Search Results (73)

Background: The treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections is extremely challenging due to its antibiotic resistance, and the combination of plant active ingredients with antibiotics represents a potential strategy to address this issue. Methods: We determined the combinatorial relationship between baicalin (BA) and kanamycin (KM) using the checkerboard dilution method. The antibacterial activity of the baicalin–kanamycin (BA/KM) combination was evaluated through growth curve determination assays and scanning electron microscopy (SEM). The effects of the BA/KM combination on the cell membrane and cell wall of MRSA were analyzed using reactive oxygen species (ROS) detection assays, intracellular protein leakage experiments, alkaline phosphatase (AKP) activity assays, laser scanning confocal microscopy (LSCM) observations, and molecular docking simulations. The antibiofilm activity and related mechanisms of the BA/KM combination were elucidated via crystal violet staining, MTT assay, phenol-sulfuric acid method, congo red staining, staphyloxanthin determination assays, and quantitative real-time polymerase chain reaction (qPCR). The safety of the BA/KM combination was assessed through hemolytic activity analysis, and its anti-MRSA efficacy was evaluated on lettuce. Results: BA/KM combination showed a synergistic antibacterial effect on MRSA USA300. Mechanistic studies revealed that BA may interact with amino acid residues of peptidoglycan synthetase PBP2a to hinder peptidoglycan synthesis, thereby facilitating KM penetration through the cell wall. Subsequently, BA binds to amino acid residues of the membrane transporter NorA, leading to disruption of cell membrane homeostasis and enhancing KM’s ability to induce intracellular ROS accumulation in MRSA. Furthermore, the BA/KM combination reduced MRSA biofilm formation by 77.85% and decreased the metabolic activity of biofilm cells by 42.93% through inhibiting the synthesis of biofilm components EPS and PIA. Additionally, this combination suppressed the synthesis of staphyloxanthin and downregulated the expression of agrA and agrC genes. When 1/8 MIC BA was combined with 1/4 MIC KM, the count of MRSA on lettuce surfaces was reduced by 0.88 log CFU/cm², an effect comparable to that of 0.2% (v/v) hydrogen peroxide. Conclusions: According to these findings, the BA/KM combination may offer a promising option for enhancing antibacterial efficacy through synergism, reducing antibiotic usage concentrations, and limiting MRSA transmission in fresh agricultural products. Full article

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring lung neoplasia in sheep caused by jaagsiekte sheep retrovirus (JSRV). JSRV infects alveolar type II pneumocytes (ATII) and club cells (CC), and the expression of viral oncoproteins induces a lung adenocarcinoma. The gross pathology of OPA exhibits differences in the anatomical patterns known as classical and atypical forms. Thirty natural OPA tumors, divided equally into early OPA tumors (Group A, GA), atypical tumors (Group B, GB), and classical tumors (Group C, GC), were obtained from adult sheep (2–9 years old). Tumor heterogeneity was studied comparing the histopathology (growth patterns, local invasion, mitotic figures, myxoid nodules), together with immunohistochemistry (IHC) using markers of JSRV-ENV, epithelial cells (ATII cells, CC, ki67), progenitor-stem epithelial cells (K5, p63, CD44), and the anterior grade protein 2 (AGR2). Papillary pattern was predominant in all groups. Lepidic pattern was also relevant in GA, and acinar pattern was relevant in GB. Low proliferation indexes and local invasion were observed in all groups. Myxoid nodules were few. IHC showed that all samples were positive for JSRV-ENV. Cell markers demonstrated that GA was different when compared to GB and GC, showing significantly the highest levels of CC, K5, and p63 positive tumor cells. There were no significant differences between GB and GC. The heterogeneity analysis of OPA tumors revealed that in early tumors, repair is important but is not reflected in classical or atypical different anatomical OPA forms. Full article

