Face-to-face Assembly Strategy of Au Nanocubes: Induced Generation of Broad Hotspot Regions for SERS-Fluorescence Dual-Signal Detection of Intracellular miRNAs.

While designing anisotropic noble metal nanoparticles (NPs) can enhance the signal intensity of Raman dyes, more sensitive surface-enhanced Raman scattering (SERS) probes can be designed by oriented self-assembly of noble metal nanomaterials into dimers or higher-order nanoclusters. In this study, we engineered a self-assembly strategy in living cells for real-time fluorescence and SERS dual-channel detection of intracellular microRNAs (miRNAs), using Mg2+-dependent 8-17E DNAzyme sequences as the driving motors, gold nanocubes (AuNCs) as the driver components, and three-branched double-stranded DNA as the linking tool. The assembly selects adenine in DNA as a reporter molecule, simplifying the labeling process of Raman reporter molecules and reducing the synthesis process. In addition, adenine is stably distributed between the faces of AuNCs and the wide hotspot region gives good reproducibility of the adenine SERS signal. In this strategy, the SERS channel was consistently stable and more sensitive compared to the fluorescence channel. Among them, the detection limit of the SERS channel was 2.1 pM and the coefficient of variation was 1.26% in the in vitro liquid phase and 1.49% in MCF-7 cells. The strategy successfully achieved accurate tracking and quantification of miRNA-21 in cancer cells, showing good reproducibility in complex samples as well as cells. The reported strategy provides ideas for exploring intracellular specific triggering of nanoparticles for precise control of self-assembly.

Biocompatible WSe2@BSA Dots with Merged Catalyst and Coreactant for Efficient Electrochemiluminescence.

Electrochemiluminescence (ECL) is a powerful tool for clinical diagnosis due to its exceptional sensitivity. However, the standard tripropylamine (TPrA) coreactant for Ru(bpy)3Cl2, the most widely studied and used ECL system, is highly toxic. Despite extensive research on alternative coreactants, they often fall short in poor efficiency. From a reaction kinetics perspective, accelerating electrooxidation rate of Ru(bpy)3Cl2 is an essential way to compensate the efficiency limitation of coreactants, but is rarely reported. Here, a hybrid electrocatalyst@coreactant dots for the ECL of Ru(bpy)3Cl2 is reported. The as-prepared WSe2@bovine serum albumin (WSe2@BSA) dots is biocompatible, and demonstrate dual functions, i.e., the BSA shell works as a coreactant, meanwhile, the WSe2 core effectively catalyzes Ru(bpy)3Cl2 oxidation. As a result, WSe2@BSA dots exhibit an exceptionally high efficiency comparable to TPrA for the ECL of Ru(bpy)3Cl2. In addition, the procedure for synthesizing WSe2@BSA dots is facile (room temperature, atmospheric conditions), rapid (5 min), and scalable (for millions of bioassays). A biosensor utilizing WSe2@BSA dots shows promise for highly sensitive detecting glypican-3 in clinical liver cancer serum samples, especially for alpha-fetoprotein-negative patients. This work opens a new avenue for developing a highly efficient ECL system for biosensing and clinical diagnosis.

Advancements in the preparation technology of small molecule artificial antigens and their specific antibodies: a comprehensive review.

Small molecules find extensive application in medicine, food safety, and environmental studies, particularly in biomedicine. Immunoassay technology, leveraging the specific recognition between antigens and antibodies, offers a superior alternative to traditional physical and chemical analysis methods. This approach allows for the rapid and accurate detection of small molecular compounds, owing to its high sensitivity, specificity, and swift analytical capabilities. However, small molecular compounds often struggle to effectively stimulate an immune response due to their low molecular weight, weak antigenicity, and limited antigenic epitopes. To overcome this, coupling small molecule compounds with macromolecular carriers to form complete antigens is typically required to induce specific antibodies in animals. Consequently, the preparation of small-molecule artificial antigens and the production of efficient specific antibodies are crucial for achieving precise immunoassays. This paper reviews recent advancements in small molecule antibody preparation technology, emphasizing the design and synthesis of haptens, the coupling of haptens with carriers, the purification and identification of artificial antigens, and the preparation of specific antibodies. Additionally, it evaluates the current technological shortcomings and limitations while projecting future trends in artificial antigen synthesis and antibody preparation technology.

