Simultaneous analysis of foodborne pathogenic bacteria by an oligonucleotide microarray assay

Rapid identification of bacterial mixtures in urine using MALDI-TOF MS-based algorithm profiling coupled with magnetic enrichment

Urinary tract infections (UTIs) are a severe public health problem caused by mono- or poly-bacteria. Culture-based methods are routinely used for the diagnosis of UTIs in clinical practice, but those are time consuming. Rapid and unambiguous identification of each pathogen in UTIs can have a significant impact on timely diagnoses and precise treatment. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an alternative method for the identification of pathogens in clinical laboratories. However, a certain number of pure bacteria are required for MALDI-TOF MS analysis. Here, we explored a strategy combining magnetic enrichment and MALDI-TOF MS for the rapid identification of pathogenic bacterial mixtures in urine. Fragment crystallizable mannose-binding lectin-modified Fe₃O₄ (Fc-MBL@Fe₃O₄) was used for rapid enrichment and the individual-peak-based similarity model as the analytical tool. Within 30 min, a mixture of the four most prevalent UTI-causing bacteria, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa, was successfully identified using this method. This rapid MALDI-TOF MS-based strategy has potential applications in the clinical identification of UTI pathogens.

Immunological Effects of Aggregation-Induced Emission Materials

Nanotechnology is widely used in the fields of biology and medicine. Some special nanoparticles with good biocompatibility, hydrophilicity, and photostability can be used as ideal systems for biomedical imaging in early diagnosis and treatment of diseases. Among them, aggregation-induced emission materials are new antiaggregation-caused quenching nano-imaging materials, which have advantages in biocompatibility, imaging contrast, and light stability. Meanwhile, heterogeneity of nanoparticles may cause various adverse immune reactions. In response to the above problems, many researchers have modified nano-materials to be multifunctional nano-composites, aiming at combining diagnosis and treatment with simultaneous imaging and targeted therapy and additionally avoiding immune reactions, which is of great potential in imaging-guided therapy. This review discusses the application of aggregation-induced emission materials, and other nano-imaging materials are also mentioned. We hope to provide new ideas and methods for the imaging of nano-materials in diagnosis and treatment.

Discrimination of antibiotic-resistant Gram-negative bacteria with a novel 3D nano sensing array

Triple optical response of a nano-composite facilitates discrimination of antibiotic-resistant Gram-negative bacteria from normal ones based on a sensing array technique.

A multifunctional luminogen with aggregation-induced emission characteristics for selective imaging and photodynamic killing of both cancer cells and Gram-positive bacteria

The increasing impact of bacteria on cancer progression and treatments has been witnessed in recent years. Insufficient attention to cancer-related bacteria may lead to distant metastasis, poor therapeutic efficiency and low survival rates for cancers. Exploiting new approaches that enable selective imaging and effective killing of cancer cells and bacteria are thus of great value for the battle against cancers. Herein, we report an aggregation-induced emission (AIE) luminogen, namely TPPCN, with intense emission and efficient reactive oxygen species production for fluorescence imaging and killing cancer cells and Gram-positive bacteria. This work not only demonstrates the potential of AIE luminogens in comprehensive cancer treatments but also stimulates the enthusiasm of scientists to design more multifunctional AIE systems for both cancer and bacteria theranostics.

Aggregation-Induced-Emission Materials with Different Electric Charges as an Artificial Tongue: Design, Construction, and Assembly with Various Pathogenic Bacteria for Effective Bacterial Imaging and Discrimination

Imaging-based total bacterial count and type identification of bacteria play crucial roles in clinical diagnostics, public health, biological and medical science, and environmental protection. Herein, we designed and synthesized a series of tetraphenylethenes (TPEs) functionalized with one or two aldehyde, carboxylic acid, and quaternary ammonium groups, which were successfully used as fluorescent materials for rapid and efficient staining of eight kinds of representative bacterial species, including pathogenic bacteria Vibrio cholera, Klebsiella pneumoniae, and Listeria monocytogenes and potential bioterrorism agent Yersinia pestis. By comparing the fluorescence intensity changes of the aggregation-induced-emission (AIE) materials before and after bacteria incubation, the sensing mechanisms (electrostatic versus hydrophobic interactions) were simply discussed. Moreover, the designed AIE materials were successfully used as an efficient artificial tongue for bacteria discrimination, and all of the bacteria tested were identified via linear discriminant analysis. Our current work provided a general method for simultaneous broad-spectrum bacterial imaging and species discrimination, which is helpful for bacteria surveillance in many fields.

A light-up probe with aggregation-induced emission characteristics (AIE) for selective imaging, naked-eye detection and photodynamic killing of Gram-positive bacteria

We report a multifunctional light-up probe based on AIEgens for selective recognition, naked-eye identification, and photodynamic killing of Gram-positive bacteria including vancomycin-resistant strains.