Danh mục
Campylobacter Agar Base Blood Free (CCDA) ISO
Principles and uses
Campylobacter Agar Base Blood Free (CCDA) is a modified formula described by Bolton et al., replacing blood by charcoal, sodium pyruvate and ferrous sulfate. This medium supports the growth of most enteric Campylobacter and it is recommended for the selective isolation of Campylobacter jejuni, Campylobacter coli and thermophilic Campylobacter in foods. It is recommended by ISO 10272. Campylobacter is considered the main cause of enteric illnesses. Campylobacter spp. can cause mild to severe diarrhea, with loose, watery stools frequently followed by bloody diarrhea. These pathogens are very infective and are transmitted by contaminated food or water.
The medium contains ferrous sulfate, sodium pyruvate and charcoal to promote the growth of Campylobacter species, as they quench the toxic forms of oxygen (hydrogen peroxide) increasing the aerotolerance and enabling the oxygen sensitive strains to be readily isolated. Sodium desoxycholate partially or completely inhibits Gram positive organisms, coliforms and Proteus. Enzymatic digest of animal tissue and casein, and beef extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Bacteriological agar is the solidifying agent. Cefoperazone increases selectivity and inhibits the growth of Gram negative enteric bacilli and some Gram-positive species, whilst Amphotericin B suppresses yeasts and fungi growth. The increment of temperature has shown an increase in selectivity.