A child presents with a white patch over the tonsils; diagnosis is made by culture in :

In a child white patch over tonsils, probable diagnosis is of Diphtheria. Culture media for corynebacterium are : i. Loefflers serum slope : Growth is very rapid and colonies seen in 6-8 hrs, before other bacteria grows. Itis also used for M. tuberculosis. Diptheria is emergency condition, so Loeffler’s slope is prefered media in this child. ii. Tellurite blood agar media : Selective media but growth is delayed and may take about 2 days to appear. Remember : LJ media, is for Mycobacteria TB. Mcleods and Hoyle’s are modified Tellurite media. Blood agar is used to differentiate Staph. and Sterpt. pharyngitis.