Nowadays, antimicrobial resistance has created an urgent need for elaborating effective and novel antibiotic agents. In effect, bioactive compounds derived from plants have attracted great interest due to their biological activities. This work intended to study and compare the antimicrobial effect of thymol and limonene against multiple clinical microorganisms including gram-positive bacteria, gram-negative bacteria, yeasts, and mycobacteria. Molecular docking and bioavailability prediction of thymol and limonene were also performed. The in vitro study was realized via disk diffusion technique, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) assays. In parallel, in silico study of these compounds evaluated their drug-likeness, pharmacokinetic, and toxicity parameters, and binding to bacterial targets. Findings showed that thymol exhibited significantly greater antimicrobial efficacy than limonene against all microorganisms. The compounds demonstrated potent antimicrobial activity against bacteria (12.0±1.7–33.1±2.1 mm), yeasts (15.87±0.81–24.5±0.8 mm), and mycobacteria (8.5±0.5–18.4±2.1 mm). These findings were supported by low MIC and MBC/MFC (8–128 μg/mL), whereas MBC/MIC and MFC/MIC ratios (< 4) confirmed their bactericidal and fungicidal effect. Thymol also exhibited higher antimicrobial effect than the reference antibiotics (kanamycin, rifampicin, fluconazole, and chloramphenicol) against the tested microorganisms Moreover, in silico data showed that these compounds satisfy the main standards for drug-like molecules, with simulations pointing to good oral absorption, an acceptable safety profile, and stable binding to key enzymes in the studied microorganisms, which supports their antibacterial potential. Overall, these combined experimental and computational results point to thymol and limonene as promising natural antimicrobial agents.
Hepatitis B virus (HBV) remains a major global health concern, and occult HBV infection (OBI) presents significant diagnostic and clinical challenges, particularly among hemodialysis (HD) patients. This study is aimed at characterizing complete HBV genomes from maintenance HD patients with OBI in Bangladesh to elucidate genetic features, mutational patterns, and clinical implications. Serum samples from two HBsAg-negative HD patients were screened by ELISA and quantitative PCR. Viral DNA was amplified by PCR across four overlapping open reading frames (ORFs) and sequenced on the Illumina platform. Genome assembly, phylogenetic analysis, and mutational profiling were performed using reference datasets and bioinformatics tools. Antigenicity and hydrophilicity of HBsAg were predicted in silico. Both patients were anti-HBc and anti-HBs positive with high HBV DNA loads (2.29 × 1010 and 2.53 × 1010 copies/mL). Full-length genomes (3182 bp) were successfully sequenced and phylogenetic analysis showed both HBV genomes clustered within Genotype D, Subgenotype D2, and subtype ayw3, consistent with previously reported Bangladeshi HBV genomes. Comparative mutational analysis identified substitutions such as T1753C in the basal core promoter, C1845T in preC, and D144E within the "a" determinant of HBsAg, suggesting potential roles in vaccine escape, immune escape, and diagnostic failure. Several nonsynonymous mutations were also detected in polymerase, though none were potentially associated with antiviral resistance. Antigenicity and hydrophilicity profiles of HBsAg and its major hydrophilic region remained largely conserved. These findings demonstrate the persistence of OBI in HD patients and provide an initial indication of the need for genomic surveillance to monitor immune-escape mutations and improve HBV diagnostic strategies in endemic regions.
