Search Results (35)

This study describes the first complete genomic sequence of an NDM-19 and QnrS11-producing multidrug-resistant (MDR) Escherichia coli isolate collected from a fecal swab from a poultry farm in 2019 in Egypt. The bla_NDM-19 was identified by PCR screening and DNA sequencing. The isolate was then subjected to antimicrobial susceptibility testing, conjugation and transformation experiments, and complete genome sequencing. The chromosome of strain M2-13-1 measures 4,738,278 bp and encodes 4557 predicted genes, with an average G + C content of 50.8%. M2-13-1 is classified under ST167, serotype O101:H5, phylogroup A, and shows an MDR phenotype, having minimum inhibitory concentrations (MICs) of 64 mg/L for both meropenem and doripenem. The genes bla_NDM-19 and qnrS11 are present on 49,816 bp IncX3 and 113,285 bp IncFII: IncFIB plasmids, respectively. M2-13-1 harbors genes that impart resistance to sulfonamides (sul1), trimethoprim (dfrA14), β-lactams (bla_TEM-1B), aminoglycosides (aph(6)-Id, aph(3′)-Ia, aph(3″)-Ib, aac(3)-IV, and aph(4)-Ia), tetracycline (tet(A)), and chloramphenicol (floR). It was susceptible to aztreonam, colistin, fosfomycin, and tigecycline. The genetic context surrounding bla_NDM-19 includes ISAba125-IS5-bla_NDM-19-ble_MBL-trpF-hp1-hp2-IS26. Hierarchical clustering of the core genome MLST (HierCC) indicated M2-13-1 clusters with global ST167 E. coli lineages, showing HC levels of 100 (HC100) core genome allelic differences. Plasmids of the IncX3 group and the insertion sequence (ISAba125) are critical vehicles for the dissemination of bla_NDM and its related variants. To our knowledge, this is the first genomic report of a bla_NDM-19/IncX3-carrying E. coli isolate of animal origin globally. Full article

Pseudomonas aeruginosa is a ubiquitous environmental bacterium that causes a variety of infections in humans and animals. Although antibiotic resistance in livestock has been extensively documented, continuous surveillance remains crucial for tracking emerging resistance trends and assessing control measures. During 2017 and 2018, 234 strains of P. aeruginosa were identified from 1063 strains of pathogenic and nonpathogenic bacteria isolated from raw milk of healthy and mastitis cows. In this study, 132 convenience P. aeruginosa isolates were recovered and tested for antimicrobial susceptibility and the presence of antimicrobial resistance genes and virulence factors. Antimicrobial susceptibility testing revealed that these P. aeruginosa isolates were resistant to three (gentamicin, tobramycin, and ceftazidime) out of eight antibiotics. Real-time PCR targeting 21 antibiotic resistance genes indicated that aminoglycoside modifying enzyme (AME) gene ant(3″)-I was most frequently identified in both antimicrobial-resistant and -susceptible P. aeruginosa isolates, followed by aac(6′)-II and aac(6′)-Ib. The β-lactamase encoding gene, bla_PDC, was mainly identified in susceptible P. aeruginosa isolates. Virulence factors screening revealed the presence of exoS, exoT, exoU, pyo, aprA, toxA, plcH, algD, lasB, lasI, lasR, rh1L, and rh1R in resistant isolates, with the detection rates ranging from 16.7% to 88.9%. Additionally, next-generation sequencing was conducted on three resistant isolates to validate these findings. This study showed the antibiotic resistance of P. aeruginosa in raw milk samples from large-scale dairy farms in Jiangsu and Shandong provinces, China. Full article

