Background: Staphylococcus epidermidis has emerged as one of the most important nosocomial pathogens, mainly because of its ability to colonize implanted biomaterials by forming a biofilm. Extensive studies are focused on the molecular mechanisms involved in biofilm formation. The LytSR two-component regulatory system regulates autolysis and biofilm formation in Staphylococcus aureus. However, the role of LytSR played in S. epidermidis remained unknown. Results: In the present study, we demonstrated that lytSR knock-out in S. epidermidis did not alter susceptibility to Triton X-100 induced autolysis. Quantitative murein hydrolase assay indicated that disruption of lytSR in S. epidermidis resulted in decreased activities of extracellular murein hydrolases, although zymogram showed no apparent differences in murein hydrolase patterns between S. epidermidis strain 1457 and its lytSR mutant. Compared to the wild-type counterpart, 1457ΔlytSR produced slightly more biofilm, with significantly decreased dead cells inside. Microarray analysis showed that lytSR mutation affected the transcription of 164 genes (123 genes were upregulated and 41 genes were downregulated). Specifically, genes encoding proteins responsible for protein synthesis, energy metabolism were downregulated, while genes involved in amino acid and nucleotide biosynthesis, amino acid transporters were upregulated. Impaired ability to utilize pyruvate and reduced activity of arginine deiminase was observed in 1457ΔlytSR, which is consistent with the microarray data. Conclusions: The preliminary results suggest that in S. epidermidis LytSR two-component system regulates extracellular murein hydrolase activity, bacterial cell death and pyruvate utilization. Based on the microarray data, it appears that lytSR inactivation induces a stringent response. In addition, LytSR may indirectly enhance biofilm formation by altering the metabolic status of the bacteria.

To investigate the diagnostic performance of alpha-fetoprotein (AFP) and neutrophil-to-lymphocyte ratio (NLR) as well as their combinations with other markers. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), AFP and levels as well as the numbers of neutrophils and lymphocytes of all enrolled patients were collected. The NLR was calculated by dividing the number of neutrophils by the number of lymphocytes. Receiver operating characteristic (ROC) curve analysis was conducted to determine the ability of each marker and combination of markers to distinguish HCC and liver disease patients. In total, 545 patients were included in this study. The area under the ROC curve (AUC) values for AFP, ALT, AST, and NLR were 0.775 (0.738–0.810), 0.504 (0.461–0.547), 0.660 (0.618–0.699), and 0.738 (0.699–0.774) with optimal cut-off values of 24.6 ng/mL, 111 IU/mL, 27 IU/mL, and 2.979, respectively. Of the four biomarkers, AFP and NLR showed comparable specificity (0.881 and 0.858) and sensitivity (0.561 and 0.539). The combination of AFP and NLR showed the highest AUC (0.769) with a significantly higher sensitivity (0.767) and a lower specificity (0.773) compared to AFP or NLR alone, and it had the highest sum of sensitivity and specificity (1.54) among all combinations. In patients with AFP < 20 ng/mL, the NLR showed the highest AUC and combination with other markers did not improve the diagnostic accuracy. Our data indicate that the combination of AFP and NLR offers better diagnostic performance than either marker alone for differentiating HCC from liver disease, which may benefit clinical screening.

The mecA gene confers methicillin resistance in both MRSA and MR-CoNS by encoding the PBP2a protein and poses a significant public health threat due to its resistance to beta-lactam antibiotics. Rapid and accurate detection of mecA is critical for timely treatment, reducing morbidity, and preventing its spread in healthcare settings. In this study, we developed an advanced one-pot recombinase polymerase amplification (RPA)-CRISPR/Cas12a system, enhanced with glycerol and betaine, for ultrasensitive detection of the mecA gene. Glycerol's viscosity effect prevents premature interaction between Cas12a and early amplification products, while betaine enhances nucleic acid amplification. The assay demonstrated superior sensitivity, detecting as low as 5 copies/μL of mecA DNA within 60 min. Specificity testing against a panel of bacterial species confirmed the high selectivity of the assay for mecA-carrying strains with negligible cross-reactivity. Furthermore, this method exhibited excellent performance across various clinical samples, including blood, urine, and bronchoalveolar lavage fluid. Our findings underscore the potential of this advanced RPA-CRISPR/Cas12a assay as a powerful diagnostic tool for rapid, cost-effective, and highly sensitive mecA detection, offering a promising solution for clinical diagnostics and infection control.

The strong non-covalent interaction between biotin and streptavidin places streptavidin-based assays, used by many laboratories, at an increased risk of interference by biotin. At present, a few manufacturers have developed fully automated anti-biotin interference methods, although compared with many detection platforms, these remain insufficient. Additionally, there is a need for more methods that can achieve fully automated anti-biotin interference. We sought to develop and evaluate a new biotin interference-resisting method based on a biotin-streptavidin chemiluminescence immunoassay. Streptavidin-coated magnetic microparticles (M) of different concentrations were prepared and tested for their biotin-resistance capabilities in an automated setting (Cobas e 601). The precision, accuracy, and detection capability were also assessed. Higher concentrations of M were found to have a stronger ability to resist biotin interference. A 2.16 mg/mL concentration of M was able to resist 500 ng/mL of biotin in samples while simultaneously having a relatively weak shielding effect on the optical signals. Moreover, the total precision and accuracy of this method, designated as M3, met acceptable standards. M3 has an improved ability to resist biotin interference, can achieve full automation, and its detection performance can meet the general laboratory quality requirements.

Rotavirus remains a leading cause of severe pediatric gastroenteritis worldwide, particularly in regions with limited healthcare resources, timely diagnosis is essential for effective patient management and outbreak containment. Loop-mediated isothermal amplification (LAMP) offers rapid nucleic acid amplification under constant temperature, yet classic LAMP assays are prone to false positives from nonspecific amplification products. Here, we present a reverse transcription LAMP (RT-LAMP) assay integrated with Thermus thermophilus Argonaute (TtAgo)–mediated probe cleavage for highly sensitive and specific detection of rotavirus. The assay targets a conserved region of the NSP5 gene, coupling rapid isothermal amplification with programmable guide DNA–directed cleavage and fluorescence signal generation. Under optimized conditions, the system reliably detected as few as 10 copies/μL within 60 minutes, without cross-reactivity to other common viral or bacterial pathogens. In clinical testing of 60 pediatric stool samples (40 rotavirus-positive, 20 negative diagnosed by RT-qPCR), the TtAgo-mediated LAMP assay achieved 100% sensitivity and specificity, outperforming classic LAMP and antigen-based methods. Receiver operating characteristic analysis yielded an area under the curve of 1.00, compared with 0.80 for classic LAMP. These findings demonstrate that integrating TtAgo into the LAMP workflow markedly enhances diagnostic accuracy and reliability, providing a practical and laboratory-ready molecular tool for rotavirus detection.