Recent progress on charge transfer engineering in reticular framework for efficient electrochemiluminescence.

Electrochemiluminescence (ECL) is a luminescence production technique triggered by electrochemistry, which has emerged as a powerful analytical technique in bioanalysis and clinical diagnosis. During ECL, charge transfer (CT) is an important process between electrochemical excitation and luminescent emission, and dramatically affects the efficiency of exciton generation, playing a pivotal role in the light-emitting properties of nanomaterials. Reticular framework materials with intramolecular/intermolecular interactions offer a promising platform for regulating CT pathways and enhancing luminescence efficiency. Deciphering the role of intramolecular/intermolecular CT processes in reticular framework materials allows for the targeted design and synthesis of emitters with precisely controlled CT properties. This sheds light on the microscopic mechanisms of electro-optical conversion in ECL, propelling advancements in their efficiency and breakthrough applications. This mini-review focuses on recent advancements in engineering CT within reticular frameworks to boost ECL efficiency. We summarized strategies including intra-reticular charge transfer, CT between the metal and ligands, and CT between guest molecules and frameworks within reticular frameworks, which holds promise for developing next-generation ECL devices with enhanced sensitivity and light emission.

RUNX1, FUS, and ELAVL1-induced circPTPN22 promote gastric cancer cell proliferation, migration, and invasion through miR-6788-5p/PAK1 axis-mediated autophagy.

BACKGROUND: An increasing number of studies have demonstrated the association of circular RNAs (circRNAs) with the pathological processes of various diseases and their involvement in the onset and progression of multiple cancers. Nevertheless, the functional roles and underlying mechanisms of circRNAs in the autophagy regulation of gastric cancer (GC) have not been fully elucidated. METHODS: We used transmission electron microscopy and the mRFP-GFP-LC3 dual fluorescent autophagy indicator to investigate autophagy regulation. The cell counting kit-8 assay, colony formation assay, 5-ethynyl-2'-deoxyuridine incorporation assay, Transwell assay, and Western blot assay were conducted to confirm circPTPN22's influence on GC progression. Dual luciferase reporter assays validated the binding between circPTPN22 and miR-6788-5p, as well as miR-6788-5p and p21-activated kinase-1 (PAK1). Functional rescue experiments assessed whether circPTPN22 modulates PAK1 expression by competitively binding miR-6788-5p, affecting autophagy and other biological processes in GC cells. We investigated the impact of circPTPN22 on in vivo GC tumors using a nude mouse xenograft model. Bioinformatics tools predicted upstream regulatory transcription factors and binding proteins of circPTPN22, while chromatin immunoprecipitation and ribonucleoprotein immunoprecipitation assays confirmed the binding status. RESULTS: Upregulation of circPTPN22 in GC has been shown to inhibit autophagy and promote cell proliferation, migration, and invasion. Mechanistically, circPTPN22 directly binds to miR-6788-5p, subsequently regulating the expression of PAK1, which activates protein kinase B (Akt) and extracellular signal-regulated kinase (Erk) phosphorylation. This modulation ultimately affects autophagy levels in GC cells. Additionally, runt-related transcription factor 1 (RUNX1) negatively regulates circPTPN22 expression, while RNA-binding proteins such as FUS (fused in sarcoma) and ELAVL1 (recombinant ELAV-like protein 1) positively regulate its expression. Inhibition of the autophagy pathway can increase FUS expression, further upregulating circPTPN22 in GC cells, thereby exacerbating the progression of GC. CONCLUSION: Under the regulation of the transcription factor RUNX1 and RNA-binding proteins FUS and ELAVL1, circPTPN22 activates the phosphorylation of Akt and Erk through the miR-6788-5p/PAK1 axis, thereby modulating autophagy in GC cells. Inhibition of autophagy increases FUS, which in turn upregulates circPTPN22, forming a positive feedback loop that ultimately accelerates the progression of GC.