This study explores the purification, characterization, and application of laccases from Trametes hirsuta CS5 for degrading synthetic dyes as models of emerging contaminants. Purification involved ion exchange chromatography, molecular exclusion, and chromatofocusing, identifying th ree laccase isoforms: ThIa, ThIb, and ThII. Characterization included determining pH and temperature stability, kinetic parameters (K_m, K_cat), and inhibition constants (K_i) for inhibitors like NaN₃, SDS, TGA, EDTA, and DMSO, using 2,6-DMP and guaiacol as substrates. ThII exhibited the highest catalytic efficiency, with the lowest K_m and highest K_cat. Optimal activity was observed at pH 3.5 and 55 °C. Decolorization tests with nine dyes showed that ThII and ThIa were particularly effective against Acid Red 44, Orange II, Indigo Blue, Brilliant Blue R, and Remazol Brilliant Blue R. ThIb displayed higher activity towards Crystal Violet and Acid Green 27. Among substrates, guaiacol showed the highest K_cat, while 2,6-DMP was preferred overall. Inhibitor studies revealed NaN₃ as the most potent inhibitor. These results demonstrate the significant potential of T. hirsuta CS5 laccases, especially ThIa and ThII, as biocatalysts for degrading synthetic dyes and other xenobiotics. Their efficiency and stability under acidic and moderate temperature conditions position them as promising tools for sustainable wastewater treatment and environmental remediation. Full article

Cell culture underpins virus isolation and virus neutralisation tests, which are both gold-standard diagnostic methods for foot-and-mouth disease (FMD). Cell culture is also crucial for the propagation of inactivated foot-and-mouth disease virus (FMDV) vaccines. Both primary cells and cell lines are utilised in FMDV isolation and propagation. Widely used cell lines for FMDV and isolation and propagation include baby hamster kidney cells (BHK-21), swine kidney cells (IB-RS-2), foetal goat tongue (ZZ-R 127), foetal porcine kidney cells (LFBKvB6), bovine kidney cells (BK), human telomerase reverse transcriptase bovine thyroid (hTERT-BTY) and porcine kidney-originating PK-15 or SK 6 cell lines. This review highlights how different receptors and molecules—integrins, heparan sulphate (HS), and the Jumonji C-domain containing Protein 6 (JMJD6)—found on the surface of different cell types contribute to differences experienced with susceptibility and sensitivity of the cells to infection with different serotypes of FMDV. This review specifically focuses on Southern African territory (SAT) serotypes, which are unique to the Southern African context and are often under-investigated in cell line development for FMDV isolation and propagation. Full article

MYB transcription factors (TFs) play vital roles in plant growth, development, and response to adversity. Although the MYB gene family has been studied in many plant species, there is still little known about the function of R2R3 MYB TFs in sweet potato in response to abiotic stresses. In this study, an R2R3 MYB gene, IbMYB330 was isolated from sweet potato (Ipomoea batatas). IbMYB330 was ectopically expressed in tobacco and the functional characterization was performed by overexpression in transgenic plants. The IbMYB330 protein has a 268 amino acid sequence and contains two highly conserved MYB domains. The molecular weight and isoelectric point of IbMYB330 are 29.24 kD and 9.12, respectively. The expression of IbMYB330 in sweet potato is tissue-specific, and levels in the root were significantly higher than that in the leaf and stem. It showed that the expression of IbMYB330 was strongly induced by PEG-6000, NaCl, and H₂O₂. Ectopic expression of IbMYB330 led to increased transcript levels of stress-related genes such as SOD, POD, APX, and P5CS. Moreover, compared to the wild-type (WT), transgenic tobacco overexpression of IbMYB330 enhanced the tolerance to drought and salt stress treatment as CAT activity, POD activity, proline content, and protein content in transgenic tobacco had increased, while MDA content had decreased. Taken together, our study demonstrated that IbMYB330 plays a role in enhancing the resistance of sweet potato to stresses. These findings lay the groundwork for future research on the R2R3-MYB genes of sweet potato and indicates that IbMYB330 may be a candidate gene for improving abiotic stress tolerance in crops. Full article

