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Anais Da Academia Brasileira de Ciencias 2024I. paraguariensis St. Hil. is a south American species of agronomic interest with studies supporting its medicinal properties. As the investigation of active ingredients...
I. paraguariensis St. Hil. is a south American species of agronomic interest with studies supporting its medicinal properties. As the investigation of active ingredients with antimicrobial effect from medicinal plants is a suitable approach to the current antibacterial resistance problem, the aim of the present study was to determine the antibacterial activity of yerba mate ethanolic extracts against carbapenemase-producing gram-negative bacteria (reference strains and clinical isolates). Extracts showed antibacterial activity against Klebsiella pneumoniae ATCC® BAA-2342™ (KPC producing), Providencia rettgeri (NDM producing), Pseudomonas aeruginosa (MBL producing) and P. aeruginosa (VIM producing) at the concentrations tested. The Minimal-Inhibitory-Concentration and Minimal-Bactericidal-Concentration values ranged between 1 and 32 mg.ml-1 for the reference strains, and between 0.125 and 1 mg.ml-1 for the clinical isolates. The MBC/MIC index characterized the extracts as bactericidal. The combinations of commercial antibiotics and extracts showed a synergistic action on the reference strains studied. The lethal concentration 50 obtained using the Artemia salina toxicity assay were higher than 1 mg.ml-1 for all the extracts, indicating a low toxicity. The in vitro activity and low toxicity suggest that ethanolic I. paraguariensis leaf extracts constitute an outstanding source for new antibacterial compounds, and further studies should be carried out to understand their mechanism of action.
Topics: Plant Extracts; Ilex paraguariensis; beta-Lactamases; Microbial Sensitivity Tests; Plant Leaves; Anti-Bacterial Agents; Gram-Negative Bacteria; Bacterial Proteins; Pseudomonas aeruginosa; Animals; Klebsiella pneumoniae
PubMed: 38922267
DOI: 10.1590/0001-3765202420221129 -
Brazilian Journal of Biology = Revista... 2024Many anuran amphibians deposit their eggs in foam nests, biostructures that help protect the eggs and tadpoles from predators. Currently, there are no other...
Many anuran amphibians deposit their eggs in foam nests, biostructures that help protect the eggs and tadpoles from predators. Currently, there are no other identification and description studies of the cultivable microbiota role in the nests of the Leptodactylid frogs such as Physalaemus cuvieri, Leptodactylus vastus and Adenomera hylaedactyla. This study aimed to isolate and identify the culturable bacteria from these three anuran species' nests, as well as to prospect enzymes produced by this microbiota. Foam nests samples and environmental samples were diluted and viable cell count was determined. Bacterial morphotypes from foam nest samples were isolated through spread plate technique. Isolates' DNAs were extracted followed by rRNA 16S gene amplification and Sanger sequencing. To evaluate their enzymatic potential, the isolates were cultured in ATGE medium supplemented with starch (0.1% w/v), gelatin (3% w/v) and skimmed milk (1% w/v), to verify amylase and protease activity. A total of 183 bacterial morphotypes were isolated, comprising 33 bacterial genera. Proteobacteria phylum was the most abundant in all the three nests (79%). The genera Pseudomonas and Aeromonas were the most abundant taxon in P. cuvieri and L. vastus. In A. Hylaedactyla, were Enterobacter and Bacillus. Regarding enzymatic activities, 130 isolates displayed protease activity and 45 isolates were positive for amylase activity. Our results provide unprecedented information concerning culturable bacterial microbiota of the foam nests of the Leptodactylid frogs, as well as their potential for biomolecules of biotechnological interest.
Topics: Animals; Anura; Bacteria; RNA, Ribosomal, 16S; Nesting Behavior; Microbiota; DNA, Bacterial
PubMed: 38922194
DOI: 10.1590/1519-6984.280884 -
Toxins Jun 2024Extensively drug-resistant infections are emerging as a significant threat associated with adverse patient outcomes. Due to this organism's inherent properties of...
