A 55yrs man presents to the OPD with low grade fever, cough since 5 days, he says that there is increased production of sputum. He is a known case of chronic bronchitis , diabetes. All of the following are used by the causative organism to cause the disease except?: (A) Pili, (B) Outer membrane protein, (C) Lipooligosaccharide, (D) Capsular polysaccharide
Answer is D. The given clinical scenario describes exacerbation of COPD, the most common cause is nontypable H. influenza. Non-typable Haemophilus influenzae lack a capsule and a capsular antigen. The exacerbations of COPD are characterized by low grade fever, increased cough, sputum production, and shoness of breath. H. influenzae has the following virulence factors: Capsular polysaccharide Outer membrane proteins (OMP) Lipo-oligosaccharide(LOS) Pili The capsule is absent in non-typable H. influenzae. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition