A Comprehensive Review of Silver and Gold Nanoparticles as Effective Antibacterial Agents.

The increasing threat from antibiotic-resistant bacteria has necessitated the development of novel methods to counter bacterial infections. In this context, the application of metallic nanoparticles (NPs), especially gold (Au) and silver (Ag), has emerged as a promising strategy due to their remarkable antibacterial properties. This review examines research published between 2006 and 2023, focusing on leading journals in nanotechnology, materials science, and biomedical research. The primary applications explored are the efficacy of Ag and Au NPs as antibacterial agents, their synthesis methods, morphological properties, and mechanisms of action. An extensive review of the literature on NPs synthesis, morphology, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and effectiveness against various Gram(+/-) bacteria confirms the antibacterial efficacy of Au and Ag NPs. The synthesis methods and characteristics of NPs, such as size, shape, and surface charge, are crucial in determining their antibacterial activity, as these factors influence their interactions with bacterial cells. Furthermore, this review underscores the urgent necessity of standardizing synthesis techniques, MICs, and reporting protocols to enhance the comparability and reproducibility of future studies. Standardization is essential for ensuring the reliability of research findings and accelerating the clinical application of NP-based antimicrobial approaches. This review aims to propel NP-based antimicrobial strategies by elucidating the properties that enhance the antibacterial activity of Ag and Au NPs. By highlighting their inhibitory effects against various bacterial strains and relatively low cytotoxicity, this work positions Ag and Au NPs as promising materials for developing antibacterial agents, making a significant contribution to global efforts to combat antibiotic-resistant pathogens.

Antarctic Streptomyces: Promising biocontrol agents for combating Fusarium oxysporum f. sp. cubense.

Fusarium wilt of Banana (FWB) caused by Fusarium oxysporum f. sp. cubense (Foc) poses a significant threat to the banana industry, with current inadequate control measures. This study evaluated the antifungal potential of nine Streptomyces strains isolated from Antarctic soil samples, using Casein-Starch media to stimulate the production of antifungal compounds. The inhibition spectrum against Foc was assessed under laboratory conditions using the well diffusion on Mueller-Hinton agar, with antifungal activity measured in arbitrary units (AU/mL) and minimum inhibitory concentration (MIC) tested using ethyl acetate extracts. Among the nine isolates, K6 and E7 were closely related to Streptomyces polyrhachis and Streptomyces fildesensis, exhibited significant antifungal activity, with K6 and E7 showing 320 and 80 AU/mL, and MIC values of 250 and >500 ppm, respectively. These findings highlight K6 and E7 as potential biocontrol agents against Foc, offering new avenues for sustainable Fusarium wilt management in banana cultivation.

Antimicrobial susceptibility of Peruvian Yersinia ruckeri isolates to oxytetracycline and florfenicol using MIC testing.

Yersiniosis, caused by Yersinia ruckeri, has become the most common disease in farmed rainbow trout Oncorhynchus mykiss in Peru, affecting Puno and Junín Regions, important aquaculture areas in the country. Florfenicol (FLO) and oxytetracycline (OXY) are the antimicrobials most frequently used to mitigate losses attributed to this pathogen. This study presents an analysis of the susceptibility patterns of 60 Y. ruckeri isolates (30 isolates each from Puno and Junín), including the type strain CECT 4319T and the strains CECT 955 and CECT 956, against FLO and OXY. Minimum inhibitory concentrations (MICs) were determined following the guideline for standard broth dilution method published by the Clinical and Laboratory Standards Institute. MIC results ranged from 4.0 to 8.0 µg ml-1 for FLO and 0.5 to 4.0 µg ml-1 for OXY. Normalized resistance interpretation (NRI) analysis identified epidemiological cut-off values of ≤16.0 µg ml-1 for FLO and ≤4.0 µg ml-1 for OXY. All Peruvian isolates, including the collection strains, were categorized as wild-type for both antimicrobials. Even though the number of Y. ruckeri isolates with MIC values of 8 µg ml-1 for FLO is more than double in Puno than in Junín (15 vs. 7 isolates), the NRI analysis showed the same epidemiological cutoff of 16 µg ml-1; while for OXY, it was 4.0 µg ml-1 for Puno and 2.0 µg ml-1 for Junín. This study establishes the basis for monitoring susceptibility to FLO and OXY in new Y. ruckeri isolates in Peruvian rainbow trout farming.

Prenatal Arsenic Exposure on DNA Methylation of C18ORF8 and ADAMTS9 Genes of Newborns from the POSGRAD Birth Cohort Study.

