Survival of Helicobacter pylori in artificially contaminated ultrahigh temperature and pasteurized milk

Helicobacter pylori (H. pylori) is a very important bacterial pathogen of humans which may cause gastrointestinal illnesses ranging from gastric and duodenal ulcers to neoplastic diseases such as MALToma and gastric cancer. Transmission via contaminated food is still uncertain but several authors believe this can realistically occur and milk may act as a vehicle of infection. This paper reports the results of H. pylori survival trials in pasteurized and ultrahigh temperature (UHT) milks artificially contaminated and aerobically stored at 4 degrees C. The results obtained showed that the four strains used in this study (H. pylori nat 18-19-20 and H. pylori ATCC 43504), had a progressive reduction in bacterial load with a median survival of 9 days in pasteurized milk and 12 days in UHT milk, with approximate average of initial inoculum of 10(5) and 10(6)cfu/ml, respectively. These findings are very important to clarify the route of transmission of H. pylori to humans via food and for implementation of a correct risk analysis for food safety purposes.