Antibacterial Substances Research Articles

Unveiling the anti-Klebsiella activity of methanol extracts from Hallea ciliata leaves and barks against multidrug-resistant strains overexpressing AcrAB-TolC efflux pumps

Background: Infectious diseases are considered one of the most critical threats to public health. The present work aimed to determine the anti-Klebsiella activity of methanol extracts (botanicals) of Hallea ciliata leaves (HCL) and bark (HCB) against multidrug-resistant phenotypes over-expressing ACrAB-TolC efflux pumps. Methods: The antibacterial activity of botanicals alone and in combination with PAβN and antibiotics, was determined using the broth microdilution method. The effects of HCL on H+/ATPases and the qualitative phytochemical screening were assessed using standard experimental protocols. Results: The results indicate that HCL and HCB had antibacterial activity against 75% and 56.25% of the tested bacterial strains, with minimum inhibitory concentrations (MIC) ranging from 64 to 1024 µg/mL and from 64 to 512 µg/mL, respectively. They showed strong activity against Klebsiella oxytoca KO107 and Klebsiella pneumoniae K2 with MICs of 64 µg/mL for HCL and HCB, respectively. When the functioning of proton pump dysfunction was assessed in the presence of HCL, it was observed to affect Klebsiella oxytoca KO107. Furthermore, when combined with PAβN, the botanicals demonstrated improved activity against 100% of the tested strains and isolates, with the activity improvement factor (AIF) ranging from 2 to 256. Additionally, the study found that the botanicals enhanced the activity of certain antibiotics at MIC/2 and MIC/4, including ampicillin, penicillin, and ciprofloxacin. Phytochemical screening of the botanicals revealed the presence of alkaloids, triterpenes, phenols, flavonoids, saponins, and anthocyanins. Conclusion: Overall, HCL and HCB are sources of antibacterial substances that could be valuable in combating multidrug-resistant (MDR) bacteria from the Klebsiella genus that over-express efflux pumps.

Effects of polypeptidin feeding on growth and intestinal flora of Apostichopus japonicus

Apostichopus japonicus (A. japonicus) is known as one of the most popular varieties in aquaculture due to its rich nourishment and potential medicinal value. In recent years, with the abnormal change of marine environment and global climate, new challenges are arising continually in the culture process of A. japonicus. Intestinal flora plays an important role in host health and growth, and a lot of studies confirmed the close relationship between the composition change of intestinal flora and the growth of sea cucumbers. In this study, polypeptidin belonging to bacteriocins, was as an additive ingredient in sea cucumber feed. The growth of A. japonicus increased significantly after polypeptidin feeding, and the growth rate reached the highest with 1 % polypeptidin especially. Subsequently 16 S rRNA of gut microbiota from 1 % polypeptidin group was sequenced and analyzed for richness and diversity index, but the results showed that polypeptidin supplement did not markedly change the diversity and main composition of gut microbiota compared to the control. So the further analyze was performed by dependent t-test for paired samples, and found that the abundance of only a few of species at the class level changed significantly, including Alphaproteobacteria, Desulfotomaculia and Chlamydiae, but many species at the genus level changed significantly. Some important metabolic pathways were identified through function prediction, like TCA cycle, streptomycin biosynthesis and phenylalanine metabolism. At this basis, the analysis combined with the genuses and the metabolic pathways demonstrated that polypeptidin might regulate the richness of some bacteria, which could be involved in enzyme degradation, antibacterial substances secreting or underlying pathogenic tendency of gut microbiota ecosystem. These fine-tunings instead of main community structure change were probably more beneficial to the intestinal flora health, and finally contributed to the growth of A. japonicus. Thus, polypeptidin serves as a mild, non-stimulating feed supplement for A. japonicus, and has good prospects for application.