Extensively drug-resistant infections are emerging as a significant threat associated with adverse patient outcomes. Due to this organism's inherent properties of developing antibiotic resistance, we sought to investigate alternative strategies such as identifying "high value" antigens for immunotherapy-based purposes. Through extensive database mining, we discovered that numerous Gram-negative bacterial (GNB) genomes, many of which are known multidrug-resistant (MDR) pathogens, including , horizontally acquired the evolutionarily conserved gene encoding Zonula occludens toxin (Zot) with a substantial degree of homology. The toxin's genomic footprint among so many different GNB stresses its evolutionary importance. By employing in silico techniques such as proteomic-based phylogenetic tracing, in conjunction with comparative structural modeling, we discovered a highly conserved intermembrane associated stretch of 70 amino acids shared among all the GNB strains analyzed. The characterization of our newly identified antigen reveals it to be a "high value" vaccine candidate specific for . This newly identified antigen harbors multiple non-overlapping B- and T-cell epitopes exhibiting very high binding affinities and can adopt identical tertiary structures among the least genetically homologous strains. Taken together, using proteomic-driven reverse vaccinology techniques, we identified multiple "high value" vaccine candidates capable of eliciting a polarized immune response against all the genetic variants tested.
Topics: Pseudomonas aeruginosa; Phylogeny; Pseudomonas Infections; Humans; Epitopes, T-Lymphocyte; Pseudomonas Vaccines; Epitopes, B-Lymphocyte
PubMed: 38922165
DOI: 10.3390/toxins16060271 -
Toxics Jun 2024This study utilizes (MI) for the first time to investigate the uptake and translocation of chlorpyrifos (CPF; 10 µg g) from soil, introducing a new approach to improve...
This study utilizes (MI) for the first time to investigate the uptake and translocation of chlorpyrifos (CPF; 10 µg g) from soil, introducing a new approach to improve the efficacy of this technique, which includes using biosurfactants ( and ) at 10 CFU/mL to degrade CPF under greenhouse conditions. Moreover, antioxidant enzymes, including superoxide dismutase (SOD) and peroxidase (Prx), and oxidative stress due to hydrogen peroxide (HO) and malondialdehyde (MDA) in MI roots and leaves were evaluated under CPF stress. Our results demonstrated that amending soil with MI and followed by significantly reduced CPF levels in the soil ( > 0.05) and enhanced CPF concentrations in MI roots and leaves after 1, 3, 7, 10, and 14 days of the experiment. Furthermore, CPF showed its longest half-life (t) in soil contaminated solely with CPF, lasting 15.36 days. Conversely, its shortest half-life occurred in soil contaminated with CPF and treated with MI along with , lasting 4.65 days. Soil contaminated with CPF and treated with MI and showed a half-life of 7.98 days. The half-life (t) of CPF-contaminated soil with MI alone was 11.41 days. A batch equilibrium technique showed that is better than for eliminating CPF from soil in In vitro experiments. Notably, CPF-polluted soil treated with coadministration of MI and the tested bacteria improved the activities of SOD and Prx and reduced HO and MDA compared with CPF-polluted soil treated with MI alone. Our findings demonstrated that using and as biosurfactants to augment phytoremediation represents a commendable strategy for enhancing the remediation of CPF contamination in affected sites while reducing the existence of harmful pesticide remnants in crop plants.
PubMed: 38922115
DOI: 10.3390/toxics12060435 -
Toxics Jun 2024Groundwater contaminated by benzene and toluene is a common issue, posing a threat to the ecosystems and human health. The removal of benzene and toluene under...
Groundwater contaminated by benzene and toluene is a common issue, posing a threat to the ecosystems and human health. The removal of benzene and toluene under sulfate-reducing condition is well known, but how the bacterial community shifts during this process remains unclear. This study aims to evaluate the shift in bacterial community structure during the biodegradation of benzene and toluene under sulfate-reducing condition. In this study, groundwater contaminated with benzene and toluene were collected from the field and used to construct three artificial samples: Control (benzene 50 mg/L, toluene 1.24 mg/L, sulfate 470 mg/L, and HgCl 250 mg/L), S1 (benzene 50 mg/L, toluene 1.24 mg/L, sulfate 470 mg/L), and S2 (benzene 100 mg/L, toluene 2.5 mg/L, sulfate 940 mg/L). The contaminants (benzene and toluene), geochemical parameters (sulfate, ORP, and pH), and bacterial community structure in the artificial samples were monitored over time. By the end of this study (day 90), approximately 99% of benzene and 96% of toluene could be eliminated in both S1 and S2 artificial samples, while in the Control artificial sample the contaminant levels remained unchanged due to microbial inactivation. The richness of bacterial communities initially decreased but subsequently increased over time in both S1 and S2 artificial samples. Under sulfate-reducing condition, key players in benzene and toluene degradation were identified as , , , , and . The results could provide scientific basis for remediation and risk management strategies at the benzene and toluene contaminated sites.
