Sr0155e

Campylobacter was isolated as described previously (Kashoma et al., 2014 (link), 2015 (link)). Approximately 2 g of feces were suspended in 9 mL of maximum recovery diluent (MRD) (Neogen, USA). One milliliters of the suspension was added to 9 mL of Preston broth containing Campylobacter growth and selective supplements (SR0117E and SR0232; Oxoid, England). The suspensions were then incubated at 42°C for 48 h in airtight jars containing the Campy Pouch system (Becton Dickinson and Co., Maryland, USA) to generate microaerobic conditions. After incubation, 100 μL of the suspension was spread onto a modified charcoal cefoperazone deoxycholate agar (mCCDA) plate (Oxoid) containing a Campylobacter selective supplement (SR0155E, Oxoid) and incubated for 48 h at 42°C under microaerobic conditions. Three to five colonies suspected as Campylobacter were selected from each mCCDA plate and further purified using Muller-Hinton (MH; Difco, MD) agar plates containing a Campylobacter selective supplement (SR0117E, Oxoid). Pure cultures were stored at −80°C in MH broth supplemented with 30% glycerol (vol/vol) until further analysis.

Purified isolates (Table 1) that were previously confirmed by PCR [5 (link)] were recovered from defibrinated horse blood at −80 °C and cultivated in modified charcoal cefoperazone agar (mCCDA, Oxoid, Basingstoke, UK), supplemented with mCCDA selective supplement (SR0155E, Oxoid, Basingstoke, UK) at 37 °C for 48 h microaerobically. They were subsequently sub-cultured onto the chosen inoculation medium for each assay and incubated for 48 h under the same conditions.