A training program for improving the capacity of infection high-throughput sequencing and diagnosis in China.

BACKGROUND: Infectious diseases are a serious threat to human especially since the COVID-19 outbreak has proved the importance and urgency of their diagnosis and treatment again. Metagenomic next-generation sequencing (mNGS) has been widely used and recognized in clinical and carried out localized testing in hospitals. Increasing the training of mNGS detection technicians can enhance their professional quality and more effectively realize the application value of the hospital platform. METHODS: Based on the initial theoretical understanding and practice of the mNGS platform for localization construction, we have designed a training program to enhance the ability of technicians to detect pathogens by utilizing mNGS, and hence to conduct training practices nationwide. RESULTS: Until August 30, 2022, the page views of online classes have reached 51,500 times and 6 of offline small-scale training courses have been conducted. A total of 67 trainees from 67 hospitals have participated in the training with a qualified rate of 100%. After the training course, the localization platform of 1 participating hospital has been put into use, 2 have added the mNGS localization platform for admission, among which 3 have expressed strong intention of localization. CONCLUSIONS: This study focuses on the training procedures and practical experience of the project which is the first systematic standardized program of mNGS in the world. It solves the training difficulties in the current industry, and effectively promotes the localization construction and application of mNGS in hospitals. It has great development potential in the future and is worth further promotion.

Clinical application and detection techniques of liquid biopsy in gastric cancer.

Gastric cancer (GC) is one of the most common tumors worldwide and the leading cause of tumor-related mortality. Endoscopy and serological tumor marker testing are currently the main methods of GC screening, and treatment relies on surgical resection or chemotherapy. However, traditional examination and treatment methods are more harmful to patients and less sensitive and accurate. A minimally invasive method to respond to GC early screening, prognosis monitoring, treatment efficacy, and drug resistance situations is urgently needed. As a result, liquid biopsy techniques have received much attention in the clinical application of GC. The non-invasive liquid biopsy technique requires fewer samples, is reproducible, and can guide individualized patient treatment by monitoring patients' molecular-level changes in real-time. In this review, we introduced the clinical applications of circulating tumor cells, circulating free DNA, circulating tumor DNA, non-coding RNAs, exosomes, and proteins, which are the primary markers in liquid biopsy technology in GC. We also discuss the current limitations and future trends of liquid biopsy technology as applied to early clinical biopsy technology.

Detection of monkeypox virus using helicase dependent amplification and recombinase polymerase amplification combined with lateral flow test.

The monkeypox virus (MPXV) is a zoonotic DNA virus that belongs to the poxvirus family. Conventional laboratory methods for detecting MPXV are complex and expensive, making them unsuitable for detecting the virus in regions with limited resources. In this study, we using the Helicase dependent amplification (HDA) method and the Recombinase polymerase amplification (RPA) technique in combination with the lateral flow test (LFT), together with a self-designed qPCR technique for the detection of the MPXV specific conserved fragment F3L, to compare the sensitivity and specificity of the three assays. By analyzing the sensitivity detection results using Probit, it can be seen that the limit of detection (LOD) of the HDA-LFT detection target is 9.86 copies/µL (95% confidence interval, CI 7.52 copies/µL lower bound), the RPA-LFT detection target is 6.97 copies/µL (95% CI 3.90 copies/µL lower bound), and the qPCR detection target is 479.24 copies/mL (95% CI 273.81 copies/mL lower bound). The specificity test results showed that the specificity of the three methods mentioned above was higher than 90% in detecting pseudoviruses of the same genus of MPXV. The simple, highly sensitive, and specific MPXV assay developed in this study is anticipated to provide a solid foundation for future applications in the early screening, diagnosis, and evaluation of the efficacy of MPXV. This is the first time the HDA-LFT assay has been utilized to detect MPXV infection.

Isothermal nucleic acid amplification technology in HIV detection.

