Charcoal broth

Following incubation, the faecal samples in charcoal broth (Sigma-Aldrich, St. Louis, MO) were filtered through a 0.65 µm cellulose nitrate filter (Sartorius Stedim Biotech, Germany) onto mCCDA (Blood-Free Agar) (Oxoid). Approximately 500 µL of the incubated charcoal broth was evenly distributed over the filter aseptically, once the liquid had been filtered through, forceps were used to aseptically remove the filter. The culture plates were then set in an inverted position in an anaerobic jar containing an atmosphere generation system (CampyGen sachet, Oxoid) and then incubated at 37 °C for 48 h. Subsequent to incubation, DNA was isolated for the purposes of species identification using PCR targeting the hipO gene specific for C. jejuni (Marinou et al. 2012 (link)) and the asp gene specific for C. coli (Table 1) (Al Amri et al. 2013 ).

A total of 100 human Campylobacter isolates were analysed. The samples were cryopreserved in Brucella broth (Oxoid) with 15% glycerol and were part of a collection that was received from a private laboratory in Durban, KwaZulu-Natal during 2014. One hundred faecal samples were randomly collected from commercial broiler chicken farms around the Durban metropolitan area between March and September 2016. Freshly excreted broiler faeces were sampled with sterile swabs and then directly inoculated into charcoal broth (Sigma-Aldrich, St. Louis, MO) and transported back to the laboratory for incubation at 37 °C for 48 h, under microaerophilic conditions (5% O₂, 10% CO₂ and 85% N₂) created by CampyGen (Oxoid, UK) gas generating packs in an anaerobic jar.