Human Pathogens and the Health Threat of the Phyllosphere

摘要

Human enteric illness has been associated traditionally with the consumption of contaminated meat products or water. However, foodborne illness linked to the contamination of fresh fruits and vegetables has been increasing dramatically since the 1970s(Sivapalasingam et al, 2004). This increase may be explained in part by a noticeable shift in dietary habits in the USA between 1970-1979 and 1997. During these periods, the consumption of fresh fruits and fresh vegetables alone increased 34% and 26%, respectively (Anonymous, 2001). This trend is mainly attributable to the introduction of salad bars in restaurants and supermarkets, and of fresh-cut fruits and vegetables, prepackaged salads and exotic and specialty produce in supermarkets (Anonymous, 2001). Along with this development, the intensification of agricultural production in industrialised countries has resulted in the disposal of increasing amounts of animal waste on agricultural fields and the frequent use of effluent or reclaimed water toirrigate crops. Application of contaminated irrigation water, or animal waste as raw or improperly composted manure, may introduce enteric pathogens in the field. Other causes for the increase in the incidence of enteric illness linked to fresh produce may include: (i) changes in processing and packaging methods, particularly the introduction of ready-to-eat fruits and vegetables on the market; (ii) the expansion of global trade, which provides fresh produce out of season in local markets; and (iii) the enhanced surveillance of foodborne illness by regulatory agencies.