Antibacterial Activity of Lactobacillus spp. Against Listeria monocytogenes Reza Aya Talal Abdulameer1, Ali Wala'a Shawkat1,* 1Department of Biology, College of Science, University of Baghdad, Baghdad, Iraq *Corresponding author: Wala'a Shawkat Ali, E-mail: microrose.2788@yahoo.com or dr.walaashali@scbaghdad.edu.iq
Online published on 4 June, 2019. Abstract A total of 18 Lactobacillus isolates were obtained from 37 clinical samples. All the isolates were subjected to morphological, microscopic examination, biochemical tests and molecular identification by 16S rRNA, the results showed that isolates belongs to Lb.fermentum, Lb. rhamnosus and Lb. paracasei. Also, in this study 46 samples from different sources were collected in order to isolate Listeria monocytogenes but unfortunately no isolate was acquired, however, eight isolates of this bacteria were obtained from Joint Diseases Unit, College of Veterinary Medicine, University of Baghdad and the identification of these isolates was confirmed by morphological, microscopic examination and API Listeria test. Lactobacillus isolates were screened for their antibacterial activity against L. monocytogenes by agar-wells diffusion method and agar-plug method. The results showed that the agar-plug method is better than agar-wells diffusion method and Lb. fermentum isolated from mouth recorded high inhibition activity against L. monocytogenes, while Lb. paracasei recorded low inhibition activity against it. It is concluded that the inhibitory effect of Lactobacillus isolates of the same species varies within the same and different source of isolation. Top Keywords Lactobacillus, Listeria monocytogenes, Antibacterial activity. Top |