α7 nicotinic acetylcholine receptors (nAChRs) are mainly distributed in the central nervous system (CNS), including the hippocampus, striatum, and cortex of the brain. The α7 nAChR has high Ca²⁺ permeability and can be quickly activated and desensitized, and is closely related to Alzheimer’s disease (AD), epilepsy, schizophrenia, lung cancer, Parkinson’s disease (PD), inflammation, and other diseases. α-conotoxins from marine cone snail venom are typically short, disulfide-rich neuropeptides targeting nAChRs and can distinguish various subtypes, providing vital pharmacological tools for the functional research of nAChRs. [Q1G, ΔR14]LvΙB is a rat α7 nAChRs selective antagonist, modified from α-conotoxin LvΙB. In this study, we utilized three types of fluorescein after N-Hydroxy succinimide (NHS) activation treatment: 6-TAMRA-SE, Cy3 NHS, and BODIPY-FL NHS, labeling the N-Terminal of [Q1G, ΔR14]LvΙB under weak alkaline conditions, obtaining three fluorescent analogs: LvIB-R, LvIB-C, and LvIB-B, respectively. The potency of [Q1G, ΔR14]LvΙB fluorescent analogs was evaluated at rat α7 nAChRs expressed in Xenopus laevis oocytes. Using a two-electrode voltage clamp (TEVC), the half-maximal inhibitory concentration (IC₅₀) values of LvIB-R, LvIB-C, and LvIB-B were 643.3 nM, 298.0 nM, and 186.9 nM, respectively. The stability of cerebrospinal fluid analysis showed that after incubation for 12 h, the retention rates of the three fluorescent analogs were 52.2%, 22.1%, and 0%, respectively. [Q1G, ΔR14]LvΙB fluorescent analogs were applied to explore the distribution of α7 nAChRs in the hippocampus and striatum of rat brain tissue and it was found that Cy3- and BODIPY FL-labeled [Q1G, ΔR14]LvΙB exhibited better imaging characteristics than 6-TAMARA-. It was also found that α7 nAChRs are widely distributed in the cerebral cortex and cerebellar lobules. Taking into account potency, imaging, and stability, [Q1G, ΔR14]LvΙB -BODIPY FL is an ideal pharmacological tool to investigate the tissue distribution and function of α7 nAChRs. Our findings not only provide a foundation for the development of conotoxins as visual pharmacological probes, but also demonstrate the distribution of α7 nAChRs in the rat brain. Full article

Background: Dysbiosis, influenced by poor diet or stress, is associated with various systemic diseases. Probiotic supplements are recognized for stabilizing gut microbiota and alleviating gastrointestinal issues, like irritable bowel syndrome (IBS). This study focused on the tryptophan pathways, which are important for the regulation of serotonin levels, and on host physiology and behavior regulation. Methods: Nanovesicles were isolated from the plasma of subjects with chronic diarrhea, both before and after 60 days of consuming a probiotic mix (Acronelle^®, Bromatech S.r.l., Milan, Italy). These nanovesicles were assessed for the presence of Tryptophan 2,3-dioxygenase 2 (TDO 2). Furthermore, the probiotics mix, in combination with H₂O₂, was used to treat HT29 cells to explore its cytoprotective and anti-stress effect. Results: In vivo, levels of TDO 2 in nanovesicles were enhanced in the blood after probiotic treatment, suggesting a role in the gut–brain axis. In the in vitro model, a typical H₂O₂-induced stress effect occurred, which the probiotics mix was able to recover, showing a cytoprotective effect. The probiotics mix treatment significantly reduced the heat shock protein 60 kDa levels and was able to preserve intestinal integrity and barrier function by restoring the expression and redistribution of tight junction proteins. Moreover, the probiotics mix increased the expression of TDO 2 and serotonin receptors. Conclusions: This study provides evidence for the gut–brain axis mediation by nanovesicles, influencing central nervous system function. Full article

