In situ fluorescence imaging of fungi via(1,3)-β-D-glucan aptamer and tyramide signal amplification technology

Fungal infections are hazardous to human health that has drawn wide attention.In this work,a specific and sensitive method combing the recognition of aptamer to(1,3)-β-D-glucan and tyramide signal amplification technology was proposed for the in situ fluorescence imaging of fungi.Fungi could be distinctly observed by fluorescence microscope rapidly.This method provides morphology and diagnostic information for identifying fungi.The combination of aptamer and tyramide signal amplification technology is a promising tool for the detection of fungi,bacteria and even eukaryotic cell with the virtue of biomarkers.

Effect of cinnamaldehyde on 1,3-β-D-glucans in cell wall of Candida albicans in immunosuppressed BALB/c mice

Objective： Invasive pulmonary candidiasis is a disease with high incidence, difficult treatment, poor prognosis, and high mortality. The present study analyzed the influence of cinnamaldehyde on 1,3-β-D-glucans in the cell wall of Candida albicans in order to provide a theoretical basis for the research of antifungal drugs.Methods： An immunosuppressed BALB/c mouse model with invasive pulmonary candidiasis was established by nasal perfusion of 50 μL of C. albicans suspension（107 cfu/mL）. 1,3-β-D-glucans examination and electron microscopy were carried out. Fluconazole was used as the control.Results： Cinnamaldehyde was administered at a dose of 240 mg/kg/d for 14 consecutive days, and the measured value of 1,3-β-D-glucans was（1160.62 ± 89.65） pg/mL, whereas that of fluconazole was（4285.87 ± 215.62） pg/m L. The difference between the two groups was statistically significant（P 〈 0.05）.Electron microscopy observation indicated that the 2-3 layers outside the cell wall of C. albicans（1,3-β-D-glucans layer） were rough, deformed, and incomplete, although the cell membrane was clear and intact.Conclusion： Cinnamaldehyde demonstrated special efficacy on 1,3-β-D-glucans in the cell wall of C. albicans.

In vivo investigation of antimicrobial effects of cinnamaldehyde using immunosuppressed ICR mice with invasive pulmonary aspergillosis

Objective:Invasive pulmonary Aspergillus infection has the characteristics of high morbidity,difficult to be treated,poor prognosis and high mortality.This study aims to investigate the effects of cinnamaldehyde on 1,3-β-D-glucans in the pulmonary Aspergillus fumigatus cell wall to provide a basis for developing novel antifungal drugs.Methods:Immunosuppressed ICR mice were intranasally inoculated with 50μL of A.fumigatus suspension(1×10~7 CFU/m L)and then separated into two groups,for the experimental group cinnamaldehyde was orally administered at 240 mg/kg/d consecutively for 14 d.While for the control group,voriconazole was used to treat the fungus infection.Pulmonary tissues were then extracted for 1,3-β-D-glucans assay and electron microscopy.Results:The concentration of 1,3-β-D-glucans was significantly different between the cinnamaldehyde and voriconazole groups,which was(1160.89±364.96)pg/m L and(3885.94±845.45)pg/m L,respectively(P<0.01).Electron microscopy showed that 2-3 outer layers(1,3-β-D-glucan layer)of A.fumigatus cell wall were damaged and fell off,resulting in serious defect of the cell wall,but the cell membrane was clear and intact.Conclusion:Cinnamaldehyde has a significant influence on the integrity of 1,3-β-D-glucans in the pulmonary A.fumigatus cell wall,but the cell membrane is unaffected,suggesting that cinnamaldehyde has unique antifungal properties depending on its action against the 1,3-β-D-glucans on the pulmonary A.fumigatus cell wall.