What is the primary organism responsible for acute sinusitis?

The primary organism responsible for acute sinusitis is Streptococcus pneumoniae. This bacterium is a common cause of respiratory infections and is frequently implicated in cases of acute bacterial sinusitis, especially following a viral upper respiratory infection. The inflammation and swelling of the sinuses can lead to the buildup of mucus, creating an environment conducive to bacterial growth.

Streptococcus pneumoniae is a gram-positive cocci that is part of the normal flora in the nasopharynx, and it can become pathogenic in the context of sinusitis. Typically, acute sinusitis follows a cold or upper respiratory infection, which can compromise the ciliary function of the nasal mucosa, trapping bacteria and mucus.

Other organisms can contribute to sinusitis; however, they are less commonly associated with the acute bacterial form. Staphylococcus aureus is more often implicated in other types of infections rather than acute sinusitis specifically. Escherichia coli is primarily associated with gastrointestinal issues and urinary tract infections. Mycobacterium tuberculosis is related to chronic respiratory conditions rather than the acute inflammation seen in sinusitis. Therefore, the relevance of Streptococcus pneumoniae in this context solidifies its position as the primary organism involved in acute sinusitis.