Nucleic acid testing for HIV plays an important role in the early diagnosis and monitoring of antiretroviral therapy outcomes in HIV patients and HIV-infected infants. Currently, the main molecular diagnostic methods employed are complex, time-consuming, and expensive to operate in resource-limited areas. Isothermal nucleic acid amplification technology overcomes some of the shortcomings of traditional assays and makes it possible to use point-of-care tests for molecular HIV detection. Here, we summarize and discuss the latest technological advances in isothermal nucleic acid amplification for HIV detection, with the intent of providing guidance for the development of subsequent HIV assays with high sensitivity and specificity.

Elevation of Metrnß and Its Association with Disease Activity in Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is an auto-immune disease, the pathogenesis of which remains to be fully addressed. Metrnß is a novel cytokine involved in the pathogenesis of inflammatory disease, but its regulatory roles in SLE are unclear. We aimed to comprehensively investigate the clinical value of Metrnß in SLE. A massive elevation of circulating Metrnß levels was observed in SLE, and patients with an active phase displayed higher Metrnß concentrations than those with inactive phases. Additionally, we found that Metrnß expression was positively correlated with clinical indicators of SLE. Longitudinal cytokine and chemokine profiles revealed a disturbed immune response in SLE, with high activity profiles displayed severe pathogenic inflammation, and a positive correlation of the serum Metrnß with CXCL9, IL10, IL18 and IL1RA was observed as well. Moreover, Metrnß expressions exhibited an inverse correlation with Treg and B10. Of note, a significant decrease of ILC2 was found in SLE, and there was a negative correlation of Metrnß with ILC2 as well. Further ROC analysis showed that the area under the curve (AUC) for Metrnß was 0.8250 (95% CI: 0.7379-0.9121), with a cutoff value of 1131 pg/mL to effectively distinguish SLE patients from healthy controls. Our study herein demonstrated for the first time that Metrnß values were increased and were immunologically correlated with SLE activity, which could be utilized as an alternative biomarker for the early identification and predicting of the immuno-response of SLE.

Ligand-induced Assembly of Copper Nanoclusters with Enhanced Electrochemical Excitation and Radiative Transition for Electrochemiluminescence.

Copper nanoclusters (CuNCs) are emerging electrochemiluminescence (ECL) emitters with unique molecule-like electronic structures, high abundance, and low cost. However, the synthesis of CuNCs with high ECL efficiency and stability in a scalable manner remains challenging. Here, we report a facile gram-scale approach for preparing self-assembled CuNCs (CuNCsAssy ) induced by ligands with exceptionally boosted anodic ECL and stability. Compared to the disordered aggregates that are inactive in ECL, the CuNCsAssy shows a record anodic ECL efficiency for CuNCs (10 %, wavelength-corrected, relative to Ru(bpy)3 Cl2 /tripropylamine). Mechanism studies revealed the unusual dual functions of ligands in simultaneously facilitating electrochemical excitation and radiative transition. Moreover, the assembly addressed the limitation of poor stability of conventional CuNCs. As a proof of concept, an ECL biosensor for alkaline phosphatase detection was successfully constructed with an ultralow limit of detection of 8.1×10-6  U/L.

Construction of Carbon Dots with Wavelength-Tunable Electrochemiluminescence and Enhanced Efficiency.

Tuning the electrochemiluminescence (ECL) wavelength of carbon dots (CDs) with enhanced efficiency is essential for multiplexed biosensing, bioimaging, and energy applications but remains challenging. Herein, we reported a facile route to finely modulate the ECL wavelength of CDs from 425 to 645 nm, the widest range ever reported, along with a more than 5-fold enhancement of ECL efficiency via phosphorous (P) incorporation. The molecular mechanism was explored experimentally and theoretically, which revealed the unusual dual roles of P dopants in the form of P-C and P-O bonding, that is, importing shallow trapping states and promoting an effective intramolecular charge transfer. This work would allow unlocking the key factors of ECL kinetics for heteroatom-doped CDs appearing out of reach and open a new avenue for the rational design of nanocarbon for desirable applications.