Background: As the anti-biofilm pharmacokinetic/pharmacodynamic (PK/PD) properties of antibiotics are not well-defined, we have evaluated the PK/PD indices for different regimens of ceftazidime (CAZ; with/without colistin) against Pseudomonas aeruginosa biofilm. Methods: We have used the Center for Disease Control and Prevention Biofilm Reactor with two susceptible (PAO1 and HUB-PAS) and one resistant (HUB-XDR) strains of P. aeruginosa. The regimens were CAZ monotherapies (mimicking a human dose of 2 g/8 h, CAZ-IB; 6 g/daily as continuous infusion at 50 mg/L, CAZ-CI₅₀; and 9 g/daily at 70 mg/L, CAZ-CI₇₀) and CAZ-colistin combinations. Efficacy was correlated with the CAZ PK/PD parameters. Results: CAZ-CI₇₀ was the most effective monotherapy against CAZ-susceptible strains (Δlog CFU/mL 54–0 h = −4.15 ± 0.59 and −3.05 ± 0.5 for HUB-PAS and PAO1, respectively; p ≤ 0.007 vs. other monotherapies), and adding colistin improved the efficacy over CAZ monotherapy. CAZ monotherapies were ineffective against the HUB-XDR strain, and CAZ-CI₅₀ plus colistin achieved higher efficacy than CAZ-IB with colistin. The PK/PD index that correlated best with anti-biofilm efficacy was fAUC_0–24h/MIC (r² = 0.78). Conclusions: CAZ exhibited dose-dependent anti-biofilm killing against P. aeruginosa, which was better explained by the fAUC_0–24h/MIC index. CAZ-CI provided benefits compared to CAZ-IB, particularly when using higher doses and together with colistin. CAZ monotherapies were ineffective against the CAZ-resistant strain, independently of the optimized strategy and only CAZ-CI plus colistin appeared useful for clinical practice. Full article

The association between H. pylori and small intestinal permeability (IP) on serum testosterone levels in men as mediated by metabolic endotoxemia remains unclear. We sought to explore relationships using correlational analysis between H. pylori IgG class antibody levels and small IP via dual sugar probe analysis on T levels in 50 male participants of reproductive age. Sleep quality, physical activity levels, and Irritable Bowel Syndrome (IBS) symptom severity were measured as potential confounders. Measures for H. pylori (antibodies) increased small IP (lactulose/rhamnose ratio), and hypogonadism (testosterone) did not exceed diagnostic cut-off values for respective pathologies. There was no correlation between lactulose/rhamnose e ratio and GI function markers, zonulin, H. pylori, and IBS questionnaire scores; inflammatory markers, high-sensitivity C-reactive Protein (hsCRP) and Lipopolysaccharide-Binding Protein (LBP); nor endocrine markers, testosterone, Luteinizing hormone (LH), and Follicle-stimulating hormone (FSH). There was a moderate inverse relationship revealed between IBS symptom severity and LBP (r = −0.457, p = 0.004); and hsCRP and testosterone (r = −0.398, p = 0.004). This was independent of physical activity level and sleep quality, but not BMI, which supports the existing link between adiposity, inflammation, and hypogonadism currently present in the literature. Full article

Pseudomonas aeruginosa (PA), one of the ESKAPE pathogens, is an opportunistic Gram-negative bacterium responsible for nosocomial infections in humans but also for infections in patients affected by AIDS, cancer, or cystic fibrosis (CF). Treatment of PA infections in CF patients is a global healthcare problem due to the ability of PA to gain antibiotic tolerance through biofilm formation. Anti-virulence compounds represent a promising approach as adjuvant therapy, which could reduce or eliminate the pathogenicity of PA without impacting its growth. Pyocyanin is one of the virulence factors whose production is modulated by the Pseudomonas quinolone signal (PQS) through its receptor PqsR. Different PqsR modulators have been synthesized over the years, highlighting this new powerful therapeutic strategy. Based on the promising structure of quinazolin-4(3H)-one, we developed compounds 7a–d, 8a,b, 9, 10, and 11a–f able to reduce biofilm formation and the production of virulence factors (pyocyanin and pyoverdine) at 50 µM in two PA strains responsible for CF acute and chronic infections. The developed compounds did not reduce the cell viability of IB3-1 bronchial CF cells, and computational studies confirmed the potential ability of novel compounds to act as potential Pqs system modulators. Full article

