Azide Dextrose HiCynthâ„¢ Broth is recommended for enumeration of faecal Streptococci by MPN technique. Enterococci are more resistant to chlorine in water, hence are better indicators of sewage pollution than Escherichia coli. This medium is prepared by completely replacing animal based peptones with chemically defined peptones to avoid BSE/TSE risks associated with animal peptones.