High expression of CLEC10A in head and neck squamous cell carcinoma indicates favorable prognosis and high-level immune infiltration status.

Immunotherapy has emerged as a promising treatment modality for HNSCC. However, only a small proportion of HNSCC patients experience clinical benefits from immunotherapy and identifying molecular markers that can serve as effective prognostic signatures and predictive indicators for immunotherapy response in patients with HNSCC is critical. CLEC10A has attracted attention because of its important role in improving the antitumor activity of immune cells. However, to our knowledge, no study has evaluated the role of CLEC10A in HNSCC prognosis, progression, and immune microenvironment. In the present study, we comprehensively analyzed expression profiles of CLEC10A and its association with tumor progression, HPV status, and survival of patients. Moreover, we explored the association between CLEC10A expression relative to immune infiltration and the response to immunotherapy. We explored the association between the timing of the receipt of palliative care relative to cancer diagnosis and survival. Our results revealed that CLEC10A has decreased expression in HNSCC compared with normal tissues, and that low expression of CLEC10A was associated with an advanced clinical stage and poor prognosis. Furthermore, a higher level of CLEC10A expression correlated with immune infiltration presence and response to immunotherapy in HNSCC. Thus, we demonstrated that CLEC10A could be a potential prognostic marker in patients with HNSCC, and a potential target for immunotherapy.

Comprehensive analysis of matrix metalloproteinases and their inhibitors in head and neck squamous cell carcinoma.

Objective: This study aimed to explore the association of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) with cancer progression and prognosis in head and neck squamous cell carcinoma (HNSCC).Methods: Differentially expressed genes (DEGs) were identified by LIMMA package using R software. The correlation between the expression levels of MMPs and TIMPs in HNSCC cancer samples and adjacent normal tissue samples was performed using Pearson correlation analysis. The Kruskal-Wallis test (H-test) was used to determine the association between the expression level of MMPs/TIMPs and HNSCC clinical stage. The survival result was expressed as a KM curve, and the log-rank test was used for statistical analysis. Lasso regression and multivariate Cox regression analyses were used to examine whether the gene signature based on MMPs and TIMPs was an independent prognostic factor in patients with HNSCC.Results: Among the top 10 most up-regulated genes in HNSCC cancer tissues when compared with normal tissues, six genes belonged to the MMPs. Spearman correlation analysis revealed that only MMP11 and MMP23B were positively correlated with tumor stage. Survival analysis showed that patients with a high expression of MMP14, MMP20, TIMP1, and TIMP4 had a worse prognosis than low expression patients. Additionally, a novel five-gene (MMP3, MMP17, MMP19, MMP24, and TIMP1) signature was constructed and significantly associated with prognosis as an independent prognostic signature.Conclusions: Our data show that the accuracy of a single gene of MMP or TIMP as predictors of progression and prognosis of HNSCC is limited, although some studies have proposed that MMPs act as driving factors for cancer progression. The prediction performance of the five-gene signature prediction model was much better than that of the gene signatures based on every single gene in prognosis prediction.

A Dual Functional Self-Enhanced Electrochemiluminescent Nanohybrid for Label-Free MicroRNA Detection.

The development of electrochemiluminescent (ECL) emitters with both intense ECL and excellent film-forming properties is highly desirable for biosensing applications. Herein, a facile one-pot preparation strategy was proposed for the synthesis of a self-enhanced ECL emitter by co-doping Ru(bpy)32+ and (diethylaminomethyl)triethoxysilane (DEAMTES) into an in situ-produced silica nanohybrid (DEAMTES@RuSiO2). DEAMTES@RuSiO2 not only possessed improved ECL properties but also exhibited outstanding film-forming ability, which are both critical for the construction of ECL biosensors. By coupling branched catalytic hairpin assembly with efficient signal amplification peculiarity, a label-free ECL biosensor was further constructed for the convenient and highly sensitive detection of miRNA-21. The as-fabricated ECL biosensor displayed a detection limit of 8.19 fM, much lower than those in previous reports for miRNA-21 and showed superior reliability for detecting miRNA-21-spiked human serum sample, demonstrating its potential for applications in miRNA-associated fundamental research and clinical diagnosis.

