Colonizzazione di prodotti ortofrutticoli da patogeni umani: aspetti fitopatologici

Fruits and vegetables are a very important source of energy in our diet. In the last few years, fruit and vegetable consumption has increased because of the growing concern for nutrition, but also ready-to-eat fresh food consumption is rising because of people's changing lifestyle. This kind of product can be potentially dangerous for human health because it is cultivated, harvest, cut, washed and packed without undergoing heat-treatments. In fact, many cases of disease occurred in several countries due to fresh fruits and vegetables consumption. The diseases are mainly caused by the growth of some bacterial species on edible parts of plants. Contamination can occur by different ways concerning farming methods like topdressing, irrigation with polluted water, contamination by insects and by using contaminated seeds. Once the contamination occurs, a pathogen can survive, grow and in some cases reproduce on the host. Escherichia coli and Listeria monocytogenes are two of the most important bacterial species involved in the development of those diseases. E. coli is the most dangerous due to its different serotypes that can cause several symptoms in humans like fever, nausea, vomit, diarrhea and stomach pains. Sometimes these microorganisms can cause hemolytic uremic syndrome that is very dangerous for children and elderly people because it can cause their death. L. monocytogenes is a psychrotrophs microorganism that can resist refrigeration temperatures, becoming very difficult to be eradicated. It can cause listeriosis, a dangerous disease that can bring acute symptoms and sometimes cause miscarriages. In order to prevent the appearance of these dangerous microorganisms, good farming practices must be applied agrofood companies have to pay attention during transformation processes. Nevertheless it is not enough to eliminate or reduce the presence of bacteria. Chemical and physical methods are the most used ones but in the last few years also microbiological treatments have gained importance. Antagonists bacteria and yeasts and aromatic oils obtained from plants have antimicrobial properties, that can be used against human pathogens on plants.