Corynebacterium diphtheriae is comm

Corynebacterium diphtheriae is commonly confused by glandular fever, Vincent’s angina or severe streptococcal sore throat. Microbiologic diagnosis is required. Diagnosis of respiratory C. diphtheriae must be fast and accurate. Swab samples obtained from the patient’s throat, nasopharynx , membranous material and material beneath it can be used for clinical diagnosis. Subsequently C. Diphtheriae should be isolated in selective and differential media (table 3) such as Tellurite Blood Agar. Diagnostic methods fall under four categories namely Pyrazinamidase, Cystinase, Toxigenecity tests and Biotyping (table 1). A positive C. Diphtheriae diagnosis would imply negative Pyrazinamidase and Cystinase catalase results, nitrate and catalase positivity, and a particular fermentation pattern characteristic of the C. diphteriae species (table1). Methods should be used in combination as none is specific for C.Diphetheriae (Efstratiou et al, 2000).Fig 2 summarises the laboratory diagnosis of diphtheria.