The intricate balance of intestinal microbiota is significantly influenced by the pivotal role of indigenous lactic acid bacteria (LAB). These LAB not only contribute to antimicrobial activity and ...enhance animal health and productivity but also serve as defense against intestinal infections. In the present study, the probiotic potential of LAB strains isolated from various intestinal sections of adult and young guinea pigs (Cavia porcellus) was comprehensively assessed. Strains belonging to the genera Ligilactobacillus, Weissella, Enterococcus, and Limosilactobacillus were also identified. The antibacterial activities of the LAB strains against Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus were quantified. Exopolysaccharide production, adherence capacity, antibiotic resistance, and bile salt tolerance (0.15 %, 0.30 %, and 0.45 %) of LAB were quantified. Further analyses focused on the effects of pH (2.9, 5.0, 6.4, and 7.4), temperature (40, 50, and 60 °C) and NaCl concentrations (3.5 % and 6.5 % w/v) on LAB growth. Strains GCI9 and GDE10 (Ligilactobacillus salivarius), isolated from the cecum and intestine of guinea pigs, exhibited significant antimicrobial activity against S. typhimurium, E. coli and S. aureus. Remarkable adherence capacity to porcine gastric mucin was demonstrated by L. salivarius strains, specifically ACI1, GCI9, and GDE10, with the highest exopolysaccharide levels produced by ACI1 and GCI9 (1.71 and 1.76 mg/mL, respectively). The probiotic potential was further underscored by remarkable bile salt tolerance, especially in strain GDE10, and substantial exopolysaccharide production. These strains displayed notable adaptability to varying environmental conditions, including NaCl concentrations at 3.5 % and 6.5 %, temperatures ranging from 40 to 60 °C, and pH levels of 2.9, 5.0, 6.4, and 7.4. This comprehensive assessment of the probiotic properties of L. salivarius strains, particularly ACI1, GCI9, and GDE10, shows promise for the development of probiotic formulations aimed at enhancing the intestinal health of guinea pigs.
•Amino functionalized graphene quantum dots were prepared and doped into a dual-network hydrogel.•The composite hydrogel exhibited excellent antibacterial activity.•The composite hydrogel possessed ...good biocompatibility.
Bacterial infections seriously impair wound healing, so the development of wound dressings with high antimicrobial activity is of critical importance. In this study, amino functionalized graphene quantum dots (His-GQDs) were prepared via thermal pyrolysis of citric acid and histidine, and doped into a dual-network gelatin/sodium alginate (His-GQDs/G/SA) hydrogel to improve the antibacterial activity. The His-GQDs/G/SA hydrogel exhibited excellent antibacterial activity after 6 h of contact with bacteria. Simultaneously, the composite hydrogel could effectively alleviate the cytotoxicity of His-GQDs. The results of antimicrobial and biocompatibility tests demonstrate that the His-GQDs/G/SA dual-network hydrogel is a promising wound dressing to promote healing of infected wounds.
Silver nanoparticles (AgNPs) used in this study were synthesized using pu-erh tea leaves extract with particle size of 4.06 nm. The antibacterial activity of green synthesized AgNPs against a diverse ...range of Gram-negative foodborne pathogens was determined using disk diffusion method, resazurin microtitre-plate assay (minimum inhibitory concentration, MIC), and minimum bactericidal concentration test (MBC). The MIC and MBC of AgNPs against
,
,
Typhimurium, and
Enteritidis were 7.8, 3.9, 3.9, 3.9 and 7.8, 3.9, 7.8, 3.9 μg/mL, respectively. Time-kill curves were used to evaluate the concentration between MIC and bactericidal activity of AgNPs at concentrations ranging from 0×MIC to 8×MIC. The killing activity of AgNPs was fast acting against all the Gram-negative bacteria tested; the reduction in the number of CFU mL
was >3 Log
units (99.9%) in 1-2 h. This study indicates that AgNPs exhibit a strong antimicrobial activity and thus might be developed as a new type of antimicrobial agents for the treatment of bacterial infection including multidrug resistant bacterial infection.
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•Evidence shows promising antimicrobial activity of probiotics.•Probiotic research needs to be bioguided until it reaches clinical trials.•There are gaps in the literature, such as ...doses definition and mechanism of action.•There is no standardization to clinical use of probiotics in infections.
Probiotics are defined as microorganisms that live in symbiosis with the human host. When ingested in adequate quantities, probiotics may modulate biological functions, with health benefits. Different biological properties have been reported for probiotics, including antimicrobial activity. However, there are few studies investigating the use of probiotics as candidates for alternative antimicrobial therapy or as a source of new antibiotics. Thus, in this review we provide a general approach to the current situation of probiotic antimicrobial research and point out future directions in the field. Despite the promising benefits of probiotics on intestinal health, there remains no consensus or standardization on the development of delivery systems and on the application of probiotic formulations for antimicrobial therapy. Thus, further bioguided studies and clinical trials are needed to address the existing gaps in the knowledge. Future research should focus on the isolation, doses, clinical efficacy, safety and mechanisms of action of probiotics in humans.
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•Ni or Fe modified BaTiO3 materials were fabricated successfully.•Effectively utilized them for Reactive Red 120 (RR 120) dye degradation under UV-A light.•Compared to bare BaTiO3, ...both metal-modified materials efficiently degraded the RR 120 dye.•Current methodology effectively used to treat color effluents with extremely low pH levels.•The ability of the produced nanocomposites to inhibit the growth of twenty pathogens was examined.
