AMB Express最新文献

Antibiotics become less effective in treating infectious diseases as resistance increases. Staphylococcus aureus is a global problem due to its ability to form biofilms and resistance mechanisms. Phage endolysin is one of the most promising methods for combating antibiotic resistance. ZAM-MSC chimeric endolysin has three domains derived from SAL1 and lysostaphin, which target the peptide bridge of peptidoglycan. In this study purified ZAM-MSC (with yield of 30 mg/lit) had bactericidal activity against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) at low concentrations (2.38 μg/ml and 1.88 μg/ml, respectively). The antibacterial spectrum revealed that ZAM-MSC was active against diverse Staphylococci. it has maintained 100% stability after 24 h incubation in pH 5 to 10 against S. aureus, as well as demonstrated significant thermostability and maintained nearly its full activity at different temperatures (4-42 °C) up to 1 day of incubation. The anti-biofilm activity of various concentrations of ZAM-MSC against MSSA and MRSA biofilms was not dose-dependent, and antibiofilm activity was observed even at low concentrations (14 μg/ml). Further, the molecular dynamics simulations demonstrated that the ZAM-MSC chimer and its parent proteins remained dynamically stable, showing similar flexibility despite the size and hydrogen bond number differences. In conclusion, the study reveals that chimeric ZAM-MSC is a distinctive enzyme with exceptional biochemical properties and rapid lytic activity against Staphylococci.

Functional fermentation strains were isolated and screened from traditional fairy beans in northern Anhui. Through technical identification, Bacillus subtilis SXD06 was determined to be the superior fermentation strain, while Wickerhamomyces anomalus YE006 was identified as the optimal aroma-producing yeast. Utilizing single-factor experiments and response surface optimization, a Central Composite Design fermentation and blending model was established. The optimal fermentation conditions were determined to be: an inoculation amount of 1.1% for Bacillus subtilis SXD06, an inoculation amount of 4.2% for Wickerhamomyces anomalus YE006, and a fermentation temperature of 34 °C, Fermentation lasted 84.2 h. SDS-PAGE electrophoresis comparison between control and sample groups indicated effective fermentation, with most fairy beans converting to amino acids. Optimal conditions were identified as 5.5% salt, 0.26% star anise powder, 0.25% cinnamon, 1.5% pepper, 4.5% edible alcohol, and 0.28% fragrant leaves. The sensory evaluation of soybean products produced under the specified conditions yielded the highest scores. This study offers robust technical support for the development of low-ammonia, high-quality fairy bean products that align with consumer preferences.

Reducing greenhouse gas (GHG) emissions from livestock is a crucial step towards mitigating the impact of climate change and improving environmental sustainability in agriculture. This study aimed to evaluate the effects of Yucca schidigera extract, chitosan, and chitosan nanoparticles as feed additives on in vitro GHG emissions and fermentation profiles in ruminal fluid from bulls. Total gas, CH₄, CO, and H₂S emissions (up to 48 h), rumen fermentation profiles, and CH₄ conversion efficiency were measured using standard protocols. The experiments involved supplementing 0.25, 0.5, and 1 mL/g dry matter (DM) of additives in different forages (alfalfa hay, corn silage, and oats hay). The chemical composition of forage showed suitable levels of DM, ash, crude protein, acid detergent fiber, neutral detergent fiber, lignin, and metabolizable energy. The addition of these supplements increased asymptotic gas production across all forages while simultaneously reducing CH₄, CO, and H₂S emissions, though the extent of reduction varied depending on forage type. Moreover, the treatments improved fermentation profiles, including pH and dry matter digestibility, and significantly influenced CH₄ conversion efficiency (CH₄:ME, CH₄:OM, and CH₄:SCFA; P < 0.05). These results underscore the potential of Y. schidigera extract, chitosan, and chitosan nanoparticles as effective strategies for mitigating GHG emissions from ruminants given these promising in vitro findings. Further in vivo studies are recommended to validate their efficacy under real-world conditions, which could pave the way for practical applications in the field.

