Ten grams of each sample was obtained aseptically and homogenised with 90 mL chilled maximum recovery diluent (Oxoid, Basingstoke, Hampshire,England) in a filter stomacher bag using a Stomacher 400 Circulator (Seward Laboratory, London, UK) for 2 min. Further decimal dilutions
were prepared with the same diluent and duplicates of at least three appropriate dilutions were plated on appropriate media.