Multiplex PCR assay-Directly on Respiratory samples:Introduction, Principle, Clinical Significance, and Keynotes

Introduction Respiratory tract infections are caused by a wide range of pathogens, including viruses, bacteria, and fungi. Conventional diagnostic methods such as culture, microscopy, and antigen detection are time-consuming and often lack sensitivity. Multiplex polymerase chain reaction (PCR) assays, applied directly to respiratory samples (sputum, …

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Mold Identification by MALDI-TOF (BRUKER)-Introduction, Principle, Clinical Significance, and Keynotes

Introduction Accurate and timely identification of molds is essential for clinical microbiology, especially in cases of invasive fungal infections caused by Aspergillus, Fusarium, Scedosporium, Mucorales, and other filamentous fungi. Traditional methods based on morphology and phenotypic characteristics are slow, require expertise, and may misidentify cryptic …

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Molds-Broth Microdilution Testing (CLSI)-Introduction, Principle, Clinical Significance, and Keynotes

Introduction Invasive mold infections such as those caused by Aspergillus, Fusarium, Scedosporium, and Mucorales present significant clinical challenges, especially in immunocompromised hosts. Mortality rates are high, and empirical antifungal therapy often fails due to intrinsic or acquired resistance. Standardized antifungal susceptibility testing (AFST) is therefore …

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Molds-Disk Diffusion Assay: Introduction, Principle, Methods, Clinical Significance, and Keynotes

Introduction The disk diffusion assay for molds is a standardized antifungal susceptibility testing (AFST) method that evaluates the sensitivity or resistance of filamentous fungi to antifungal agents. While primarily standardized for yeasts (e.g., CLSI M44-A2), disk diffusion has also been adapted for molds, particularly Aspergillus …

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Yeasts-Broth Microdilution Testing (EUCAST): Introduction, Principle, Clinical Significance, and Keynotes

Yeasts-Broth Microdilution Testing (EUCAST) Introduction, Principle, Clinical Significance, and Keynotes

Introduction Fungal infections caused by yeasts, particularly Candida and Cryptococcus species, represent a significant clinical challenge in immunocompromised and critically ill patients. Antifungal susceptibility testing (AFST) is crucial for guiding therapy, particularly in cases of treatment failure or the emergence of resistance. The broth microdilution …

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Fungal Identification by Artificial Intelligence (AI): Introduction, Working Mechanisms, Clinical Significance, and Keynotes

Yeast and mold growth on SDA agar

Introduction Fungal infections represent a growing concern in both immunocompromised and immunocompetent individuals. Conventional identification methods, including culture, microscopy, and biochemical testing, often require several days and may lack sensitivity or specificity for certain opportunistic fungi. Molecular techniques such as PCR and sequencing have improved …

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Leucine Crystals: Introduction, Identification Features, and Clinical Significance

Leucine crystal in urine microscopy at a magnification of 1600X

Introduction Leucine crystals are rare urinary findings that typically appear in patients with severe liver disease, such as advanced cirrhosis, severe hepatitis, or metabolic disorders like maple syrup urine disease. They form in acidic urine and indicate a disturbance in amino acid metabolism. Identification Features …

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Sulfonamide Crystals: Introduction, Identification Features, and Clinical Significance

Sulfonamide (sulfadiazine) crystals in urine sediment microscopy

Introduction Sulfonamide crystals are drug-induced urinary crystals that appear in patients receiving sulfonamide (sulfa) therapy, particularly when urine is acidic, concentrated, or dehydrated. They occur due to precipitation of unmetabolized sulfonamide compounds in urine, especially older drugs like sulfadiazine, which are less soluble in acidic …

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