For the sustainable advancement of industrial expansion that is environmentally conscious, harmful dyes must be removed from wastewater. Untreated effluents containing colors have the potential to harm the ecosystem and pose major health risks to people, animals, and aquatic life. Here, we have fabricated Ni or Fe modified with BaTiO3 materials and effectively utilized them for Reactive Red 120 (RR 120) dye degradation under UV-A light. The synthesized materials were characterized, and their structural, and photo-physical properties were reported. Phase segregation was not present in the XRD pattern, as evidenced by the absence of secondary phase peaks linked to iron, nickel, or oxides. Low metal ion concentrations may be the cause of this, and the presence of those elements was confirmed by XPS measurements. The Raman spectra of the BaTiO3/Ni and BaTiO3/Fe samples show a widened peak at 500 cm−1, which suggests that Ni or Fe are efficiently loaded onto the BaTiO3. RR 120 dye photodegradation under UV light conditions was effectively catalyzed by BaTiO3/Fe, as evidenced by its superior performance in the UV irradiation technique over both BaTiO3 and BaTiO3/Ni. Compared to bare BaTiO3, both metal-modified materials efficiently degraded the RR 120 dye. Acidic pH facilitated the degradation process, which makes sense given that the heterogeneous photo-Fenton reaction was the mechanism of degradation along with BaTiO3 sensitization. High-acidity sewage can be dangerous and carcinogenic, and conventional biological treatment methods are not appropriate for managing it. In the current investigation, it may be used to treat color effluents with extremely low pH levels. Additionally, the ability of the produced nanocomposites to inhibit the growth of twenty pathogens was examined, along with two fungi, fifteen Gram-negative Bacilli (GNB), one Gram-positive Bacilli (GPB), and two Gram-positive Cocci (GBC).
The excessive use of synthetic chemicals in agriculture demands sustainable alternatives to combat crop-affecting microorganisms. Plant-derived secondary metabolites have garnered attention as ...promising candidates with antimicrobial properties. This study investigates the antimicrobial potential of tobacco plants, specifically non-commercial accessions Nic 1015 (“TI 1341”) and BHmN, recognized for their rich bioactive compounds. Our objectives encompassed the extraction of leaf surface compounds and the assessment of their in vitro antimicrobial activity against crop-damaging microorganisms. Ethanol-based extracts, abundant in diterpenes, were meticulously analyzed. Notably, BHmN contained cis-abienol, while both accessions featured α-CBT diol, as confirmed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). TLC-Bioautography and microdilution assays unveiled substantial antifungal activity. The growth inhibition percentages correlated with extract concentrations, highlighting the pivotal role of diterpenes. These extracts exhibited pronounced efficacy against Rhizoctonia solani and Stemphylium solani but displayed relatively weaker activity against Sarocladium oryzae. Notably, Nic 1015 extract demonstrated remarkable antifungal activity at a minimal concentration of 78 µg·mL−1, while cis-abienol and sclareol inhibited the growth of Fusarium graminearum and Alternaria alternata. Additionally, the extracts demonstrated in vitro antibacterial activity against common plant culture contaminants, Bacillus licheniformis and Stenotrophomonas maltophilia. In conclusion, the findings underscore the potential of these extracts as effective tools for controlling pathogenic fungi and bacterial contaminants in plant in vitro cultures. Harnessing plant-derived secondary metabolites, especially those from tobacco leaf surface, presents a sustainable and eco-friendly strategy to mitigate the detrimental impact of microorganisms on agricultural crops, promising a greener alternative to synthetic chemical products.
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•Interaction between BSA and four antibiotics was studied by fluorescence quenching.•Static quenching occurred and binding ability followed order: TTC > CPC > OTC > PEG.•β-lactam ...showed higher removal rate than tetracycline by γ-radiation only or with BSA.•No correlation between k/kBSA and the binding affinity was observed.•BSA has little effect trend of abatement of antimicrobial activity by γ-irradiation.
In this study, to explore the influence of protein on antibiotics degradation during ionizing irradiation, the binding interaction between bovine serum albumin (BSA) and the broad spectrum β-lactam and tetractycline antibiotics and its effect on antibiotic degradation were investigated. Static quenching happened between BSA and antibiotics involving penicillin G (PEG), cephalosporin C (CPC), oxytetracycline (OTC) and tetracycline hydrochloride (TTC), indicating the formation of non-fluorescence complexes. The binding capacity followed the order: TTC > CPC > OTC > PEG. As exposed to γ-irradiation, the β-lactam antibiotics showed a higher degradation rate than the tetracyclines. The degradation rate constant (k) of CPC and PEG was 1.4–2.0 times higher than that of OTC and TTC. In presence of BSA, the k values (kBSA) of all the four antibiotics decreased greatly and the degradation rate of CPC and PEG was still higher by 1.2–1.3 times than that of OTC and TTC. No correlation between k/kBSA and the binding affinity was observed. The presence of BSA has little effect on the trend of abatement of antimicrobial activity to S. aureus during γ-irradiation. This suggests that the inhibition of protein to antibiotic degradation was mainly attributed to the competition of protein for the active species such as ·OH radical formed during γ-irradiation, while the binding ability of protein to antibiotics has no obvious effect. The results of this study contributed to develop technical strategies to improve the removal of antibiotics completely in real water matrices.
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