Exposure to arsenic (As) is a public health problem associated with cancer (skin and colon) and it has been reported that epigenetic changes may be a potential mechanism of As carcinogenesis. It is pertinent to evaluate this process in genes that have been associated with cancer, such as ADAMTS9 and C18ORF8. Gestation and delivery data were obtained from the POSGRAD study. Exposure to As was measured in urine during pregnancy. Gene methylation was performed by sodium bisulfite sequencing; 26 CpG sites for the C18ORF8 gene and 21 for ADAMTS9 were analyzed. These sites are located on the CpG islands near the start of transcription. Sociodemographic characteristics were obtained by a questionnaire. The statistical analysis was performed using multiple linear regression models adjusted for potential confounders. Newborns with an As exposure above 49.4 µg g-1 showed a decrease of 0.21% on the methylation rate in the sites CpG15, CpG19, and CpG21 of the C18ORF8 gene (adjusted ß = -0.21, p-value = 0.02). No statistically significant association was found between prenatal exposure to As and methylation of the ADAMTS9 gene. Prenatal exposure to As was associated with decreased DNA methylation at the CpG15, CpG19, and CpG21 sites of the C18ORF8 gene. These sites can provide information to elucidate epigenetic mechanisms associated with prenatal exposure to As and cancer.

Chemical Profiling of Drimys granadensis (Winteraceae) Essential Oil, and Their Antimicrobial, Antioxidant, and Anticholinesterase Properties.

A complete and comprehensive chemical and biological study of Drimys granadensis, a native Ecuadorian aromatic plant, was conducted. By conventional steam distillation from dried leaves, a yellowish, translucent essential oil (EO) with a density of 0.95 and a refractive index of 1.5090 was obtained. The EO was analyzed by gas chromatography coupled to a mass spectrometer (GC/MS) and an FID detector (GC/FID), respectively. Enantiomeric distribution was also carried out by GC/MS using a chiral selective column (diethyl tert-butylsilyl-BETA-cyclodextrin). The microdilution broth method was employed to assess the antibacterial and antifungal activity of the EO against a panel of opportunistic microorganisms. Antioxidant capacity was measured using diphenyl picryl hydrazyl (DPPH) and azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. Finally, the inhibitory potential of the EO against acetylcholinesterase was also valued. Sixty-four chemical compounds, constituting 93.27% of the total composition, were identified, with major components including γ-muurolene (10.63%), spathulenol (10.13%), sabinene (5.52%), and δ-cadinene (4.22%). The characteristic taxonomic marker of the Drimys genus, Drimenol, was detected at very low percentages (<2%). Two pairs of enantiomers ((1S,5R)-(+)-α-pinene/(1S,5S)-(-)-α-pinene; (1S,5R)-(+)-ß-pinene/(1S,5S)-(-)-ß-pinene) and one pure enantiomer (1R,4S)-(-)-camphene were identified. Regarding antimicrobial potency, the EO exhibited a significant moderate effect on Listeria monocytogenes with a minimal inhibitory concentration (MIC) value of 250 µg/mL, while with the remaining microorganisms, it exerted less potency, ranging from 500 to 2000 µg/mL. The EO displayed moderate effects against the ABTS radical with a half scavenging capacity of 210.48 µg/mL and no effect against the DPPH radical. The most notable effect was noticed for acetylcholinesterase, with a half inhibition concentration (IC50) of 63.88 ± 1.03 µg/mL. These antiradical and anticholinesterase effects hint at potential pharmacological applications in Alzheimer's disease treatment, although the presence of safrole, albeit in low content (ca. 2%), could limit this opportunity. Further in vivo studies are necessary to fully understand their potential applications.

Antifungal Activity of ZnO Nanoparticles Synthesized from Eichhornia crassipes Extract for Construction Applications.

Fungal growth on construction materials in tropical climates can degrade aesthetics and manifestations on modern and historical sick buildings, affecting the health of their inhabitants. This study synthesized ZnO nanoparticles with enhanced antifungal properties using a precipitation method. Different concentrations (25%, 50%, and 100%) of Eichhornia crassipes aqueous extract were used with Zn(NO3)2·6H2O as the precursor to evaluate their spectroscopic, morphological, textural, and antifungal properties. X-ray diffraction confirmed the hexagonal wurtzite phase of ZnO with crystallite sizes up to 20 nm. Fourier-transform infrared spectroscopy identified absorption bands at 426, 503, and 567 cm-1 for ZnO-100, ZnO-50, and ZnO-25, respectively. Nitrogen physisorption indicated a type II isotherm with macropores and a fractal dimension coefficient near 2 across all concentrations. Polydispersity index analysis showed that ZnO-50 had a higher PDI, indicating a broader size distribution, while ZnO-25 and ZnO-100 exhibited lower PDI values, reflecting uniform and monodisperse particle sizes. FESEM observations revealed semi-spherical ZnO morphologies prone to agglomeration, particularly in ZnO-25. Antifungal tests highlighted ZnO-25 as the most effective, especially against Phoma sp. with an MFC/MIC ratio of 78 µg/mL. Poisoned plate assays demonstrated over 50% inhibition at 312 µg/mL for all tested fungi, outperforming commercial antifungals. The results indicate that ZnO NPs synthesized using E. crassipes extract effectively inhibit fungal growth on construction materials. This procedure offers a practical approach to improving the durability of building aesthetics and may contribute to reducing the health risks associated with exposure to fungal compounds.

