Transmission Electron – Microscopic Study of Listeria monocytogenes isolated from raw milk and soft cheese in Baghdad Province

Abstract

The study was designed to confirm and understand the internal and external features of Listeria monocytogenes by Transmission electron microscopy (TEM). A study was conducted at the College of Veterinary Medicine/ University of Baghdad and College of Medicine/AL-Nahrain University during April-May 2008. Standard listerial broth was prepared in food Lab. at Baghdad Vet. Coll. from locally isolated strains of Listeria monocytogenes (from raw milk and soft cheese in Baghdad province) according to standard protocols of food microbiology, transmitted in refrigerated containers to TEM-section at AL-Nahrain Coll. of Med. for processing and photographing the different forms and components of isolates. The results revealed polyforms and components of Listeria monocytogenes that important for diagnosis and therapy such as V-shape phenomenon in listerial cells, periplasmic space, DNA, plasmids, pathogenicity islands, type 3 secretion systems, and sausage chain in listerial cells (Incomplete-dissociation). In conclusion TEM technology is an important tool for diagnosing of zoonotic food borne diseases between animals and man.