Congenital central hypoventilation syndrome (CCHS) is a genetic disorder caused by mutations in the PHOX2B gene, characterized by impaired autonomic control of breathing and systemic consequences that may affect gut homeostasis. This study provides the first integrated multi-omics analysis in a CCHS group and matched controls, combining fecal DNA-based gut taxonomic profiling with targeted quantification of fatty acids and aromatic carboxylic acids. While overall microbial diversity and community structure remained largely preserved, significant alterations were observed in specific taxa within the CCHS group. Notably, the control group exhibited an enrichment of short-chain fatty acid (SCFA)-producing genera, which are associated with eubiotic gut ecosystems, whereas the CCHS group showed higher abundance of taxa commonly linked to inflammatory contexts. Consistently, fecal levels of beneficial SCFAs-particularly valeric acid, and to a lesser extent butyric acid-were reduced in CCHS group. These findings point to a dysbiotic gut microbiota in patients with CCHS, likely supporting putative inflammatory processes that would further worsen overall health status if confirmed. Furthermore, this work provides exploratory functional signatures for future studies aimed at understanding systemic consequences, guiding mechanistic investigations, and informing strategies to improve supportive care and long-term health outcomes in this rare patient population.
The rapid rise of multidrug-resistant (MDR) Klebsiella pneumoniae has created a major global health challenge due to the limited availability of conserved therapeutic targets effective across diverse resistant strains. In this study, an integrative computational target-discovery and drug-repurposing framework was applied to six clinically relevant K. pneumoniae strains. Comparative genomic analysis identified 3012 conserved genes, which were subsequently filtered to nine essential, non-host homologous proteins. Among these, three conserved cytoplasmic proteins (accD, cpxR, and mraZ) were prioritized for functional analysis, with acetyl-CoA carboxylase subunit beta (accD) emerging as the most promising therapeutic target based on sequence conservation, predicted essentiality, subcellular localization, and pathway association. Structural assessment supported the reliability of the predicted accD model, whereas consensus binding-site analysis identified key residues suitable for ligand interaction. Virtual screening of FDA-approved drugs followed by molecular docking identified several compounds with favorable binding profiles toward accD. Subsequent molecular dynamics simulations, including root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), hydrogen-bond occupancy, principal component analysis (PCA), and PCA-based free energy landscape (FEL) analyses, consistently identified tenapanor, micafungin, deferoxamine, and cobicistat as the most stable protein-ligand complexes, with tenapanor exhibiting the most favorable overall structural and thermodynamic stability profile. These findings identify accD as a promising therapeutic target in MDR K. pneumoniae and suggest several FDA-approved compounds as potential candidates for drug repurposing. Although experimental validation is needed to confirm their biological activity and therapeutic potential, this study demonstrates the potential of integrating comparative genomics with molecular dynamics analyses to support antimicrobial target identification and drug repurposing against MDR bacterial pathogens.
Immunostimulants are widely used in aquaculture to prevent diseases and have also been observed to promote growth in aquatic animals. The current study investigated the growth-promoting mechanism of dietary peptidoglycan (PG) in black tiger shrimp (Penaeus monodon). PG was supplemented into the experimental diets at varying concentrations (0.00, 0.10, 0.20, and 0.40 g·kg-1 of feed) and administered to the shrimp over a 60-day feeding trial. Shrimp growth in terms of weight gain and specific growth rate, total feed intake, feed conversion efficiency, protein efficiency ratio, and survival was monitored during the feeding trial. Immune parameters and shrimp viral resistance against white spot syndrome virus (WSSV) were also assessed. Results showed that supplementation of 0.20 g PG kg-1 diet enhanced shrimp growth compared with the control. This is supported by the biochemical analyses (nutrient retention, feed digestibility, digestive enzyme activities, and cellular energy allocation) showing improved feed conversion efficiency and lipid retention resulting from improved apparent dry matter digestibility of the diet, enzyme activities, and energy allocation in shrimp provided with 0.20 g PG kg-1 diet compared with the control. Furthermore, the 0.20-g PG kg-1 diet also resulted in the highest survival rate in the WSSV challenge test compared with the control and other PG-treated diets. This enhanced resistance was associated with an elevated total hemocyte count, increased respiratory burst activity, and increased phenoloxidase activity compared with the control. Collectively, the present data suggest that immunostimulant supplementation at 0.20 g PG kg-1 diet has growth-promoting effects in juvenile P. monodon.
