Identification and Frequency of Listeria Monocytogenes in Vegetables and Ready to Eat Salads of Tehran, Iran



Dallal MMS¹ ; Shojaeizinjanab M¹ ; Rad FH¹ Show Affiliations
Source: Scientific Journal of Kurdistan University of Medical Sciences Published:2015

Abstract

Background and Aim: Vegetables are considered as one of the main components of food basket and their consumption is on the rise. Meanwhile, disease outbreaks due to this group of food stuffs have been on the increase. Listeria is a bacteria related to disease outbreaks due to consumption of vegetables and salad. The purpose of this study was to investigate the prevalence of Listeria in vegetables and salads consumed in Tehran. Material and Methods: This is a descriptive study conducted from May to October 2013. 100 samples from different kinds of salads collected from different restaurants and 100 samples of 10 different types of vegetables were obtained from the city green groceries. Samples were examined according to FDA protocol. Results: 48 isolates (24%) of Listeria were identified by use of phenotypic tests from which 15 isolates (7.5%) were related to salads of restaurants and delicatessens and 33 isolates (16.5%) were related to vegetable samples. Only 1 isolate (0.5%) of Listeria monocytogenes was obtained from a ready to eat mixed leafy vegetable sample and the rest belonged to other Listeria species. Conclusions: The results of this study showed that consumption of raw vegetables is one of the main ways of transmission of Listeria. Therefore, health education on avoidance of consumption of raw and unwashed vegetables is necessary. © 2015, Kurdistan University of Medical Sciences. All rights reserved.