Development of Banana Peel Powder Incorporated Functional Cookies

Nendran Banana is one of the most common fruits consumed worldwide, and it contributes significantly to the waste produced by food consumption. Banana peel waste has a significant amount of food fibre, phenols, flavonoids, antioxidants, antibacterial, and anticarcinogenic substances. Repurposing banana processing waste, such as peel, has the potential to boost raw material output and, as a result, reduce food industry waste while simultaneously improving the availability of nutritional and nutraceutical potential among the human population. This study is aimed to assess the nutritional, functional and bioactive compounds of prepared nendran banana peel flour and its incorporation in to various proportion of cookies formulation. Nendran bananas were purchased from a local market, sorted, peeled, soaked in 2% lime juice for 15 minutes, dried, powdered with a mixer grinder, sieved to produce a fine powder, and analysed for physical and functional properties such as length, width, and dimension, water and oil holding capacity, swelling powder, and proximate composition such as moisture, ash, carbohydrate, protein, fat, and fibre. The approximate composition of the banana flour was determined using AOAC standard techniques. Bioactive components were also assessed. The two varieties of cookies were prepared with the incorporation of nendran banana peel powder at the rate of 5 % and 10% and analysed for their nutritional components. The functional features of nendran banana peel powder revealed that it had a higher water-holding capacity, good oil-holding capacity, high solubility, and a high swelling capacity. Nendran Banana Peel Flour was discovered to be high in protein and crude fibre. It possesses greater antioxidant scavenging activity as well as possible polyphenolic substances. The produced food formulation was organoleptically evaluated using a 5-point hedonic rating scale, and the best product was chosen based on the sensory scores. The study suggested that the nendran banana peel flour is a versatile nutritional supplementation and provides a great health impact.

Research progress of antibacterial and antioxidant packaging materials for meat: A review

AbstractDue to the easy spoilage of meat products and the improper preservation and transportation technology, the loss rate of meat is relatively high. Most of the fresh‐keeping films are made by adding natural antioxidants and various film‐forming methods. This study expounds the latest progress in the application of antibacterial and antioxidant packaging materials in meat products. With the addition of antibacterial and antioxidant active substances to the packaging, challenges regarding the stability, safety, compatibility and regulations of active substances emerge. This research status in the direction of prospects and challenges about antibacterial and antioxidant packaging materials for meat.

Antibacterial Activity of Vernonia Amygdalina (Bitter Leaf) Extracts against Clinical Isolates of Salmonella Species

Study’s Novelty/Excerpt This study investigates the antibacterial activity of Vernonia amygdalina (bitter leaves) extracts against clinical isolates of Salmonella, addressing the urgent need for new antibacterial agents due to rising drug resistance. The research highlights the phytochemical composition of V. amygdalina, including alkaloids and saponins, and demonstrates significant inhibitory effects at specific concentrations, with a notable 11 mm zone of inhibition for the ethanolic extract. The findings suggest that V. amygdalina could be a promising candidate for developing new anti-Salmonella treatments, contributing to the management of salmonellosis in underdeveloped nations. Full Abstract Salmonellosis is becoming a common illness in underdeveloped nations, and specifically, typhoid fever is a major public health concern due to its high likelihood of recurrence. Salmonella has become resistant to numerous drugs, making it necessary to look for effective novel antibacterial substances from alternative sources, including plants. The antibacterial activity of Vernonia amygdalina (bitter leaves) extracts was assessed in this study against ten (10) Salmonella species clinical isolates. The bitter leave was cleaned, dried, and ground into powder. The phytochemical content of the leaves was extracted using ethanol and aqueous solvent; the extracts' antibacterial activity was tested against clinical isolates of Salmonella. Alkaloids, cardiac glycosides, saponins, steroids, tannins, and glycosides were among the constituents present, according to the phytochemical analysis. The highest zone of inhibition was 11 mm for the ethanolic extract at 100mg/mL concentration demonstrated against SS 4 isolate, while 9 mm was the highest zone of inhibition for the aqueous extract at 100mg/mL concentration against SS 6 isolate. For both extracts, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of all Salmonella isolates tested were found at 50 mg/mL and 100 mg/mL concentrations, respectively. V. amygdalina has antibacterial activity against Salmonella and should be investigated further for potential application in developing anti-Salmonella medications and managing salmonellosis.

Residues of veterinary antibiotics in solid natural and organic fertilizers-method development and sample analysis.