PubMed: 38922103
DOI: 10.3390/toxics12060423 -
Veterinary Sciences May 2024The direct effects and antimicrobial activity of synthetic antimicrobial peptides (AMPs) obtained from dogs, including cBD, cBD103, and cCath, against wild-type strain...
The direct effects and antimicrobial activity of synthetic antimicrobial peptides (AMPs) obtained from dogs, including cBD, cBD103, and cCath, against wild-type strain PAO1 and canine keratinocytes were analyzed. Antibacterial effects on planktonic bacteria were assessed by determining the minimum bactericidal concentrations (MBCs) of AMPs and by a time-kill assay. Antibiofilm effects were assessed using the microtiter plate assay. We also evaluated the effects of AMPs on cell cytotoxicity and host immune response induced by stimulating canine epidermal keratinocyte progenitor (CPEK) cells with PAO1 and its LPS. cBD, cBD103, and cCath all exhibited dose-dependent antimicrobial and antibiofilm effects. In particular, 25 μg/mL cBD103 showed rapid bactericidal activity within 60 min and inhibited biofilm formation. In addition, pretreatment with cBD103 (25 µg/mL) and cCath (50 µg/mL) 1 h before stimulation significantly reduced the cytotoxicity of the CPEK cells by PAO1 and LPS-induced IL-6 and TNF-a expressions. cBD had little effect on the response to PAO1 and LPS in the cells. These results indicate the therapeutic potential of AMPs in skin infections. However, further studies on the mechanism of action of AMPs in keratinocytes and clinical trials are needed.
PubMed: 38921982
DOI: 10.3390/vetsci11060235 -
Nanomaterials (Basel, Switzerland) Jun 2024Tetrahedral amorphous carbon (taC) is a hydrogen-free carbon with extensive properties such as hardness, optical transparency, and chemical inertness. taC coatings have...
Tetrahedral amorphous carbon (taC) is a hydrogen-free carbon with extensive properties such as hardness, optical transparency, and chemical inertness. taC coatings have attracted much attention in recent times, as have coatings doped with a noble metal. A known antimicrobial metal agent, silver (Ag), has been used as a dopant in taC, with different Ag concentrations on the Ti64 coupons using a hybrid filtered cathodic vacuum arc (FCVA) and magnetron sputtering system. The physiochemical properties of the coated surface were investigated using spectroscopic and electron microscopy techniques. A doping effect of Ag-taC on biofilm formation was investigated and found to have a significant effect on the bacterial-biofilm-forming bacteria and depending on the concentration of Ag. Further, the effect of coated and uncoated Ag-taC films on a pathogenic bacterium was examined using SEM. The result revealed that the Ag-taC coatings inhibited the biofilm formation of . Therefore, this study demonstrated the possible use of Ag-taC coatings against biofilm-related complications on medical devices and infections from pathogenic bacteria.
PubMed: 38921893
DOI: 10.3390/nano14121017 -
Pathogens (Basel, Switzerland) Jun 2024is a common pathogen associated with recreational water facilities and poses risks to public health. However, data on the prevalence of in tourist destinations like...
is a common pathogen associated with recreational water facilities and poses risks to public health. However, data on the prevalence of in tourist destinations like the Canary Islands, Spain, remain limited. We assessed prevalence in 23 tourist facilities from 2016 to 2019. Compliance with water quality standards was evaluated, and 3962 samples were collected and analyzed. We examined different types of recreational water installations, including outer swimming pools, whirlpools, and cold wells. Of the sampled facilities, 31.2% did not comply with the current legislation's parametric values, mainly due to inadequate disinfectant levels, water temperature, and presence. The prevalence of was 4.8%, comparable to some European countries but lower than others. Cold wells displayed the highest non-compliance rate (89.2%) and yet exhibited a lower prevalence (1.9%) than outer swimming pools and whirlpools. Children's presence did not significantly impact contamination. Chlorine-based disinfectants are more effective than bromine-based ones in controlling . Regional variability in contamination was observed, with Fuerteventura showing lower colonization rates. Disinfectant levels play a critical role in control, and maintaining adequate levels is essential, particularly in bromine-treated installations. Our findings provide valuable insights into the prevalence and distribution of in recreational waters within tourist facilities. Tailored strategies are needed to ensure water safety in different Spanish regions. Continued monitoring and assessment, combined with artificial intelligence and machine learning, will enable the implementation of targeted interventions to protect the health of recreational water users.
