Listeria : A practical approach to the organism and its control in foods

The independent investigations some 70 years ago by E. G. D. Murray and colleagues in Cambridge (UK) and J, H. H. Pirie in Johannesburg (South Mrica) resulted in the first detailed descriptions of listeriosis (in both instances in small animals), together with the isolation and naming of Lis- teria monocytogenes. These descriptions in 1926 and 1927 show the pre- cision and care of these experimentalists, for not only did they show much skill and attention to detail but also great insight in surmising that the consumption of contaminated food was associated with the trans- mission of listeriosis. In the words of Pirie in 1927, Infection can be pro- duced by subcutaneous inoculation or by feeding and it is thought that it is by feeding that the disease is spread in nature. These observations were largely forgotten and listeriosis was regarded as a rather obscure disease of animals and occasionally humans. However, the 1980s saw dramatic changes and the elevation of Listeria to a topic of concern not only amongst microbiologists (particularly food micro- biologists) but also the general public.