Novel Study on Chemical Characterization and Antimicrobial, Antioxidant, and Anticholinesterase Activity of Essential Oil from Ecuadorian Bryophyte Syzygiella rubricaulis (Nees) Stephani.

Our research focuses on exploring the chemical composition and some biological properties of the essential oil derived from Syzygiella rubricaulis (Nees) Stephani, a bryophyte species. To conduct a comprehensive analysis, we utilized a DB5MS capillary column along with gas chromatography coupled to mass spectrometry (GC-MS) and flame ionization (GC-FID). The qualitative and quantitative examination revealed the presence of 50 compounds, with hydrocarbon sesquiterpenes (48.35%) and oxygenated sesquiterpenes (46.89%) being the predominant constituents. Noteworthy compounds identified include bicyclogermacrene (12.004%), cedranone <5-> (9.034%), spathulenol (6.835%), viridiflorol (6.334%), silphiperfol-5,7(14)-diene (6.216%), biotol <ß-> (6.075%), guaiol (4.607%), viridiflorene (4.65%), and α-guaienol (3.883%). Furthermore, we assessed the antimicrobial, antioxidant, and anticholinesterase activity of the essential oil, revealing a compelling inhibitory effect against acetylcholinesterase (AChE) with an IC50 value of 26.75 ± 1.03 µg/mL and a moderate antimicrobial (MIC 500 µg/mL, Enterococcus faecium, Lysteria monocytogenes) and antioxidant effect (ABTS: SC50 343.38 and DPPH 2650.23 µg/mL). These findings suggest the potential therapeutic application of the bryophyte essential oil in the treatment of Alzheimer's disease due to its potent anticholinesterase properties.

Intracranial non-germinomatous germ cell tumors in children and adolescents: how can the experience from an uppermiddle-income country contribute to the worldwide effort to improve outcomes?

Background: Non-germinomatous germ cell tumors (NGGCT) accounts for one third of intracranial GCT. While the germinoma group have an excellent overall survival, the standard of practice for children with NGGCT is still under evaluation. Aims: Describe the results of the of the Brazilian consortium protocol. Methods: Since 2013, 15 patients with a diagnosis of NGGCT by histopathology and/or serum/cerebrospinal fluid (CSF) tumor markers, ßHCG >200mlU/ml and/or positive alpha-fetoprotein were treated with neoadjuvant chemotherapy with carboplatin, cyclophosphamide and etoposide followed by ventricular radiotherapy (RTV) of 18Gy with boost (32Gy) to the primary site. Metastatic patients underwent craniospinal irradiation (CSI) and "slow responders" to the four initial cycles of CT, to autologous stem cell transplantation (ASCT) followed by CSI. Results: Mean age, 13.1 years. Thirteen males. Primary sites: pineal (n=12), suprasellar (n=2) and bifocal (n=1). Four patients were metastatic at diagnosis. Eight patients had CSF and/or serum alpha-fetoprotein levels > 1,000ng/ml. Tumor responses after chemotherapy demonstrated complete in six cases and partial in seven, with "second-look" surgery being performed in five cases, and two patients presenting viable lesions being referred to ASCT. The main toxicity observed was hematological grades 3/4. Two patients with metastatic disease, one with Down Syndrome and AFP > 1,000ng/ml and the other with choriocarcinoma and pulmonary metastases, developed progressive disease resulting in death, as well as two other patients without evidence of disease, due to endocrinological disorders. Event-free and overall survival at 2 and 5 years were 80% and 72.7%, respectively, with a mean follow-up of 48 months (range, 7-107). Conclusions: Despite the small number of patients, in our series, treatment with six cycles of chemotherapy and RTV with focal boost for localized disease (n=11) and ACST for identified slow responders (n=2) seem to be effective strategies contributing to the overall effort to improve outcomes of this group of patients.

Biological capacities of seven Chilean ferns.

