Detection of Helicobacter pylori in tap water, raw cow's milk, traditional cheese and ice-cream using the culture method and polymerase chain reaction

Helicobacter pylori is one of the most widespread infections worldwide. However the origin and transmission of this bacterium has not been clearly identified. One of the suggested theories is transmission via raw milk from animals to human beings. This study was conducted to detect H. pylori from tap water, raw cow milk, traditional cheese and ice-cream. From June 2008 to June 2009, a total of 182 samples from tap water (n= 40), cow milk (n= 70), traditional cheese (n= 47) and ice-cream (n = 25), were purchased from randomly selected retail outlets in Shahrekord & Shiraz of Iran and were then evaluated for the presence of H. pylori by the culture method and polymerase chain reaction (PCR). A total only one H. pylori was isolated from 70 raw cow milk samples, whereas it was not isolated from tap water, traditional cheese and ice-cream samples. Out of the 182 samples examined, 16 (8.8%) resulted positive for the presence of ureC gene. In particular, 2 of the 40 tap water samples (5%), 7 of the 70 raw cow's milk samples (10%), 6 of the 47 traditional cheese (12.8%) and 1 of the 25 traditional ice-cream samples (4%) examined, resulted positive. The results deserve further investigations on the contamination sources of the water and milk samples and on the major impact that it may have on consumers.