Background: Serum markers are commonly used to diagnose bone and joint infections; however, their accuracy for diagnosing pyogenic spondylitis remains unproven. This study aimed to validate the diagnostic accuracy of inflammatory, nutritional, and immunological serum markers for spinal infections and identify the most effective combinations. Methods: The retrospective cohort study analyzed 656 patients who visited the hospital for spinal diseases between 1 January 2004 and 31 March 2021; a total of 76 were diagnosed with pyogenic spondylitis. Blood samples were analyzed for serum albumin (Alb), total protein (TP), globulin (Glb), C-reactive protein (CRP), platelet count, white blood cell count, neutrophil count, lymphocyte count, and monocyte count. Combination markers, including albumin–globulin ratio (AGR), CRP–albumin ratio (CAR), CRP–AGR (CAGR), neutrophil–lymphocyte ratio (NLR), and platelet–lymphocyte ratio (PLR), were also evaluated. Receiver operating characteristic curves were used to determine each marker’s diagnostic performance. Furthermore, multivariate analysis was performed to examine the odds ratios. Results: Patients with pyogenic spondylitis showed significantly different levels in Alb (p < 0.0001), Glb (p < 0.0001), CRP (p < 0.0001), platelet count (p < 0.0001), WBC count (p < 0.0006), neutrophil count (p = 0.0019), lymphocyte count (p = 0.0085), AGR (p < 0.0001), CAR (p < 0.0001), CAGR (p < 0.0001), NLR (p < 0.0001), and PLR (p < 0.0001). CRP (AUC = 0.80) showed good diagnostic accuracy, while combination markers CAR (AUC = 0.82) and CAGR (AUC = 0.83) had the highest areas under the curve (AUC). Multivariate analysis indicated that decreased age and the presence of comorbidities (including chronic kidney disease, chronic liver disease, malignancy, or diabetes), were independent predictors of early pyogenic spondylitis (OR_age = 0.93, OR_comorbidities = 16.98, p_age = 0.0005, and p_comorbidities = 0.0001). In patients with low-inflammatory pyogenic spondylitis, significant differences were observed in TP (p = 0.0293), Glb (p = 0.0012), CRP (p = 0.0023), platelet count (p = 0.0108), AGR (p = 0.0044), CAR (p = 0.0006), CAGR (p = 0.0004), PLR (p = 0.0192), and NLR (p = 0.0027), with CAGR showing the highest AUC (AUC = 0.70) among them. Conclusions: Serum combination markers (AGR, CAGR, CAR, PLR, and NLR) showed diagnostic value for pyogenic spondylitis, with CAGR achieving the highest accuracy. In low-inflammatory pyogenic spondylitis patients (CRP ≤ 1.0 mg/dL), these markers may aid diagnosis. Full article

Protein Disulfide Isomerases (PDIs) are emerging targets in anticancer therapy, with several PDI inhibitors demonstrating anticancer efficacy in preclinical models. Research has largely focused on “canonical” PDIs, such as PDIA1, which contain CXXC active site motifs where C represents Cysteine. Canonical PDIs have well-studied, critical roles in forming, breaking, and exchanging/scrambling disulfide bonds during protein folding. In contrast, non-canonical PDIs, which harbor CXXS active site motifs, remain less well-studied despite their role as sensors or effectors of protein folding quality control during protein trafficking in the secretory pathway. Here, we provide a review of the literature relating to the non-canonical PDIs ERp44, AGR2, and AGR3, which have been identified as strong dependencies in specific cancer subtypes according to the DepMap database. The biological and biochemical functions of ERp44, AGR2, and AGR3 are discussed, highlighting the role of ERp44 in two mechanisms of protein folding quality control, AGR2 as a selective sensor of mucin protein misfolding, and a unique role for AGR3 in cilia. Finally, we discuss recent efforts to develop small molecule inhibitors of ERp44, AGR2, and AGR3 as tool compounds and experimental therapeutics. Full article

