CLOSTRIDIUM BRAZIER AGAR BASE

The spectrum of disease caused by Clostridium difficile (a pathogenic Clostridium affecting the bowel) ranges from pseudomembranous colitis (PMC) through antibiotic associated colitis (AAC). It also includes chronic inflammatory bowel diseases, post-operative diarrhoea and non-antibiotic associated diarrhoea Smith and King first reported the presence of C. difficile in human infections.
This medium was developed by Jon Brazier based on similar work carried out by Ken Phillips and Paul Levett. Many pathological labs including Anaerobe Reference Unit are using this medium for isolating C. difficile. Typical characteristics of C. difficile appears on this medium after 24 hours on anaerobic incubation at 35-37?C. C. difficile appears as grey, opaque, flat raised colonies generally circular but may tend to elongate, which on further incubation upto 48 hours may result in lighter grey or may impart white centre to the medium and form opaque colonies, 4-6 mm in diameter. Typical Gram stain morphology of C. difficile may not be seen in colonies taken from this medium due to the presence of antibiotics. The selective agents in Clostridium difficile supplement, D-cycloserine and cefoxitin used in this medium inhibits the growth of the majority of Enterobacteriaceae and also Enterococcus faecalis, Staphylococci, gram negative anaerobic bacilli and Clostridium species other than C. difficile which may be found abundantly in samples. The Egg Yolk Emulsion added to the medium helps to differentiate C. difficile from lecithinase positive Clostridia. Addition of lysed horse blood to the base enhances recognition of colony fluorescence when cultures are examined using UV light. Cholic acid present in the medium promotes spore germination following shock treatment, and p-hydroxyphenylacetic acid to enhance production of pcresol, a distinctive metabolite of C. difficile.

for isolation and di?erentiation of Clostridium di?cile with added supplements