Conotoxins are widely distributed and important for studying ligand-gated ion channels. TxIB, a conotoxin consisting of 16 amino acids derived from Conus textile, is a unique selective ligand that blocks rat α6/α3β2β3 nAChR (IC₅₀ = 28 nM) without affecting other rat subtypes. However, when the activity of TxIB against human nAChRs was examined, it was unexpectedly found that TxIB had a significant blocking effect on not only human α6/α3β2β3 nAChR but also human α6/α3β4 nAChR, with an IC₅₀ of 537 nM. To investigate the molecular mechanism of this species specificity and to establish a theoretical basis for drug development studies of TxIB and its analogs, different amino acid residues between human and rat α6/α3 and β4 nAChR subunits were identified. Each residue of the human species was then substituted with the corresponding residue of the rat species via PCR-directed mutagenesis. The potencies of TxIB towards the native α6/α3β4 nAChRs and their mutants were evaluated through electrophysiological experiments. The results showed that the IC₅₀ of TxIB against h[α6_{V32L, K61R}/α3]β4_{L107V, V115I} was 22.5 μM, a 42-fold decrease in potency compared to the native hα6/α3β4 nAChR. Val-32 and Lys-61 in the human α6/α3 subunit and Leu-107 and Val-115 in the human β4 subunit, together, were found to determine the species differences in the α6/α3β4 nAChR. These results also demonstrate that the effects of species differences between humans and rats should be fully considered when evaluating the efficacy of drug candidates targeting nAChRs in rodent models. Full article

FODMAPs are fermentable oligo-, di-, monosaccharides, and polyols. The application of homofermentative lactic acid bacteria (LAB) has been investigated as a promising approach for producing low-FODMAP whole-wheat bread. The low-FODMAP diet is recommended to treat irritable bowel syndrome (IBS). Wheat flour is staple to many diets and is a significant source of fructans, which are considered FODMAPs. The reduction of fructans via sourdough fermentation, generally associated with heterofermentative lactic acid bacteria (LAB), often leads to the accumulation of other FODMAPs. A collection of 244 wild-type LAB strains was isolated from different environments and their specific FODMAP utilisation profiles established. Three homofermentative strains were selected for production of whole-wheat sourdough bread. These were Lactiplantibacillus plantarum FST1.7 (FST1.7), Lacticaseibacillus paracasei R3 (R3), and Pediococcus pentosaceus RYE106 (RYE106). Carbohydrate levels in flour, sourdoughs (before and after 48 h fermentation), and resulting breads were analysed via HPAEC-PAD and compared with whole-wheat bread leavened with baker’s yeast. While strain R3 was the most efficient in FODMAP reduction, breads produced with all three test strains had FODMAP content below cut-off levels that would trigger IBS symptoms. Results of this study highlighted the potential of homofermentative LAB in producing low-FODMAP whole-wheat bread. Full article