Sticherus squamulosus, Hymenophyllum dentatum, Blechnum microphyllum, Polypodium Feuillei, Blechnum chilense, Lophosoria quadripinnata, and Lissopimpla excelsa are native fern species found in southern Chile and are often used in traditional medicine. However, their bioactive properties have not been confirmed. In this study, ethanolic extracts of ferns exhibited significant antibacterial capacity against human pathogens. H. dentatum and S. squamulosus were selected for further analysis owing to their antimicrobial and antioxidant capacities. The entire H. dentatum extract exhibited fungistatic and fungicidal capacity on Botrytis cinerea and Penicillium digitatum, with minimum inhibitory concentration values of 1.56 mg/mL and 6.25 mg/mL and minimum fungicidal concentration values of 6.25 mg/mL and 12.5 mg/mL, respectively. The S. squamulosus extract presented the highest rutin content (222.5 µg/g fern). In addition, the ethanolic extract of H. dentatum inhibited 91% of DPPH radicals. Therefore, both types of ferns can be used in the food industry.

Low temperatures do not impair the bacterial plasmid conjugation on poultry meat.

Conjugation plays an important role in the dissemination of antimicrobial resistance genes. Besides, this process is influenced by many biotic and abiotic factors, especially temperature. This study aimed to investigate the effect of different conditions of temperature and storage (time and recipient) of poultry meat, intended for the final consumer, affect the plasmid transfer between pathogenic (harboring the IncB/O-plasmid) and non-pathogenic Escherichia coli organisms. The determination of minimal inhibitory concentrations (MIC) of ampicillin, cephalexin, cefotaxime, and ceftazidime was performed before and after the conjugation assay. It was possible to recover transconjugants in the poultry meat at all the treatments, also these bacteria showed a significant increase of the MIC for all antimicrobials tested. Our results show that a non-pathogenic E. coli can acquire an IncB/O-plasmid through a conjugation process in poultry meat, even stored at low temperatures. Once acquired, the resistance genes endanger public health especially when it is about critically and highly important antimicrobials to human medicine.

Essential oils on the control of fungi causing postharvest diseases in mango.

The use of fungicides in the postharvest treatment of mangoes has been widespread due to the incidence of pathogens, but awareness of the health risks arising from their use has increased, driving the search for more sustainable treatments. This study aimed to evaluate the activity of antifungal treatment of seven essential oils (EO) against four fungi that cause postharvest diseases in mangoes and define the minimum inhibitory concentration (MIC) and chemical composition, analyzed by gas chromatography (GC-MS). The results showed that the EOs of oregano, rosemary pepper, cinnamon bark, and clove inhibited 100% of the mycelial growth of the studied pathogens, with MIC ranging from 250 to 2000 µL.L-1. The main compound found in oregano was carvacrol (69.1%); in rosemary and pepper oil, it was thymol (77.2%); cinnamaldehyde (85.1%) was the main constituent of cinnamon bark, and the eugenol (84.84%) in cloves. When evaluating the antifungal activity of these compounds, thymol and carvacrol showed greater inhibitory activity against fungi. Therefore, this study showed the great potential of oregano, clove, rosemary pepper, and cinnamon bark essential oil as alternative treatments to synthetic fungicides in controlling postharvest diseases in mangoes.

In vitro anticancer and antifungal properties of the essential oil from the leaves of Lippia origanoides kunth.

The essential oil from Lippia origanoides (EOLO) is employed in traditional medicine as it has both antimicrobial and anti-inflammatory properties. The current investigation first evaluated the EOLO's cytotoxic activity in tumour (SiHa and HT-29) and non-tumour (human lymphocyte) cells by MTT. The effect on ROS production was further evaluated in cancer cells by fluorimetry. The oil's mutagenic and antifungal activities were also evaluated using, respectively, the in vitro micronucleus test and the broth microdilution method. The EOLO displayed significant cytotoxicity in both cancer cell lines, with IC50 values of 20.2 µg/mL and 24.3 µg/mL for HT-29 and for SiHa cell lines, respectively. EOLO increased ROS production, was unable to raise the micronucleus frequencies and significantly reduced the cytokinesis block proliferation indices, revealing its anti-proliferative action. The results demonstrate that EOLO is devoid of mutagenic activity but possesses significant activity against tumour and non-tumour human cells, reinforcing its biological potential.

Lymphocyte subsets and soluble forms of MIC-A and MIC-B are prognostic factors in non-Hodgkin lymphoma patients.