Elodea nuttallii is a significant submerged macrophyte utilized in shrimp and crab aquaculture, yet it exhibits low thermotolerance. This study investigated the physiological responses and transcriptomic characteristics of E. nuttallii under high-temperature stress (HTS). The results indicated that HTS significantly reduced the absolute growth rate (AGR) and photosynthetic efficiency of E. nuttallii while concurrently elevating antioxidant enzyme activities, malondialdehyde (MDA) content, and concentrations of osmotic adjustment compounds. Furthermore, the apical segments of E. nuttallii demonstrated greater sensitivity to HTS compared to the middle segments. Under exposure to 35 °C and 40 °C, antioxidant enzyme activities, MDA content, and osmotic adjustment compound levels were significantly higher in the apical segments than in the middle segments. Transcriptomic analysis revealed 7526 differentially expressed genes (DEGs) in the apical segments at 35 °C, a number substantially exceeding that observed in the middle segments. Enrichment analysis of DEGs revealed significant upregulation of key metabolic regulators under HTS, including carbohydrate metabolism genes (HXK, FRK) and phenylpropanoid biosynthesis enzymes (4CL, COMT). This transcriptional reprogramming demonstrates E. nuttallii’s adaptive strategy of modulating carbon allocation and phenolic compound synthesis to mitigate thermal damage. Our findings not only elucidate novel thermotolerance mechanisms in aquatic plants but also provide candidate genetic targets (HXK, 4CL) for molecular breeding of heat-resilient cultivars through transcriptomic screening. Full article

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) and its biofilm-forming ability underscore the limitations of current antibiotics. In this study, a new compound named tripterhyponoid A was found to effectively combat MRSA, with an MIC of 2.0 μg/mL. It inhibited biofilm formation by downregulating genes related to the quorum sensing (QS) pathway (sarA, agrA, agrB, agrC, agrD, and hld) and eradicated mature biofilms. Furthermore, it induced DNA damage by binding to bacterial DNA, enhancing its efficiency against MRSA. Therefore, its anti-MRSA properties with multiple mechanisms of action make it less prone to developing resistance over 20 days. In addition, it reduced the bacterial load and regulated the levels of inflammatory cytokines IL-6 and IL-10 at the wound site in a mouse skin infection model. This paper provides the first in-depth investigation of the mechanisms of triterpenoids against MRSA by inhibiting the expression of QS system genes and binding to DNA. Full article

Background/Objectives: Clostridium perfringens is a normal inhabitant of the intestinal tract of poultry, and it has the potential to induce cholangiohepatitis and necrotic enteritis (NE). The poultry industry suffers significant financial losses because of NE, and treatment becomes more challenging due to resistant C. perfringens strains. Methods: The antimicrobial and antibiofilm activities of cellulose nanocrystals/zinc oxide nanocomposite (CNCs/ZnO) were assesses against pan drug-resistant (PDR) C. perfringens isolated from chickens and turkeys using phenotypic and molecular assays. Results: The overall prevalence rate of C. perfringens was 44.8% (43.75% in chickens and 58.33% in turkeys). Interestingly, the antimicrobial susceptibility testing of C. perfringens isolates revealed the alarming PDR (29.9%), extensively drug-resistant (XDR, 54.5%), and multidrug-resistant (MDR, 15.6%) isolates, with multiple antimicrobial resistance (MAR) indices ranging from 0.84 to 1. All PDR C. perfringens isolates could synthesize biofilms; among them, 21.7% were strong biofilm producers. The antimicrobial potentials of CNCs/ZnO against PDR C. perfringens isolates were evaluated by the agar well diffusion and broth microdilution techniques, and the results showed strong antimicrobial activity of the green nanocomposite with inhibition zones’ diameters of 20–40 mm and MIC value of 0.125 µg/mL. Moreover, the nanocomposite exhibited a great antibiofilm effect against the pre-existent biofilms of PDR C. perfringens isolates in a dose-dependent manner [MBIC50 up to 83.43 ± 1.98 for the CNCs/ZnO MBC concentration (0.25 μg/mL)]. The transcript levels of agrB quorum sensing gene and pilA2 type IV pili gene responsible for biofilm formation were determined by the quantitative real time-PCR technique, pre- and post-treatment with the CNCs/ZnO nanocomposite. The expression of both genes downregulated (0.099 ± 0.012–0.454 ± 0.031 and 0.104 ± 0.006–0.403 ± 0.035, respectively) when compared to the non-treated isolates. Conclusions: To the best of our knowledge, this is the first report of CNCs/ZnO nanocomposite’s antimicrobial and antibiofilm activities against PDR C. perfringens isolated from chickens and turkeys. Full article