Sweet potato (Ipomoea batatas (L.) Lam) is one of the most crucial food crops widely cultivated worldwide. In plants, MYB transcription factors play crucial roles in plant growth, defense regulation, and stress resistance. However, the regulatory mechanism of MYBs in salt and drought response remain poorly studied in sweet potato. By screening a transcriptome database for differentially expressed genes between the sweet potato variety Jingshu 6 and its mutant JS6-5 with high anthocyanin and increased tolerance to salt and drought stresses, we identified a R2R3-MYB gene IbMYB48, for which expression was induced by PEG6000, NaCl, abscisic acid (ABA), methyl jasmonic acid (MeJA), salicylic acid (SA) and H₂O₂. Particle-mediated transient transformation of onion epidermal cells showed IbMYB48 is localized in the nucleus. Transactivation activity assay in yeast cells revealed that IbMYB48 has transactivation activity, and its active domain is located in the carboxyl (C)-terminal region. Furthermore, expression of IbMYB48 confers enhanced tolerance to salt and drought stresses in transgenic Arabidopsis. The contents of endogenous ABA, JA, and proline in transgenic lines were higher than control, and the activity of superoxide dismutase (SOD) was significantly increased under salt and drought stress conditions. By contrast, the accumulation of malondialdehyde (MDA) and H₂O₂ were lower. Moreover, genes encoding enzymes involved in ABA biosynthetic pathway, JA biosynthesis and signaling pathway, and reactive oxygen species (ROS) scavenging system were significantly up-regulated in transgenic Arabidopsis under salt or drought stress. Altogether, these results suggest IbMYB48 may be a candidate gene for improvement of abiotic stress tolerance. Full article

Osteosarcoma (OS) is a bone tumour affecting adolescents and elderly people. Unfortunately, basic treatment methods are still underdeveloped, which has a high impact on the poor survivability of the patients. Studies designed to understand the underlying mechanisms of osteosarcoma development, as well as preclinical investigations aimed at establishing novel therapeutic strategies, rely significantly upon in vitro models, which apply well-established cell lines such as U-2 OS, Saos-2 and MG-63. In this study, the expression of chosen markers associated with tumour progression, metastasis and survival were identified using RT-qPCR. Levels of several onco-miRs (miR-21-5p, miR-124-3p, miR-223-3p and miR-320a-3p) and long non-coding RNA MEG3 were established. The mRNA expression of bone morphogenetic proteins (BMPs), including BMP-2, BMP-3, BMP-4, BMP-6, BMP-7, as well as their receptors: BMPR-IA, BMPR-IB and BMPR-II was also determined. Other tested markers included metalloproteinases, i.e., MMP-7 and MMP-14 and survivin (BIRC5), C-MYC, as well as CYCLIN D (CCND1). The analysis included comparing obtained profiles with transcript levels established for the osteogenic HeLa cell line and human adipose-derived stromal cells (hASCs). The tested OS cell lines were characterised by a cancer-related phenotype, such as increased expression of mRNA for BMP-7, as well as MMP-7 and MMP-14. Osteosarcoma cells differ considerably in miR-21-5p and miR-124-3p levels, which can be related to uncontrolled tumour growth. The comprehensive examination of osteosarcoma transcriptome profiles may facilitate the selection of appropriate cell models for preclinical investigations aimed at the development of new strategies for OS treatment. Full article

Recently, patients with glycogen storage disease (GSD) have been described as having gut dysbiosis, lower fecal pH, and an imbalance in SCFAs due to an increase in acetate and propionate levels. Here, we report the fecal measurement of bacterial-related metabolites formic, acetic, lactic, propionic, and succinic acid, a key metabolite of both host and microbiota, on a previously described cohort of 24 patients (GSD Ia = 15, GSD Ib = 5, 1 GSD III = 1 and GSD IX = 3) and 16 healthy controls, with similar sex and age, using the high-performance liquid chromatography technique. The succinic acid levels were higher in the GSD patients than in the controls (patients = 38.02; controls = 27.53; p = 0.045), without differences between the groups for other metabolites. Fecal pH present inverse correlation with lactic acid (R = −0.54; p = 0.0085), while OTUs were inversely correlated with both lactic (R = −0.46; p = 0.026) and formic (R = −0.54; p = 0.026) acids. Using two distinct metrics of diversity, borderline significance was obtained for propionic acid, affecting the microbial structure on Euclidean basis in 8% (r² = 0.081; p = 0.079), and for lactic acid, affecting 6% of microbial structure using Bray–Curtis distance (r² = 0.065; p = 0.060). No correlation was found between SCFAs and total carbohydrate consumption among the participants or uncooked cornstarch consumption among the patients. Full article