MIC-A and MIC-B are the natural ligands for NKG2D, an activator receptor expressed in NK cells. Soluble isoforms of MIC-A and MIC-B (sMICA, sMICB) have been identified in different malignancies, affecting NK cells' cytotoxicity. The study was performed to determine the levels of sMICA, sMICB, the expression of MIC-A, and MIC-B on tumor tissues, and lymphocyte subpopulations (CD4 + , CD8 + , NK, NKT, Tγδ cells, B cells, monocytes) in 94 patients with non-Hodgkin's lymphoma (NHL) and 72 healthy donors.The most frequent lymphoma was diffuse large B cell lymphoma (48%). Patients with NHL had decreased numbers of CD4 T cells, CD8 T cells, B cells, monocytes, NK cells, type 1 dendritic cells, γδ T cells, and increased iNKT cells. Patients showed higher levels of sMIC-A and similar serum levels of sMIC-B.Survival was poorer in patients having higher LDH values and lower numbers of CD4 T cells, type 1 dendritic cells, gamma-delta T cells, and high levels of sMIC-A.In conclusion, high levels of sMIC and decreased numbers in circulating lymphocyte subsets are related to poor outcomes in NHL.

Comparative study on Antibacterial efficacy of a series of chromone sulfonamide derivatives against drug-resistant and MDR-isolates.

Sulfonamide derivatives have numerous pharmaceutical applications having antiviral, antibacterial, antifungal, antimalarial, anticancer, and antidepressant activities. The structural flexibility of sulfonamide derivatives makes them an excellent candidate for the development of new multi-target agents, although long-time exposure to sulfonamide drugs results in many toxic impacts on human health. However, sulfonamides may be functionalized for developing less toxic and more competent drugs. In this work, sulfonamides including Sulfapyridine (a), Sulfathiazole (b), Sulfamethoxazole (c), and Sulfamerazine (d) are used to synthesize Schiff bases of 7-hydroxy-4-methyl-2-oxo-2H-chromene-8-carbalde-hyde (1a-1d). The synthesized compounds were spectroscopically characterized and tested against hospital isolates of three Gram-positive (Methicillin-resistant Staphylococcus aureus PH217, Ampicillin-resistant Coagulase-negative Staphylococcus aureus, multidrug-resistant (MDR) Enterococcus faecalis PH007R) and two Gram-negative bacteria (multidrug-resistant Escherichia coli, and Salmonella enterica serovar Typhi), compared to the quality control strains from ATCC (S. aureus 29213, E. faecalis 25922, E. coli 29212) and MTCC (S. Typhi 734). Two of the four Schiff bases 1a and 1b are found to be more active than their counterpart 1c and 1d; while 1a have showed significant activity by inhibiting MRSA PH217 and MDR isolates of E. coli at the minimum inhibitory concentration (MIC) of 150 µg/mL and 128 µg/mL with MBC of 1024 µg/mL, respectively. On the other hand, the MIC of 1b was 150 µg/mL against both S. aureus ATCC 29213 and Salmonella Typhi MTCC 734, compared to the control antibiotics Ampicillin and Gentamycin. Scanning electron microscopy demonstrated the altered surface structure of bacterial cells as a possible mechanism of action, supported by the in-silico molecular docking analysis.

Antibacterial effect of Asphodelus fistulosus aqueous and ethanolic crude extracts on gram positive and gram negative bacteria / Efeito antibacteriano de extratos brutos aquosos e etanólicos de Asphodelus fistulosus sobre bactérias gram-positivas e gram-negativas

Asphodelus fistulosus (A. fistulosus) is a wild plant grows in Jordan. Traditionally, it is used to treat different medical conditions and diseases such as respiratory ailments, against burns and dermatomucosal infections.This study aims to find out the effects of A. fistulosus aqueous and ethanolic crude extracts on Staphylococcus aureus(S. aureus) as gram positive bacteria and Escherichia coli (E. coli) as gram negative bacteria and to investigate which one will be affected either by aqueous and/or ethanolic crude extracts of A. fistulosus shooting parts that were collected from Jerash in the north of Jordan. Agar well diffusion method was used to evaluate the antibacterial activity of the crude extracts. In addition, MIC (minimum inhibitory concentration) as well as MBC (minimum bactericidal concentration) were determined against both types of bacteria. The results showed that flower aqueous extract of A. fistulosus was very effective against E. coli (20.0 ± 0.50) mm and caused a (14.0 ± 0.50) mm inhibition to S. aureus. The ethanolic extract of stem was very effective cauesed a (19.0 ± 0.50) mm inhibition in both bacterial species. Respectively, both S. aureus and E. coli were inhibited by ethanolic and aqueous extracts (mixture1 and mixture2) (15.0 ± 0.00 mm and 10.5 ± 0.50 mm). The highest antimbacterial activity was observed for the leaves aqueous extract against E.coli (0.06120 mg/mL). The obtained MIC values from A. fistulosus parts extracts demonstrated antibacterial activity ranged between 7.606 and 0.06120 mg/mL. The highest antimicrobial activity was recorded in the leaves aqueous extract against E. coli.The MBC value of stem aqueous extract was 5.00 mg/mL against both S. aureus and E. coli. On the other hand, ethanolic and aqueous extracts of the leaves gave MBC values 5.00 mg/mL, and 0.156 mg/mL, respectively, against E. coli.Based on the results of this study, it can be concluded that there is good inhibitory effect of aqueous and ethanolic of A. fistulosus shooting parts extracts on growth of E. coli and S. aureus. Adding to that, stem ethanolic extract has the most effective against S. aureus while aqueous extract of flower has the most effective against E. coli.So, it is recommended to have further future studies on the A. fistulosus shooting parts crude extract bioactive components and the mechanism of how these constituents affect these types of bacteria.

