AMB Express最新文献

Strengthening knowledge through surveillance and research is one of the main steps in treating antibiotic-resistant infections. The present study was therefore designed to analyse long-term antimicrobial resistance trends over the 12 years in Iran. Data from the patient's clinical specimens were collected over 12 years from January 2012 until December 2023. Antimicrobial susceptibility patterns of gram-positive bacteria (GPB) were identified using the Kirby-Bauer disk diffusion method (DDM) and resistance proportions to most commonly used antibiotics were calculated for each GPB. All data were analysed using descriptive statistics. A total of 30,548 cultures were positive for GPB. Staphylococcus aureus (S. aureus) with 59.5% and coagulase-negative staphylococci (CoNS) with 26.6% frequently isolated from blood specimens. S. aureus was the frequently isolated organism in ≥ 6 years of age groups. S. aureus isolates showed the highest and lowest resistance rates to penicillin (91.8%) and vancomycin (1.1%), respectively. Nitrofurantoin (10.5%) was the most effective antimicrobial agent on Enterococcus spp. Time trends in antibiotic resistance revealed a sharp increase for several antibiotics: from 33.9% in 2013 to 54.5% in 2023 for gentamicin; from 51.2% in 2013 to 76.4% in 2023 for ceftriaxone; from 34.5% in 2013 to 54.8% in 2023 for imipenem; and from 66.7% in 2012 to 81.8% in 2023 for cefixime. The present research suggests that vancomycin and nitrofurantoin are effective antibiotics against infections caused by Staphylococcus and Enterococcus spp., respectively. This data revealed that the continuous monitoring of antimicrobial resistance (AMR) patterns is necessary for selecting the suitable drug.

This study investigates the interaction of alkaloids of Withania somnifera with Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), an enzyme implicated in the pathology of various neurodegenerative diseases. Initially, the Withania somnifera phytochemicals were optimised then molecular dockings were performed. The molecular docking results identified key interactions between these alkaloids and active sites of the enzyme. Several alkaloids from Withania somnifera exhibited better binding affinities to GAPDH such as Withanolides G, I, and K with binding affinity of -10.1, -10, and - 10 kcal/mol. The binding orientations and stability of these withanolide derivatives complexes GAPDH were investigated through comprehensive molecular dynamics simulations over 100 nanoseconds. The molecular dynamics simulations revealed stable interactions over the simulation period, suggesting a strong binding propensity. Furthermore, we determined the free energy binding profiles with GAPDH using BAR method, whichresulted in improved free energybinding forWithanolide-G and I.The results envisage that withanolides showed excellent bindings and stable interaction with the GAPDH, making them an effective therapeutic agent. The current study providesan excellent platform for developing new therapeutic agents derived from Withania somniferaagainst neurodegenerative diseasesassociated with GAPDH malfunction. These novel results open novel avenues for future research in drug discovery, particularly in developing novel treatments for Alzheimer's, Parkinson's, and other neurodegenerative diseases where GAPDH dysfunction plays crucial roles.Furthermore, experimental validation is required to validate the results of the current study.

This study evaluates the influence of various substrates (glucose, glycerol, and acetic acid) on the growth and metabolite production of Yarrowia lipolytica in fed-batch bioreactors. The primary aim is to understand how substrate choice impacts lipid and β-carotene production, critical for bioenergy and bioproducts. The study demonstrates that the choice of substrate significantly influences biomass yield, lipid content, and β-carotene levels. Among the substrates tested, glycerol yielded the highest biomass concentration of 5.31 g/L. Glucose led to the highest lipid content, with a yield of 35.8% (g lipids/g biomass), while acetic acid resulted in the highest lipid concentration, reaching 1.42 g/L. In terms of β-carotene production, glucose showed the highest content per cell at 63.3 mg/g, whereas glycerol led to the highest overall concentration of 202 mg/L. These findings highlight Y. lipolytica's versatility and potential as a flexible platform to produce lipids and β-carotene, which are essential for developing sustainable biofuels and bioproducts. The study underscores the significant variations in metabolite production based on substrate choice, emphasizing on the importance of tailored strategies to optimize industrial applications. Further research may explore optimizing fermentation conditions to enhance production yields, making this yeast a viable option for various biotechnological applications.

D-tagatose, a low-calorie rare sugar, has significant potential in food, medicine, cosmetics, and other industries owing to its high application value and market potential. In this study, Escherichia coli BL21 was used as the starting strain to express the β-galactosidase (β-Gal) gene-BgaB-derived from Bacillus stearothermophilus and the L-arabinose isomerase (L-AI) gene-araA-derived from Thermus sp., yielding the genetically engineered strains E. coli BL21-pET28a-BgaB and E. coli BL21-pET28a-araA. These strains synthesized D-tagatose using β-Gal and L-AI with a conversion rate of 23.73%. Based on this, we constructed a multienzyme cascade pathway comprising β-Gal, L-AI, glucose isomerase (GI), fructose kinase (FK), D-tagatose-bisphosphate aldolase (GatZ), polyphosphate kinase (PPK), and phosphatase (PGP), further enhancing D-tagatose biosynthesis. This multienzyme approach improved the conversion of the intermediate product D-glucose to D-tagatose by 3.84% compared with the dual-enzyme system. Thus, our study provides a theoretical basis and technical support for the industrial production of D-tagatose.