Opsonization of multiple drug resistant (MDR)-bacteria by antimicrobial peptide fused hepatitis B virus surface antigen (HBsAg) in vaccinated individuals.

Vaccination evoking immunity in susceptible individuals has become the most effective solution to combat infectious diseases. The surface antigen of hepatitis B virus (HBsAg) is a mandatory vaccine for children in China. Herein, we designed an antimicrobial protein consisting of an antimicrobial peptide Thanatin at the N-terminus fused with the HBsAg at the C-terminus. The expressed Thanatin-GFP-HBsAg (TGH) quantitively bound with the anti-HBsAg antibody by ELISA, and after exposure to TGH, Gram-negative E. coli cells became fluorescencent indicating the binding of TGH with the bacterial cells. We also demonstrated that TGH could intercalated into the lipid bilayer as shown by the quartz crystal microbalance with dissipation (QCM-D) and TEM. Moreover, the TGH bound E. coli cells attracted anti-HBsAg IgG as shown by the experiments that in turn treated the E. coli cells with TGF, anti-HBsAg serum and PE labelled goat anti-mouse IgG antibodies. After supplementation with serum from HBsAg vaccinated individuals, TGH showed improved bactericidal effect in vitro. In vivo experiments showed that the mice receiving TGH vaccination show quicker clearance of MDR E. coli pretreated with TGH and better survive in comparison with groups treated with piperacillin plus subatan. In addition, anti-HBsAg serum supplementation also improved the endocytosis of TGH decorated bacteria by leukocytes. This study reported a novel solution to combat infectious pathogens based on the membrane penetrating effect of antimicrobial peptides.

Rapid point-of-care testing for SARS-CoV-2 virus nucleic acid detection by an isothermal and nonenzymatic Signal amplification system coupled with a lateral flow immunoassay strip.

An outbreak of a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began in December 2019. Accurate, rapid, convenient, and relatively inexpensive diagnostic methods for SARS-CoV-2 infection are important for public health and optimal clinical care. The current gold standard for diagnosing SARS-CoV-2 infection is reverse transcription-polymerase chain reaction (RT-PCR). However, RTPCR assays are designed for use in well-equipped laboratories with sophisticated laboratory infrastructure and highly trained technicians, and are unsuitable for use in under-equipped laboratories and in the field. In this study, we report the development of an accurate, rapid, and easy-to-implement isothermal and nonenzymatic signal amplification system (a catalytic hairpin assembly (CHA) reaction) coupled with a lateral flow immunoassay (LFIA) strip-based detection method that can detect SARSCoV-2 in oropharyngeal swab samples. Our method avoids RNA isolation, PCR amplification, and elaborate result analysis, which typically takes 6-8 h. The entire CHA-LFIA detection method, from nasopharyngeal sampling to obtaining test results, takes less than 90 min. Such methods are simple and require no expensive equipment, only a simple thermostatically controlled water bath and a fluorescence reader device. We validated our method using synthetic oligonucleotides and clinical samples from 15 patients with SARS-CoV-2 infection and 15 healthy individuals. Our detection method provides a fast, simple, and sensitive (with a limit of detection (LoD) of 2000 copies/mL) alternative to the SARS-CoV-2 RT-PCR assay, with 100 % positive and negative predictive agreements.

Using a Membrane-Penetrating-Peptide to Anchor Ligands in the Liposome Membrane Facilitates Targeted Drug Delivery.