Antibiotic resistance by methicillin-resistant Staphylococcus aureus (MRSA) is an urgent threat to human health. The biofilm and persister cells formation ability of MRSA and Staphylococcus epidermidis often companied with extremely high antimicrobial resistance. Pinaverium bromide (PVB) is an antispasmodic compound mainly used for irritable bowel syndrome. Here we demonstrate that PVB could rapidly kill MRSA and S. epidermidis planktonic cells and persister cells avoiding resistance occurrence. Moreover, by crystal violet staining, viable cells counting and SYTO9/PI staining, PVB exhibited strong biofilm inhibition and eradication activities on the 96-well plates, glass surface or titanium discs. And the synergistic antimicrobial effects were observed between PVB and conventional antibiotics (ampicillin, oxacillin, and cefazolin). Mechanism study demonstrated the antimicrobial and antibiofilm effects by PVB were mainly mediated by proton motive force disrupting as well as reactive oxygen species inducing. Although, relatively poor pharmacokinetics were observed by systemic use, PVB could significantly reduce the viable bacterial cell loads and inflammatory infiltration in abscess in vivo caused by the biofilm forming strain ATCC 43,300. In all, our results indicated that PVB could be an alternative antimicrobial reagent for the treatment of MRSA, S. epidermidis and its biofilm related skin and soft tissue infections.

Sodium butyrate (NaBu), well-known as a histone deacetylase inhibitor and for its capacity to impede cell growth, can enhance the production of a specific protein, such as an antibody, in recombinant Chinese hamster ovary (CHO) cell cultures. In this study, two CHO cell lines, namely K1 and DG44, along with their corresponding mAb-producing lines, K1-Pr and DG44-Pr, were cultivated with or without NaBu. A SWATH-based profiling method was employed to analyze the proteome. Cells cultured in the presence of NaBu exhibited a reduction in mitosis and gene expression, supported by their culture data demonstrating growth inhibition. The presence of NaBu corresponded to upregulation of intracellular trafficking and secretion pathways, aligned with an observed increase in mAb production, and was associated with an elevated glycosylation pathway and a slight alteration in the glycosylation profile of the mAbs. Increased fatty acid oxidation, redox interactions, and lipid biosynthesis were also observed and are likely attributable to the metabolism of NaBu. A comprehensive understanding of the systemic effects of NaBu will facilitate the discovery of strategies to enhance or prolong the productivity of CHO cells.

Antimicrobial resistance (AMR) represents a critical public health issue that requiring immediate action. Wild halophytic plants can be the solution for the AMR crisis because they harbor unique endophytes capable of producing potent antimicrobial metabolites. This study aimed at identifying promising and antimicrobial metabolites produced by endophytic/epiphytic bacteria recovered from the wild Bassia scoparia plant. Standard methods were employed for the isolation of endophytes/epiphytes. Whole genome sequence (WGS) using Oxford Nanopore technology followed by antiSMASH analysis coupled with advanced LC-MS spectroscopic analysis were used for identification of the active antimicrobial metabolites. This study identified Bacillus licheniformis strain CCASU-B18 as a promising endophytic bacterium from the Bassia scoparia plant. In addition, the strain showed broad-spectrum antibacterial activity against three standard and five MDR clinical Gram-positive and Gram-negative isolates, and antifungal activity against the standard C. albicans strain. Six main antimicrobial metabolites-thermoactinoamide A, bacillibactins, lichenysins, lichenicidins, fengycin, and bacillomycin-were verified to exist by whole genome sequencing for identifying the respective conserved biosynthetic gene clusters in conjunction with LC/MS-MS analysis. The complete genomic DNA (4125835) and associated plasmid (205548 bp) of the promising endophytic isolate were sequenced, assembled, annotated, and submitted into the NCBI GenBank database under the accession codes, CP157373. In conclusion, Bacillus licheniformis strain CCASU-B18, a promising endophytic bacterium exhibiting broad-spectrum antimicrobial activities, was isolated. Future research is highly recommended to optimize the culture conditions that will be employed to enhance the production of respective antimicrobial metabolites, as well as testing these compounds against a broader range of MDR-resistant pathogens.