This study aims to elucidate the synergistic antibacterial mechanism of benzyl isothiocyanate (BITC) and resveratrol (RES) on Staphylococcus aureus (S. aureus) at the transcriptional level. Compared with the individuals, the combination of BITC and RES (BITC_RES) reduced S. aureus growth, inhibited biofilm formation, and increased cell membrane disruption. The transcriptomic results showed that the BITC_RES group presented 245 and 1150 more DEGs than the BITC group and the RES group, respectively. In addition, some other key genes in the BITC_RES group, including serine protease (splA, splE), Sae regulatory system (saeR, saeS, tsaE, sau300), accessory gene regulator protein C (agrC), cysteine protease (sspB), glutamyl endopeptidase (sspA), and hemolysin toxin family-related genes (hly, lukDv, lukEv), and the relative expression of these 12 genes was downregulated by 2.2–259.8-fold, 0.8–259.8-fold and 1.2–158.2-fold greater than those in the BITC group and the RES group, respectively. Finally, a synergistic antimicrobial effect of this combination was also observed in fresh lean beef at 4 °C and 25 °C. These findings provide information for future studies on the synergistic antimicrobial effects of BITC and RES on S. aureus. Full article

Silver-white, matte, smooth, and durable deposits of silver-rhenium, with thicknesses ranging from 2.0 to 13.7 μm and containing 0.15 to 13.5 wt.% Re, were obtained with a current efficiency of 66–98% from a developed dicyanoargentate–perrhenate bath based on a borate–phosphate–carbonate silver-plating electrolyte. This study was focused on the influence of bath composition, the [Ag(I)]:[ReO₄⁻] ratio, surfactant additives, applied current density, temperature, and stirring, on the alloys’ composition, structure, morphology, microhardness, adhesion, and porosity. A voltammetric analysis was conducted, considering the influence of ethanolamines on electrode processes. In baths with triethanolamine (TEA), coatings similar to a silver matrix with rhenium doped in mass fractions are likely achievable. Monoethanolamine (MEA) is recommended due to its process-activating properties. All coatings were nanocrystalline (τ = 28.5–35 nm). For deposits containing less than 10 wt.% Re, characteristic silver XRD peaks were observed, while for other deposits, additional peaks attributed probably to Re(VII) and Re(VI) oxides. A linear relationship H_v − τ^−1/2, typical for Hall–Petch plots, was obtained, confirming that grain boundaries play a crucial role in mechanical properties of coatings. The conditions for stable electrochemical synthesis of promising functional Ag-Re coatings of predetermined composition (0.7–1.5 wt.% Re) were proposed for practical use in power electronics and energy sectors for manufacturing electrical contacts operating across a wide temperature range. This was realized by deposition from an Ag-rich bath in the area of mixed electrochemical kinetics, at potential values corresponding to the region of half the limiting current: j = 2.5–6 mA cm⁻², t = 19–33 °C. Full article

Staphylococcus aureus is one of the most diverse bacterial pathogens. This is reflected in its ability to cause a wide array of infections and in genotypic and phenotypic differences between clinical isolates that extend beyond their antibiotic resistance status. Many S. aureus infections, including those involving indwelling medical devices, are therapeutically defined by the formation of a biofilm. This is reflected in the number of reports focusing on S. aureus biofilm formation and biofilm-associated infections. These infections are characterized by a level of intrinsic resistance that compromises conventional antibiotic therapy irrespective of acquired resistance, suggesting that an inhibitor of biofilm formation would have tremendous clinical value. Many reports have described large-scale screens aimed at identifying compounds that limit S. aureus biofilm formation, but relatively few examined whether the limitation was sufficient to overcome this intrinsic resistance. Similarly, while many of these reports examined the impact of putative inhibitors on S. aureus phenotypes, very few took a focused approach to identify and optimize an effective inhibitor of specific biofilm-associated targets. Such approaches are dependent on validating a target, hopefully one that is not restricted by the diversity of S. aureus as a bacterial pathogen. Rigorous biological validation of such a target would allow investigators to virtually screen vast chemical libraries to identify potential inhibitors that warrant further investigation based on their predicted function. Here, we summarize reports describing S. aureus regulatory loci implicated in biofilm formation to assess whether they are viable targets for the development of an anti-biofilm therapeutic strategy with an emphasis on whether sarA has been sufficiently validated to warrant consideration in this important clinical context. Full article

Staphylococcus aureus (S. aureus) can contaminate food by forming biofilms, leading to significant food safety concerns. Amomum tsaoko essential oil (AEO) has been shown to be an effective plant-derived antibacterial agent. This study investigated the antibiofilm activity of AEO and evaluated its potential benefit in pork preservation. The results showed that AEO solution (2 mg/mL) can effectively remove the biofilm of S. aureus on food contact materials, achieving a removal rate of over 90%. Scanning electron microscopy (SEM) revealed that the S. aureus biofilm structure was disrupted after treatment with AEO. Meanwhile, AEO treatment significantly reduced the initial formation of S. aureus biofilms and extracellular polymeric substance (EPS) production. In addition, AEO down-regulated the expression of key biofilm-associated genes, including icaA, icaB, agrA, cidA, cidB, and cidC, thereby regulating formation. AEO also exhibited significant antibiofilm activity in pork preservation, effectively controlling key indicators associated with pork spoilage. This study revealed the potential of AEO in food preservation, demonstrating its ability to disrupt S. aureus biofilms by inhibiting initial formation, reducing the release of EPS secretion, and regulating the expression of biofilm-associated genes. Full article

Background/Objectives: The elimination of bacterial biofilm formation is an effective strategy against bacterial infections. The objective was to design 27 colchicine C-ring modified amine derivatives and evaluate their inhibitory activities against the biofilms of MRSA USA300. Methods: Design 27 colchicine C-ring modified amine derivatives. Evaluate their inhibitory activities against MRSA USA300 biofilms. Conduct antibacterial or synergistic antibacterial experiments. Research the phenotypic mechanisms related to biofilm-related genes icaA and agrA. Results: The experiments showed that most compounds in this series exhibited varying degrees of biofilm inhibitory activity (with inhibition rates ranging from 7.72% to 40.79%). Further verification through antibacterial or synergistic antibacterial experiments revealed that the compounds with biofilm-inhibiting effects (compounds 7b–11b) generally had certain antibacterial activities (MICs = 16–32 μg/mL) or synergistic antibacterial effects (FICIs < 0.5). Furthermore, through in-depth research on their phenotypic mechanisms (i.e., research on biofilm-related mechanisms), it was found that the compounds with antibacterial or synergistic antibacterial properties could inhibit the formation of biofilms by affecting the regulation of the biofilm-related genes icaA and agrA. Conclusions: The designed colchicine C-ring modified amine derivatives showed potential in inhibiting MRSA biofilms, and their antibacterial or synergistic antibacterial properties are related to the regulation of biofilm-related genes icaA and agrA, demonstrating inhibitory activity against MRSA. Full article

Background: Giant cell tumor of bone (GCTB) is a locally aggressive tumor. It accounts for only 5% of all bony tumors. Early diagnosis, and follow-up for recurrence is often difficult due to a lack of biogenetic markers. Giant cells are multinucleated epithelioid cells derived from macrophages. Histologically, giant cells are also present in other pathologies of bone, e.g., aneurysmal bone cyst, chondroblastoma, giant cell granuloma, and malignant giant cell tumor, etc. Similarly, radiographic findings overlap with other osteolytic lesions, making the diagnosis and prognosis of giant cell tumor very challenging. Aims and Objectives: The purpose of this study was to explore biological and genetic markers which can be used for detection, differentiation, recurrence, and prognosis of GCTB. This will help to better understand the clinical outcome of GCTB and minimize the need for interventions. Methods: We conducted a literature search using Google, Google Scholar, PubMed, Wiley Library, Medline, Clinical trials.org, and Web of Science. Our search strategy included MeSH terms and key words for giant cell tumor and biogenetic markers from date of inception to September 2020. After excluding review articles, 246 duplicates, and non-relevant articles, we included 24 articles out of 1568 articles, summarizing the role of biogenetic markers in the prognosis of GCT. Results: P63 is 98.6% sensitive and relatively specific for GCT as compared to other multinucleated giant cells containing neoplasms. MDM2 (mouse double minute 2 homolog), IGF1 (insulin-like growth factor 1), STAT1 (signal transducer and activator of transcription 1), and RAC1 (Ras-related C3 botulinum toxin substrate 1) are associated with GCTB recurrence, and might serve as biomarkers for it. Increased expression of the proteins STAT5B, GRB2, and OXSR1 was related to a higher probability of metastasis. H3F3A and H3F3B mutation analysis appears to be a highly specific, although less sensitive, diagnostic tool for the distinction of giant cell tumor of bone (GCTB) and chondroblastoma from other giant cell-containing tumors. A neutrophil to lymphocyte ratio (NLR) > 2.70, platelet to lymphocyte ratio (PLR) > 215.80, lymphocyte to monocyte ratio (LMR) ≤ 2.80, and albumin to globulin ratio (AGR) < 1.50 were significantly associated with decreased disease-free survival (DFS) (p < 0.05). Large amounts of osteoclast-related mRNA (cathepsin K, tartrate-resistant acid phosphatase, and matrix metalloproteinase9) in GCTs (p < 0.05) are associated with the grade of bone resorption. We propose that subarticular primary malignant bone sarcomas with H3.3 mutations represent true malignant GCTB, even in the absence of a benign GCTB component. IMP3 and IGF2 might be potential biomarkers for GCT of the spine in regulating the angiogenesis of giant cell tumor of bone and predicting patients’ prognosis. Conclusions: This review study shows serological markers, genetic factors, cell membrane receptor markers, predictive markers for malignancy, and prognostic protein markers which are highly sensitive for GCT and relatively specific for giant cell tumor. MDM2, IGF1, STAT1, RAC1 are important makers in determining recurrence, while P63 and H3F3A differentiate GCT from other giant cell-containing tumors. STAT5B, GRB2, and OXSR1 are significant in determining the prognosis of GCT. Apart from using radiological and histological parameters, we can add them to tumor work-up for definitive diagnosis and prognosis. Full article

