Isolation of Listeria monocytogenes from gallbladder of sheep and cattle in slaughterhouse of Najaf


Abstract: Listeria monocytogenes is the etiologic agent of listeriosis, a severe food-borne disease. The presence of L. monocytogenes in gallbladder explained that ability of the organism to survive and resistance the bile salt effect. The aim of this study was undertaken to explore the occurrence of L. monocytogenes in gallbladder of cattle and sheep. Three hundred gallbladder samples were collected randomly from sheep and cattle and screened for the presence of L. monocytogenes by using International Dairy Federation (IDF) protocol. The isolates were confirmed by API- Listeria system and the presence of haemolysin (hly) gene. A total of 8 (2.7%) Listeria spp were recovered in 6 (4.0%) samples of sheep and 2 (1.3%) samples of cattle. The isolates were identified to the level of species and it was found that all isolates belonged to L. monocytogenes. The isolates were obtained separately during the study period, the frequency of L. monocytogenes positive gallbladder samples tend to occur during cold months of the year. All isolates gave positive results with Hly specific primers. The present study concluded that the gallbladders of cattle and sheep may play a role in meat contamination and establishment of human infections.