The production of industrial enzymes requires an efficient expression system with a suitable host. This study investigated the isolated Bacillus subtilis 007 as a host for expressing three enzymes with potential application in the food industry. Firstly, testing the P_aprE and P₄₃ promoters and the corresponding 5' untranslated regions revealed great differences in the production of the recently discovered β-galactosidase from Paenibacillus wnnyii. Expression controlled by the P_aprE promoter yielded a significantly higher activity of 2515 µkat/L, compared to 56 µkat/L with the P₄₃ promoter. Modifications on the P_aprE core promoter region or the spacer, the sequence between the Shine-Dalgarno sequence and the start codon, did not improve β-galactosidase production. Since the aprE 5' untranslated region contributes to a high mRNA stability, it was incorporated into the P₄₃ construct to determine whether mRNA stability is responsible for the differences observed in β-galactosidase production. Interestingly, mRNA stability was significantly improved and led to a nearly 50-fold higher β-galactosidase production of 2756 µkat/L. This strategy was successfully validated by the expression of two other enzymes: the cellobiose-2-epimerase from Caldicellulosiruptor saccharolyticus and the β-glucosidase from Pyrococcus furiosus. These findings underscored the crucial role of post-transcriptional regulation and emphasized mRNA stability as a key role in recombinant enzyme production in B. subtilis 007.

The purpose of this study was to examine the fermentation of A. membranaceus by L. plantarum and its effects on broiler chickens. L. plantarum solid-state fermentation was employed to solve the problem of releasing the active components of A. membranaceus. The effect of L. plantarum on astragalus was examined by measuring the contents of protein, carbohydrate, calycoflavone, and formononetin in A. membranaceus before and after fermentation. The effect of A. membranaceus on L. plantarum was demonstrated by detecting the changes in galactosidase in L. plantarum before and after fermentation. Fermented A. membranaceus was fed to broiler chickens, and the indices of growth performance, antioxidants, immune function, and intestinal short-chain fatty acids were recorded. The results showed that the cellulose and pectin on the surface of A. membranaceus were decomposed by L. plantarum solid-state fermentation, and the macromolecular proteins were degraded into small molecules. A. membranaceus increased the content of galactosidase in L. plantarum. Solid-state fermentation increased the contents of functional sugars, calycosin, and formononetin in A. membranaceus. Fermentation of A. membranaceus significantly improved the production performance of broilers as well as the antioxidant index, immune index, intestinal morphology, and intestinal short-chain fatty acid content.

This study investigates the effect of Paracoccus sp. EGY7 carotenoids on the triple-negative breast cancer cell line (MDA-MB-231). The bacterial strain was isolated, and its carotenoids profile was analyzed via HPLC-DAD-MS. Cytotoxicity, migration tests and the expression of BAX and BCL-2 at the gene and protein levels were carried out to evaluate the therapeutic efficiency of the produced carotenoids. Molecular docking analysis estimated the binding affinity between zeaxanthin and BCL-2 protein. Chromatographic analysis revealed zeaxanthin as the major carotenoid (48.3%). The extract exhibited significant cytotoxicity against MDA-MB-231 cells with an IC₅₀ of 1200 µg. It notably reduced cell migration, with wound closure percentages of 37.50% and 79.17% for the 600 µg group, while the percentages were 12.50% and 53.50% for the 1200 µg group, compared to 71.67% and 95.67% for the control at 24 and 48 h post-treatment, respectively. The extract induced apoptosis, as evidenced by significantly increased BAX/BCL-2 gene expression ratios at 600 and 1200 µg (p < 0.05). Western blotting showed increased BAX protein expression at 600 and 1200 µg compared to the control group (p < 0.001), and significantly lower BCL-2 protein expression (p = 0.000005 for 1200 µg and p = 0.0001 for 600 µg). Docking analysis indicated a strong affinity of zeaxanthin to BCL-2 (ΔG = -9.773241 kcal/mol) compared to obatoclax (ΔG = -7.419345 kcal/mol). Paracoccus sp. EGY7 carotenoids are a promising anticancer agent against MDA-MB-231 cells. They effectively promote apoptosis and prevent metastasis, crucial for disease advancement in cancer cells.