Livestock excrement is used around the world as natural fertilizers or, after processing, as organic fertilizers for crops and grasslands. But due to the presence of veterinary antibiotics in them, they may pose a threat not only to the natural environment, mainly to soil microorganisms, but also to human and animal health. This article describes a method for detecting 21 antibacterial substances in solid natural and organic fertilizers. Antibiotics from fertilizers were extracted with a mixture of acetonitrile and McIlvain-Na2EDTA buffer, twice. The extracts were purified by solid phase extraction technique on Strata-X cartridges and analyzed with the use UHPLC-MS/MS technique. The method was validated in accordance with EU Commission Implementing Regulation 2021/808; the obtained recovery ranged from 93.6 to 116.6% (depending on the analytes), and the linearity ranged from 50 to 1000µg/kg. The developed method was used to analyze 73 samples of solid natural and organic fertilizers. Our research has shown that over 38% of natural fertilizers were contaminated with antibiotics, mainly doxycycline in concentrations reaching several dozen milligrams per kilogram of fertilizers. In the case of processed organic fertilizers, the presence of antibiotics was found in over 37% of the analyzed samples. The research results showed that the developed and validated analytical method may be useful for assessing the presence and content of antibacterial substances in solid natural and organic fertilizers.

Optimized Novel Antibacterial Production from Geobacillus kaustophilus Tm6T2 (a) as Treatment for Salmonella typhimurium

Geobacillus sp. is recognized for its potential to produce bacteriocins, antibacterial substances that hold promise in addressing gastrointestinal illnesses. This study aimed to optimize the medium and pH conditions for producing antibacterial substances by Geobacillus kaustophilus Tm6T2 (a). The research employed a descriptive and experimental methodology. Growth studies were conducted in Mueller Hinton Broth with CaCl2 and MgSO4 and Nutrient Broth with KCl and MgCl2 across 6, 7, and 8 pH values. Subsequently, antibacterial substance production was achieved at the late logarithmic phase and was assessed against the gastrointestinal pathogen Salmonella typhimurium. Interestingly, findings indicated that antibacterial substance production might not solely correlate with bacterial cell count. Despite a lower bacterial cell count, the highest inhibition zone against S.typhimurium was observed at 13.11 mm in NB salt at pH 8. Analytical results show that the variation of pH and both mediums significantly affects the presence of the inhibition zone (p < 0.10). This finding suggests the complexity of factors influencing antibacterial activity. Overall, the optimum condition for antibacterial production in G.kaustophilus Tm6T2(a) was identified at pH 8 using NB salt. These findings have potential implications for developing antibacterial solutions targeting gastrointestinal pathogens.

Activity of the Ethanolic Extract Obtained from Citrus microcarpa Pericarps against Meloidogyne enterolobii, and Chemical Composition Analysis

Citrus microcarpa is a popular nutritious fruit that is widely cultivated in China. In recent years, many compounds with significant pharmacological activities have been isolated successfully from the pericarp of C. microcarpa. However, to date, there are no reports on the activity of C. microcarpa pericarp against root-knot nematodes. This study used the ethanolic extract from the pericarp of Hainan C. microcarpa and the impregnation method to determine its activity on J2 Meloidogyne enterolobii specimens and on single-egg hatching. The results showed that when J2 individuals were treated with 50 mg⋅mL–1 of the extract, the lethal concentration 50 values after 24 and 48 hours were 17.124 and 8.858 mg⋅mL–1, respectively. The mortality rate of nematodes after 48 hours of treatment was 100%, and the inhibition rate of single-egg hatching after 24 hours was 89.29%. The ethanolic extract of C. microcarpa peels showed high inhibitory and lethal activity against the M. enterolobii. The analysis of the chemical composition of the extract revealed 28 substances with insecticidal and antibacterial effects, including lignans, flavonoids, fatty acids, organic acids, terpenoids, and imidazole. The formulas of the chemical structures and pharmacological effects of these potential insecticidal and antibacterial substances were elucidated to provide a scientific basis and a theoretical reference for the use of C. microcarpa pericarps as a raw material for the development of new, natural plant nematicides.

Insight into the antibacterial properties of terpinen-4-ol on planktonic growth and biofilm-formation of Vibrio parahaemolyticus

Vibrio parahaemolyticus outbreaks emphasize the urgency of highly efficient prevention strategies to control this foodborne pathogen. This study investigated the antibacterial effects of terpinen-4-ol on V. parahaemolyticus RIMD2210633 and explored the underlying mechanism via RNA-seq analysis. The results showed that terpinen-4-ol inhibited V. parahaemolyticus efficiently with minimum inhibitory concentration and minimum bactericidal concentration values at 0.8 μL/mL. Scanning electron microscopy and PI/SYTO 9 staining assay demonstrated that cell morphology and cell membrane integrity were dose-dependently destructed. Additionally, biofilm formation was significantly inhibited according to crystal violet and MTT assay analysis. Notably, terpinen-4-ol showed good inhibitory activity against V. parahaemolyticus on salmon fillets via fumigation at 4 °C. Transcriptional analysis revealed significant downregulation of genes participated in cell wall formation (oppB, oppF), cell membrane integrity, pilus assembly protein, biofilm formation and cell motility (ToxR , LuxR), capsular polysaccharide biosynthesis protein, type IV pilin MshA and mannose-sensitive haemagglutinin type-IV pili (MSHA) biogenesis protein (MshJ, MshJ, MshK, MshL, MshN). The results demonstrated that terpinen-4-ol can efficiently inhibit the growth and pathogenicity of V. parahaemolyticus. With its safety and pleasant odor, terpinen-4-ol can be developed as a natural antibacterial substance to tackle V. parahaemolyticus contamination in food preservation and prevent associated diseases.

