(1) Background: The detection of methylated SEPT9 (mSEPT9) in plasma is a promising approach to non-invasive colorectal cancer (CRC) screening. Traditional approaches have limitations in sensitivity and cost-effectiveness, particularly in resource-limited settings. (2) Methods: We developed a semi-nested realtime PCR assay utilizing extendable blocking probes (ExBP) to enhance the detection of low-level mSEPT9 based on DNA melting. This assay allows for the discrimination of mSEPT9 in the presence of high concentrations of non-methylated SEPT9 (up to 100,000 times higher). (3) Results: The assay demonstrated a sensitivity of 73.91% and specificity of 80%, showcasing its ability to detect very low levels of methylated DNA effectively. The innovative use of ExBP without costly modified probes simplifies the assay setup and reduces the overall costs, enhancing its applicability in diverse clinical settings. (4) Conclusions: This novel assay significantly improves the detection of mSEPT9, offering a potential advance in CRC screening and monitoring. Its cost-efficiency and high sensitivity make it particularly suitable for the early detection and management of CRC, especially in settings with limited resources. Future studies are encouraged to validate this assay in larger populations to establish its clinical benefits and practical utility.

Lung cancer is the leading cause of cancer deaths globally, necessitating effective early detection methods. Traditional diagnostics like low-dose computed tomography (LDCT) often yield high false positive rates. SHOX2 gene methylation has emerged as a promising biomarker. This study aimed to develop and validate a novel semi-nested real-time PCR assay enhancing sensitivity and specificity for detecting SHOX2 methylation using extendable blocking probes (ExBPs). The assay integrates a semi-nested PCR approach with ExBPs, enhancing the detection of low-abundance methylated SHOX2 DNA amidst unmethylated sequences. It was tested on spiked samples with varied methylation levels and on clinical samples from lung cancer patients and individuals with benign lung conditions. The assay detected methylated SHOX2 DNA down to 0.01%. Clinical evaluations confirmed its ability to effectively differentiate between lung cancer patients and those with benign conditions, demonstrating enhanced sensitivity and specificity. The use of ExBPs minimized non-target sequence amplification, crucial for reducing false positives. The novel semi-nested real-time PCR assay offers a cost-effective, highly sensitive, and specific method for detecting SHOX2 methylation, enhancing early lung cancer detection and monitoring, particularly valuable in resource-limited settings.

(1) Background: Pediatric urinary tract infections (UTIs) pose significant challenges due to drug-resistant Escherichia coli (E. coli) strains. This study utilizes whole-genome sequencing to analyze temporal trends in antibiotic resistance genes (ARGs) in clinical E. coli isolates from pediatric UTI cases in central Vietnam. (2) Methods: We conducted whole-genome sequencing on 71 E. coli isolates collected from pediatric UTI patients between 2018 and 2020. ARGs were identified, and their prevalence over time was analyzed. Statistical tests were used to correlate ARG presence with antibiotic resistance. (3) Results: Of the 47 E. coli isolates with complete data, 40 distinct ARGs were identified, with a median of 10 resistance genes per isolate. A significant increase in the total number of ARGs per isolate was observed over time, from an average of 8.88 before June 2019 to 11.63 after. Notably, the prevalence of the aadA2 gene (aminoglycoside resistance) rose from 0% to 26.7%, and that of the blaNDM-5 gene (beta-lactam and carbapenem resistance) increased from 0% to 23.3%. Key correlations include blaEC with cephalosporin resistance, blaNDM-5 with carbapenem resistance, and sul2 with sulfamethoxazole/trimethoprim resistance. (4) Conclusions: Whole-genome sequencing reveals complex and evolving antibiotic resistance patterns in pediatric E. coli UTIs in central Vietnam, with a marked increase in ARG prevalence over time. Continuous surveillance and targeted treatments are essential to address these trends. Understanding genetic foundations is crucial for effective intervention strategies.

Objectives: To determine the changes in serum HBV RNA levels in treatment-naïve chronic hepatitis B (CHB) patients who were treated with Tenofovir Disoproxil Fumarate (TDF). Methods: 77 treatment-naïve CHB patients were treated with long-term TDF monotherapy at the Department of Infectious Diseases, Military Hospital 103, Vietnam Military Medical University from 2017 to 2020. Samples were collected at several time points: At the baseline, after 3, 6, 9, and 12 months of TDF treatment. Serum HBV DNA and HBV RNA levels were quantified by the Real Time RT-PCR method. Statistical analyses were performed with Medcalc 20.019. Results: Serum HBV RNA levels tended to decrease during the TDF treatment in a biphasic pattern. In the first phase, from baseline to 3 months of treatment, HBV RNA levels decreased rapidly (the median slope of the decrease was 0.38 log copies/mL/month). In the second phase, from 3 - 12 months of treatment, serum HBV RNA levels decreased more slowly than in the first phase (the median slope of the decrease was 0.09 log copies/mL/month; p < 0.05). Serum HBV RNA levels decreased more slowly than serum HBV DNA levels in the first phase, but there was no significant difference in the second phase (p > 0.05). Conclusion: Serum HBV RNA levels decreased in a biphasic pattern with a different slope during TDF treatment. Serum HBV RNA levels decreased more slowly than HBV DNA and may complement this marker in the assessment of treatment outcomes and prognosis for chronic hepatitis B.