Most common organism causing UI in adult?
Ans. is 'd' i.e., Streptococcus pyogenes Most common cause of upper respiratory tract infection is viral infection. Rhinovirus is the most common cause. Among the bacteria, group A beta-hemolytic streptococci (streptococcus pyogenes) is the most common cause. And most common type of infection is pharyngitis.
H influenza
Stap aureus
Strepto pneumonia
Streptococcus pyogenes