Secretion of 2,4 di-tertbutylphenol by a new Pseudomonas strain SBMCH11: A tert-butyl substituted phenolic compound displayed antibacterial efficacy

Pseudomonas sp. SBMCH11 was newly isolated from maritime soil samples which was identified by morphological, biochemical, and 16S rRNA gene sequencing. The isolated Pseudomonas sp. SBMCH11 had significant antibacterial activity against clinical bacterial strains including Pseudomonas aeruginosa and Staphylococcus aureus. Subsequently, high concentrations of antibacterial substances were achieved by optimizing the following parameters: pH (7.0), carbon (1 %), nitrogen sources (casein 0.2 %), NaCl (10 %), and incubation time (120 hrs). Furthermore, the extracted component from the Pseudomonas sp. SBMCH11 was shown to have a significant inhibitory effect on tested clinical pathogens. On the other hand, the extracted compound was confirmed as 2,4 di-tertbutylphenol (2,4 DTBP) by GC–MS with a molecular weight of 206.5 Daltons. Based on these findings, the isolated 2,4 DTBP could be recognized as a promising bioactive molecule for further antibacterial medication development. Compounds identified in the maritime environment from microorganisms, especially Pseudomonas sp. SBMCH11 could be regarded as a potential bio-factory for the synthesis of antibacterial compounds to suppress large numbers of pathogenic bacteria in the natural environment.

Structure revision of tricholomenyn B, an antimitotic geranylcyclohexenone rediscovered as a bitter and antibacterial substance, from a basidiomycete Tricholoma japonicum (Shiro-shimeji).

Tricholomenyn B, an antimitotic geranylcyclohexenone originally discovered from a basidiomycete Tricholoma acerbum, was isolated as a bitter and antibacterial constituent from fruiting bodies of T. japonicum. Careful comparison of NMR, MS, and other physicochemical properties of the isolated substance with the literature values revised a previously proposed macrolide structure 1 to a macrodiolide 2. Compound 2 was perceived bitter at a minimum dose of 37.5 μg, showed weak antimicrobial activity against Kocuria rhizophila and Staphylococcus aureus, and was marginally cytotoxic (IC50 2.6 µM) against P388 murine leukemia cells.

Multi-Faceted Antimicrobial Efficacy of a Quinoline-Derived Bidentate Copper(II) Ligand Complex and Its Hydrogel Encapsulated Formulation in Methicillin-Resistant Staphylococcus aureus Inhibition and Wound Management.

The emergence of antimicrobial resistance, exemplified by methicillin-resistant Staphylococcus aureus (MRSA), poses a grave threat to public health globally. Over time, MRSA has evolved resistance to multiple antibiotics, challenging conventional treatment strategies. The relentless adaptability of MRSA underscores the urgent need for innovative and targeted antimicrobial approaches to combat this resilient pathogen. Ancient knowledge and practices, along with scientific evidence, have established that metallic copper, and its organic coordination complexes can act as potential antibacterial substances. In search of a smart and effective antimicrobial against MRSA, we designed, synthesized, and characterized a bidentate copper(II) ligand complex (SG-Cu) utilizing a comprehensive array of analytical techniques, including ESI-MS, elemental analysis, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and others. Antibacterial efficacy and mechanism of action of the complex were assessed through bacterial growth analyses, bacterial membrane perturbation assays, ROS elicitation assays, and field emission scanning electron microscopy. SG-Cu was found to maintain robust biocompatibility against the mammalian cell lines HEK-293, WI-38, and NIH/3T3. Remarkably, SG-Cu demonstrated significant biofilm disruptive tendency evidenced by the retardation of sliding motility, reduction in slime production, reduction in biofilm viability, and enhanced biofilm eradication, both in vitro and in urinary catheters. In vivo studies on murine excisional wounds, with SG-Cu impregnated in a palmitic acid conjugated NAVSIQ hexapeptide (PA-NV) hydrogel, revealed the sustained release of SG-Cu from the gel matrix, facilitating accelerated wound healing and effective wound disinfection. This multifaceted investigation highlights the potential of SG-Cu as a versatile option for combating MRSA infections and promoting wound healing, solidifying its claim to be developed into a viable therapeutic.

