Survival of Escherichia coli O157:H7 during the manufacture and ripening of Cacioricotta goat cheese

The aim of this study was to assess the growth and survival of Escherichia coli O157:H7 during the manufacturing and ripening of Cacioricotta goat cheese. Goat milk was artificially contaminated with E. coli O157:H7 and the bacterial load was monitored from production up to 90 days of ripening. Goat milk was inoculated with 102 cfu ml−1 of E. coli O157:H7 and the bacterial count of the curd at time zero was 2.31 log10 cfu g−1. During the first day of ripening, the bacterial load has increased to 5.73 log10 cfu g−1 to more than 6.20 log10 cfu g−1 during the first week. The bacterial load remained constant up to 28 days and then slightly decreased until the end of ripening, with values of aw and pH of 0.88 and 5.41 respectively. The results of this study highlighted that E. coli O157:H7 is able to survive the manufacturing process and they suggest that the 90-day period of ripening alone is insufficient to remove E. coli O157:H7 in contaminated Cacioricotta goat cheese. Moreover, these results support the assumption that the presence of a low contamination of milk with E. coli O157:H7 could represent a potential source of infection and a threat to consumers.