the growth indices, intestinal morphological parameters, and reduced the feed conversion ratio. The 2% MP treatment significantly (P < 0.05) increased hematological parameters (red blood cell (RBC) count, white blood cell (WBC) count, packed cell volume% (PCV%), hemoglobin) compared with those of the CTR (P < 0.05). Additionally, feeding fish 2% MP diets decreased the levels of cholesterol and LDL (low-density lipoprotein). There were significant increases in immune responses (serum protein and phagocytic activity and index) and non-significant increases in the expression of IL-1β in the 2% MP group comparing with the other groups and the CTR group (P < 0.05). At the end of the feeding trial (60 days), fish were challenged with a virulent strain of Vibrio alginolyticus and the results showed that the mortality rate decreased in the 2% MP treatment group, followed by the 3% and 4% MP groups. Overall, the results revealed that the dietary inclusion of 2% MP can exhibit growth-promoting and immunostimulant effects for sustainable aquaculture.

Weissella sp. SNUL2 as potential probiotics with broad-spectrum antimicrobial activities

Probiotics have been applied to a wide range of bacteria, causing gastrointestinal and vaginal infections. However, probiotics generally possess limited antimicrobial spectra and are primarily utilized as dietary supplements. Recognizing the need for more versatile probiotics, this study focuses on isolating and characterizing strains suitable for antibiotic replacement. Among these strains, Weissella sp. SNUL2, derived from a traditional fermented food in Korea (i.e., Sikhae), emerged as a promising candidate. The correlation between optical density at 600 nm and colony-forming units was verified and applied in subsequent experiments. To assess the therapeutic potential of probiotics, antibacterial tests were conducted using a microplate reader to evaluate the inhibition of 60 bacterial strains (including common foodborne pathogens) induced by Weissella sp. SNUL2 cell-free supernatant (CFS). The results confirmed its broad-spectrum antibacterial properties compared to previously known probiotics. Furthermore, enzymatic treatment with proteinases (trypsin and pepsin) and a time-kill assay were conducted to elucidate the nature of the antibacterial substance in Weissella sp. SNUL2 CFS. Through sequential chromatography involving gel filtration and ion-exchange chromatography, specific fractions with enhanced antibacterial properties were identified. LC-MS/MS analysis of the secretome fraction revealed the presence of various proteins from the C39 family, peptidoglycan endopeptidases, and N-acetylmuramoyl-l-alanine amidase domain-containing protein precursors. Hence, the combined action of these proteins may contribute to Weissella sp. SNUL2's broad antimicrobial activity.

Managing Helicobacter pylori infection: transitioning from conventional to alternative treatment approaches

Helicobacter pylori, an essential constituent of the gastric microbiome in those infected, is commonly associated with medical conditions such as chronic gastritis, peptic ulcer disease, and gastric cancer. In recent years, the growing resistance to antibiotics worldwide has emerged as a substantial hurdle in the effective treatment of H. pylori infection. Consequently, it has necessitated the exploration of innovative treatment strategies aimed at bolstering the potency of existing antibiotic-based eradication therapies. Such avant-garde strategies include the incorporation of probiotics and prebiotics as complementary measures to H. pylori treatment, the use of antimicrobial peptides as potential replacements for traditional antibiotics, and the application of photodynamic therapy via ingestible devices. Other advanced methodologies entail deploying drug delivery systems that utilize microparticles and nanoparticles, the invention of vaccines, the exploration of natural products, and the potential use of phage therapy. This review offers a contemporary synopsis of these burgeoning strategies designed to suppress H. pylori, delving into their strengths, hurdles, and aspects to consider during their development. A significant achievement would be the creation of an efficient human vaccine; however, previous attempts at developing such vaccines have met with obstacles or even cessation. Numerous natural products have displayed anti-H. pylori properties, predominantly in laboratory environments. Nonetheless, a requirement remains for more extensive clinical studies to fully comprehend their role in exterminating H. pylori. Finally, phage therapy, while demonstrating potential as a suitable alternative, grapples with considerable challenges, chiefly the isolation of highly virulent bacteriophages that specifically target H. pylori.

Effects of different additives on cattle feed intake and performance - a systematic review and meta-analysis.

In the last few years, there has been a growing interest in the use of natural feed additives in animal feed. These can be used as replacements for antibiotics, to alter rumen fermentation and increase feed efficiency in ruminants. Therefore, the objective of this study is to evaluate the effects of adding different feed additives in the diet of beef and dairy cattle on their performance, dry matter intake (DMI) and feed efficiency, through a systematic review followed by meta-analysis. The systematic review suggested 43 peer-reviewed publications, according to the pre-established criteria. In beef cattle, the ionophore antibiotics reduced the DMI, improved the feed efficiency without interfering in the average daily gain (ADG). Non-ionophore antibiotics and propolis extract increased the ADG. In dairy cattle, the ionophores, yeast-based additives, and enzyme additives increased the feed efficiency, DMI, and daily milk production (MY), respectively. Essential oil supplementation in beef and dairy cattle had no effect on the feed intake and animal performance. The systematic review and meta-analysis allowed us to conclude that different feed additives have different effects on cattle performance, however, our results suggest that there are a few gaps regarding their effects on animal performance.