Antibiotic Activity of a Newly Discovered Aspergillus Species Isolated from Sewage Dump Site

Infectious agents causing diseases are becoming resistant to drugs produced to manage them. This has continued to spur scientific investigations for newer and better antibiotics to aid and/or replace existing ones. Soil samples were collected from sewage dump sites with the sole aim of isolating and screening fungi species for antibacterial substances using the cultural method. A newly discovered fungi species of Aspergillus was used to produce crude antibiotic, fractionated by column chromatography and tested on clinical isolates – Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Candida albicans and Pseudomonas aeruginosa. The result of zones of inhibition was 45 mm, 47 mm, 48 mm, 49 mm and 47 mm in order of listing of organisms. Gas chromatography mass spectrometry analysis of the fractionated extract revealed the following compounds as being responsible for the observed inhibition – methylene chloride, heptanoic acid, octanoic acid, methyl hydrogen phthalate, 2,4-di-tert-butylphenol, dodecanoic acid, z-10-tetradecen-1-ol acetate, tetradecanoic acid, 2-tetradecyloxy-ethanol, n-hexadecanoic acid, hexadecanamide, octadecenamide and octadecanamide. A cocktail of organic compounds – fatty acids and amides that displayed strong antimicrobial ability, if well tapped, hold a future in the development of new antibiotics.

Therapeutic effects of white poplar (Populus alba) leave extract on hepatorenal, stress, and antioxidant-immune parameters of Oreochromis niloticus challenged with Aeromonas veronii

Herbal plants have gained enormous interest due to their immune, antioxidant, and antibacterial activities. The present study proposed that white poplar (Populus alba) leave extract (WPE) might provide a promising alternative to traditional antibiotics to treat Aeromonas veronii infection in Nile tilapia (Oreochromis niloticus). WPE showed an in vitro antibacterial activity [22 ± 0.45 mm inhibition zone, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 60 µg/mL] against A. veronii. For the in-vivo study, a factorial (2 × 2) design was used to investigate the therapeutic effects of WPE on the antioxidant/immune status and blood biochemical parameters of Nile tilapia challenged with A. veronii. One-hundred sixty fish (33 ± 1.5 g) were assigned into four experimental groups, each with four replicates (4 glass tanks/group, 40 fish/group, 10 fish/tank) for 10 days. In the first (1st) and 2nd groups, 0 and 1.5 mg/L WPE were applied in tank water, respectively, without fish being challenged. In the 3rd and 4th groups, 0 and 1.5 mg/L WPE were applied in tank water, respectively, with fish intraperitoneal inoculated with 0.2 mL of A. veronii (0.5 × 107 CFU). Aeromonas veronii infection significantly diminished the survivability, hepatic catalase, lysozyme activity, nitric oxide, immunoglobulin M, phagocytic %, total protein, albumin, and globulin. Moreover, a significant rise in the hepatic malondialdehyde, serum hepatorenal function indicators, cortisol, and glucose levels were consequences of A. veronii challenge. Interestingly, the interaction between bacterial challenge and WPE application increased the survivability, antioxidant activity, and immune responses and reduced ALT levels of fish treated with WPE during the bacterial challenge. The serum creatinine, cortisol, and glucose levels were decreased in fish treated with WPE during the infection but still higher than in the non-infected fish either treated or not treated with WPE. In conclusion, WPE (1.5 mg/L) can be used as an antibacterial substance in fish farming to alleviate the detrimental impacts of A. veronii infection by enhancing the antioxidant/immune status of the infected fish. These outcomes could help reduce antibiotic usage in fish farms, which is conducive to the sustainable development of aquaculture.

