Tiep Khac Nguyen

This study aimed to compare the chemical composition and antimicrobial activity of essential oils obtained from the rhizomes and leaves of Conamomum pierreanum (Zingiberaceae), and to evaluate interactions of selected constituents with microbial targets using molecular docking and molecular dynamics simulations. Gas chromatography–mass spectrometry (GC-MS) identified 21 compounds in the rhizome essential oil (EO) and 10 in the leaf EO of C. pierreanum, with 1,8-cineole (54.44% and 75.73%, respectively) as the predominant constituent. Notably, the rhizome EO was uniquely characterized by epi-γ-eudesmol (3.47%) and isobornyl acetate (3.39%), which were absent in the leaf oil. In vitro assays revealed that the rhizome EO possessed stronger antibacterial and antifungal activities (MIC = MBC = MFC = 0.4%) compared to the leaf EO (0.8%) against Staphylococcus aureus and Candida albicans. Molecular docking identified epi-γ-eudesmol as the most potential ligand, exhibiting remarkably high binding affinities for S. aureus DHFR (−8.1 kcal/mol) and C. albicans CYP51 (−8.5 kcal/mol), significantly outperforming the major constituents. A total of 100 ns molecular dynamics simulations and MM-PBSA analysis further confirmed the structural stability and energetically favorable binding of these complexes, with epi-γ-eudesmol maintaining a low average RMSD (C. pierreanum rhizome EO may serve as a potential source of bioactive compounds for antimicrobial applications, warranting further investigation.

Ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) poses a significant therapeutic challenge with high mortality rates. This study evaluated the clinical efficacy of high-dose ampicillin–sulbactam combined with colistin compared to standard colistin-based regimens. This retrospective study was conducted on 83 patients with CRAB-VAP at Hanoi Medical University Hospital, Vietnam, from May 2024 to May 2025. Patients were divided into an intervention group ( n = 33) treated with high-dose ampicillin–sulbactam combined with colistin and a control group ( n = 50) receiving other antibiotic regimens combined with colistin. Primary outcomes included 28-day mortality and total ventilation duration. The intervention group achieved significantly lower 28-day mortality (6.1% vs. 38.0%; p < 0.001) and higher microbiological clearance rates by day 14 (93.9% vs. 30.0%; p < 0.001). While early acute kidney injury was more frequent in the intervention group (66.7% vs. 24.0%), renal function outcomes were comparable by day 14. Multivariable analysis identified day-14 microbiological clearance as the strongest independent predictor of survival (hazard ratio [HR] = 13.03; p < 0.001). High-dose ampicillin–sulbactam combined with colistin significantly improves microbiological clearance and survival in patients with CRAB-VAP. Despite a higher incidence of transient nephrotoxicity, the regimen provides a substantial survival benefit.

An ethnobotanical survey in the northern mountainous region of Vietnam identified four Elsholtzia species, E. blanda, E. ciliata, E. communis, and E. penduliflora, growing naturally above 1500 m and traditionally used by local ethnic communities to treat skin-related ailments. This study investigates their essential oil possible chemotypes, antimicrobial properties, and potential mechanisms of action through molecular docking. Essential oils obtained by steam distillation were analyzed using GC–MS. E. blanda (yield 1.17%) was characterized by high levels of 1,8-cineole (29.0%) and camphor (17.0%). E. ciliata (1.02%) represented a possible limonene-dominant chemotype (71.0%). E. communis (1.91%) contained an exceptionally high proportion of rosefuran oxide (86.2%), whereas E. penduliflora (0.91%) exhibited a pronounced 1,8-cineole chemotype (92.1%). All essential oils showed antimicrobial activity against Staphylococcus aureus (MSSA and MRSA), Escherichia coli, and Candida albicans, with MIC values ranging from 0.4% to 3.2%. Except for E. ciliata against C. albicans, MBC/MIC and MFC/MIC ratios ≤ 4 indicated predominantly bactericidal or fungicidal effects. Molecular docking further identified nine of twenty-eight detected constituents as strong binders to microbial target proteins. These findings expand current knowledge on possible chemotypic diversity within the genus, particularly the discovery of a high-altitude limonene chemotype in E. ciliata and the identification of E. penduliflora as a rich natural source of 1,8-cineole. The convergence of chemical, biological, and in silico evidence supports the ethnomedicinal relevance of Elsholtzia species and highlights their potential as candidates for developing natural antimicrobial agents.

