What is the shape of Neisseria bacteria?

Neisseria bacteria are classified as gram-negative diplococci, which means they appear as pairs of spherical (coccus) bacteria that do not retain the crystal violet stain used in the Gram staining procedure. This characteristic is a defining feature of their morphology. Neisseria species typically have a round shape and are often found in pairs, which distinguishes them from other bacterial shapes such as rods or spirals.

Their classification as gram-negative refers to the structure of their cell wall, which has a thin peptidoglycan layer surrounded by an outer membrane containing lipopolysaccharides. This structural composition is critical in determining the bacteria's response to antibiotics and helps guide treatment strategies.

Understanding the unique morphology of Neisseria is important in microbiology and infectious disease, as it informs laboratory identification and influences the pathogenic mechanisms of infections caused by these bacteria, such as gonorrhea and meningococcal disease.