A 6-month-old infant presents with fever, tachypnea, cough, and bilateral wheezing during winter. Chest X-ray shows hyperinflation with peribronchial thickening. Nasopharyngeal swab immunofluorescence is positive for respiratory syncytial virus (RSV). Which structural feature characterizes RSV?
- A Non-enveloped double-stranded DNA virus
- B Enveloped single-stranded negative-sense RNA virus with F (fusion) protein causing syncytia formation ✓
- C Non-enveloped single-stranded positive-sense RNA virus with icosahedral capsid
- D Enveloped double-stranded DNA virus with tegument
Correct answer: B. Enveloped single-stranded negative-sense RNA virus with F (fusion) protein causing syncytia formation
Explanation
RSV is an enveloped ss negative-sense RNA virus of the Paramyxoviridae family. Its F (fusion) protein causes infected cells to fuse forming syncytia, from which the virus derives its name. It is the most common cause of bronchiolitis in infants. Options A, C, and D describe adenovirus, rhinovirus, and herpesvirus respectively.
Reference: Lippincott's Illustrated Reviews: Microbiology, 3rd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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