This study aimed to explore the mechanism by which phenethyl isothiocyanate (PEITC) inhibited the adhesion and biofilm formation of Staphylococcus aureus (S. aureus). PEITC exhibited antimicrobial efficacy against S. aureus, demonstrating a minimum inhibition concentration (MIC) of 1 mmol/L. PEITC exerted its antibacterial effect by disrupting cell membrane integrity, and it decreased total adenosine triphosphate (ATP) production after 1 and 4 h treatment. PEITC at 0.5 mmol/L increased the level of intracellular reactive oxygen species (ROS) by 26.39% compared to control. The mature biofilm of S. aureus was destroyed by 86.4% after treatment with PEITC for 24 h. Adhesion tests revealed that PEITC at 0.5 mmol/L reduced 44.51% of the S. aureus that adhered to NCM460 cells. Furthermore, at the genetic level, PEITC significantly downregulated the related genes by 31.26% to 97.04%, including agrB, agrD, isdA, ebh, luxS, fnbA, and icaR. Moreover, PEITC markedly inhibited S. aureus proliferation in beef preserved at temperatures of 25 and 4 °C, respectively. In summary, the present study suggests that PEITC effectively inhibits the adhesion and biofilm formation of S. aureus by affecting the relevant genes of S. aureus and holds promise for microbial management in meat products. Full article

Staphylococcus spp. is the most common cause of mastitis, with a significantly low cure rate. Bacterial characteristics like adhesion and biofilm formation, as well as extracellular factors, can affect the pathogenesis of staphylococcal mastitis. The study’s objectives were to confirm S. aureus, assess their antibiotic resistance, identify methicillin resistance genes, verify biofilm formation, and detect biofilm-associated genes from bovine mastitis samples using multiplex PCR (mPCR). From 215 milk samples, six were confirmed as S. aureus. Most isolates were sensitive to all measured antibiotics. One isolate was identified as an inducible form of MLSB resistance (macrolides, lincosamides, and streptogramin B resistance), while the other two isolates were resistant to penicillins and carboxypenicillins. In S. aureus cultures used for methicillin resistance genotypic analysis by PCR, the mecA and mecC genes were not found. Biofilm formation phenotypes were determined in four strains. An mPCR analysis revealed that all strains of S. aureus carried icaABCD, agrA, srtA, fnbA, clfA, and clfB genes. Only in one isolate was the fnbB gene detected; the bap gene was not detected in any of the isolates. This emphasizes the importance of using appropriate treatment and continuous monitoring of S. aureus to prevent the spread of antibiotic-resistant strains in dairy cow farms. Full article