Antimicrobial peptides (AMPs) are typical cell penetrating peptides (CPPs) that intercalate into biomembranes and exhibit broad activities. We designed a triple fusion protein consisting of an AMP, Ib-AMP4 at the N-terminus, a fluorescent GFP probe in the center, and the tumor-targeting peptide P1c at the other terminus. After purification from E. coli, the interaction between the Ib-AMP4-GFP-P1c fusion protein (IGP) and the lipid membrane was characterized. Experiments using isothermal titration calorimetry (ITC) and quartz crystal microbalance with dissipation (QCM-D) demonstrated that IGP proteins spontaneously bound the lipid bilayer with a maximal molar ratio of 1:52 (protein:lipid). Furthermore, transmission electron microscopy (TEM) confirmed that the IGP protein was present in the liposome membrane. After decoration with IGP proteins, the DOPC:DOPG liposomes were applied to cancer cells. Microscopy and flow cytometry reveal that the decorated liposomes selectively bound integrin αvß3-positive A549 cells. In addition, compared with the common chemical conjugation method, the reported method seemed to be superior in certain aspects, such as simple sample preparation and cost-effectiveness. Next, the IGP protein was applied to decorate red blood cell (RBC) liposomes for targeted delivery in both in vitro and in vivo applications. The IGP-decorated RBC liposomes preferentially targeted integrin αvß3 expressing A549 cancer cells. The in vivo imaging showed that IGP-decorated RBC liposomes were concentrated in tumor tissue and were primarily metabolized by the liver and kidney.

Case report: Mycobacterium monacense isolated from the blood culture of a patient with pulmonary infection.

BACKGROUND: The poorly known mycobacterial species Mycobacterium monacense is a rapidly growing non-tuberculous mycobacterium that was first described in 2006 (Reischl et al., Int J Syst Evol Microbiol 56:2575-8, 2006); it has been reported that its isolation is usually associated with skin and lung infections, especially in immunosuppressed patients (Hogardt et al., Jpn J Infect Dis 61:77-8, 2008; Taieb et al., J Hand Surg Am 33:94-6, 2008; Therese et al., Lung India 28:124-6, 2011; Shojaei et al., Ann Lab Med 32:87-90, 2012; Romero et al., New Microbes New Infect 10:112-5, 2016 ). The clinical significance of Mycobacterium monacense is not yet fully understood. Here, we report the first isolation of Mycobacterium monacense from the blood culture of a patient in China with severe pneumonia. CASE PRESENTATION: On June 26, 2018, a 38-year-old man was admitted to the intensive care unit with breathing difficulty. One day prior, he was discovered with his face immersed in a small pond (non-chlorinated water) and with limb convulsions. He had undergone craniocerebral surgery after trauma 5 years earlier, which left him with epilepsy as a sequela. Bilateral diffuse ground-glass opacity was found in the lungs on chest X ray and chest CT image at admission. The result of the HIV serology test of the patient was negative. The patient was diagnosed with severe pneumonia. Drug-susceptible Klebsiella pneumoniae and Candida glabrata were isolated in the BALF, and yellow-pigmented colonies were isolated from blood cultures of the patient. The strain isolated from blood was identified by 16S rDNA sequencing as Mycobacteria monacense, which is a rapidly growing mycobacterium (RGM). The patient was treated with a combination of cefoperazone sulbactam, linezolid and voriconazole for 10 days, and the symptoms improved. During the one-year follow-up time, the patient did not relapse. CONCLUSIONS: We report the first case of M. monacense isolated from blood cultures in a patient with severe pneumonia, which provided evidence that the environmental microorganism possessed pathogenic characteristics.

Multiple Mechanisms of the Synthesized Antimicrobial Peptide TS against Gram-Negative Bacteria for High Efficacy Antibacterial Action In Vivo.

The emergence of drug-resistant bacteria emphasizes the urgent need for novel antibiotics. The antimicrobial peptide TS shows extensive antibacterial activity in vitro and in vivo, especially in gram-negative bacteria; however, its antibacterial mechanism is unclear. Here, we find that TS without hemolytic activity disrupts the integrity of the outer bacterial cell membrane by displacing divalent cations and competitively binding lipopolysaccharides. In addition, the antimicrobial peptide TS can inhibit and kill E. coli by disintegrating the bacteria from within by interacting with bacterial DNA. Thus, antimicrobial peptide TS's multiple antibacterial mechanisms may not easily induce bacterial resistance, suggesting use as an antibacterial drug to be for combating bacterial infections in the future.