Doyle’s Enrichment HiVeg™ Broth Base

Principle And Interpretation

Campylobacter have long been known as pathogens of animal but two species i.e. Campylobacter jejuni and Campylobacter coli are now among the commonest identified cause of enteritis in man. It was due to the former lack of selective culture medium for their isolation from faeces that their role as human pathogens was not recognized (1). Doyles Enrichment Broth Base is recommended by APHA (2) for enrichment of Campylobacter species. Dekeyser et al (3) reported the isolation of Campylobacter jejuni from the faeces of patients with diarrhoea and acute gastroenteritis using a filtration technique and a selective medium with antimicrobics to suppress the normal enteric flora. Skirrow (4) reported a selective medium containing three antimicrobics. Blaser et al (5) reported success in isolating Campylobacter jejuni with a medium containing four antimicrobics added to Brucella Agar supplemented with defibrinated sheep blood. Doyle's Enrichment HiVeg™ Broth Base is prepared by completely replacing animal based peptone with vegetable peptones to avoid BSE/TSE risks associate with animal peptones. HiVeg™ peptone, HiVeg™ hydrolysate, yeast extract, and blood provide the nitrogenous compounds, vitamin B, X factor (heme) and other growth factors for the growth of Campylobacter species. Dextrose serves as a source of energy. Inclusion of antibiotics like vancomycin, trimethoprim, polymyxin B and cycloheximide suppresses the growth of the normal microbial flora in faecal specimens, thereby facilitating easy isolation of Campylobacter species. Inoculate 10 to 25 grams of the test food sample in 100 ml Doyles Enrichment Broth Base. After incubation at 35-37°C for 18-24 hours under reduced oxygen atmosphere, isolate onto a suitable selective medium.