Asphodelus fistulosus (A. fistulosus) é uma planta selvagem que cresce na Jordânia. Tradicionalmente, é usada para tratar diferentes condições médicas e doenças, como doenças respiratórias, contra queimaduras e infecções dermatomucosas. Bactérias positivas e Escherichia coli (E. coli) como bactérias gram-negativas e investigar qual delas será afetada por extratos brutos aquosos e/ou etanólicos de partes de tiro de A. fistulosus que foram coletadas em Jerash no norte da Jordânia. O método de difusão em poço de ágar foi utilizado para avaliar a atividade antibacteriana dos extratos brutos. Além disso, MIC (concentração inibitória mínima) e MBC (concentração bactericida mínima) foram determinados contra ambos os tipos de bactérias. Os resultados mostraram que o extrato aquoso de flores de A. fistulosus foi muito eficaz contra E. coli (20,0 + 0,50 mm) e causou uma inibição (14,0 + 0,50 mm) para S. aureus. O extrato etanólico do caule foi muito eficaz, causando inibição (19,0 + 0,50 mm) em ambas as espécies bacterianas. Respectivamente, tanto S. aureus quanto E. coli foram inibidos pelos extratos etanólico e aquoso (mistura 1 e mistura 2) (15,0 + 0,00 mm e 10,5 + 0,50 mm). A maior atividade antibacteriana foi observada para o extrato aquoso das folhas contra E. coli (0,06120 mg/mL). Os valores de CIM obtidos dos extratos de partes de A. fistulosus demonstraram atividade antibacteriana variando entre 7,606 e 0,06120 mg/mL. A maior atividade antimicrobiana foi registrada no extrato aquoso das folhas contra E. coli. O valor de CBM do extrato aquoso do caule foi de 5,00 mg/mL contra S. aureus e E. coli. Por outro lado, os extratos etanólico e aquoso das folhas apresentaram valores de CBM de 5,00 mg/mL e 0,156 mg/mL, respectivamente, contra E. coli, efeito de extratos aquosos e etanólicos de partes de tiro de A. fistulosus no crescimento de E. coli e S. aureus. Somando-se a isso, o extrato etanólico do caule é o mais eficaz contra S. aureus enquanto o extrato aquoso da flor é o mais eficaz contra E. coli. Assim, recomenda-se a realização de estudos futuros sobre os componentes bioativos do extrato bruto de partes fotografais de A. fistulosus e o mecanismo de como esses constituintes afetam esses tipos de bactérias.

Extraction and quantification of antivenomous antibodies in chicken eggs against scorpion venom / Extração e quantificação de anticorpos entivenenos em ovos de galinha contra veneno de escorpião

Avian-derived IgY is thought to be the best therapy for scorpion bites concerning low-level side effects. The present study analyzed a hypothesis about the neutralization of scorpion venom Androcotonus australis through antibodies produced in the egg yolks of chickens. The venom used for inoculation was obtained from Androctonus australis (yellow fat-tailed scorpion) from southern Punjab, Pakistan. The lethal dose of LD50 against scorpion venom was calculated in chickens and mice. Safe doses were given to egg-laying chickens to produce IgY antibodies. The antivenom IgY antibodies were extracted from the egg yolks of immunized chicken using the polyethylene glycol (PEG) method. Moreover, IgY was confirmed through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the Ouchterlony double immunodiffusion assay test. The antibody titers were evaluated by the enzyme-linked immunosorbent assay (ELISA). The neutralisation capacity of extracted anti-scorpion antibodies was tested on mice. The calculated LD50 of scorpion venom for chicken and mice was 4 mg/kg and 2.5 mg/kg, respectively. SDS-PAGE and Ouchterlony double immunodiffusion confirmed the presence of IgY against scorpion venom. The maximum titer value of specific IgY produced against scorpion venom was 3.5 ug/ml. A concentration of 220 ul/LD50 was effective to neutralize 1 mg of scorpion venom. It is suggested that IgY obtained from egg yolks is safe against targeted venom and can be used as an effective alternative to equine IgG antibodies against scorpion envenoming.