PubMed: 38921799
DOI: 10.3390/pathogens13060501 -
Marine Drugs Jun 2024This study aimed to improve the conventional procedure of alginate isolation from the brown seaweed ( L.) biomass and investigate the possibility of further valorization...
This study aimed to improve the conventional procedure of alginate isolation from the brown seaweed ( L.) biomass and investigate the possibility of further valorization of the ethanolic fraction representing the byproduct after the degreasing and depigmentation of biomass. The acid treatment of biomass supported by ultrasound was modeled and optimized regarding the alginate yield using a response surface methodology based on the Box-Behnken design. A treatment time of 30 min, a liquid-to-solid ratio of 30 mL/g, and a treatment temperature of 47 °C were proposed as optimal conditions under which the alginate yield related to the mass of dry biomass was 30.9%. The use of ultrasonic radiation significantly reduced the time required for the acid treatment of biomass by about 4 to 24 times compared to other available conventional procedures. The isolated alginate had an M/G ratio of 1.08, which indicates a greater presence of M-blocks in its structure and the possibility of forming a soft and elastic hydrogel with its use. The chemical composition of the ethanolic fraction including total antioxidant content (293 mg gallic acid equivalent/g dry weight), total flavonoid content (14.9 mg rutin equivalent/g dry weight), contents of macroelements (the highest content of sodium, 106.59 mg/g dry weight), and microelement content (the highest content of boron, 198.84 mg/g dry weight) was determined, and the identification of bioactive compounds was carried out. The results of ultra high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry analysis confirmed the presence of 48 compounds, of which 41 compounds were identified as sugar alcohol, phenolic compounds, and lipids. According to the 2,2-diphenyl-1-picrylhydrazyl assay, the radical scavenging activity of the ethanolic fraction (the half-maximal inhibitory concentration of 42.84 ± 0.81 μg/mL) indicated its strong activity, which was almost the same as in the case of the positive control, synthetic antioxidant butylhydroxytoluene (the half-maximal inhibitory concentration of 36.61 ± 0.79 μg/mL). Gram-positive bacteria (, , and ) were more sensitive to the ethanolic fraction compared to Gram-negative bacteria (, , and ). The obtained results indicated the possibility of the further use of the ethanolic fraction as a fertilizer for plant growth in different species and antifouling agents, applicable in aquaculture.
Topics: Alginates; Laminaria; Antioxidants; Ethanol; Seaweed; Biomass; Flavonoids; Edible Seaweeds
PubMed: 38921591
DOI: 10.3390/md22060280 -
Marine Drugs May 2024Five new naphthalene derivatives dalesconosides A-D, F (-, ), a known synthetic analogue named dalesconoside E (), and eighteen known compounds (-) were isolated from...
Five new naphthalene derivatives dalesconosides A-D, F (-, ), a known synthetic analogue named dalesconoside E (), and eighteen known compounds (-) were isolated from MCZ-18, which is an endophytic fungus obtained from the Chinese mangrove plant . Differing from previously reported naphthalenes, compounds and were bearing a rare ribofuranoside substituted at C-1 and the 5-methyltetrahydrofuran-2,3-diol moiety, respectively. Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. Compounds , , - and showed broad ranges of antimicrobial spectrum against five indicator test microorganisms (, Methicillin-resistant , , and ); especially, , and were most potent. The variations in structure and attendant biological activities provided fresh insights concerning structure-activity relationships for the naphthalene derivatives.
Topics: Naphthalenes; Microbial Sensitivity Tests; Structure-Activity Relationship; Magnetic Resonance Spectroscopy; Anti-Bacterial Agents; Candida albicans; Molecular Structure; Rhizophoraceae; Endophytes; Anti-Infective Agents
PubMed: 38921554
DOI: 10.3390/md22060242