Optochin Resistance - Streptococcus pneumoniae in case of Pneumonia – A case report

We report a case of Pneumonia due to Streptococcus pneumoniae which was resistant to optochin in 50 yr old female patient who presented with high fever and chills to hospital. She also complained of productive cough. Sputum for microbiological evaluation was sent to lab from which streptococcus pneumoniae resistant to optochin was isolated .Isolate was resistant to major antibiotic used for pneumonia treatment. She was put on linezolid treatment as per antibiotic susceptibility testing report given by microbiology lab. After two weeks of treatment fever and cough subsided. Repeat induced sputum culture after two week didn’t showed growth of streptococcus pneumoniae. Traditionally, Streptococcus pneumoniae is identified in the laboratory by demonstrating susceptibility to optochin. Misidentification of optochin-resistant S. pneumoniae as a viridans streptococcus can have significant implications. Minimum invasive α-hemolytic streptococci resistant to optochin be checked for lack of bile solubility before being identified as viridans streptococci. The addition of this latter test should minimize the possibility of misidentification.