Acredita-se que a IgY derivada de aves seja a melhor terapia para picadas de escorpião em relação aos efeitos colaterais. O presente estudo teve como objetivo analisar uma hipótese sobre a neutralização do veneno do escorpião Androcotonus australis através de anticorpos produzidos na gema de ovos de galinhas. O veneno usado para inoculação foi obtido de Androctonus australis (escorpião amarelo de cauda gorda) do sul de Punjab, Paquistão. A dose letal de LD50 contra veneno de escorpião foi calculada em galinhas e camundongos. Doses seguras foram dadas a galinhas poedeiras para produzir anticorpos IgY. Os anticorpos antiveneno IgY foram extraídos das gemas de ovos de galinhas imunizadas pelo método do polietilenoglicol (PEG). Além disso, a IgY foi confirmada por eletroforese em gel de poliacrilamida e dodecil sulfato de sódio (SDS-PAGE) e pelo teste de imunodifusão dupla de Ouchterlony. Os títulos de anticorpos foram avaliados pelo ensaio imunoenzimático (ELISA). A capacidade de neutralização dos anticorpos anti-escorpião extraídos foi testada em camundongos. A LD50 calculada do veneno de escorpião para galinhas e camundongos foi de 4 mg/kg e 2,5 mg/kg, respectivamente. SDS-PAGE e imunodifusão dupla Ouchterlony confirmaram a presença de IgY contra veneno de escorpião. O valor máximo do título de IgY específico produzido contra veneno de escorpião foi de 3,5 ug/ml. Uma concentração de 220 ul/LD50 foi considerada eficaz para neutralizar 1 mg de veneno de escorpião. Sugere-se que a IgY obtida da gema do ovo seja segura contra o veneno direcionado e possa ser usada como uma alternativa eficaz aos anticorpos IgG equinos contra o envenenamento por escorpiões.

Association between fractional exhaled nitric oxide and therapeutic adherence to controller management in pediatric asthma patients.

OBJECTIVES: Guidelines for asthma management recommend, before establishing additional therapeutic behaviors, to confirm correct use and adequate therapeutic adherence to treatment. Evidence exists on the use of fractional exhaled nitric oxide (FeNO) values for monitoring therapeutic adherence in adults. It is important to establish whether there is a correlation between FeNO and therapeutic adherence in children. This study aims to provide new knowledge about the relationship between FeNO and therapeutic adherence in asthmatic children. MATERIALS AND METHODS: Analytical cross-sectional study including asthma patients 5-18 years of age, attending follow-up at Hospital Militar Central (HMC) between May and November 2022 in Colombia. A sociodemographic survey was carried out, followed by the Pediatric Inhaler Adherence Questionnaire (PIAQ), and asthma control test (ACT) or childhood asthma control test (cACT). We defined adequate therapeutic adherence as not missing a single application of inhaled steroids in the last 15 days according to PIAQ. A poisson regression model was carried out including relevant predictors for therapeutic adherence such as FeNO values, age, tobacco exposure at home, atopy, and time since initiation of use of inhaled controller. RESULTS: Eighty-two children with a median age of 10 years (interquartile range: 7-12 years) were included. Adequate therapeutic adherence was reported by 68.3%. After adjusting for age, sex, exposure to cigarette smoke, duration of controller therapy, and atopy, FeNO < 20 ppb was independently associated with adequate therapeutic adherence (RR = 1.5, p = .04, 95% confidence interval: 1.03-2.19). CONCLUSIONS: FeNO values seem to be useful to identify pediatric patients with asthma who have adequate adherence to inhaled steroids in a MIC.

Significant increase in MIC-A and MIC-B and soluble MIC-A and MIC-B in canine lymphomas.