Synbiotic encapsulation against Vibrio parahaemolyticus infection in whiteleg shrimps

Vibrio parahaemolyticus is a severe pathogenic bacterium which causes significant mortality and economical loss in shrimp farming. To control vibriosis in whiteleg shrimps (Litopenaeus vannamei), we developed synbiotic beads by microencapsulating probiotic of Lactobacillus plantarum and prebiotic of xanthan gum in agarose matrix through emulsion technique. Coculture method indicated that synbiotic beads reduce viability of Vibrio parahaemolyticus by 3 orders of magnitude. The high inhibitory activity of synbiotic beads against pathogen could result from the antibacterial substances secreted from encapsulated probiotics, and access blocking of pathogens to prebiotics as food source so that the encapsulated prebiotics solely stimulate nearby probiotic growth without boosting pathogen growth. Bacterial challenge test indicated that exposure to synbiotic beads in advance can delay mortality and increase shrimp survival from 10% to 57%. As a smart encapsulation platform, our design can be extended to various probiotics, prebiotics, and pathogens, thus providing an alternative strategy to the use of antibiotics for disease prevention and sustainable aquaculture.

Pristimerin Exerts Pharmacological Effects Through Multiple Signaling Pathways: A Comprehensive Review.

Pristimerin, a natural triterpenoid isolated from the plants of southern snake vine and Maidenwood in the family Weseraceae, is anti-inflammatory, insecticidal, antibacterial, and antiviral substance and has been used for its cardioprotective and antitumor effects and in osteoporosis treatment. These qualities explain Pristimerin's therapeutic effects on different types of tumors and other diseases. More and more studies have shown that pristimerin acts in a wide range of biological activities and has shown great potential in various fields of modern and Chinese medicine. While Pristimerin's wide range of pharmacological effects have been widely studied by others, our comprehensive review suggests that its mechanism of action may be through affecting fundamental cellular events, including blocking the cell cycle, inducing apoptosis and autophagy, and inhibiting cell migration and invasion, or through activating or inhibiting certain key molecules in several cell signaling pathways, including nuclear factor κB (NF-κB), phosphatidylinositol 3-kinase/protein kinase B/mammalian-targeted macromycin (PI3K/Akt/mTOR), mitogen-activated protein kinases (MAPKs), extracellular signal-regulated protein kinase 1/2 (ERK1/2), Jun amino-terminal kinase (JNK1/2/3), reactive oxygen species (ROS), wingless/integrin1 (Wnt)/β-catenin, and other signaling pathways. This paper reviews the research progress of Pristimerin's pharmacological mechanism of action in recent years to provide a theoretical basis for the molecular targeting therapy and further development and utilization of Pristimerin. It also provides insights into improved treatments and therapies for clinical patients and the need to explore pristimerin as a potential facet of treatment.

A study on antibacterial and anti‐inflammatory activity of xylitol‐based polymeric nano‐bioactive glass nanocomposites

AbstractBioactive glasses have been shown effective in promoting bone healing by interacting with the body, gradual degradation, and supporting new bone growth. They present a promising option for therapies aimed at regenerating bone tissue. In this study, we developed a novel material, PXMA/n‐BG, by combining xylitol, maleic acid, and adipic acid, and incorporating nano‐bioactive glass, all synthesized without the use of a catalyst. The sol–gel method was used to fabricate the n‐BG (SiO2–CaO–P2O5). The incorporation of n‐BG into the polymer was found to enhance its biocompatibility and effectiveness for orthopedic applications. The synthesized polymer and its nanocomposite were characterized by FTIR, 1H NMR, 13C NMR, DSC, GPC, UTM, XRD and HR‐SEM. X‐ray diffraction and high‐resolution scanning electron microscopy are utilized to investigate the structure and surface of the n‐BG and polymeric composite material. The strength and flexibility of a plastic material with tiny particles mixed in were tested using a universal testing machine. We examined the elemental composition and thermal stability of n‐BG through specialized testing like energy‐dispersive X‐ray analysis (EDX) and thermogravimetric analysis (TGA). The research focused on the potential of xylitol‐based polymer and its nanocomposite to inhibit the growth of harmful bacteria in food. We conducted experiments to determine the efficacy of the antibacterial substance against various bacteria strains. The antibacterial potential of the extracts was assessed by the agar diffusion method using MHA plate. Furthermore, we investigated the ability of the material and its nanoparticles to reduce inflammation.

Antiparasitic Activity of Enterocin M and Durancin-like from Beneficial Enterococci in Mice Experimentally Infected with Trichinella spiralis.

