title: Optochin revisited: defining the optimal type of blood agar for presumptive identification of Streptococcus pneumoniae.
abstract: To determine the optimal media for optochin susceptibility testing of Streptococcus pneumoniae, we measured inhibition zones for 72 S. pneumoniae and 22 Streptococcus viridans isolates on three blood-containing media. Because 15.3, 0, and 22.2% of S. pneumoniae organisms were misidentified on Columbia agar, Trypticase soy agar (TSA), and Mueller-Hinton agar, respectively, each containing sheep blood, we recommend that TSA-sheep blood agar be used.
authors.affiliation: Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Canada.
authors.forename: M A
authors.initials: MA
authors.lastname: Gardam
authors.forename: M A
authors.initials: MA
authors.lastname: Miller
mesh_terms: D000818:Animals; D001769:Blood; D002245:Carbon Dioxide; D003470:Culture Media; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D011803:Quinine / Q000031:analogs & derivatives* / Q000494:pharmacology; D012756:Sheep; D013291:Streptococcus / Q000145:classification / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D003470:Culture Media; D002245:Carbon Dioxide; C017303:ethylhydrocupreine; D011803:Quinine