Prevalence of Listeria monocytogenes in traditional ice cream, Yazd, IRAN (1394) and compared to other studies in different parts of Iran

The bacterium causes listeriosis with severe clinical consequences such as meningitis, septicemia and abortion. There are a minimum data on dairy products contamination of Listeria in Iran. Thus, the objective of this study was to assess the prevalence of Listeria monocytogenes in traditional ice cream in Yazd, Iran and to summarize the studies that reported Listeria monocytogenes contamination in traditional dairy and if possible conduct metaanalyses to report single estimates for raw milk and ice cream for the whole country.
A total of 85 samples of traditional ice cream were examined for the presence of Listeria monocytogenes using a two-step selective enrichment. All isolates were subjected to standard biochemical test. We searched PubMed, science direct, Scopus, Google Scholar and Iranian local databases including Iranian Scientific Information database (www.sid.ir), Magiran (www.magiran.com) using the following keywords: prevalence, Listeria monocytogenes, raw milk, ice cream and Iran. Twenty-six items of related articles on raw milk and ice cream were conducted of different cities. Studies were included in the meta-analysis. Statistical heterogeneity between studies was evaluated using Cochran's Q test and I-squared. All Statistical analyses were conducted using STATA version 11.2.
On the basis of biological tests, none of the samples were contaminated with Listeria monocytogenes. The results of the meta-analysis showed that the prevalence of L. monocytogenes in raw milk 4% and 7.1% traditional ice cream. P values less than0.05 were considered statistically significant.
Consumption of raw milk with mild heat treatment or its usage in traditional dairy a common practice in Iran. Therefore, the lack of appropriate control measures could pose serious health problems.