A new study led by researchers at Children's Hospital of Philadelphia (CHOP) and the University of Pennsylvania School of Medicine (Penn Medicine) has identified which strains of Staphylococcus aureus ...

Gram staining is one way scientists can identify bacteria. Gram-positive bacteria, such as Staphylococcus, appear blue or purple under a microscope when scientists apply a stain. Conversely, ...

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 ...