As an opportunistic pathogen, Pseudomonas aeruginosa is often associated with severe respiratory infections. A study conducted in an ICU of a tertiary hospital in Vietnam, where infection management is relatively good, yielded only 18 clinical isolates of P. aeruginosa over 6 months. Though the number is small, treating P. aeruginosa infections is highly complicated. Out of 18 patients, 15 showed no improvement after treatment, leading to worsening conditions or death, possibly due to various factors. High rates of mechanical ventilation (83.3%) may be a contributing factor, suggesting a certain correlation between ventilation and treatment failure. The antibiotic resistance rate in these isolates is relatively high, with a multidrug-resistant rate of 44.4%, resulting in treatment failures when empirical antibiotics are used without susceptibility testing. All isolates have the ability to form biofilms. Moreover, bacteria in stationary phase or within biofilms exhibited poor responses to meropenem and amikacin (about 10% of bacteria survive after antibiotic exposure). Conversely, ciprofloxacin shows much better efficacy, indicating that fluoroquinolones should be used in combination therapy for P. aeruginosa infection to eliminate persistent cells and biofilm-embedded microorganisms, thus enhancing treatment effectiveness.

Klebsiella pneumoniae stands out as a major opportunistic pathogen responsible for both hospital- and community-acquired bacterial infections. This study comprehensively assesses the antibiotic resistance, amikacin persistent patterns, and biofilm-forming ability of 247 isolates of K. pneumoniae obtained from an intensive care unit of a tertiary hospital in Vietnam. Microdilution assays, conducted on a 96-well plate, determined the minimum inhibitory concentrations (MICs) of amikacin. Susceptibility data for other antibiotics were gathered from the antibiogram profile. Stationary-phase bacteria were exposed to 50 × MIC, and viable bacteria counts were measured to determine amikacin persistence. Biofilm forming capacity on 96-well polystyrene surfaces was assessed by biomass and viable bacteria. The prevalence of resistance was notably high across most antibiotics, with 64.8% classified as carbapenem-resistant K. pneumoniae and 81.4% as multidrug resistant. Amikacin, however, exhibited a relatively low rate of resistance. Of the isolates, 58.2% demonstrated a moderate to strong biofilm formation capacity, and these were found to be poorly responsive to amikacin. K. pneumoniae reveals a significant inclination for amikacin persistence, with ∼45% of isolates displaying an antibiotic antibiotic-survival ratio exceeding 10%. The study sheds light on challenges in treating of K. pneumoniae infection in Vietnam, encompassing a high prevalence of antibiotic resistance, a substantial ability to form biofilm, and a notable rate of antibiotic persistence.

Nine known compounds were isolated from the P. serrata roots and showed promising inhibitory activity against α-glucosidase. The molecular docking study of them was exhibited the 4-hydroxyl group in the aromatic ring of benzoic acid derivatives improves the bioactivity. Network pharmacology was performed to investigate the molecular mechanisms of isolated compounds and suggested that the insulin resistance pathway would be a primary mechanism of action. This is the first time the α-glucosidase inhibitors of P. serrata roots were reported.

The HLA-C gene, which belongs to the HLA superfamily (Human Leukocyte Antigen), codes for the Major Histocompatibility Complex (MHC), which plays crucial roles in the human immune system. This study aimed to develop a simple sequencing protocol by the Sanger method using fewer primers and reactions for genotyping the HLA-C gene than published protocols. The simple protocol with three primers includes one PCR reaction and two sequencing reactions. The primer set comprising SEQ ID1 and SEQ ID2 was used for the PCR reaction to specifically amplify the exon 2 – exon 3 region of the HLA-C locus, which contains the typical SNPs of each HLA-C allele. The PCR product was purified and used as a template for the sequencing reactions. Two forward primers, SEQ ID1 and SEQ ID3 were used for sequencing, in which, the SEQ ID1 forward primer is located in the intron 1 region and the SEQ ID3 forward primer is located in the intron 2 region of the HLA-C gene. Testing the simple sequencing protocol on four samples of known HLA-C genotypes showed 100% accurate results. The established Sanger sequencing protocol is simple to implement, and reduces cost and time. Thus, this protocol can be used for HLA-C sequencing for pharmacogenetic studies and applications.

Indoleamine 2,3-dioxygenase 1 (IDO1) is an enzyme participating in tryptophan metabolism that has been implicated in numerous cancers. In the present study, a series of novel 5/6-amino indazole deriva...