Beneficial/probiotic strains protect the host from pathogens by competitive displacement and production of antibacterial substances, i.e., bacteriocins. The antiparasitic potential of bacteriocins/enterocins and their producing strains in experimental murine trichinellosis were tested as a new therapeutic strategy. Enterocin M and Durancin-like and their producers Enterococcus faecium CCM8558 and Enterococcus durans ED26E/7 were administered daily to mice that were challenged with Trichinella spiralis. Our study confirmed the antiparasitic effect of enterocins/enterococci, which reduced the number of adults in the intestine (Enterocin M-43.8%, E. faecium CCM8558-54.5%, Durancin-like-16.4%, E. durans ED26E/7-35.7%), suppressed the Trichinella reproductive capacity ex vivo (Enterocin M-61%, E. faecium CCM8558-74%, Durancin-like-38%, E. durans ED26E/7-66%), and reduced the number of muscle larvae (Enterocin M-39.6%, E. faecium CCM8558-55.7%, Durancin-like-15%, E. durans ED26E/7-36.3%). The direct effect of enterocins on Trichinella fecundity was documented by an in vitro test in which Durancin-like showed a comparable reducing effect to Enterocin M (40-60%) in contrast to the ex vivo test. The reducing activity of T.spiralis infection induced by Enterocin M was comparable to its strain E. faecium CCM8558; Durancin-like showed lower antiparasitic activity than its producer E. durans ED26E/7.

PENGARUH BERKUMUR LARUTAN MADU HUTAN (APIS DORSATA) TERHADAP INDEKS PLAK PADA MAHASISWA TINGKAT 1 JURUSAN KESEHATAN GIGI POLTEKKES KEMENKES MANADO

Plaque is a soft and sticky layer that sticks to teeth consisting of protein and bacteria. Removing plaque from the surface of the teeth is not only by brushing your teeth, but also by gargling with mouthwash that contains antibacterial substances. Honey is able to stop the development of bacteria in the mouth which causes a reduction in the plaque layer so that it can influence a decrease in the plaque index in a person's mouth. The aim of this research is to determine the effect of gargling forest honey solution (Apis Dorsata) on the plaque index in Level 1 Students of the Department of Dental Health, Health Polytechnic of the Ministry of Health Manado. This research method uses a tru experimental method to determine the influence between variables. This research was carried out on 19-23 May 2023 at the Department of Dental Health, Poltekkes, Ministry of Health, Manado. The total population is 51 people, and the sample is the total population. Sampling was determined based on inclusion and exclusion criteria. So the sample obtained in this research was 50 people. The data obtained was tabulated and analyzed using the paired sample t-test statistical test. And this research instrument uses a diagnostic tool and plaque index assessment format. The results of the study showed that the average before gargling with honey solution was 3.16 and after gargling with honey solution was 1.19, with a difference of 1.97. Based on analysis using the paired sample t-test, it shows that there is a significant difference seen from the p value = 0.000 (0.000 <0.05). This means that gargling with honey solution has an effect on reducing the plaque index.

Mechanism of Ligilactobacillus salivarius GX118 in Regulating the Growth of Rainbow Trout (Oncorhynchus mykiss) and Resistance to Aeromonas salmonicida Infection

Lactic acid bacteria Ligilactobacillus salivarius has been shown to be a substitute for antibiotics in the treatment of bacterial disease in high animals. However, its beneficial mechanism in fish farming is still unclear. This study evaluated the antagonistic effects of the Ligilactobacillus salivarius GX118 strain on Aeromonas salmonicida and its regulation of rainbow trout growth in vivo and in vitro. The results found that GX118 produces an antibacterial substance that can directly destroy the cell wall of A. salmonicida. Whole-genome sequencing of GX118 revealed that Enterolysin A is a type III bacteriocin with antibacterial properties. An in vivo experiment showed that the supplementation of GX118 in diet competitively inhibited the colonization of A. salmonicida in the intestine. In addition, it was able to improve the growth performance of rainbow trout within a 21-day feeding experiment. The supplementation of GX118 increased the diversity of gut microbiota, in which the abundance of Bacteroidota, Blautia, and Rhodobacteraceae increased. In addition, the use of GX118 activated the expression of IFN-γ and NF-κB genes and reduced the expression level of IL-6 and IL-8, thus exhibiting a certain effect on activating the immunity of rainbow trout. This study provides a scientific basis for the development of antibacterial probiotics in the healthy farming of rainbow trout.