Rheumatoid arthritis (RA) is an autoimmune disorder with synovial inflammation of joints and extra articular manifestations. The results of recent researches consider the relationship between microbiota and the immune system as a double-edged sword. Considering that the relationship between the composition of intestinal microbiota and the immunological and clinical status of the body has been confirmed, it is very important to investigate the effect of each genus and species of bacteria on the state of the immune system. The current study was determined using 16S rRNA gene sequencing to explore the 4 selected gut microbiota from 25 people suffering from rheumatism (RA group) with a time interval of at least 3 years from the onset of the disease and 25 Healthy people by real time PCR. Gut dysbiosis in patients with rheumatoid arthritis (RA) is identified alongside key serological and clinical markers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), immunofluorescence (IF), anti-cyclic citrullinated peptide (Anti-CCP), white blood cell count (WBC), mean corpuscular volume (MCV), aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), Platelet count (PLT), thyroid-stimulating hormone (TSH), creatinine (Cr), and hemoglobin (Hb). Additionally, data from individuals with incomplete or unverified records were excluded from the study to ensure accuracy and reliability. Bacteroides fragilis, Roseburia faecis and Fusobacterium nucleatum genera showed a much lower median in Rheumatoid arthritis patients in comparison with healthy people (P > 0.001, p = 0.002, P < 0.001 respectively). While the difference in the median of E. coli genera was not significant in the two studied groups (p = 0.31). In such a way that the change in the Gut normal flora homeostasis and the reduction of beneficial bacteria such as Bacteroides fragilis, Roseburia faecis, Fusobacterium nucleatum genera, may stimulate the immune system to initiate autoimmunity.

During the 2023 autumn-winter period in China, Mycoplasma pneumoniae (MP) infections have increased. To address this, rapid and accurate MP DNA detection methods are crucial. Three nucleic acid detection assays (Ustar, Coyote Flash10, Coyote Flash 20) that are widely used in China are currently being evaluated for their effectiveness in detecting MP DNA in nasopharyngeal specimens. Reference standard materials for MP and a total of 35 NPS collected from Peking Union Medical College Hospital were tested using the Ustar, Coyote Flash10 and Coyote Flash 20 assays to assess analytical sensitivity, analytical specificity, diagnostic performance and workflow. The assays showed differing limits of detection (LOD) based on the absolute quantification of reference standards, with LODs of 500 copies/mL for the Ustar assays and 200 copies/mL for both Coyote Flash10 and Coyote Flash 20 assays. Additionally, all three assays displayed excellently analytical specificity in detecting MP DNA.The clinical correlation analysis demonstrated that the Ustar assay exhibited a sensitivity of 90.00%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 62.50%. In contrast, both the Coyote Flash10 and Coyote Flash 20 assays displayed perfect diagnostic accuracy with 100% sensitivities, specificities, PPVs, and NPVs. Despite variations in detection principles, sample volume, and pre-preparation among the three assays, they all had a turnaround time of less than 30 min with low-throughput processing. Overall, all three rapid nucleic acid detection assays displayed excellent clinical performance in detecting MP DNA, offering a solid foundation for the quick clinical diagnosis of MP infection.

Leishmaniasis is a vector-borne disease and one of the most significant neglected tropical diseases. Current anti-leishmanial treatments are often ineffective over extended periods and are associated with toxic side effects, highlighting the urgent need for new, effective, and safe alternative treatments for this infectious disease. The objective of this study was to evaluate the anti-leishmanial effects of a hydroalcoholic extract of Hypericum scabrum (H. scabrum), comparing its efficacy to that of the control drug glucantime against the standard strain of Leishmania major. The H. scabrum plants were collected from the western regions of Iran. A hydroalcoholic extract was prepared from the flower and stem of the plant using a maceration method. High-performance liquid chromatography analysis was conducted to identify the chemical compounds present in the extract. Promastigotes of L. major were cultured, and the anti-leishmanial activity of the extracts was assessed at concentrations ranging from 12.5 to 800 µg/ml using the MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay. The half-maximal inhibitory concentration (IC50) values for the H. scabrum plant extract at 24, 48, and 72 h were 245.47, 141.25 and 85.11 μg/ml, respectively. The IC50 values for glucantime (the control drug) at 24 h, 48 h, and 72 h were 30.19, 21.37, and 12.58 μg/ml, respectively. While the H. scabrum extract exhibited a lower effect compared to the control drug, it still demonstrated a significant inhibitory effect on the promastigote form of L. major. Given that the plant extract of H. scabrum has demonstrated promising anti-leishmanial effects against L. major promastigotes, further studies are warranted to evaluate the efficacy of these extracts in animal models of leishmaniasis.