A person presents with pneumonia. His sputum was sent for culture. The bacterium obtained was gram positive cocci in chains and alpha haemolytic colonies on sheep agar. Which of the following will help in confirming the diagnosis?
High-Yield Explanation
Ans. b. Optochin (Ref: Ananthanarayan 8/e p205-206)Gram-positive cocci with alpha hemolytic colonies on sheep agar are Streptococcus viridians and Streptococcus pneumoniae. They can be further differentiated on basis of optochin sensitivity, Streptococcus viridians-optochin resistant or Streptococcus pneumonia-optochin sensitive. Streptococci ViridansStreptococcus pneumoniaeBile solubilityInsolubleQSolubleQFermentation of inulinNot a fermenterQFermenter with acid productionQSensitivity to optochinNot sensitiveQSensitiveQPathogenicity to miceNonpathogenicQPathogenicQQuel lung testNegativeQPositiveQ