Dual-Toehold-Probe-Mediated Exonuclease-III-Assisted Signal Recycles Integrated with CHA for Detection of mecA Gene Using a Personal Glucose Meter in Skin and Soft Tissue Infection.

Staphylococcus aureus integrated with mecA gene, which codes for penicillin-binding protein 2a, is resistant to all penicillins and other beta-lactam antibiotics, resulting in poor treatment expectations in skin and soft tissue infections. The development of a simple, sensitive and portable biosensor for mecA gene analysis in S. aureus is urgently needed. Herein, we propose a dual-toehold-probe (sensing probe)-mediated exonuclease-III (Exo-III)-assisted signal recycling for portable detection of the mecA gene in S. aureus. When the target mecA gene is present, it hybridizes with the sensing probe, initiating Exo III-assisted dual signal recycles, which in turn release numerous "3" sequences. The released "3" sequences initiate catalytic hairpin amplification, resulting in the fixation of a sucrase-labeled H2 probe on the surface of magnetic beads (MBs). After magnet-based enrichment of an MB-H1-H2-sucrase complex and removal of a liquid supernatant containing free sucrase, the complex is then used to catalyze sucrose to glucose, which can be quantitatively detected by a personal glucose meter. With a limit of detection of 4.36 fM for mecA gene, the developed strategy exhibits high sensitivity. In addition, good selectivity and anti-interference capability were also attained with this method, making it promising for antibiotic tolerance analysis at the point-of-care.

Co-Infection Talaromyces marneffei and Pneumocystis jirovecii in a Patient with Systemic Lupus Erythematosus.

Talaromyces marneffei (TM) and Pneumocystis jirovecii (PJ) infection are opportunistic infections that typically affect individuals with compromised immune systems, such as those with HIV or immunodeficiency. However, these infections are rarely seen in patients with systemic lupus erythematosus (SLE). We present a case study of a 52-year-old woman diagnosed with SLE who developed a co-infection of TM and PJ after receiving glucocorticoids, mycophenolate mofetil (MMF), and belimumab therapy. The patient's pneumonia improved following treatment with voriconazole, clarithromycin, and compound sulfamethoxazole. This case highlights the potential risk of serious opportunistic infections in SLE patients receiving a combination of glucocorticoids, MMF, and belimumab. Close monitoring of lymphocyte count, immunoglobulin levels, and chest computed tomography scans can aid in the early detection of infections. To the best of our knowledge, this is the first reported case of TM and PJ co-infection in an SLE patient.

Proximity ligation initiated DNAzyme-powered catalytic hairpin assembly for sensitive and accurate microRNA analysis.

MicroRNAs (miRNAs) play a significant role in regulating diverse physiological processes, and are regarded as novel diagnostic biomarkers. However, the sensitive and reliable miRNA detection remains a huge challenge. Herein, we propose a proximity ligated initiated magnesium ion (Mg2+)-dependent DNAzyme-powered signal cascade for sensitive, accurate and reliable detection of miRNAs. Three signal amplification processes are involved in this approach, including the target miRNA recycle, DNAzyme powered substrate cleavage, and catalytic hairpin reaction (CHA). Based on this, the approach shows a low limit of detection of 523 aM and a wide detection range of 7 orders of magnitudes, which is comparable or superior to most of the former miRNA detection methods. In addition, the approach also possesses a high selectivity to target miRNA, suggesting a potential promising future of the approach for rapid detection of miRNAs in the application of developing novel tools for skin cancer diagnosis, and recovery evaluation.