Branhamella

Branhamella is a genus of bacteria that has undergone taxonomic reclassification. Historically, it was used to describe Gram-negative cocci, often found in pairs, that were primarily associated with the respiratory tract and mucous membranes. These bacteria were often identified based on their morphological characteristics and biochemical reactions.

A key species previously classified under Branhamella was Branhamella catarrhalis. This bacterium is a common commensal organism found in the upper respiratory tract of humans, particularly in children. While often harmless, it can also be an opportunistic pathogen, causing infections such as otitis media (middle ear infections), sinusitis, and bronchitis. In more severe cases, it has been implicated in pneumonia, meningitis, and endocarditis, especially in individuals with compromised immune systems or underlying respiratory conditions.

However, through advances in molecular techniques, particularly 16S ribosomal RNA gene sequencing, it was determined that Branhamella catarrhalis is more closely related to the genus Neisseria. Consequently, Branhamella catarrhalis has been reclassified as Neisseria catarrhalis. The genus Branhamella is now considered obsolete by many taxonomic authorities, with its former members largely integrated into other genera, most notably Neisseria. The term "Branhamella" is sometimes still encountered in older literature.