Microscopy of bronchial aspirate showing gram-positive bacilli. A 71-year-old male with a history of chronic obstructive pulmonary disease (COPD) developed fever, anorexia, and shortness of breath. He ...

Gram-positive bacteria have thick cell walls. A Gram stain test, which involves a chemical dye, stains the bacterium’s cell wall purple. On the other hand, gram-negative bacteria stain pink instead.

So far, 2025 has been the winter of respiratory ailments, with influenza, COVID-19, and respiratory syncytial virus (RSV) making up three-fourths of what some are referring to as the "quademic." But ...

Bacterial species, and even specific strains can be differentiated using a number of molecular techniques such as PCR, quantitative PCR, genome sequencing and mass spectrometry. But even without ...