The oleaginous fungus, Aspergillus terreus when subjected to random chemical mutagenesis led to isolation of TB21 variant with improved lipid content (78.1%) as compared to wild type (49.8%). The fungal wet biomass grown on sugarcane bagasse hydrolysate (SCBH) was subjected to one-step in-situ (direct) acid transesterification to optimize its conversion to biodiesel using a 2-level factorial statistical design of experiments. The process optimization revealed that wet biomass and methanol were the most significant factors and in a short reaction time period of 5 min with low methanol: wet biomass ratio (10:1) influenced FAME production Statistical optimization studies showed that TB21 exhibited a higher FAME content of 76.5 and 38.1% (w/w) from wet and dry biomass, respectively when compared to wild type (48.1 and 24.5%). FAME productivity (0.55^-1 h^-1) and a yield (66 gL^-1) were achieved when TB21 was grown on SCBH for 120 h at 30 °C. The FAME profile from the wet biomass of TB21 grown on SCBH had desirable amounts of saturated (77.7%), monounsaturated (7.2%), and polyunsaturated (2.4%) methyl esters. Physico-chemical properties of TB21-derived biodiesel were determined, namely, density(0.88 g cm^-3), kinematic viscosity (4.1 mm s^-2), iodine value (96.82), cetane number (55.31), free fatty acid content (0.15%), total acid number (0.3 NaOH mg g^-1), meeting international (ASTM D6751, EN 14214) and Indian (IS 15607) standards. Thus, the direct one-pot in situ transesterification reaction using wet biomass of variant TB21 strain showed improved production and quality of biodiesel with potential large scale application using the low-cost substrate (SCBH).

Brucellosis is a significant zoonotic disease caused by intracellular, gram-negative bacteria from the genus Brucella. Although camels are classified as secondary hosts for Brucella species, they are among the most susceptible and vulnerable animals to brucellosis, particularly Brucella abortus (B. abortus) and Brucella melitensis (B. melitensis). The present study aimed to investigate the epidemiology of camel brucellosis as a zoonotic disease by determining the seroprevalence of brucellosis in both camels and humans, assessing potential risk factors (e.g., age, size, and location), and conducting molecular characterization of Brucella spp. associated with abortion in camels. The Rose Bengal Test (RBT), Antigen Rapid Brucella Antibody Test (ARBT), indirect enzyme-linked immunosorbent assay (I-ELISA), and complement fixation test (CFT) were used to detect brucellosis in both camels and humans. Additionally, a molecular method using polymerase chain reaction was used as a confirmatory technique. A total of 625 camel serum samples and 100 human serum samples were collected in sterile vacuum tubes from various camel farms and individuals across different localities in the Al Qassim region. Additionally, samples from 10 confirmed Brucella-infected camels (including the uterus and supramammary lymph nodes) were analyzed. The results indicated that the overall prevalence of brucellosis in camel sera was 9.72%, as determined by RBT, and 8.16%, as determined by ARBT. In contrast, the overall prevalence of brucellosis in human sera from febrile patients was found to be 17% via RBT. Notably, 57.98% of camel sera that tested positive for Brucella antibodies via RBT were also positive according to I-ELISA and CFT. Furthermore, 42.1%, 70.58%, and 47.05% of human sera that were positive for Brucella antibodies as determined by RBT were also positive according to I-ELISA and CFT, respectively. The highest seropositivity for camel brucellosis was observed in female camels, particularly in the Unaizah area of the Qassim region and among the Homr breed. The prevalence of human brucellosis was highest among females and individuals who consumed raw milk. At the molecular level, B. melitensis biovar 3 was detected in the examined tissues. In conclusion, intervention measures are vital for reducing brucellosis in humans and camels. Public awareness campaigns should highlight the importance of protective clothing when handling aborted she-camels and the need to boil or pasteurize milk. Additionally, studies should differentiate between vaccinated and nonvaccinated camels, and standardizing serological tests for diagnosing brucellosis should be prioritized.

Mycoplasma pneumoniae and influenza A virus are common pathogens that cause respiratory tract infection in children. Both pathogens present with similar clinical symptoms, and their epidemic periods often overlap. Consequently, it is challenging for clinicians to make a rapid preliminary diagnosis. However, common blood tests is simple and efficient, Therefore, the purpose of this study is to preliminarily distinguish Mycoplasma pneumoniae and influenza A virus infection in children by analyzing the results of common blood tests, thereby guiding clinical diagnosis and treatment.The results showed that, compared with children in the influenza A virus-positive group, children in the Mycoplasma pneumoniae-positive group had higher white blood cell (WBC), red blood cell (RBC), haemoglobin (HGB), platelet (PLT) counts, lymphocyte (LYM) and eosinophil (EOS) counts and ratios, as well as higher concentrations of C-reactive protein (CRP) and serum amyloid A (SAA), while neutrophil (NEU) and monocyte (MONO) counts and ratios, Neutrophil to Lymphocyte ratio( NLR) were lower, in addition, LYM, EOS counts and ratios, and NLR were all more effective in differentiating between the two pathogen infections, A combined analysis of these indicators further improved the differentiation efficacy. Therefore, LYM and EOS counts and ratios, along with NLR, can serve as effective blood parameters for differentiating Mycoplasma pneumoniae infections from influenza A virus infections in children.