Non-Hodkin's lymphoma (NHL) is the most frequent hematologic malignancy in humans and dogs. NKG2D is one of the most critical receptors on NK cells, recognizing their natural ligands on malignant cells such as A and B major histocompatibility complex-related proteins (MIC-A and MIC-B). Soluble molecules (sMIC-A and sMIC-B) can interfere with immune synapsis between NK cells and tumor cells, impeding NK cytotoxicity. The main objectives of this study were to analyze, in dogs with diffuse large B cell lymphoma, NK cell lymphoma, and reactive lymphadenopathies, the role of NK cells, their activating receptors NKG2D and NKp46, and their ligands MIC-A and MIC-B, as well as soluble molecules sMIC-A and sMIC-B. Thirty-six dogs with a possible diagnosis of NHL and eight healthy dogs were studied. NHL was diagnosed in 28 (78 %) dogs; in the other 8 (22 %), reactive lymphadenopathies were present. Most of the lymphomas corresponded to B cell NHL (82 %). The most predominant subtype was diffuse large B cell lymphoma (21, 71.5 %), followed by five cases (18 %) that were Non-B Non-T lymphomas (presumably NK cell lymphomas) and other B cell lymphomas (3, 10.5%). There were no cases of T cell NHL. MIC-A was positive in 7 of 27 (26 %) cases of NHL, and MIC-B in 20 of 27 (74 %) NHL. In non-malignant lymphadenopathies, three (37.5 %) dogs were positive for MIC-A, and five (62.5 %) expressed MIC-B. Dogs with lymphoma had higher numbers of NK cells than eight healthy dogs. In 15 dogs (12 cases with NHL and three cases with reactive adenopathies) and eight controls, there were no differences in the number of NK cells expressing NKP46 and NKG2D. NHL dogs had higher values of sMIC-A and sMIC-B. B-cell and NK cell lymphomas correspond to 86 % and 14 % of all canine lymphomas. MIC-A, MIC-B, and sMIC-A and sMIC-B were increased in canine lymphomas.

Identification of Eimeria tenella sporozoite immunodominant mimotopes by random phage-display peptide libraries-a proof of concept study.

Introduction: Coccidiosis, caused by parasites of numerous Eimeria species, has long been recognized as an economically significant disease in the chicken industry worldwide. The rise of anti-coccidian resistance has driven a search for other parasite management techniques. Recombinant antigen vaccination presents a highly feasible alternative. Properly identifying antigens that might trigger a potent immune response is one of the major obstacles to creating a viable genetically modified vaccine. Methods: This study evaluated a reverse immunology approach for the identification of B-cell epitopes. Antisera from rabbits and hens inoculated with whole-sporozoites of E. tenella were used to identify Western blot antigens. The rabbit IgG fraction from the anti-sporozoite serum exhibited the highest reactogenicity; consequently, it was purified and utilized to screen two random Phage-display peptide libraries (12 mer and c7c mer). After three panning rounds, 20 clones from each library were randomly selected, their nucleotide sequences acquired, and their reactivity to anti-sporozoite E. tenella serum assessed. The selected peptide clones inferred amino acid sequences matched numerous E. tenella proteins. Results and Conclusions: The extracellular domain of the epidermal growth factor-like (EGF-like) repeats, and the thrombospondin type-I (TSP-1) repeats of E. tenella micronemal protein 4 (EtMIC4) matched with the c7c mer selected clones CNTGSPYEC (2/20) and CMSTGLSSC (1/20) respectively. The clone CSISSLTHC that matched with a conserved hypothetical protein of E. tenella was widely selected (3/20). Selected clones from the 12-mer phage display library AGHTTQFNSKTT (7/20), GPNSAFWAGSER (2/20) and HFAYWWNGVRGP (8/20) showed similarities with a cullin homolog, elongation factor-2 and beta-dynein chain a putative E. tenella protein, respectively. Four immunodominant clones were previously selected and used to immunize rabbits. By ELISA and Western blot, all rabbit anti-clone serums detected E. tenella native antigens. Discussion: Thus, selected phagotopes contained recombinant E. tenella antigen peptides. Using antibodies against E. tenella sporozoites, this study demonstrated the feasibility of screening Phage-display random peptide libraries for true immunotopes. In addition, this study looked at an approach for finding novel candidates that could be used as an E. tenella recombinant epitope-based vaccine.

A simple, low cost and fast sample preparation method for fluorine determination by ISE in leguminous seeds and oilseeds.

This work presents the first report of the application of microwave-induced combustion in disposable vessels (MIC-DV) as a simple and fast sample preparation step for fluoride determination by ion-selective electrode (ISE) in leguminous seeds and oilseeds samples. Several experimental conditions of MIC-DV were evaluated, such as sample mass, absorbing solution, volume of combustion igniter, purging time with oxygen, and the use of successive combustion cycles. The accuracy of MIC-DV/ISE method was evaluated by comparing the results obtained by microwave-induced combustion and determination by ion chromatography, with agreements ranged from 94 to 106%. The method allowed to achieve relatively low limits of quantification (8.3 to 16 µg g-1) comparing to AOAC method (40 µg g-1), besides the use of small amounts of reagents, less handling of digests, making the method greener and with portable features comparing to other methods.