<prompt> common organisms causing sinusititis:PseudomonasMoraxella catarrhalisStreptococcus pneumoniaeH.influenza  <response>: B and C and E according to scott Brown 7e,p 1441 MC Organism causing sinusitis in adults is also Streptococcus pneumoniae followed by H.influenza. In childreb MC is streptococcus pnuemonia followef by both H.influenza and moraxella catarrhalis. 